/*------------------------------------------------------------------------- * * tablecmds.c * Commands for creating and altering table structures and settings * * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * * IDENTIFICATION * src/backend/commands/tablecmds.c * *------------------------------------------------------------------------- */ #include "postgres.h" #include "access/genam.h" #include "access/heapam.h" #include "access/multixact.h" #include "access/reloptions.h" #include "access/relscan.h" #include "access/sysattr.h" #include "access/tupconvert.h" #include "access/xact.h" #include "access/xlog.h" #include "catalog/catalog.h" #include "catalog/dependency.h" #include "catalog/heap.h" #include "catalog/index.h" #include "catalog/indexing.h" #include "catalog/namespace.h" #include "catalog/objectaccess.h" #include "catalog/partition.h" #include "catalog/pg_am.h" #include "catalog/pg_collation.h" #include "catalog/pg_constraint.h" #include "catalog/pg_constraint_fn.h" #include "catalog/pg_depend.h" #include "catalog/pg_foreign_table.h" #include "catalog/pg_inherits.h" #include "catalog/pg_inherits_fn.h" #include "catalog/pg_namespace.h" #include "catalog/pg_opclass.h" #include "catalog/pg_tablespace.h" #include "catalog/pg_trigger.h" #include "catalog/pg_type.h" #include "catalog/pg_type_fn.h" #include "catalog/storage.h" #include "catalog/storage_xlog.h" #include "catalog/toasting.h" #include "commands/cluster.h" #include "commands/comment.h" #include "commands/defrem.h" #include "commands/event_trigger.h" #include "commands/policy.h" #include "commands/sequence.h" #include "commands/tablecmds.h" #include "commands/tablespace.h" #include "commands/trigger.h" #include "commands/typecmds.h" #include "commands/user.h" #include "executor/executor.h" #include "foreign/foreign.h" #include "miscadmin.h" #include "nodes/makefuncs.h" #include "nodes/nodeFuncs.h" #include "nodes/parsenodes.h" #include "optimizer/clauses.h" #include "optimizer/planner.h" #include "optimizer/predtest.h" #include "optimizer/prep.h" #include "optimizer/var.h" #include "parser/parse_clause.h" #include "parser/parse_coerce.h" #include "parser/parse_collate.h" #include "parser/parse_expr.h" #include "parser/parse_oper.h" #include "parser/parse_relation.h" #include "parser/parse_type.h" #include "parser/parse_utilcmd.h" #include "parser/parser.h" #include "pgstat.h" #include "rewrite/rewriteDefine.h" #include "rewrite/rewriteHandler.h" #include "rewrite/rewriteManip.h" #include "storage/bufmgr.h" #include "storage/lmgr.h" #include "storage/lock.h" #include "storage/predicate.h" #include "storage/smgr.h" #include "utils/acl.h" #include "utils/builtins.h" #include "utils/fmgroids.h" #include "utils/inval.h" #include "utils/lsyscache.h" #include "utils/memutils.h" #include "utils/relcache.h" #include "utils/ruleutils.h" #include "utils/snapmgr.h" #include "utils/syscache.h" #include "utils/tqual.h" #include "utils/typcache.h" /* * ON COMMIT action list */ typedef struct OnCommitItem { Oid relid; /* relid of relation */ OnCommitAction oncommit; /* what to do at end of xact */ /* * If this entry was created during the current transaction, * creating_subid is the ID of the creating subxact; if created in a prior * transaction, creating_subid is zero. If deleted during the current * transaction, deleting_subid is the ID of the deleting subxact; if no * deletion request is pending, deleting_subid is zero. */ SubTransactionId creating_subid; SubTransactionId deleting_subid; } OnCommitItem; static List *on_commits = NIL; /* * State information for ALTER TABLE * * The pending-work queue for an ALTER TABLE is a List of AlteredTableInfo * structs, one for each table modified by the operation (the named table * plus any child tables that are affected). We save lists of subcommands * to apply to this table (possibly modified by parse transformation steps); * these lists will be executed in Phase 2. If a Phase 3 step is needed, * necessary information is stored in the constraints and newvals lists. * * Phase 2 is divided into multiple passes; subcommands are executed in * a pass determined by subcommand type. */ #define AT_PASS_UNSET -1 /* UNSET will cause ERROR */ #define AT_PASS_DROP 0 /* DROP (all flavors) */ #define AT_PASS_ALTER_TYPE 1 /* ALTER COLUMN TYPE */ #define AT_PASS_OLD_INDEX 2 /* re-add existing indexes */ #define AT_PASS_OLD_CONSTR 3 /* re-add existing constraints */ #define AT_PASS_COL_ATTRS 4 /* set other column attributes */ /* We could support a RENAME COLUMN pass here, but not currently used */ #define AT_PASS_ADD_COL 5 /* ADD COLUMN */ #define AT_PASS_ADD_INDEX 6 /* ADD indexes */ #define AT_PASS_ADD_CONSTR 7 /* ADD constraints, defaults */ #define AT_PASS_MISC 8 /* other stuff */ #define AT_NUM_PASSES 9 typedef struct AlteredTableInfo { /* Information saved before any work commences: */ Oid relid; /* Relation to work on */ char relkind; /* Its relkind */ TupleDesc oldDesc; /* Pre-modification tuple descriptor */ /* Information saved by Phase 1 for Phase 2: */ List *subcmds[AT_NUM_PASSES]; /* Lists of AlterTableCmd */ /* Information saved by Phases 1/2 for Phase 3: */ List *constraints; /* List of NewConstraint */ List *newvals; /* List of NewColumnValue */ bool new_notnull; /* T if we added new NOT NULL constraints */ int rewrite; /* Reason for forced rewrite, if any */ Oid newTableSpace; /* new tablespace; 0 means no change */ bool chgPersistence; /* T if SET LOGGED/UNLOGGED is used */ char newrelpersistence; /* if above is true */ Expr *partition_constraint; /* for attach partition validation */ /* Objects to rebuild after completing ALTER TYPE operations */ List *changedConstraintOids; /* OIDs of constraints to rebuild */ List *changedConstraintDefs; /* string definitions of same */ List *changedIndexOids; /* OIDs of indexes to rebuild */ List *changedIndexDefs; /* string definitions of same */ } AlteredTableInfo; /* Struct describing one new constraint to check in Phase 3 scan */ /* Note: new NOT NULL constraints are handled elsewhere */ typedef struct NewConstraint { char *name; /* Constraint name, or NULL if none */ ConstrType contype; /* CHECK or FOREIGN */ Oid refrelid; /* PK rel, if FOREIGN */ Oid refindid; /* OID of PK's index, if FOREIGN */ Oid conid; /* OID of pg_constraint entry, if FOREIGN */ Node *qual; /* Check expr or CONSTR_FOREIGN Constraint */ ExprState *qualstate; /* Execution state for CHECK expr */ } NewConstraint; /* * Struct describing one new column value that needs to be computed during * Phase 3 copy (this could be either a new column with a non-null default, or * a column that we're changing the type of). Columns without such an entry * are just copied from the old table during ATRewriteTable. Note that the * expr is an expression over *old* table values. */ typedef struct NewColumnValue { AttrNumber attnum; /* which column */ Expr *expr; /* expression to compute */ ExprState *exprstate; /* execution state */ } NewColumnValue; /* * Error-reporting support for RemoveRelations */ struct dropmsgstrings { char kind; int nonexistent_code; const char *nonexistent_msg; const char *skipping_msg; const char *nota_msg; const char *drophint_msg; }; static const struct dropmsgstrings dropmsgstringarray[] = { {RELKIND_RELATION, ERRCODE_UNDEFINED_TABLE, gettext_noop("table \"%s\" does not exist"), gettext_noop("table \"%s\" does not exist, skipping"), gettext_noop("\"%s\" is not a table"), gettext_noop("Use DROP TABLE to remove a table.")}, {RELKIND_SEQUENCE, ERRCODE_UNDEFINED_TABLE, gettext_noop("sequence \"%s\" does not exist"), gettext_noop("sequence \"%s\" does not exist, skipping"), gettext_noop("\"%s\" is not a sequence"), gettext_noop("Use DROP SEQUENCE to remove a sequence.")}, {RELKIND_VIEW, ERRCODE_UNDEFINED_TABLE, gettext_noop("view \"%s\" does not exist"), gettext_noop("view \"%s\" does not exist, skipping"), gettext_noop("\"%s\" is not a view"), gettext_noop("Use DROP VIEW to remove a view.")}, {RELKIND_MATVIEW, ERRCODE_UNDEFINED_TABLE, gettext_noop("materialized view \"%s\" does not exist"), gettext_noop("materialized view \"%s\" does not exist, skipping"), gettext_noop("\"%s\" is not a materialized view"), gettext_noop("Use DROP MATERIALIZED VIEW to remove a materialized view.")}, {RELKIND_INDEX, ERRCODE_UNDEFINED_OBJECT, gettext_noop("index \"%s\" does not exist"), gettext_noop("index \"%s\" does not exist, skipping"), gettext_noop("\"%s\" is not an index"), gettext_noop("Use DROP INDEX to remove an index.")}, {RELKIND_COMPOSITE_TYPE, ERRCODE_UNDEFINED_OBJECT, gettext_noop("type \"%s\" does not exist"), gettext_noop("type \"%s\" does not exist, skipping"), gettext_noop("\"%s\" is not a type"), gettext_noop("Use DROP TYPE to remove a type.")}, {RELKIND_FOREIGN_TABLE, ERRCODE_UNDEFINED_OBJECT, gettext_noop("foreign table \"%s\" does not exist"), gettext_noop("foreign table \"%s\" does not exist, skipping"), gettext_noop("\"%s\" is not a foreign table"), gettext_noop("Use DROP FOREIGN TABLE to remove a foreign table.")}, {RELKIND_PARTITIONED_TABLE, ERRCODE_UNDEFINED_TABLE, gettext_noop("table \"%s\" does not exist"), gettext_noop("table \"%s\" does not exist, skipping"), gettext_noop("\"%s\" is not a table"), gettext_noop("Use DROP TABLE to remove a table.")}, {'\0', 0, NULL, NULL, NULL, NULL} }; struct DropRelationCallbackState { char relkind; Oid heapOid; bool concurrent; }; /* Alter table target-type flags for ATSimplePermissions */ #define ATT_TABLE 0x0001 #define ATT_VIEW 0x0002 #define ATT_MATVIEW 0x0004 #define ATT_INDEX 0x0008 #define ATT_COMPOSITE_TYPE 0x0010 #define ATT_FOREIGN_TABLE 0x0020 static void truncate_check_rel(Relation rel); static List *MergeAttributes(List *schema, List *supers, char relpersistence, bool is_partition, List **supOids, List **supconstr, int *supOidCount); static bool MergeCheckConstraint(List *constraints, char *name, Node *expr); static void MergeAttributesIntoExisting(Relation child_rel, Relation parent_rel); static void MergeConstraintsIntoExisting(Relation child_rel, Relation parent_rel); static void StoreCatalogInheritance(Oid relationId, List *supers, bool child_is_partition); static void StoreCatalogInheritance1(Oid relationId, Oid parentOid, int16 seqNumber, Relation inhRelation, bool child_is_partition); static int findAttrByName(const char *attributeName, List *schema); static void AlterIndexNamespaces(Relation classRel, Relation rel, Oid oldNspOid, Oid newNspOid, ObjectAddresses *objsMoved); static void AlterSeqNamespaces(Relation classRel, Relation rel, Oid oldNspOid, Oid newNspOid, ObjectAddresses *objsMoved, LOCKMODE lockmode); static ObjectAddress ATExecAlterConstraint(Relation rel, AlterTableCmd *cmd, bool recurse, bool recursing, LOCKMODE lockmode); static ObjectAddress ATExecValidateConstraint(Relation rel, char *constrName, bool recurse, bool recursing, LOCKMODE lockmode); static int transformColumnNameList(Oid relId, List *colList, int16 *attnums, Oid *atttypids); static int transformFkeyGetPrimaryKey(Relation pkrel, Oid *indexOid, List **attnamelist, int16 *attnums, Oid *atttypids, Oid *opclasses); static Oid transformFkeyCheckAttrs(Relation pkrel, int numattrs, int16 *attnums, Oid *opclasses); static void checkFkeyPermissions(Relation rel, int16 *attnums, int natts); static CoercionPathType findFkeyCast(Oid targetTypeId, Oid sourceTypeId, Oid *funcid); static void validateCheckConstraint(Relation rel, HeapTuple constrtup); static void validateForeignKeyConstraint(char *conname, Relation rel, Relation pkrel, Oid pkindOid, Oid constraintOid); static void createForeignKeyTriggers(Relation rel, Oid refRelOid, Constraint *fkconstraint, Oid constraintOid, Oid indexOid); static void ATController(AlterTableStmt *parsetree, Relation rel, List *cmds, bool recurse, LOCKMODE lockmode); static void ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd, bool recurse, bool recursing, LOCKMODE lockmode); static void ATRewriteCatalogs(List **wqueue, LOCKMODE lockmode); static void ATExecCmd(List **wqueue, AlteredTableInfo *tab, Relation rel, AlterTableCmd *cmd, LOCKMODE lockmode); static void ATRewriteTables(AlterTableStmt *parsetree, List **wqueue, LOCKMODE lockmode); static void ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap, LOCKMODE lockmode); static AlteredTableInfo *ATGetQueueEntry(List **wqueue, Relation rel); static void ATSimplePermissions(Relation rel, int allowed_targets); static void ATWrongRelkindError(Relation rel, int allowed_targets); static void ATSimpleRecursion(List **wqueue, Relation rel, AlterTableCmd *cmd, bool recurse, LOCKMODE lockmode); static void ATTypedTableRecursion(List **wqueue, Relation rel, AlterTableCmd *cmd, LOCKMODE lockmode); static List *find_typed_table_dependencies(Oid typeOid, const char *typeName, DropBehavior behavior); static void ATPrepAddColumn(List **wqueue, Relation rel, bool recurse, bool recursing, bool is_view, AlterTableCmd *cmd, LOCKMODE lockmode); static ObjectAddress ATExecAddColumn(List **wqueue, AlteredTableInfo *tab, Relation rel, ColumnDef *colDef, bool isOid, bool recurse, bool recursing, bool if_not_exists, LOCKMODE lockmode); static bool check_for_column_name_collision(Relation rel, const char *colname, bool if_not_exists); static void add_column_datatype_dependency(Oid relid, int32 attnum, Oid typid); static void add_column_collation_dependency(Oid relid, int32 attnum, Oid collid); static void ATPrepAddOids(List **wqueue, Relation rel, bool recurse, AlterTableCmd *cmd, LOCKMODE lockmode); static void ATPrepDropNotNull(Relation rel, bool recurse, bool recursing); static ObjectAddress ATExecDropNotNull(Relation rel, const char *colName, LOCKMODE lockmode); static void ATPrepSetNotNull(Relation rel, bool recurse, bool recursing); static ObjectAddress ATExecSetNotNull(AlteredTableInfo *tab, Relation rel, const char *colName, LOCKMODE lockmode); static ObjectAddress ATExecColumnDefault(Relation rel, const char *colName, Node *newDefault, LOCKMODE lockmode); static ObjectAddress ATExecAddIdentity(Relation rel, const char *colName, Node *def, LOCKMODE lockmode); static ObjectAddress ATExecSetIdentity(Relation rel, const char *colName, Node *def, LOCKMODE lockmode); static ObjectAddress ATExecDropIdentity(Relation rel, const char *colName, bool missing_ok, LOCKMODE lockmode); static void ATPrepSetStatistics(Relation rel, const char *colName, Node *newValue, LOCKMODE lockmode); static ObjectAddress ATExecSetStatistics(Relation rel, const char *colName, Node *newValue, LOCKMODE lockmode); static ObjectAddress ATExecSetOptions(Relation rel, const char *colName, Node *options, bool isReset, LOCKMODE lockmode); static ObjectAddress ATExecSetStorage(Relation rel, const char *colName, Node *newValue, LOCKMODE lockmode); static void ATPrepDropColumn(List **wqueue, Relation rel, bool recurse, bool recursing, AlterTableCmd *cmd, LOCKMODE lockmode); static ObjectAddress ATExecDropColumn(List **wqueue, Relation rel, const char *colName, DropBehavior behavior, bool recurse, bool recursing, bool missing_ok, LOCKMODE lockmode); static ObjectAddress ATExecAddIndex(AlteredTableInfo *tab, Relation rel, IndexStmt *stmt, bool is_rebuild, LOCKMODE lockmode); static ObjectAddress ATExecAddConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel, Constraint *newConstraint, bool recurse, bool is_readd, LOCKMODE lockmode); static ObjectAddress ATExecAddIndexConstraint(AlteredTableInfo *tab, Relation rel, IndexStmt *stmt, LOCKMODE lockmode); static ObjectAddress ATAddCheckConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel, Constraint *constr, bool recurse, bool recursing, bool is_readd, LOCKMODE lockmode); static ObjectAddress ATAddForeignKeyConstraint(AlteredTableInfo *tab, Relation rel, Constraint *fkconstraint, LOCKMODE lockmode); static void ATExecDropConstraint(Relation rel, const char *constrName, DropBehavior behavior, bool recurse, bool recursing, bool missing_ok, LOCKMODE lockmode); static void ATPrepAlterColumnType(List **wqueue, AlteredTableInfo *tab, Relation rel, bool recurse, bool recursing, AlterTableCmd *cmd, LOCKMODE lockmode); static bool ATColumnChangeRequiresRewrite(Node *expr, AttrNumber varattno); static ObjectAddress ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel, AlterTableCmd *cmd, LOCKMODE lockmode); static ObjectAddress ATExecAlterColumnGenericOptions(Relation rel, const char *colName, List *options, LOCKMODE lockmode); static void ATPostAlterTypeCleanup(List **wqueue, AlteredTableInfo *tab, LOCKMODE lockmode); static void ATPostAlterTypeParse(Oid oldId, Oid oldRelId, Oid refRelId, char *cmd, List **wqueue, LOCKMODE lockmode, bool rewrite); static void RebuildConstraintComment(AlteredTableInfo *tab, int pass, Oid objid, Relation rel, char *conname); static void TryReuseIndex(Oid oldId, IndexStmt *stmt); static void TryReuseForeignKey(Oid oldId, Constraint *con); static void change_owner_fix_column_acls(Oid relationOid, Oid oldOwnerId, Oid newOwnerId); static void change_owner_recurse_to_sequences(Oid relationOid, Oid newOwnerId, LOCKMODE lockmode); static ObjectAddress ATExecClusterOn(Relation rel, const char *indexName, LOCKMODE lockmode); static void ATExecDropCluster(Relation rel, LOCKMODE lockmode); static bool ATPrepChangePersistence(Relation rel, bool toLogged); static void ATPrepSetTableSpace(AlteredTableInfo *tab, Relation rel, char *tablespacename, LOCKMODE lockmode); static void ATExecSetTableSpace(Oid tableOid, Oid newTableSpace, LOCKMODE lockmode); static void ATExecSetRelOptions(Relation rel, List *defList, AlterTableType operation, LOCKMODE lockmode); static void ATExecEnableDisableTrigger(Relation rel, char *trigname, char fires_when, bool skip_system, LOCKMODE lockmode); static void ATExecEnableDisableRule(Relation rel, char *rulename, char fires_when, LOCKMODE lockmode); static void ATPrepAddInherit(Relation child_rel); static ObjectAddress ATExecAddInherit(Relation child_rel, RangeVar *parent, LOCKMODE lockmode); static ObjectAddress ATExecDropInherit(Relation rel, RangeVar *parent, LOCKMODE lockmode); static void drop_parent_dependency(Oid relid, Oid refclassid, Oid refobjid); static ObjectAddress ATExecAddOf(Relation rel, const TypeName *ofTypename, LOCKMODE lockmode); static void ATExecDropOf(Relation rel, LOCKMODE lockmode); static void ATExecReplicaIdentity(Relation rel, ReplicaIdentityStmt *stmt, LOCKMODE lockmode); static void ATExecGenericOptions(Relation rel, List *options); static void ATExecEnableRowSecurity(Relation rel); static void ATExecDisableRowSecurity(Relation rel); static void ATExecForceNoForceRowSecurity(Relation rel, bool force_rls); static void copy_relation_data(SMgrRelation rel, SMgrRelation dst, ForkNumber forkNum, char relpersistence); static const char *storage_name(char c); static void RangeVarCallbackForDropRelation(const RangeVar *rel, Oid relOid, Oid oldRelOid, void *arg); static void RangeVarCallbackForAlterRelation(const RangeVar *rv, Oid relid, Oid oldrelid, void *arg); static bool is_partition_attr(Relation rel, AttrNumber attnum, bool *used_in_expr); static PartitionSpec *transformPartitionSpec(Relation rel, PartitionSpec *partspec, char *strategy); static void ComputePartitionAttrs(Relation rel, List *partParams, AttrNumber *partattrs, List **partexprs, Oid *partopclass, Oid *partcollation); static void CreateInheritance(Relation child_rel, Relation parent_rel); static void RemoveInheritance(Relation child_rel, Relation parent_rel); static ObjectAddress ATExecAttachPartition(List **wqueue, Relation rel, PartitionCmd *cmd); static ObjectAddress ATExecDetachPartition(Relation rel, RangeVar *name); /* ---------------------------------------------------------------- * DefineRelation * Creates a new relation. * * stmt carries parsetree information from an ordinary CREATE TABLE statement. * The other arguments are used to extend the behavior for other cases: * relkind: relkind to assign to the new relation * ownerId: if not InvalidOid, use this as the new relation's owner. * typaddress: if not null, it's set to the pg_type entry's address. * * Note that permissions checks are done against current user regardless of * ownerId. A nonzero ownerId is used when someone is creating a relation * "on behalf of" someone else, so we still want to see that the current user * has permissions to do it. * * If successful, returns the address of the new relation. * ---------------------------------------------------------------- */ ObjectAddress DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId, ObjectAddress *typaddress, const char *queryString) { char relname[NAMEDATALEN]; Oid namespaceId; List *schema = stmt->tableElts; Oid relationId; Oid tablespaceId; Relation rel; TupleDesc descriptor; List *inheritOids; List *old_constraints; bool localHasOids; int parentOidCount; List *rawDefaults; List *cookedDefaults; Datum reloptions; ListCell *listptr; AttrNumber attnum; static char *validnsps[] = HEAP_RELOPT_NAMESPACES; Oid ofTypeId; ObjectAddress address; /* * Truncate relname to appropriate length (probably a waste of time, as * parser should have done this already). */ StrNCpy(relname, stmt->relation->relname, NAMEDATALEN); /* * Check consistency of arguments */ if (stmt->oncommit != ONCOMMIT_NOOP && stmt->relation->relpersistence != RELPERSISTENCE_TEMP) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("ON COMMIT can only be used on temporary tables"))); if (stmt->partspec != NULL) { if (relkind != RELKIND_RELATION) elog(ERROR, "unexpected relkind: %d", (int) relkind); relkind = RELKIND_PARTITIONED_TABLE; } /* * Look up the namespace in which we are supposed to create the relation, * check we have permission to create there, lock it against concurrent * drop, and mark stmt->relation as RELPERSISTENCE_TEMP if a temporary * namespace is selected. */ namespaceId = RangeVarGetAndCheckCreationNamespace(stmt->relation, NoLock, NULL); /* * Security check: disallow creating temp tables from security-restricted * code. This is needed because calling code might not expect untrusted * tables to appear in pg_temp at the front of its search path. */ if (stmt->relation->relpersistence == RELPERSISTENCE_TEMP && InSecurityRestrictedOperation()) ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("cannot create temporary table within security-restricted operation"))); /* * Select tablespace to use. If not specified, use default tablespace * (which may in turn default to database's default). */ if (stmt->tablespacename) { tablespaceId = get_tablespace_oid(stmt->tablespacename, false); } else { tablespaceId = GetDefaultTablespace(stmt->relation->relpersistence); /* note InvalidOid is OK in this case */ } /* Check permissions except when using database's default */ if (OidIsValid(tablespaceId) && tablespaceId != MyDatabaseTableSpace) { AclResult aclresult; aclresult = pg_tablespace_aclcheck(tablespaceId, GetUserId(), ACL_CREATE); if (aclresult != ACLCHECK_OK) aclcheck_error(aclresult, ACL_KIND_TABLESPACE, get_tablespace_name(tablespaceId)); } /* In all cases disallow placing user relations in pg_global */ if (tablespaceId == GLOBALTABLESPACE_OID) ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("only shared relations can be placed in pg_global tablespace"))); /* Identify user ID that will own the table */ if (!OidIsValid(ownerId)) ownerId = GetUserId(); /* * Parse and validate reloptions, if any. */ reloptions = transformRelOptions((Datum) 0, stmt->options, NULL, validnsps, true, false); if (relkind == RELKIND_VIEW) (void) view_reloptions(reloptions, true); else (void) heap_reloptions(relkind, reloptions, true); if (stmt->ofTypename) { AclResult aclresult; ofTypeId = typenameTypeId(NULL, stmt->ofTypename); aclresult = pg_type_aclcheck(ofTypeId, GetUserId(), ACL_USAGE); if (aclresult != ACLCHECK_OK) aclcheck_error_type(aclresult, ofTypeId); } else ofTypeId = InvalidOid; /* * Look up inheritance ancestors and generate relation schema, including * inherited attributes. */ schema = MergeAttributes(schema, stmt->inhRelations, stmt->relation->relpersistence, stmt->partbound != NULL, &inheritOids, &old_constraints, &parentOidCount); /* * Create a tuple descriptor from the relation schema. Note that this * deals with column names, types, and NOT NULL constraints, but not * default values or CHECK constraints; we handle those below. */ descriptor = BuildDescForRelation(schema); /* * Notice that we allow OIDs here only for plain tables and partitioned * tables, even though some other relkinds can support them. This is * necessary because the default_with_oids GUC must apply only to plain * tables and not any other relkind; doing otherwise would break existing * pg_dump files. We could allow explicit "WITH OIDS" while not allowing * default_with_oids to affect other relkinds, but it would complicate * interpretOidsOption(). */ localHasOids = interpretOidsOption(stmt->options, (relkind == RELKIND_RELATION || relkind == RELKIND_PARTITIONED_TABLE)); descriptor->tdhasoid = (localHasOids || parentOidCount > 0); /* * If a partitioned table doesn't have the system OID column, then none * of its partitions should have it. */ if (stmt->partbound && parentOidCount == 0 && localHasOids) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot create table with OIDs as partition of table without OIDs"))); /* * Find columns with default values and prepare for insertion of the * defaults. Pre-cooked (that is, inherited) defaults go into a list of * CookedConstraint structs that we'll pass to heap_create_with_catalog, * while raw defaults go into a list of RawColumnDefault structs that will * be processed by AddRelationNewConstraints. (We can't deal with raw * expressions until we can do transformExpr.) * * We can set the atthasdef flags now in the tuple descriptor; this just * saves StoreAttrDefault from having to do an immediate update of the * pg_attribute rows. */ rawDefaults = NIL; cookedDefaults = NIL; attnum = 0; foreach(listptr, schema) { ColumnDef *colDef = lfirst(listptr); attnum++; if (colDef->raw_default != NULL) { RawColumnDefault *rawEnt; Assert(colDef->cooked_default == NULL); rawEnt = (RawColumnDefault *) palloc(sizeof(RawColumnDefault)); rawEnt->attnum = attnum; rawEnt->raw_default = colDef->raw_default; rawDefaults = lappend(rawDefaults, rawEnt); descriptor->attrs[attnum - 1]->atthasdef = true; } else if (colDef->cooked_default != NULL) { CookedConstraint *cooked; cooked = (CookedConstraint *) palloc(sizeof(CookedConstraint)); cooked->contype = CONSTR_DEFAULT; cooked->conoid = InvalidOid; /* until created */ cooked->name = NULL; cooked->attnum = attnum; cooked->expr = colDef->cooked_default; cooked->skip_validation = false; cooked->is_local = true; /* not used for defaults */ cooked->inhcount = 0; /* ditto */ cooked->is_no_inherit = false; cookedDefaults = lappend(cookedDefaults, cooked); descriptor->attrs[attnum - 1]->atthasdef = true; } if (colDef->identity) descriptor->attrs[attnum - 1]->attidentity = colDef->identity; } /* * Create the relation. Inherited defaults and constraints are passed in * for immediate handling --- since they don't need parsing, they can be * stored immediately. */ relationId = heap_create_with_catalog(relname, namespaceId, tablespaceId, InvalidOid, InvalidOid, ofTypeId, ownerId, descriptor, list_concat(cookedDefaults, old_constraints), relkind, stmt->relation->relpersistence, false, false, localHasOids, parentOidCount, stmt->oncommit, reloptions, true, allowSystemTableMods, false, typaddress); /* Store inheritance information for new rel. */ StoreCatalogInheritance(relationId, inheritOids, stmt->partbound != NULL); /* * We must bump the command counter to make the newly-created relation * tuple visible for opening. */ CommandCounterIncrement(); /* * Open the new relation and acquire exclusive lock on it. This isn't * really necessary for locking out other backends (since they can't see * the new rel anyway until we commit), but it keeps the lock manager from * complaining about deadlock risks. */ rel = relation_open(relationId, AccessExclusiveLock); /* Process and store partition bound, if any. */ if (stmt->partbound) { Node *bound; ParseState *pstate; Oid parentId = linitial_oid(inheritOids); Relation parent; /* Already have strong enough lock on the parent */ parent = heap_open(parentId, NoLock); /* * We are going to try to validate the partition bound specification * against the partition key of parentRel, so it better have one. */ if (parent->rd_rel->relkind != RELKIND_PARTITIONED_TABLE) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("\"%s\" is not partitioned", RelationGetRelationName(parent)))); /* Tranform the bound values */ pstate = make_parsestate(NULL); pstate->p_sourcetext = queryString; bound = transformPartitionBound(pstate, parent, stmt->partbound); /* * Check first that the new partition's bound is valid and does not * overlap with any of existing partitions of the parent - note that * it does not return on error. */ check_new_partition_bound(relname, parent, bound); /* Update the pg_class entry. */ StorePartitionBound(rel, parent, bound); heap_close(parent, NoLock); /* * The code that follows may also update the pg_class tuple to update * relnumchecks, so bump up the command counter to avoid the "already * updated by self" error. */ CommandCounterIncrement(); } /* * Process the partitioning specification (if any) and store the partition * key information into the catalog. */ if (stmt->partspec) { char strategy; int partnatts, i; AttrNumber partattrs[PARTITION_MAX_KEYS]; Oid partopclass[PARTITION_MAX_KEYS]; Oid partcollation[PARTITION_MAX_KEYS]; List *partexprs = NIL; List *cmds = NIL; /* * We need to transform the raw parsetrees corresponding to partition * expressions into executable expression trees. Like column defaults * and CHECK constraints, we could not have done the transformation * earlier. */ stmt->partspec = transformPartitionSpec(rel, stmt->partspec, &strategy); ComputePartitionAttrs(rel, stmt->partspec->partParams, partattrs, &partexprs, partopclass, partcollation); partnatts = list_length(stmt->partspec->partParams); StorePartitionKey(rel, strategy, partnatts, partattrs, partexprs, partopclass, partcollation); /* Force key columns to be NOT NULL when using range partitioning */ if (strategy == PARTITION_STRATEGY_RANGE) { for (i = 0; i < partnatts; i++) { AttrNumber partattno = partattrs[i]; Form_pg_attribute attform = descriptor->attrs[partattno - 1]; if (partattno != 0 && !attform->attnotnull) { /* Add a subcommand to make this one NOT NULL */ AlterTableCmd *cmd = makeNode(AlterTableCmd); cmd->subtype = AT_SetNotNull; cmd->name = pstrdup(NameStr(attform->attname)); cmds = lappend(cmds, cmd); } } /* * Although, there cannot be any partitions yet, we still need to * pass true for recurse; ATPrepSetNotNull() complains if we don't */ if (cmds != NIL) AlterTableInternal(RelationGetRelid(rel), cmds, true); } } /* * Now add any newly specified column default values and CHECK constraints * to the new relation. These are passed to us in the form of raw * parsetrees; we need to transform them to executable expression trees * before they can be added. The most convenient way to do that is to * apply the parser's transformExpr routine, but transformExpr doesn't * work unless we have a pre-existing relation. So, the transformation has * to be postponed to this final step of CREATE TABLE. */ if (rawDefaults || stmt->constraints) AddRelationNewConstraints(rel, rawDefaults, stmt->constraints, true, true, false); ObjectAddressSet(address, RelationRelationId, relationId); /* * Clean up. We keep lock on new relation (although it shouldn't be * visible to anyone else anyway, until commit). */ relation_close(rel, NoLock); return address; } /* * Emit the right error or warning message for a "DROP" command issued on a * non-existent relation */ static void DropErrorMsgNonExistent(RangeVar *rel, char rightkind, bool missing_ok) { const struct dropmsgstrings *rentry; if (rel->schemaname != NULL && !OidIsValid(LookupNamespaceNoError(rel->schemaname))) { if (!missing_ok) { ereport(ERROR, (errcode(ERRCODE_UNDEFINED_SCHEMA), errmsg("schema \"%s\" does not exist", rel->schemaname))); } else { ereport(NOTICE, (errmsg("schema \"%s\" does not exist, skipping", rel->schemaname))); } return; } for (rentry = dropmsgstringarray; rentry->kind != '\0'; rentry++) { if (rentry->kind == rightkind) { if (!missing_ok) { ereport(ERROR, (errcode(rentry->nonexistent_code), errmsg(rentry->nonexistent_msg, rel->relname))); } else { ereport(NOTICE, (errmsg(rentry->skipping_msg, rel->relname))); break; } } } Assert(rentry->kind != '\0'); /* Should be impossible */ } /* * Emit the right error message for a "DROP" command issued on a * relation of the wrong type */ static void DropErrorMsgWrongType(const char *relname, char wrongkind, char rightkind) { const struct dropmsgstrings *rentry; const struct dropmsgstrings *wentry; for (rentry = dropmsgstringarray; rentry->kind != '\0'; rentry++) if (rentry->kind == rightkind) break; Assert(rentry->kind != '\0'); for (wentry = dropmsgstringarray; wentry->kind != '\0'; wentry++) if (wentry->kind == wrongkind) break; /* wrongkind could be something we don't have in our table... */ ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg(rentry->nota_msg, relname), (wentry->kind != '\0') ? errhint("%s", _(wentry->drophint_msg)) : 0)); } /* * RemoveRelations * Implements DROP TABLE, DROP INDEX, DROP SEQUENCE, DROP VIEW, * DROP MATERIALIZED VIEW, DROP FOREIGN TABLE */ void RemoveRelations(DropStmt *drop) { ObjectAddresses *objects; char relkind; ListCell *cell; int flags = 0; LOCKMODE lockmode = AccessExclusiveLock; /* DROP CONCURRENTLY uses a weaker lock, and has some restrictions */ if (drop->concurrent) { flags |= PERFORM_DELETION_CONCURRENTLY; lockmode = ShareUpdateExclusiveLock; Assert(drop->removeType == OBJECT_INDEX); if (list_length(drop->objects) != 1) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("DROP INDEX CONCURRENTLY does not support dropping multiple objects"))); if (drop->behavior == DROP_CASCADE) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("DROP INDEX CONCURRENTLY does not support CASCADE"))); } /* * First we identify all the relations, then we delete them in a single * performMultipleDeletions() call. This is to avoid unwanted DROP * RESTRICT errors if one of the relations depends on another. */ /* Determine required relkind */ switch (drop->removeType) { case OBJECT_TABLE: relkind = RELKIND_RELATION; break; case OBJECT_INDEX: relkind = RELKIND_INDEX; break; case OBJECT_SEQUENCE: relkind = RELKIND_SEQUENCE; break; case OBJECT_VIEW: relkind = RELKIND_VIEW; break; case OBJECT_MATVIEW: relkind = RELKIND_MATVIEW; break; case OBJECT_FOREIGN_TABLE: relkind = RELKIND_FOREIGN_TABLE; break; default: elog(ERROR, "unrecognized drop object type: %d", (int) drop->removeType); relkind = 0; /* keep compiler quiet */ break; } /* Lock and validate each relation; build a list of object addresses */ objects = new_object_addresses(); foreach(cell, drop->objects) { RangeVar *rel = makeRangeVarFromNameList((List *) lfirst(cell)); Oid relOid; ObjectAddress obj; struct DropRelationCallbackState state; /* * These next few steps are a great deal like relation_openrv, but we * don't bother building a relcache entry since we don't need it. * * Check for shared-cache-inval messages before trying to access the * relation. This is needed to cover the case where the name * identifies a rel that has been dropped and recreated since the * start of our transaction: if we don't flush the old syscache entry, * then we'll latch onto that entry and suffer an error later. */ AcceptInvalidationMessages(); /* Look up the appropriate relation using namespace search. */ state.relkind = relkind; state.heapOid = InvalidOid; state.concurrent = drop->concurrent; relOid = RangeVarGetRelidExtended(rel, lockmode, true, false, RangeVarCallbackForDropRelation, (void *) &state); /* Not there? */ if (!OidIsValid(relOid)) { DropErrorMsgNonExistent(rel, relkind, drop->missing_ok); continue; } /* OK, we're ready to delete this one */ obj.classId = RelationRelationId; obj.objectId = relOid; obj.objectSubId = 0; add_exact_object_address(&obj, objects); } performMultipleDeletions(objects, drop->behavior, flags); free_object_addresses(objects); } /* * Before acquiring a table lock, check whether we have sufficient rights. * In the case of DROP INDEX, also try to lock the table before the index. */ static void RangeVarCallbackForDropRelation(const RangeVar *rel, Oid relOid, Oid oldRelOid, void *arg) { HeapTuple tuple; struct DropRelationCallbackState *state; char relkind; char expected_relkind; Form_pg_class classform; LOCKMODE heap_lockmode; state = (struct DropRelationCallbackState *) arg; relkind = state->relkind; heap_lockmode = state->concurrent ? ShareUpdateExclusiveLock : AccessExclusiveLock; /* * If we previously locked some other index's heap, and the name we're * looking up no longer refers to that relation, release the now-useless * lock. */ if (relOid != oldRelOid && OidIsValid(state->heapOid)) { UnlockRelationOid(state->heapOid, heap_lockmode); state->heapOid = InvalidOid; } /* Didn't find a relation, so no need for locking or permission checks. */ if (!OidIsValid(relOid)) return; tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relOid)); if (!HeapTupleIsValid(tuple)) return; /* concurrently dropped, so nothing to do */ classform = (Form_pg_class) GETSTRUCT(tuple); /* * Both RELKIND_RELATION and RELKIND_PARTITIONED_TABLE are OBJECT_TABLE, * but RemoveRelations() can only pass one relkind for a given relation. * It chooses RELKIND_RELATION for both regular and partitioned tables. * That means we must be careful before giving the wrong type error when * the relation is RELKIND_PARTITIONED_TABLE. */ if (classform->relkind == RELKIND_PARTITIONED_TABLE) expected_relkind = RELKIND_RELATION; else expected_relkind = classform->relkind; if (relkind != expected_relkind) DropErrorMsgWrongType(rel->relname, classform->relkind, relkind); /* Allow DROP to either table owner or schema owner */ if (!pg_class_ownercheck(relOid, GetUserId()) && !pg_namespace_ownercheck(classform->relnamespace, GetUserId())) aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS, rel->relname); if (!allowSystemTableMods && IsSystemClass(relOid, classform)) ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("permission denied: \"%s\" is a system catalog", rel->relname))); ReleaseSysCache(tuple); /* * In DROP INDEX, attempt to acquire lock on the parent table before * locking the index. index_drop() will need this anyway, and since * regular queries lock tables before their indexes, we risk deadlock if * we do it the other way around. No error if we don't find a pg_index * entry, though --- the relation may have been dropped. */ if (relkind == RELKIND_INDEX && relOid != oldRelOid) { state->heapOid = IndexGetRelation(relOid, true); if (OidIsValid(state->heapOid)) LockRelationOid(state->heapOid, heap_lockmode); } } /* * ExecuteTruncate * Executes a TRUNCATE command. * * This is a multi-relation truncate. We first open and grab exclusive * lock on all relations involved, checking permissions and otherwise * verifying that the relation is OK for truncation. In CASCADE mode, * relations having FK references to the targeted relations are automatically * added to the group; in RESTRICT mode, we check that all FK references are * internal to the group that's being truncated. Finally all the relations * are truncated and reindexed. */ void ExecuteTruncate(TruncateStmt *stmt) { List *rels = NIL; List *relids = NIL; List *seq_relids = NIL; EState *estate; ResultRelInfo *resultRelInfos; ResultRelInfo *resultRelInfo; SubTransactionId mySubid; ListCell *cell; /* * Open, exclusive-lock, and check all the explicitly-specified relations */ foreach(cell, stmt->relations) { RangeVar *rv = lfirst(cell); Relation rel; bool recurse = rv->inh; Oid myrelid; rel = heap_openrv(rv, AccessExclusiveLock); myrelid = RelationGetRelid(rel); /* don't throw error for "TRUNCATE foo, foo" */ if (list_member_oid(relids, myrelid)) { heap_close(rel, AccessExclusiveLock); continue; } truncate_check_rel(rel); rels = lappend(rels, rel); relids = lappend_oid(relids, myrelid); if (recurse) { ListCell *child; List *children; children = find_all_inheritors(myrelid, AccessExclusiveLock, NULL); foreach(child, children) { Oid childrelid = lfirst_oid(child); if (list_member_oid(relids, childrelid)) continue; /* find_all_inheritors already got lock */ rel = heap_open(childrelid, NoLock); truncate_check_rel(rel); rels = lappend(rels, rel); relids = lappend_oid(relids, childrelid); } } else if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("must truncate child tables too"))); } /* * In CASCADE mode, suck in all referencing relations as well. This * requires multiple iterations to find indirectly-dependent relations. At * each phase, we need to exclusive-lock new rels before looking for their * dependencies, else we might miss something. Also, we check each rel as * soon as we open it, to avoid a faux pas such as holding lock for a long * time on a rel we have no permissions for. */ if (stmt->behavior == DROP_CASCADE) { for (;;) { List *newrelids; newrelids = heap_truncate_find_FKs(relids); if (newrelids == NIL) break; /* nothing else to add */ foreach(cell, newrelids) { Oid relid = lfirst_oid(cell); Relation rel; rel = heap_open(relid, AccessExclusiveLock); ereport(NOTICE, (errmsg("truncate cascades to table \"%s\"", RelationGetRelationName(rel)))); truncate_check_rel(rel); rels = lappend(rels, rel); relids = lappend_oid(relids, relid); } } } /* * Check foreign key references. In CASCADE mode, this should be * unnecessary since we just pulled in all the references; but as a * cross-check, do it anyway if in an Assert-enabled build. */ #ifdef USE_ASSERT_CHECKING heap_truncate_check_FKs(rels, false); #else if (stmt->behavior == DROP_RESTRICT) heap_truncate_check_FKs(rels, false); #endif /* * If we are asked to restart sequences, find all the sequences, lock them * (we need AccessExclusiveLock for ResetSequence), and check permissions. * We want to do this early since it's pointless to do all the truncation * work only to fail on sequence permissions. */ if (stmt->restart_seqs) { foreach(cell, rels) { Relation rel = (Relation) lfirst(cell); List *seqlist = getOwnedSequences(RelationGetRelid(rel), 0); ListCell *seqcell; foreach(seqcell, seqlist) { Oid seq_relid = lfirst_oid(seqcell); Relation seq_rel; seq_rel = relation_open(seq_relid, AccessExclusiveLock); /* This check must match AlterSequence! */ if (!pg_class_ownercheck(seq_relid, GetUserId())) aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS, RelationGetRelationName(seq_rel)); seq_relids = lappend_oid(seq_relids, seq_relid); relation_close(seq_rel, NoLock); } } } /* Prepare to catch AFTER triggers. */ AfterTriggerBeginQuery(); /* * To fire triggers, we'll need an EState as well as a ResultRelInfo for * each relation. We don't need to call ExecOpenIndices, though. */ estate = CreateExecutorState(); resultRelInfos = (ResultRelInfo *) palloc(list_length(rels) * sizeof(ResultRelInfo)); resultRelInfo = resultRelInfos; foreach(cell, rels) { Relation rel = (Relation) lfirst(cell); InitResultRelInfo(resultRelInfo, rel, 0, /* dummy rangetable index */ NULL, 0); resultRelInfo++; } estate->es_result_relations = resultRelInfos; estate->es_num_result_relations = list_length(rels); /* * Process all BEFORE STATEMENT TRUNCATE triggers before we begin * truncating (this is because one of them might throw an error). Also, if * we were to allow them to prevent statement execution, that would need * to be handled here. */ resultRelInfo = resultRelInfos; foreach(cell, rels) { estate->es_result_relation_info = resultRelInfo; ExecBSTruncateTriggers(estate, resultRelInfo); resultRelInfo++; } /* * OK, truncate each table. */ mySubid = GetCurrentSubTransactionId(); foreach(cell, rels) { Relation rel = (Relation) lfirst(cell); /* Skip partitioned tables as there is nothing to do */ if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) continue; /* * Normally, we need a transaction-safe truncation here. However, if * the table was either created in the current (sub)transaction or has * a new relfilenode in the current (sub)transaction, then we can just * truncate it in-place, because a rollback would cause the whole * table or the current physical file to be thrown away anyway. */ if (rel->rd_createSubid == mySubid || rel->rd_newRelfilenodeSubid == mySubid) { /* Immediate, non-rollbackable truncation is OK */ heap_truncate_one_rel(rel); } else { Oid heap_relid; Oid toast_relid; MultiXactId minmulti; /* * This effectively deletes all rows in the table, and may be done * in a serializable transaction. In that case we must record a * rw-conflict in to this transaction from each transaction * holding a predicate lock on the table. */ CheckTableForSerializableConflictIn(rel); minmulti = GetOldestMultiXactId(); /* * Need the full transaction-safe pushups. * * Create a new empty storage file for the relation, and assign it * as the relfilenode value. The old storage file is scheduled for * deletion at commit. */ RelationSetNewRelfilenode(rel, rel->rd_rel->relpersistence, RecentXmin, minmulti); if (rel->rd_rel->relpersistence == RELPERSISTENCE_UNLOGGED) heap_create_init_fork(rel); heap_relid = RelationGetRelid(rel); toast_relid = rel->rd_rel->reltoastrelid; /* * The same for the toast table, if any. */ if (OidIsValid(toast_relid)) { rel = relation_open(toast_relid, AccessExclusiveLock); RelationSetNewRelfilenode(rel, rel->rd_rel->relpersistence, RecentXmin, minmulti); if (rel->rd_rel->relpersistence == RELPERSISTENCE_UNLOGGED) heap_create_init_fork(rel); heap_close(rel, NoLock); } /* * Reconstruct the indexes to match, and we're done. */ reindex_relation(heap_relid, REINDEX_REL_PROCESS_TOAST, 0); } pgstat_count_truncate(rel); } /* * Restart owned sequences if we were asked to. */ foreach(cell, seq_relids) { Oid seq_relid = lfirst_oid(cell); ResetSequence(seq_relid); } /* * Process all AFTER STATEMENT TRUNCATE triggers. */ resultRelInfo = resultRelInfos; foreach(cell, rels) { estate->es_result_relation_info = resultRelInfo; ExecASTruncateTriggers(estate, resultRelInfo); resultRelInfo++; } /* Handle queued AFTER triggers */ AfterTriggerEndQuery(estate); /* We can clean up the EState now */ FreeExecutorState(estate); /* And close the rels (can't do this while EState still holds refs) */ foreach(cell, rels) { Relation rel = (Relation) lfirst(cell); heap_close(rel, NoLock); } } /* * Check that a given rel is safe to truncate. Subroutine for ExecuteTruncate */ static void truncate_check_rel(Relation rel) { AclResult aclresult; /* * Only allow truncate on regular tables and partitioned tables (although, * the latter are only being included here for the following checks; no * physical truncation will occur in their case.) */ if (rel->rd_rel->relkind != RELKIND_RELATION && rel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is not a table", RelationGetRelationName(rel)))); /* Permissions checks */ aclresult = pg_class_aclcheck(RelationGetRelid(rel), GetUserId(), ACL_TRUNCATE); if (aclresult != ACLCHECK_OK) aclcheck_error(aclresult, ACL_KIND_CLASS, RelationGetRelationName(rel)); if (!allowSystemTableMods && IsSystemRelation(rel)) ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("permission denied: \"%s\" is a system catalog", RelationGetRelationName(rel)))); /* * Don't allow truncate on temp tables of other backends ... their local * buffer manager is not going to cope. */ if (RELATION_IS_OTHER_TEMP(rel)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot truncate temporary tables of other sessions"))); /* * Also check for active uses of the relation in the current transaction, * including open scans and pending AFTER trigger events. */ CheckTableNotInUse(rel, "TRUNCATE"); } /* * storage_name * returns the name corresponding to a typstorage/attstorage enum value */ static const char * storage_name(char c) { switch (c) { case 'p': return "PLAIN"; case 'm': return "MAIN"; case 'x': return "EXTENDED"; case 'e': return "EXTERNAL"; default: return "???"; } } /*---------- * MergeAttributes * Returns new schema given initial schema and superclasses. * * Input arguments: * 'schema' is the column/attribute definition for the table. (It's a list * of ColumnDef's.) It is destructively changed. * 'supers' is a list of names (as RangeVar nodes) of parent relations. * 'relpersistence' is a persistence type of the table. * 'is_partition' tells if the table is a partition * * Output arguments: * 'supOids' receives a list of the OIDs of the parent relations. * 'supconstr' receives a list of constraints belonging to the parents, * updated as necessary to be valid for the child. * 'supOidCount' is set to the number of parents that have OID columns. * * Return value: * Completed schema list. * * Notes: * The order in which the attributes are inherited is very important. * Intuitively, the inherited attributes should come first. If a table * inherits from multiple parents, the order of those attributes are * according to the order of the parents specified in CREATE TABLE. * * Here's an example: * * create table person (name text, age int4, location point); * create table emp (salary int4, manager text) inherits(person); * create table student (gpa float8) inherits (person); * create table stud_emp (percent int4) inherits (emp, student); * * The order of the attributes of stud_emp is: * * person {1:name, 2:age, 3:location} * / \ * {6:gpa} student emp {4:salary, 5:manager} * \ / * stud_emp {7:percent} * * If the same attribute name appears multiple times, then it appears * in the result table in the proper location for its first appearance. * * Constraints (including NOT NULL constraints) for the child table * are the union of all relevant constraints, from both the child schema * and parent tables. * * The default value for a child column is defined as: * (1) If the child schema specifies a default, that value is used. * (2) If neither the child nor any parent specifies a default, then * the column will not have a default. * (3) If conflicting defaults are inherited from different parents * (and not overridden by the child), an error is raised. * (4) Otherwise the inherited default is used. * Rule (3) is new in Postgres 7.1; in earlier releases you got a * rather arbitrary choice of which parent default to use. *---------- */ static List * MergeAttributes(List *schema, List *supers, char relpersistence, bool is_partition, List **supOids, List **supconstr, int *supOidCount) { ListCell *entry; List *inhSchema = NIL; List *parentOids = NIL; List *constraints = NIL; int parentsWithOids = 0; bool have_bogus_defaults = false; int child_attno; static Node bogus_marker = {0}; /* marks conflicting defaults */ List *saved_schema = NIL; /* * Check for and reject tables with too many columns. We perform this * check relatively early for two reasons: (a) we don't run the risk of * overflowing an AttrNumber in subsequent code (b) an O(n^2) algorithm is * okay if we're processing <= 1600 columns, but could take minutes to * execute if the user attempts to create a table with hundreds of * thousands of columns. * * Note that we also need to check that we do not exceed this figure after * including columns from inherited relations. */ if (list_length(schema) > MaxHeapAttributeNumber) ereport(ERROR, (errcode(ERRCODE_TOO_MANY_COLUMNS), errmsg("tables can have at most %d columns", MaxHeapAttributeNumber))); /* * In case of a partition, there are no new column definitions, only dummy * ColumnDefs created for column constraints. We merge them with the * constraints inherited from the parent. */ if (is_partition) { saved_schema = schema; schema = NIL; } /* * Check for duplicate names in the explicit list of attributes. * * Although we might consider merging such entries in the same way that we * handle name conflicts for inherited attributes, it seems to make more * sense to assume such conflicts are errors. */ foreach(entry, schema) { ColumnDef *coldef = lfirst(entry); ListCell *rest = lnext(entry); ListCell *prev = entry; if (coldef->typeName == NULL) /* * Typed table column option that does not belong to a column from * the type. This works because the columns from the type come * first in the list. */ ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" does not exist", coldef->colname))); while (rest != NULL) { ColumnDef *restdef = lfirst(rest); ListCell *next = lnext(rest); /* need to save it in case we * delete it */ if (strcmp(coldef->colname, restdef->colname) == 0) { if (coldef->is_from_type) { /* * merge the column options into the column from the type */ coldef->is_not_null = restdef->is_not_null; coldef->raw_default = restdef->raw_default; coldef->cooked_default = restdef->cooked_default; coldef->constraints = restdef->constraints; coldef->is_from_type = false; list_delete_cell(schema, rest, prev); } else ereport(ERROR, (errcode(ERRCODE_DUPLICATE_COLUMN), errmsg("column \"%s\" specified more than once", coldef->colname))); } prev = rest; rest = next; } } /* * Scan the parents left-to-right, and merge their attributes to form a * list of inherited attributes (inhSchema). Also check to see if we need * to inherit an OID column. */ child_attno = 0; foreach(entry, supers) { RangeVar *parent = (RangeVar *) lfirst(entry); Relation relation; TupleDesc tupleDesc; TupleConstr *constr; AttrNumber *newattno; AttrNumber parent_attno; /* * A self-exclusive lock is needed here. If two backends attempt to * add children to the same parent simultaneously, and that parent has * no pre-existing children, then both will attempt to update the * parent's relhassubclass field, leading to a "tuple concurrently * updated" error. Also, this interlocks against a concurrent ANALYZE * on the parent table, which might otherwise be attempting to clear * the parent's relhassubclass field, if its previous children were * recently dropped. * * If the child table is a partition, then we instead grab an * exclusive lock on the parent because its partition descriptor will * be changed by addition of the new partition. */ if (!is_partition) relation = heap_openrv(parent, ShareUpdateExclusiveLock); else relation = heap_openrv(parent, AccessExclusiveLock); /* * We do not allow partitioned tables and partitions to participate in * regular inheritance. */ if (relation->rd_rel->relkind == RELKIND_PARTITIONED_TABLE && !is_partition) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot inherit from partitioned table \"%s\"", parent->relname))); if (relation->rd_rel->relispartition && !is_partition) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot inherit from partition \"%s\"", parent->relname))); if (relation->rd_rel->relkind != RELKIND_RELATION && relation->rd_rel->relkind != RELKIND_FOREIGN_TABLE && relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("inherited relation \"%s\" is not a table or foreign table", parent->relname))); /* Permanent rels cannot inherit from temporary ones */ if (relpersistence != RELPERSISTENCE_TEMP && relation->rd_rel->relpersistence == RELPERSISTENCE_TEMP) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg(!is_partition ? "cannot inherit from temporary relation \"%s\"" : "cannot create a permanent relation as partition of temporary relation \"%s\"", parent->relname))); /* If existing rel is temp, it must belong to this session */ if (relation->rd_rel->relpersistence == RELPERSISTENCE_TEMP && !relation->rd_islocaltemp) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg(!is_partition ? "cannot inherit from temporary relation of another session" : "cannot create as partition of temporary relation of another session"))); /* * We should have an UNDER permission flag for this, but for now, * demand that creator of a child table own the parent. */ if (!pg_class_ownercheck(RelationGetRelid(relation), GetUserId())) aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS, RelationGetRelationName(relation)); /* * Reject duplications in the list of parents. */ if (list_member_oid(parentOids, RelationGetRelid(relation))) ereport(ERROR, (errcode(ERRCODE_DUPLICATE_TABLE), errmsg("relation \"%s\" would be inherited from more than once", parent->relname))); parentOids = lappend_oid(parentOids, RelationGetRelid(relation)); if (relation->rd_rel->relhasoids) parentsWithOids++; tupleDesc = RelationGetDescr(relation); constr = tupleDesc->constr; /* * newattno[] will contain the child-table attribute numbers for the * attributes of this parent table. (They are not the same for * parents after the first one, nor if we have dropped columns.) */ newattno = (AttrNumber *) palloc0(tupleDesc->natts * sizeof(AttrNumber)); for (parent_attno = 1; parent_attno <= tupleDesc->natts; parent_attno++) { Form_pg_attribute attribute = tupleDesc->attrs[parent_attno - 1]; char *attributeName = NameStr(attribute->attname); int exist_attno; ColumnDef *def; /* * Ignore dropped columns in the parent. */ if (attribute->attisdropped) continue; /* leave newattno entry as zero */ /* * Does it conflict with some previously inherited column? */ exist_attno = findAttrByName(attributeName, inhSchema); if (exist_attno > 0) { Oid defTypeId; int32 deftypmod; Oid defCollId; /* * Yes, try to merge the two column definitions. They must * have the same type, typmod, and collation. */ ereport(NOTICE, (errmsg("merging multiple inherited definitions of column \"%s\"", attributeName))); def = (ColumnDef *) list_nth(inhSchema, exist_attno - 1); typenameTypeIdAndMod(NULL, def->typeName, &defTypeId, &deftypmod); if (defTypeId != attribute->atttypid || deftypmod != attribute->atttypmod) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("inherited column \"%s\" has a type conflict", attributeName), errdetail("%s versus %s", format_type_with_typemod(defTypeId, deftypmod), format_type_with_typemod(attribute->atttypid, attribute->atttypmod)))); defCollId = GetColumnDefCollation(NULL, def, defTypeId); if (defCollId != attribute->attcollation) ereport(ERROR, (errcode(ERRCODE_COLLATION_MISMATCH), errmsg("inherited column \"%s\" has a collation conflict", attributeName), errdetail("\"%s\" versus \"%s\"", get_collation_name(defCollId), get_collation_name(attribute->attcollation)))); /* Copy storage parameter */ if (def->storage == 0) def->storage = attribute->attstorage; else if (def->storage != attribute->attstorage) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("inherited column \"%s\" has a storage parameter conflict", attributeName), errdetail("%s versus %s", storage_name(def->storage), storage_name(attribute->attstorage)))); def->inhcount++; /* Merge of NOT NULL constraints = OR 'em together */ def->is_not_null |= attribute->attnotnull; /* Default and other constraints are handled below */ newattno[parent_attno - 1] = exist_attno; } else { /* * No, create a new inherited column */ def = makeNode(ColumnDef); def->colname = pstrdup(attributeName); def->typeName = makeTypeNameFromOid(attribute->atttypid, attribute->atttypmod); def->inhcount = 1; def->is_local = false; def->is_not_null = attribute->attnotnull; def->is_from_type = false; def->storage = attribute->attstorage; def->raw_default = NULL; def->cooked_default = NULL; def->collClause = NULL; def->collOid = attribute->attcollation; def->constraints = NIL; def->location = -1; inhSchema = lappend(inhSchema, def); newattno[parent_attno - 1] = ++child_attno; } /* * Copy default if any */ if (attribute->atthasdef) { Node *this_default = NULL; AttrDefault *attrdef; int i; /* Find default in constraint structure */ Assert(constr != NULL); attrdef = constr->defval; for (i = 0; i < constr->num_defval; i++) { if (attrdef[i].adnum == parent_attno) { this_default = stringToNode(attrdef[i].adbin); break; } } Assert(this_default != NULL); /* * If default expr could contain any vars, we'd need to fix * 'em, but it can't; so default is ready to apply to child. * * If we already had a default from some prior parent, check * to see if they are the same. If so, no problem; if not, * mark the column as having a bogus default. Below, we will * complain if the bogus default isn't overridden by the child * schema. */ Assert(def->raw_default == NULL); if (def->cooked_default == NULL) def->cooked_default = this_default; else if (!equal(def->cooked_default, this_default)) { def->cooked_default = &bogus_marker; have_bogus_defaults = true; } } } /* * Now copy the CHECK constraints of this parent, adjusting attnos * using the completed newattno[] map. Identically named constraints * are merged if possible, else we throw error. */ if (constr && constr->num_check > 0) { ConstrCheck *check = constr->check; int i; for (i = 0; i < constr->num_check; i++) { char *name = check[i].ccname; Node *expr; bool found_whole_row; /* ignore if the constraint is non-inheritable */ if (check[i].ccnoinherit) continue; /* Adjust Vars to match new table's column numbering */ expr = map_variable_attnos(stringToNode(check[i].ccbin), 1, 0, newattno, tupleDesc->natts, &found_whole_row); /* * For the moment we have to reject whole-row variables. We * could convert them, if we knew the new table's rowtype OID, * but that hasn't been assigned yet. */ if (found_whole_row) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot convert whole-row table reference"), errdetail("Constraint \"%s\" contains a whole-row reference to table \"%s\".", name, RelationGetRelationName(relation)))); /* check for duplicate */ if (!MergeCheckConstraint(constraints, name, expr)) { /* nope, this is a new one */ CookedConstraint *cooked; cooked = (CookedConstraint *) palloc(sizeof(CookedConstraint)); cooked->contype = CONSTR_CHECK; cooked->conoid = InvalidOid; /* until created */ cooked->name = pstrdup(name); cooked->attnum = 0; /* not used for constraints */ cooked->expr = expr; cooked->skip_validation = false; cooked->is_local = false; cooked->inhcount = 1; cooked->is_no_inherit = false; constraints = lappend(constraints, cooked); } } } pfree(newattno); /* * Close the parent rel, but keep our lock on it until xact commit. * That will prevent someone else from deleting or ALTERing the parent * before the child is committed. */ heap_close(relation, NoLock); } /* * If we had no inherited attributes, the result schema is just the * explicitly declared columns. Otherwise, we need to merge the declared * columns into the inherited schema list. Although, we never have any * explicitly declared columns if the table is a partition. */ if (inhSchema != NIL) { int schema_attno = 0; foreach(entry, schema) { ColumnDef *newdef = lfirst(entry); char *attributeName = newdef->colname; int exist_attno; schema_attno++; /* * Does it conflict with some previously inherited column? */ exist_attno = findAttrByName(attributeName, inhSchema); if (exist_attno > 0) { ColumnDef *def; Oid defTypeId, newTypeId; int32 deftypmod, newtypmod; Oid defcollid, newcollid; /* * Partitions have only one parent and have no column * definitions of their own, so conflict should never occur. */ Assert(!is_partition); /* * Yes, try to merge the two column definitions. They must * have the same type, typmod, and collation. */ if (exist_attno == schema_attno) ereport(NOTICE, (errmsg("merging column \"%s\" with inherited definition", attributeName))); else ereport(NOTICE, (errmsg("moving and merging column \"%s\" with inherited definition", attributeName), errdetail("User-specified column moved to the position of the inherited column."))); def = (ColumnDef *) list_nth(inhSchema, exist_attno - 1); typenameTypeIdAndMod(NULL, def->typeName, &defTypeId, &deftypmod); typenameTypeIdAndMod(NULL, newdef->typeName, &newTypeId, &newtypmod); if (defTypeId != newTypeId || deftypmod != newtypmod) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("column \"%s\" has a type conflict", attributeName), errdetail("%s versus %s", format_type_with_typemod(defTypeId, deftypmod), format_type_with_typemod(newTypeId, newtypmod)))); defcollid = GetColumnDefCollation(NULL, def, defTypeId); newcollid = GetColumnDefCollation(NULL, newdef, newTypeId); if (defcollid != newcollid) ereport(ERROR, (errcode(ERRCODE_COLLATION_MISMATCH), errmsg("column \"%s\" has a collation conflict", attributeName), errdetail("\"%s\" versus \"%s\"", get_collation_name(defcollid), get_collation_name(newcollid)))); /* * Identity is never inherited. The new column can have an * identity definition, so we always just take that one. */ def->identity = newdef->identity; /* Copy storage parameter */ if (def->storage == 0) def->storage = newdef->storage; else if (newdef->storage != 0 && def->storage != newdef->storage) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("column \"%s\" has a storage parameter conflict", attributeName), errdetail("%s versus %s", storage_name(def->storage), storage_name(newdef->storage)))); /* Mark the column as locally defined */ def->is_local = true; /* Merge of NOT NULL constraints = OR 'em together */ def->is_not_null |= newdef->is_not_null; /* If new def has a default, override previous default */ if (newdef->raw_default != NULL) { def->raw_default = newdef->raw_default; def->cooked_default = newdef->cooked_default; } } else { /* * No, attach new column to result schema */ inhSchema = lappend(inhSchema, newdef); } } schema = inhSchema; /* * Check that we haven't exceeded the legal # of columns after merging * in inherited columns. */ if (list_length(schema) > MaxHeapAttributeNumber) ereport(ERROR, (errcode(ERRCODE_TOO_MANY_COLUMNS), errmsg("tables can have at most %d columns", MaxHeapAttributeNumber))); } /* * Now that we have the column definition list for a partition, we can * check whether the columns referenced in the column constraint specs * actually exist. Also, we merge the constraints into the corresponding * column definitions. */ if (is_partition && list_length(saved_schema) > 0) { schema = list_concat(schema, saved_schema); foreach(entry, schema) { ColumnDef *coldef = lfirst(entry); ListCell *rest = lnext(entry); ListCell *prev = entry; /* * Partition column option that does not belong to a column from * the parent. This works because the columns from the parent * come first in the list (see above). */ if (coldef->typeName == NULL) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" does not exist", coldef->colname))); while (rest != NULL) { ColumnDef *restdef = lfirst(rest); ListCell *next = lnext(rest); /* need to save it in case we * delete it */ if (strcmp(coldef->colname, restdef->colname) == 0) { /* * merge the column options into the column from the * parent */ coldef->is_not_null = restdef->is_not_null; coldef->raw_default = restdef->raw_default; coldef->cooked_default = restdef->cooked_default; coldef->constraints = restdef->constraints; list_delete_cell(schema, rest, prev); } prev = rest; rest = next; } } } /* * If we found any conflicting parent default values, check to make sure * they were overridden by the child. */ if (have_bogus_defaults) { foreach(entry, schema) { ColumnDef *def = lfirst(entry); if (def->cooked_default == &bogus_marker) ereport(ERROR, (errcode(ERRCODE_INVALID_COLUMN_DEFINITION), errmsg("column \"%s\" inherits conflicting default values", def->colname), errhint("To resolve the conflict, specify a default explicitly."))); } } *supOids = parentOids; *supconstr = constraints; *supOidCount = parentsWithOids; return schema; } /* * MergeCheckConstraint * Try to merge an inherited CHECK constraint with previous ones * * If we inherit identically-named constraints from multiple parents, we must * merge them, or throw an error if they don't have identical definitions. * * constraints is a list of CookedConstraint structs for previous constraints. * * Returns TRUE if merged (constraint is a duplicate), or FALSE if it's * got a so-far-unique name, or throws error if conflict. */ static bool MergeCheckConstraint(List *constraints, char *name, Node *expr) { ListCell *lc; foreach(lc, constraints) { CookedConstraint *ccon = (CookedConstraint *) lfirst(lc); Assert(ccon->contype == CONSTR_CHECK); /* Non-matching names never conflict */ if (strcmp(ccon->name, name) != 0) continue; if (equal(expr, ccon->expr)) { /* OK to merge */ ccon->inhcount++; return true; } ereport(ERROR, (errcode(ERRCODE_DUPLICATE_OBJECT), errmsg("check constraint name \"%s\" appears multiple times but with different expressions", name))); } return false; } /* * StoreCatalogInheritance * Updates the system catalogs with proper inheritance information. * * supers is a list of the OIDs of the new relation's direct ancestors. */ static void StoreCatalogInheritance(Oid relationId, List *supers, bool child_is_partition) { Relation relation; int16 seqNumber; ListCell *entry; /* * sanity checks */ AssertArg(OidIsValid(relationId)); if (supers == NIL) return; /* * Store INHERITS information in pg_inherits using direct ancestors only. * Also enter dependencies on the direct ancestors, and make sure they are * marked with relhassubclass = true. * * (Once upon a time, both direct and indirect ancestors were found here * and then entered into pg_ipl. Since that catalog doesn't exist * anymore, there's no need to look for indirect ancestors.) */ relation = heap_open(InheritsRelationId, RowExclusiveLock); seqNumber = 1; foreach(entry, supers) { Oid parentOid = lfirst_oid(entry); StoreCatalogInheritance1(relationId, parentOid, seqNumber, relation, child_is_partition); seqNumber++; } heap_close(relation, RowExclusiveLock); } /* * Make catalog entries showing relationId as being an inheritance child * of parentOid. inhRelation is the already-opened pg_inherits catalog. */ static void StoreCatalogInheritance1(Oid relationId, Oid parentOid, int16 seqNumber, Relation inhRelation, bool child_is_partition) { TupleDesc desc = RelationGetDescr(inhRelation); Datum values[Natts_pg_inherits]; bool nulls[Natts_pg_inherits]; ObjectAddress childobject, parentobject; HeapTuple tuple; /* * Make the pg_inherits entry */ values[Anum_pg_inherits_inhrelid - 1] = ObjectIdGetDatum(relationId); values[Anum_pg_inherits_inhparent - 1] = ObjectIdGetDatum(parentOid); values[Anum_pg_inherits_inhseqno - 1] = Int16GetDatum(seqNumber); memset(nulls, 0, sizeof(nulls)); tuple = heap_form_tuple(desc, values, nulls); CatalogTupleInsert(inhRelation, tuple); heap_freetuple(tuple); /* * Store a dependency too */ parentobject.classId = RelationRelationId; parentobject.objectId = parentOid; parentobject.objectSubId = 0; childobject.classId = RelationRelationId; childobject.objectId = relationId; childobject.objectSubId = 0; /* * Partition tables are expected to be dropped when the parent partitioned * table gets dropped. */ if (child_is_partition) recordDependencyOn(&childobject, &parentobject, DEPENDENCY_AUTO); else recordDependencyOn(&childobject, &parentobject, DEPENDENCY_NORMAL); /* * Post creation hook of this inheritance. Since object_access_hook * doesn't take multiple object identifiers, we relay oid of parent * relation using auxiliary_id argument. */ InvokeObjectPostAlterHookArg(InheritsRelationId, relationId, 0, parentOid, false); /* * Mark the parent as having subclasses. */ SetRelationHasSubclass(parentOid, true); } /* * Look for an existing schema entry with the given name. * * Returns the index (starting with 1) if attribute already exists in schema, * 0 if it doesn't. */ static int findAttrByName(const char *attributeName, List *schema) { ListCell *s; int i = 1; foreach(s, schema) { ColumnDef *def = lfirst(s); if (strcmp(attributeName, def->colname) == 0) return i; i++; } return 0; } /* * SetRelationHasSubclass * Set the value of the relation's relhassubclass field in pg_class. * * NOTE: caller must be holding an appropriate lock on the relation. * ShareUpdateExclusiveLock is sufficient. * * NOTE: an important side-effect of this operation is that an SI invalidation * message is sent out to all backends --- including me --- causing plans * referencing the relation to be rebuilt with the new list of children. * This must happen even if we find that no change is needed in the pg_class * row. */ void SetRelationHasSubclass(Oid relationId, bool relhassubclass) { Relation relationRelation; HeapTuple tuple; Form_pg_class classtuple; /* * Fetch a modifiable copy of the tuple, modify it, update pg_class. */ relationRelation = heap_open(RelationRelationId, RowExclusiveLock); tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relationId)); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for relation %u", relationId); classtuple = (Form_pg_class) GETSTRUCT(tuple); if (classtuple->relhassubclass != relhassubclass) { classtuple->relhassubclass = relhassubclass; CatalogTupleUpdate(relationRelation, &tuple->t_self, tuple); } else { /* no need to change tuple, but force relcache rebuild anyway */ CacheInvalidateRelcacheByTuple(tuple); } heap_freetuple(tuple); heap_close(relationRelation, RowExclusiveLock); } /* * renameatt_check - basic sanity checks before attribute rename */ static void renameatt_check(Oid myrelid, Form_pg_class classform, bool recursing) { char relkind = classform->relkind; if (classform->reloftype && !recursing) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot rename column of typed table"))); /* * Renaming the columns of sequences or toast tables doesn't actually * break anything from the system's point of view, since internal * references are by attnum. But it doesn't seem right to allow users to * change names that are hardcoded into the system, hence the following * restriction. */ if (relkind != RELKIND_RELATION && relkind != RELKIND_VIEW && relkind != RELKIND_MATVIEW && relkind != RELKIND_COMPOSITE_TYPE && relkind != RELKIND_INDEX && relkind != RELKIND_FOREIGN_TABLE && relkind != RELKIND_PARTITIONED_TABLE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is not a table, view, materialized view, composite type, index, or foreign table", NameStr(classform->relname)))); /* * permissions checking. only the owner of a class can change its schema. */ if (!pg_class_ownercheck(myrelid, GetUserId())) aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS, NameStr(classform->relname)); if (!allowSystemTableMods && IsSystemClass(myrelid, classform)) ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("permission denied: \"%s\" is a system catalog", NameStr(classform->relname)))); } /* * renameatt_internal - workhorse for renameatt * * Return value is the attribute number in the 'myrelid' relation. */ static AttrNumber renameatt_internal(Oid myrelid, const char *oldattname, const char *newattname, bool recurse, bool recursing, int expected_parents, DropBehavior behavior) { Relation targetrelation; Relation attrelation; HeapTuple atttup; Form_pg_attribute attform; AttrNumber attnum; /* * Grab an exclusive lock on the target table, which we will NOT release * until end of transaction. */ targetrelation = relation_open(myrelid, AccessExclusiveLock); renameatt_check(myrelid, RelationGetForm(targetrelation), recursing); /* * if the 'recurse' flag is set then we are supposed to rename this * attribute in all classes that inherit from 'relname' (as well as in * 'relname'). * * any permissions or problems with duplicate attributes will cause the * whole transaction to abort, which is what we want -- all or nothing. */ if (recurse) { List *child_oids, *child_numparents; ListCell *lo, *li; /* * we need the number of parents for each child so that the recursive * calls to renameatt() can determine whether there are any parents * outside the inheritance hierarchy being processed. */ child_oids = find_all_inheritors(myrelid, AccessExclusiveLock, &child_numparents); /* * find_all_inheritors does the recursive search of the inheritance * hierarchy, so all we have to do is process all of the relids in the * list that it returns. */ forboth(lo, child_oids, li, child_numparents) { Oid childrelid = lfirst_oid(lo); int numparents = lfirst_int(li); if (childrelid == myrelid) continue; /* note we need not recurse again */ renameatt_internal(childrelid, oldattname, newattname, false, true, numparents, behavior); } } else { /* * If we are told not to recurse, there had better not be any child * tables; else the rename would put them out of step. * * expected_parents will only be 0 if we are not already recursing. */ if (expected_parents == 0 && find_inheritance_children(myrelid, NoLock) != NIL) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("inherited column \"%s\" must be renamed in child tables too", oldattname))); } /* rename attributes in typed tables of composite type */ if (targetrelation->rd_rel->relkind == RELKIND_COMPOSITE_TYPE) { List *child_oids; ListCell *lo; child_oids = find_typed_table_dependencies(targetrelation->rd_rel->reltype, RelationGetRelationName(targetrelation), behavior); foreach(lo, child_oids) renameatt_internal(lfirst_oid(lo), oldattname, newattname, true, true, 0, behavior); } attrelation = heap_open(AttributeRelationId, RowExclusiveLock); atttup = SearchSysCacheCopyAttName(myrelid, oldattname); if (!HeapTupleIsValid(atttup)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" does not exist", oldattname))); attform = (Form_pg_attribute) GETSTRUCT(atttup); attnum = attform->attnum; if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot rename system column \"%s\"", oldattname))); /* * if the attribute is inherited, forbid the renaming. if this is a * top-level call to renameatt(), then expected_parents will be 0, so the * effect of this code will be to prohibit the renaming if the attribute * is inherited at all. if this is a recursive call to renameatt(), * expected_parents will be the number of parents the current relation has * within the inheritance hierarchy being processed, so we'll prohibit the * renaming only if there are additional parents from elsewhere. */ if (attform->attinhcount > expected_parents) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot rename inherited column \"%s\"", oldattname))); /* new name should not already exist */ (void) check_for_column_name_collision(targetrelation, newattname, false); /* apply the update */ namestrcpy(&(attform->attname), newattname); CatalogTupleUpdate(attrelation, &atttup->t_self, atttup); InvokeObjectPostAlterHook(RelationRelationId, myrelid, attnum); heap_freetuple(atttup); heap_close(attrelation, RowExclusiveLock); relation_close(targetrelation, NoLock); /* close rel but keep lock */ return attnum; } /* * Perform permissions and integrity checks before acquiring a relation lock. */ static void RangeVarCallbackForRenameAttribute(const RangeVar *rv, Oid relid, Oid oldrelid, void *arg) { HeapTuple tuple; Form_pg_class form; tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid)); if (!HeapTupleIsValid(tuple)) return; /* concurrently dropped */ form = (Form_pg_class) GETSTRUCT(tuple); renameatt_check(relid, form, false); ReleaseSysCache(tuple); } /* * renameatt - changes the name of an attribute in a relation * * The returned ObjectAddress is that of the renamed column. */ ObjectAddress renameatt(RenameStmt *stmt) { Oid relid; AttrNumber attnum; ObjectAddress address; /* lock level taken here should match renameatt_internal */ relid = RangeVarGetRelidExtended(stmt->relation, AccessExclusiveLock, stmt->missing_ok, false, RangeVarCallbackForRenameAttribute, NULL); if (!OidIsValid(relid)) { ereport(NOTICE, (errmsg("relation \"%s\" does not exist, skipping", stmt->relation->relname))); return InvalidObjectAddress; } attnum = renameatt_internal(relid, stmt->subname, /* old att name */ stmt->newname, /* new att name */ stmt->relation->inh, /* recursive? */ false, /* recursing? */ 0, /* expected inhcount */ stmt->behavior); ObjectAddressSubSet(address, RelationRelationId, relid, attnum); return address; } /* * same logic as renameatt_internal */ static ObjectAddress rename_constraint_internal(Oid myrelid, Oid mytypid, const char *oldconname, const char *newconname, bool recurse, bool recursing, int expected_parents) { Relation targetrelation = NULL; Oid constraintOid; HeapTuple tuple; Form_pg_constraint con; ObjectAddress address; AssertArg(!myrelid || !mytypid); if (mytypid) { constraintOid = get_domain_constraint_oid(mytypid, oldconname, false); } else { targetrelation = relation_open(myrelid, AccessExclusiveLock); /* * don't tell it whether we're recursing; we allow changing typed * tables here */ renameatt_check(myrelid, RelationGetForm(targetrelation), false); constraintOid = get_relation_constraint_oid(myrelid, oldconname, false); } tuple = SearchSysCache1(CONSTROID, ObjectIdGetDatum(constraintOid)); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for constraint %u", constraintOid); con = (Form_pg_constraint) GETSTRUCT(tuple); if (myrelid && con->contype == CONSTRAINT_CHECK && !con->connoinherit) { if (recurse) { List *child_oids, *child_numparents; ListCell *lo, *li; child_oids = find_all_inheritors(myrelid, AccessExclusiveLock, &child_numparents); forboth(lo, child_oids, li, child_numparents) { Oid childrelid = lfirst_oid(lo); int numparents = lfirst_int(li); if (childrelid == myrelid) continue; rename_constraint_internal(childrelid, InvalidOid, oldconname, newconname, false, true, numparents); } } else { if (expected_parents == 0 && find_inheritance_children(myrelid, NoLock) != NIL) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("inherited constraint \"%s\" must be renamed in child tables too", oldconname))); } if (con->coninhcount > expected_parents) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot rename inherited constraint \"%s\"", oldconname))); } if (con->conindid && (con->contype == CONSTRAINT_PRIMARY || con->contype == CONSTRAINT_UNIQUE || con->contype == CONSTRAINT_EXCLUSION)) /* rename the index; this renames the constraint as well */ RenameRelationInternal(con->conindid, newconname, false); else RenameConstraintById(constraintOid, newconname); ObjectAddressSet(address, ConstraintRelationId, constraintOid); ReleaseSysCache(tuple); if (targetrelation) relation_close(targetrelation, NoLock); /* close rel but keep lock */ return address; } ObjectAddress RenameConstraint(RenameStmt *stmt) { Oid relid = InvalidOid; Oid typid = InvalidOid; if (stmt->renameType == OBJECT_DOMCONSTRAINT) { Relation rel; HeapTuple tup; typid = typenameTypeId(NULL, makeTypeNameFromNameList(castNode(List, stmt->object))); rel = heap_open(TypeRelationId, RowExclusiveLock); tup = SearchSysCache1(TYPEOID, ObjectIdGetDatum(typid)); if (!HeapTupleIsValid(tup)) elog(ERROR, "cache lookup failed for type %u", typid); checkDomainOwner(tup); ReleaseSysCache(tup); heap_close(rel, NoLock); } else { /* lock level taken here should match rename_constraint_internal */ relid = RangeVarGetRelidExtended(stmt->relation, AccessExclusiveLock, stmt->missing_ok, false, RangeVarCallbackForRenameAttribute, NULL); if (!OidIsValid(relid)) { ereport(NOTICE, (errmsg("relation \"%s\" does not exist, skipping", stmt->relation->relname))); return InvalidObjectAddress; } } return rename_constraint_internal(relid, typid, stmt->subname, stmt->newname, (stmt->relation && stmt->relation->inh), /* recursive? */ false, /* recursing? */ 0 /* expected inhcount */ ); } /* * Execute ALTER TABLE/INDEX/SEQUENCE/VIEW/MATERIALIZED VIEW/FOREIGN TABLE * RENAME */ ObjectAddress RenameRelation(RenameStmt *stmt) { Oid relid; ObjectAddress address; /* * Grab an exclusive lock on the target table, index, sequence, view, * materialized view, or foreign table, which we will NOT release until * end of transaction. * * Lock level used here should match RenameRelationInternal, to avoid lock * escalation. */ relid = RangeVarGetRelidExtended(stmt->relation, AccessExclusiveLock, stmt->missing_ok, false, RangeVarCallbackForAlterRelation, (void *) stmt); if (!OidIsValid(relid)) { ereport(NOTICE, (errmsg("relation \"%s\" does not exist, skipping", stmt->relation->relname))); return InvalidObjectAddress; } /* Do the work */ RenameRelationInternal(relid, stmt->newname, false); ObjectAddressSet(address, RelationRelationId, relid); return address; } /* * RenameRelationInternal - change the name of a relation * * XXX - When renaming sequences, we don't bother to modify the * sequence name that is stored within the sequence itself * (this would cause problems with MVCC). In the future, * the sequence name should probably be removed from the * sequence, AFAIK there's no need for it to be there. */ void RenameRelationInternal(Oid myrelid, const char *newrelname, bool is_internal) { Relation targetrelation; Relation relrelation; /* for RELATION relation */ HeapTuple reltup; Form_pg_class relform; Oid namespaceId; /* * Grab an exclusive lock on the target table, index, sequence, view, * materialized view, or foreign table, which we will NOT release until * end of transaction. */ targetrelation = relation_open(myrelid, AccessExclusiveLock); namespaceId = RelationGetNamespace(targetrelation); /* * Find relation's pg_class tuple, and make sure newrelname isn't in use. */ relrelation = heap_open(RelationRelationId, RowExclusiveLock); reltup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(myrelid)); if (!HeapTupleIsValid(reltup)) /* shouldn't happen */ elog(ERROR, "cache lookup failed for relation %u", myrelid); relform = (Form_pg_class) GETSTRUCT(reltup); if (get_relname_relid(newrelname, namespaceId) != InvalidOid) ereport(ERROR, (errcode(ERRCODE_DUPLICATE_TABLE), errmsg("relation \"%s\" already exists", newrelname))); /* * Update pg_class tuple with new relname. (Scribbling on reltup is OK * because it's a copy...) */ namestrcpy(&(relform->relname), newrelname); CatalogTupleUpdate(relrelation, &reltup->t_self, reltup); InvokeObjectPostAlterHookArg(RelationRelationId, myrelid, 0, InvalidOid, is_internal); heap_freetuple(reltup); heap_close(relrelation, RowExclusiveLock); /* * Also rename the associated type, if any. */ if (OidIsValid(targetrelation->rd_rel->reltype)) RenameTypeInternal(targetrelation->rd_rel->reltype, newrelname, namespaceId); /* * Also rename the associated constraint, if any. */ if (targetrelation->rd_rel->relkind == RELKIND_INDEX) { Oid constraintId = get_index_constraint(myrelid); if (OidIsValid(constraintId)) RenameConstraintById(constraintId, newrelname); } /* * Close rel, but keep exclusive lock! */ relation_close(targetrelation, NoLock); } /* * Disallow ALTER TABLE (and similar commands) when the current backend has * any open reference to the target table besides the one just acquired by * the calling command; this implies there's an open cursor or active plan. * We need this check because our lock doesn't protect us against stomping * on our own foot, only other people's feet! * * For ALTER TABLE, the only case known to cause serious trouble is ALTER * COLUMN TYPE, and some changes are obviously pretty benign, so this could * possibly be relaxed to only error out for certain types of alterations. * But the use-case for allowing any of these things is not obvious, so we * won't work hard at it for now. * * We also reject these commands if there are any pending AFTER trigger events * for the rel. This is certainly necessary for the rewriting variants of * ALTER TABLE, because they don't preserve tuple TIDs and so the pending * events would try to fetch the wrong tuples. It might be overly cautious * in other cases, but again it seems better to err on the side of paranoia. * * REINDEX calls this with "rel" referencing the index to be rebuilt; here * we are worried about active indexscans on the index. The trigger-event * check can be skipped, since we are doing no damage to the parent table. * * The statement name (eg, "ALTER TABLE") is passed for use in error messages. */ void CheckTableNotInUse(Relation rel, const char *stmt) { int expected_refcnt; expected_refcnt = rel->rd_isnailed ? 2 : 1; if (rel->rd_refcnt != expected_refcnt) ereport(ERROR, (errcode(ERRCODE_OBJECT_IN_USE), /* translator: first %s is a SQL command, eg ALTER TABLE */ errmsg("cannot %s \"%s\" because " "it is being used by active queries in this session", stmt, RelationGetRelationName(rel)))); if (rel->rd_rel->relkind != RELKIND_INDEX && AfterTriggerPendingOnRel(RelationGetRelid(rel))) ereport(ERROR, (errcode(ERRCODE_OBJECT_IN_USE), /* translator: first %s is a SQL command, eg ALTER TABLE */ errmsg("cannot %s \"%s\" because " "it has pending trigger events", stmt, RelationGetRelationName(rel)))); } /* * AlterTableLookupRelation * Look up, and lock, the OID for the relation named by an alter table * statement. */ Oid AlterTableLookupRelation(AlterTableStmt *stmt, LOCKMODE lockmode) { return RangeVarGetRelidExtended(stmt->relation, lockmode, stmt->missing_ok, false, RangeVarCallbackForAlterRelation, (void *) stmt); } /* * AlterTable * Execute ALTER TABLE, which can be a list of subcommands * * ALTER TABLE is performed in three phases: * 1. Examine subcommands and perform pre-transformation checking. * 2. Update system catalogs. * 3. Scan table(s) to check new constraints, and optionally recopy * the data into new table(s). * Phase 3 is not performed unless one or more of the subcommands requires * it. The intention of this design is to allow multiple independent * updates of the table schema to be performed with only one pass over the * data. * * ATPrepCmd performs phase 1. A "work queue" entry is created for * each table to be affected (there may be multiple affected tables if the * commands traverse a table inheritance hierarchy). Also we do preliminary * validation of the subcommands, including parse transformation of those * expressions that need to be evaluated with respect to the old table * schema. * * ATRewriteCatalogs performs phase 2 for each affected table. (Note that * phases 2 and 3 normally do no explicit recursion, since phase 1 already * did it --- although some subcommands have to recurse in phase 2 instead.) * Certain subcommands need to be performed before others to avoid * unnecessary conflicts; for example, DROP COLUMN should come before * ADD COLUMN. Therefore phase 1 divides the subcommands into multiple * lists, one for each logical "pass" of phase 2. * * ATRewriteTables performs phase 3 for those tables that need it. * * Thanks to the magic of MVCC, an error anywhere along the way rolls back * the whole operation; we don't have to do anything special to clean up. * * The caller must lock the relation, with an appropriate lock level * for the subcommands requested, using AlterTableGetLockLevel(stmt->cmds) * or higher. We pass the lock level down * so that we can apply it recursively to inherited tables. Note that the * lock level we want as we recurse might well be higher than required for * that specific subcommand. So we pass down the overall lock requirement, * rather than reassess it at lower levels. */ void AlterTable(Oid relid, LOCKMODE lockmode, AlterTableStmt *stmt) { Relation rel; /* Caller is required to provide an adequate lock. */ rel = relation_open(relid, NoLock); CheckTableNotInUse(rel, "ALTER TABLE"); ATController(stmt, rel, stmt->cmds, stmt->relation->inh, lockmode); } /* * AlterTableInternal * * ALTER TABLE with target specified by OID * * We do not reject if the relation is already open, because it's quite * likely that one or more layers of caller have it open. That means it * is unsafe to use this entry point for alterations that could break * existing query plans. On the assumption it's not used for such, we * don't have to reject pending AFTER triggers, either. */ void AlterTableInternal(Oid relid, List *cmds, bool recurse) { Relation rel; LOCKMODE lockmode = AlterTableGetLockLevel(cmds); rel = relation_open(relid, lockmode); EventTriggerAlterTableRelid(relid); ATController(NULL, rel, cmds, recurse, lockmode); } /* * AlterTableGetLockLevel * * Sets the overall lock level required for the supplied list of subcommands. * Policy for doing this set according to needs of AlterTable(), see * comments there for overall explanation. * * Function is called before and after parsing, so it must give same * answer each time it is called. Some subcommands are transformed * into other subcommand types, so the transform must never be made to a * lower lock level than previously assigned. All transforms are noted below. * * Since this is called before we lock the table we cannot use table metadata * to influence the type of lock we acquire. * * There should be no lockmodes hardcoded into the subcommand functions. All * lockmode decisions for ALTER TABLE are made here only. The one exception is * ALTER TABLE RENAME which is treated as a different statement type T_RenameStmt * and does not travel through this section of code and cannot be combined with * any of the subcommands given here. * * Note that Hot Standby only knows about AccessExclusiveLocks on the master * so any changes that might affect SELECTs running on standbys need to use * AccessExclusiveLocks even if you think a lesser lock would do, unless you * have a solution for that also. * * Also note that pg_dump uses only an AccessShareLock, meaning that anything * that takes a lock less than AccessExclusiveLock can change object definitions * while pg_dump is running. Be careful to check that the appropriate data is * derived by pg_dump using an MVCC snapshot, rather than syscache lookups, * otherwise we might end up with an inconsistent dump that can't restore. */ LOCKMODE AlterTableGetLockLevel(List *cmds) { /* * This only works if we read catalog tables using MVCC snapshots. */ ListCell *lcmd; LOCKMODE lockmode = ShareUpdateExclusiveLock; foreach(lcmd, cmds) { AlterTableCmd *cmd = (AlterTableCmd *) lfirst(lcmd); LOCKMODE cmd_lockmode = AccessExclusiveLock; /* default for compiler */ switch (cmd->subtype) { /* * These subcommands rewrite the heap, so require full locks. */ case AT_AddColumn: /* may rewrite heap, in some cases and visible * to SELECT */ case AT_SetTableSpace: /* must rewrite heap */ case AT_AlterColumnType: /* must rewrite heap */ case AT_AddOids: /* must rewrite heap */ cmd_lockmode = AccessExclusiveLock; break; /* * These subcommands may require addition of toast tables. If * we add a toast table to a table currently being scanned, we * might miss data added to the new toast table by concurrent * insert transactions. */ case AT_SetStorage:/* may add toast tables, see * ATRewriteCatalogs() */ cmd_lockmode = AccessExclusiveLock; break; /* * Removing constraints can affect SELECTs that have been * optimised assuming the constraint holds true. */ case AT_DropConstraint: /* as DROP INDEX */ case AT_DropNotNull: /* may change some SQL plans */ cmd_lockmode = AccessExclusiveLock; break; /* * Subcommands that may be visible to concurrent SELECTs */ case AT_DropColumn: /* change visible to SELECT */ case AT_AddColumnToView: /* CREATE VIEW */ case AT_DropOids: /* calls AT_DropColumn */ case AT_EnableAlwaysRule: /* may change SELECT rules */ case AT_EnableReplicaRule: /* may change SELECT rules */ case AT_EnableRule: /* may change SELECT rules */ case AT_DisableRule: /* may change SELECT rules */ cmd_lockmode = AccessExclusiveLock; break; /* * Changing owner may remove implicit SELECT privileges */ case AT_ChangeOwner: /* change visible to SELECT */ cmd_lockmode = AccessExclusiveLock; break; /* * Changing foreign table options may affect optimization. */ case AT_GenericOptions: case AT_AlterColumnGenericOptions: cmd_lockmode = AccessExclusiveLock; break; /* * These subcommands affect write operations only. */ case AT_EnableTrig: case AT_EnableAlwaysTrig: case AT_EnableReplicaTrig: case AT_EnableTrigAll: case AT_EnableTrigUser: case AT_DisableTrig: case AT_DisableTrigAll: case AT_DisableTrigUser: cmd_lockmode = ShareRowExclusiveLock; break; /* * These subcommands affect write operations only. XXX * Theoretically, these could be ShareRowExclusiveLock. */ case AT_ColumnDefault: case AT_AlterConstraint: case AT_AddIndex: /* from ADD CONSTRAINT */ case AT_AddIndexConstraint: case AT_ReplicaIdentity: case AT_SetNotNull: case AT_EnableRowSecurity: case AT_DisableRowSecurity: case AT_ForceRowSecurity: case AT_NoForceRowSecurity: case AT_AddIdentity: case AT_DropIdentity: case AT_SetIdentity: cmd_lockmode = AccessExclusiveLock; break; case AT_AddConstraint: case AT_ProcessedConstraint: /* becomes AT_AddConstraint */ case AT_AddConstraintRecurse: /* becomes AT_AddConstraint */ case AT_ReAddConstraint: /* becomes AT_AddConstraint */ if (IsA(cmd->def, Constraint)) { Constraint *con = (Constraint *) cmd->def; switch (con->contype) { case CONSTR_EXCLUSION: case CONSTR_PRIMARY: case CONSTR_UNIQUE: /* * Cases essentially the same as CREATE INDEX. We * could reduce the lock strength to ShareLock if * we can work out how to allow concurrent catalog * updates. XXX Might be set down to * ShareRowExclusiveLock but requires further * analysis. */ cmd_lockmode = AccessExclusiveLock; break; case CONSTR_FOREIGN: /* * We add triggers to both tables when we add a * Foreign Key, so the lock level must be at least * as strong as CREATE TRIGGER. */ cmd_lockmode = ShareRowExclusiveLock; break; default: cmd_lockmode = AccessExclusiveLock; } } break; /* * These subcommands affect inheritance behaviour. Queries * started before us will continue to see the old inheritance * behaviour, while queries started after we commit will see * new behaviour. No need to prevent reads or writes to the * subtable while we hook it up though. Changing the TupDesc * may be a problem, so keep highest lock. */ case AT_AddInherit: case AT_DropInherit: cmd_lockmode = AccessExclusiveLock; break; /* * These subcommands affect implicit row type conversion. They * have affects similar to CREATE/DROP CAST on queries. don't * provide for invalidating parse trees as a result of such * changes, so we keep these at AccessExclusiveLock. */ case AT_AddOf: case AT_DropOf: cmd_lockmode = AccessExclusiveLock; break; /* * Only used by CREATE OR REPLACE VIEW which must conflict * with an SELECTs currently using the view. */ case AT_ReplaceRelOptions: cmd_lockmode = AccessExclusiveLock; break; /* * These subcommands affect general strategies for performance * and maintenance, though don't change the semantic results * from normal data reads and writes. Delaying an ALTER TABLE * behind currently active writes only delays the point where * the new strategy begins to take effect, so there is no * benefit in waiting. In this case the minimum restriction * applies: we don't currently allow concurrent catalog * updates. */ case AT_SetStatistics: /* Uses MVCC in getTableAttrs() */ case AT_ClusterOn: /* Uses MVCC in getIndexes() */ case AT_DropCluster: /* Uses MVCC in getIndexes() */ case AT_SetOptions: /* Uses MVCC in getTableAttrs() */ case AT_ResetOptions: /* Uses MVCC in getTableAttrs() */ cmd_lockmode = ShareUpdateExclusiveLock; break; case AT_SetLogged: case AT_SetUnLogged: cmd_lockmode = AccessExclusiveLock; break; case AT_ValidateConstraint: /* Uses MVCC in * getConstraints() */ cmd_lockmode = ShareUpdateExclusiveLock; break; /* * Rel options are more complex than first appears. Options * are set here for tables, views and indexes; for historical * reasons these can all be used with ALTER TABLE, so we can't * decide between them using the basic grammar. */ case AT_SetRelOptions: /* Uses MVCC in getIndexes() and * getTables() */ case AT_ResetRelOptions: /* Uses MVCC in getIndexes() and * getTables() */ cmd_lockmode = AlterTableGetRelOptionsLockLevel((List *) cmd->def); break; case AT_AttachPartition: case AT_DetachPartition: cmd_lockmode = AccessExclusiveLock; break; default: /* oops */ elog(ERROR, "unrecognized alter table type: %d", (int) cmd->subtype); break; } /* * Take the greatest lockmode from any subcommand */ if (cmd_lockmode > lockmode) lockmode = cmd_lockmode; } return lockmode; } /* * ATController provides top level control over the phases. * * parsetree is passed in to allow it to be passed to event triggers * when requested. */ static void ATController(AlterTableStmt *parsetree, Relation rel, List *cmds, bool recurse, LOCKMODE lockmode) { List *wqueue = NIL; ListCell *lcmd; /* Phase 1: preliminary examination of commands, create work queue */ foreach(lcmd, cmds) { AlterTableCmd *cmd = (AlterTableCmd *) lfirst(lcmd); ATPrepCmd(&wqueue, rel, cmd, recurse, false, lockmode); } /* Close the relation, but keep lock until commit */ relation_close(rel, NoLock); /* Phase 2: update system catalogs */ ATRewriteCatalogs(&wqueue, lockmode); /* Phase 3: scan/rewrite tables as needed */ ATRewriteTables(parsetree, &wqueue, lockmode); } /* * ATPrepCmd * * Traffic cop for ALTER TABLE Phase 1 operations, including simple * recursion and permission checks. * * Caller must have acquired appropriate lock type on relation already. * This lock should be held until commit. */ static void ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd, bool recurse, bool recursing, LOCKMODE lockmode) { AlteredTableInfo *tab; int pass = AT_PASS_UNSET; /* Find or create work queue entry for this table */ tab = ATGetQueueEntry(wqueue, rel); /* * Copy the original subcommand for each table. This avoids conflicts * when different child tables need to make different parse * transformations (for example, the same column may have different column * numbers in different children). */ cmd = copyObject(cmd); /* * Do permissions checking, recursion to child tables if needed, and any * additional phase-1 processing needed. */ switch (cmd->subtype) { case AT_AddColumn: /* ADD COLUMN */ ATSimplePermissions(rel, ATT_TABLE | ATT_COMPOSITE_TYPE | ATT_FOREIGN_TABLE); ATPrepAddColumn(wqueue, rel, recurse, recursing, false, cmd, lockmode); /* Recursion occurs during execution phase */ pass = AT_PASS_ADD_COL; break; case AT_AddColumnToView: /* add column via CREATE OR REPLACE * VIEW */ ATSimplePermissions(rel, ATT_VIEW); ATPrepAddColumn(wqueue, rel, recurse, recursing, true, cmd, lockmode); /* Recursion occurs during execution phase */ pass = AT_PASS_ADD_COL; break; case AT_ColumnDefault: /* ALTER COLUMN DEFAULT */ /* * We allow defaults on views so that INSERT into a view can have * default-ish behavior. This works because the rewriter * substitutes default values into INSERTs before it expands * rules. */ ATSimplePermissions(rel, ATT_TABLE | ATT_VIEW | ATT_FOREIGN_TABLE); ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode); /* No command-specific prep needed */ pass = cmd->def ? AT_PASS_ADD_CONSTR : AT_PASS_DROP; break; case AT_AddIdentity: ATSimplePermissions(rel, ATT_TABLE | ATT_VIEW | ATT_FOREIGN_TABLE); pass = AT_PASS_ADD_CONSTR; break; case AT_DropIdentity: ATSimplePermissions(rel, ATT_TABLE | ATT_VIEW | ATT_FOREIGN_TABLE); pass = AT_PASS_DROP; break; case AT_SetIdentity: ATSimplePermissions(rel, ATT_TABLE | ATT_VIEW | ATT_FOREIGN_TABLE); pass = AT_PASS_COL_ATTRS; break; case AT_DropNotNull: /* ALTER COLUMN DROP NOT NULL */ ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE); ATPrepDropNotNull(rel, recurse, recursing); ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode); /* No command-specific prep needed */ pass = AT_PASS_DROP; break; case AT_SetNotNull: /* ALTER COLUMN SET NOT NULL */ ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE); ATPrepSetNotNull(rel, recurse, recursing); ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode); /* No command-specific prep needed */ pass = AT_PASS_ADD_CONSTR; break; case AT_SetStatistics: /* ALTER COLUMN SET STATISTICS */ ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode); /* Performs own permission checks */ ATPrepSetStatistics(rel, cmd->name, cmd->def, lockmode); pass = AT_PASS_MISC; break; case AT_SetOptions: /* ALTER COLUMN SET ( options ) */ case AT_ResetOptions: /* ALTER COLUMN RESET ( options ) */ ATSimplePermissions(rel, ATT_TABLE | ATT_MATVIEW | ATT_INDEX | ATT_FOREIGN_TABLE); /* This command never recurses */ pass = AT_PASS_MISC; break; case AT_SetStorage: /* ALTER COLUMN SET STORAGE */ ATSimplePermissions(rel, ATT_TABLE | ATT_MATVIEW | ATT_FOREIGN_TABLE); ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode); /* No command-specific prep needed */ pass = AT_PASS_MISC; break; case AT_DropColumn: /* DROP COLUMN */ ATSimplePermissions(rel, ATT_TABLE | ATT_COMPOSITE_TYPE | ATT_FOREIGN_TABLE); ATPrepDropColumn(wqueue, rel, recurse, recursing, cmd, lockmode); /* Recursion occurs during execution phase */ pass = AT_PASS_DROP; break; case AT_AddIndex: /* ADD INDEX */ ATSimplePermissions(rel, ATT_TABLE); /* This command never recurses */ /* No command-specific prep needed */ pass = AT_PASS_ADD_INDEX; break; case AT_AddConstraint: /* ADD CONSTRAINT */ ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE); /* Recursion occurs during execution phase */ /* No command-specific prep needed except saving recurse flag */ if (recurse) cmd->subtype = AT_AddConstraintRecurse; pass = AT_PASS_ADD_CONSTR; break; case AT_AddIndexConstraint: /* ADD CONSTRAINT USING INDEX */ ATSimplePermissions(rel, ATT_TABLE); /* This command never recurses */ /* No command-specific prep needed */ pass = AT_PASS_ADD_CONSTR; break; case AT_DropConstraint: /* DROP CONSTRAINT */ ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE); /* Recursion occurs during execution phase */ /* No command-specific prep needed except saving recurse flag */ if (recurse) cmd->subtype = AT_DropConstraintRecurse; pass = AT_PASS_DROP; break; case AT_AlterColumnType: /* ALTER COLUMN TYPE */ ATSimplePermissions(rel, ATT_TABLE | ATT_COMPOSITE_TYPE | ATT_FOREIGN_TABLE); /* Performs own recursion */ ATPrepAlterColumnType(wqueue, tab, rel, recurse, recursing, cmd, lockmode); pass = AT_PASS_ALTER_TYPE; break; case AT_AlterColumnGenericOptions: ATSimplePermissions(rel, ATT_FOREIGN_TABLE); /* This command never recurses */ /* No command-specific prep needed */ pass = AT_PASS_MISC; break; case AT_ChangeOwner: /* ALTER OWNER */ /* This command never recurses */ /* No command-specific prep needed */ pass = AT_PASS_MISC; break; case AT_ClusterOn: /* CLUSTER ON */ case AT_DropCluster: /* SET WITHOUT CLUSTER */ ATSimplePermissions(rel, ATT_TABLE | ATT_MATVIEW); /* These commands never recurse */ /* No command-specific prep needed */ pass = AT_PASS_MISC; break; case AT_SetLogged: /* SET LOGGED */ ATSimplePermissions(rel, ATT_TABLE); tab->chgPersistence = ATPrepChangePersistence(rel, true); /* force rewrite if necessary; see comment in ATRewriteTables */ if (tab->chgPersistence) { tab->rewrite |= AT_REWRITE_ALTER_PERSISTENCE; tab->newrelpersistence = RELPERSISTENCE_PERMANENT; } pass = AT_PASS_MISC; break; case AT_SetUnLogged: /* SET UNLOGGED */ ATSimplePermissions(rel, ATT_TABLE); tab->chgPersistence = ATPrepChangePersistence(rel, false); /* force rewrite if necessary; see comment in ATRewriteTables */ if (tab->chgPersistence) { tab->rewrite |= AT_REWRITE_ALTER_PERSISTENCE; tab->newrelpersistence = RELPERSISTENCE_UNLOGGED; } pass = AT_PASS_MISC; break; case AT_AddOids: /* SET WITH OIDS */ ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE); if (!rel->rd_rel->relhasoids || recursing) ATPrepAddOids(wqueue, rel, recurse, cmd, lockmode); /* Recursion occurs during execution phase */ pass = AT_PASS_ADD_COL; break; case AT_DropOids: /* SET WITHOUT OIDS */ ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE); /* Performs own recursion */ if (rel->rd_rel->relhasoids) { AlterTableCmd *dropCmd = makeNode(AlterTableCmd); dropCmd->subtype = AT_DropColumn; dropCmd->name = pstrdup("oid"); dropCmd->behavior = cmd->behavior; ATPrepCmd(wqueue, rel, dropCmd, recurse, false, lockmode); } pass = AT_PASS_DROP; break; case AT_SetTableSpace: /* SET TABLESPACE */ ATSimplePermissions(rel, ATT_TABLE | ATT_MATVIEW | ATT_INDEX); /* This command never recurses */ ATPrepSetTableSpace(tab, rel, cmd->name, lockmode); pass = AT_PASS_MISC; /* doesn't actually matter */ break; case AT_SetRelOptions: /* SET (...) */ case AT_ResetRelOptions: /* RESET (...) */ case AT_ReplaceRelOptions: /* reset them all, then set just these */ ATSimplePermissions(rel, ATT_TABLE | ATT_VIEW | ATT_MATVIEW | ATT_INDEX); /* This command never recurses */ /* No command-specific prep needed */ pass = AT_PASS_MISC; break; case AT_AddInherit: /* INHERIT */ ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE); /* This command never recurses */ ATPrepAddInherit(rel); pass = AT_PASS_MISC; break; case AT_DropInherit: /* NO INHERIT */ ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE); /* This command never recurses */ /* No command-specific prep needed */ pass = AT_PASS_MISC; break; case AT_AlterConstraint: /* ALTER CONSTRAINT */ ATSimplePermissions(rel, ATT_TABLE); pass = AT_PASS_MISC; break; case AT_ValidateConstraint: /* VALIDATE CONSTRAINT */ ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE); /* Recursion occurs during execution phase */ /* No command-specific prep needed except saving recurse flag */ if (recurse) cmd->subtype = AT_ValidateConstraintRecurse; pass = AT_PASS_MISC; break; case AT_ReplicaIdentity: /* REPLICA IDENTITY ... */ ATSimplePermissions(rel, ATT_TABLE | ATT_MATVIEW); pass = AT_PASS_MISC; /* This command never recurses */ /* No command-specific prep needed */ break; case AT_EnableTrig: /* ENABLE TRIGGER variants */ case AT_EnableAlwaysTrig: case AT_EnableReplicaTrig: case AT_EnableTrigAll: case AT_EnableTrigUser: case AT_DisableTrig: /* DISABLE TRIGGER variants */ case AT_DisableTrigAll: case AT_DisableTrigUser: ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE); pass = AT_PASS_MISC; break; case AT_EnableRule: /* ENABLE/DISABLE RULE variants */ case AT_EnableAlwaysRule: case AT_EnableReplicaRule: case AT_DisableRule: case AT_AddOf: /* OF */ case AT_DropOf: /* NOT OF */ case AT_EnableRowSecurity: case AT_DisableRowSecurity: case AT_ForceRowSecurity: case AT_NoForceRowSecurity: ATSimplePermissions(rel, ATT_TABLE); /* These commands never recurse */ /* No command-specific prep needed */ pass = AT_PASS_MISC; break; case AT_GenericOptions: ATSimplePermissions(rel, ATT_FOREIGN_TABLE); /* No command-specific prep needed */ pass = AT_PASS_MISC; break; case AT_AttachPartition: case AT_DetachPartition: ATSimplePermissions(rel, ATT_TABLE); /* No command-specific prep needed */ pass = AT_PASS_MISC; break; default: /* oops */ elog(ERROR, "unrecognized alter table type: %d", (int) cmd->subtype); pass = AT_PASS_UNSET; /* keep compiler quiet */ break; } Assert(pass > AT_PASS_UNSET); /* Add the subcommand to the appropriate list for phase 2 */ tab->subcmds[pass] = lappend(tab->subcmds[pass], cmd); } /* * ATRewriteCatalogs * * Traffic cop for ALTER TABLE Phase 2 operations. Subcommands are * dispatched in a "safe" execution order (designed to avoid unnecessary * conflicts). */ static void ATRewriteCatalogs(List **wqueue, LOCKMODE lockmode) { int pass; ListCell *ltab; /* * We process all the tables "in parallel", one pass at a time. This is * needed because we may have to propagate work from one table to another * (specifically, ALTER TYPE on a foreign key's PK has to dispatch the * re-adding of the foreign key constraint to the other table). Work can * only be propagated into later passes, however. */ for (pass = 0; pass < AT_NUM_PASSES; pass++) { /* Go through each table that needs to be processed */ foreach(ltab, *wqueue) { AlteredTableInfo *tab = (AlteredTableInfo *) lfirst(ltab); List *subcmds = tab->subcmds[pass]; Relation rel; ListCell *lcmd; if (subcmds == NIL) continue; /* * Appropriate lock was obtained by phase 1, needn't get it again */ rel = relation_open(tab->relid, NoLock); foreach(lcmd, subcmds) ATExecCmd(wqueue, tab, rel, (AlterTableCmd *) lfirst(lcmd), lockmode); /* * After the ALTER TYPE pass, do cleanup work (this is not done in * ATExecAlterColumnType since it should be done only once if * multiple columns of a table are altered). */ if (pass == AT_PASS_ALTER_TYPE) ATPostAlterTypeCleanup(wqueue, tab, lockmode); relation_close(rel, NoLock); } } /* Check to see if a toast table must be added. */ foreach(ltab, *wqueue) { AlteredTableInfo *tab = (AlteredTableInfo *) lfirst(ltab); /* * If the table is source table of ATTACH PARTITION command, we did * not modify anything about it that will change its toasting * requirement, so no need to check. */ if (((tab->relkind == RELKIND_RELATION || tab->relkind == RELKIND_PARTITIONED_TABLE) && tab->partition_constraint == NULL) || tab->relkind == RELKIND_MATVIEW) AlterTableCreateToastTable(tab->relid, (Datum) 0, lockmode); } } /* * ATExecCmd: dispatch a subcommand to appropriate execution routine */ static void ATExecCmd(List **wqueue, AlteredTableInfo *tab, Relation rel, AlterTableCmd *cmd, LOCKMODE lockmode) { ObjectAddress address = InvalidObjectAddress; switch (cmd->subtype) { case AT_AddColumn: /* ADD COLUMN */ case AT_AddColumnToView: /* add column via CREATE OR REPLACE * VIEW */ address = ATExecAddColumn(wqueue, tab, rel, (ColumnDef *) cmd->def, false, false, false, false, lockmode); break; case AT_AddColumnRecurse: address = ATExecAddColumn(wqueue, tab, rel, (ColumnDef *) cmd->def, false, true, false, cmd->missing_ok, lockmode); break; case AT_ColumnDefault: /* ALTER COLUMN DEFAULT */ address = ATExecColumnDefault(rel, cmd->name, cmd->def, lockmode); break; case AT_AddIdentity: address = ATExecAddIdentity(rel, cmd->name, cmd->def, lockmode); break; case AT_SetIdentity: address = ATExecSetIdentity(rel, cmd->name, cmd->def, lockmode); break; case AT_DropIdentity: address = ATExecDropIdentity(rel, cmd->name, cmd->missing_ok, lockmode); break; case AT_DropNotNull: /* ALTER COLUMN DROP NOT NULL */ address = ATExecDropNotNull(rel, cmd->name, lockmode); break; case AT_SetNotNull: /* ALTER COLUMN SET NOT NULL */ address = ATExecSetNotNull(tab, rel, cmd->name, lockmode); break; case AT_SetStatistics: /* ALTER COLUMN SET STATISTICS */ address = ATExecSetStatistics(rel, cmd->name, cmd->def, lockmode); break; case AT_SetOptions: /* ALTER COLUMN SET ( options ) */ address = ATExecSetOptions(rel, cmd->name, cmd->def, false, lockmode); break; case AT_ResetOptions: /* ALTER COLUMN RESET ( options ) */ address = ATExecSetOptions(rel, cmd->name, cmd->def, true, lockmode); break; case AT_SetStorage: /* ALTER COLUMN SET STORAGE */ address = ATExecSetStorage(rel, cmd->name, cmd->def, lockmode); break; case AT_DropColumn: /* DROP COLUMN */ address = ATExecDropColumn(wqueue, rel, cmd->name, cmd->behavior, false, false, cmd->missing_ok, lockmode); break; case AT_DropColumnRecurse: /* DROP COLUMN with recursion */ address = ATExecDropColumn(wqueue, rel, cmd->name, cmd->behavior, true, false, cmd->missing_ok, lockmode); break; case AT_AddIndex: /* ADD INDEX */ address = ATExecAddIndex(tab, rel, (IndexStmt *) cmd->def, false, lockmode); break; case AT_ReAddIndex: /* ADD INDEX */ address = ATExecAddIndex(tab, rel, (IndexStmt *) cmd->def, true, lockmode); break; case AT_AddConstraint: /* ADD CONSTRAINT */ address = ATExecAddConstraint(wqueue, tab, rel, (Constraint *) cmd->def, false, false, lockmode); break; case AT_AddConstraintRecurse: /* ADD CONSTRAINT with recursion */ address = ATExecAddConstraint(wqueue, tab, rel, (Constraint *) cmd->def, true, false, lockmode); break; case AT_ReAddConstraint: /* Re-add pre-existing check * constraint */ address = ATExecAddConstraint(wqueue, tab, rel, (Constraint *) cmd->def, true, true, lockmode); break; case AT_ReAddComment: /* Re-add existing comment */ address = CommentObject((CommentStmt *) cmd->def); break; case AT_AddIndexConstraint: /* ADD CONSTRAINT USING INDEX */ address = ATExecAddIndexConstraint(tab, rel, (IndexStmt *) cmd->def, lockmode); break; case AT_AlterConstraint: /* ALTER CONSTRAINT */ address = ATExecAlterConstraint(rel, cmd, false, false, lockmode); break; case AT_ValidateConstraint: /* VALIDATE CONSTRAINT */ address = ATExecValidateConstraint(rel, cmd->name, false, false, lockmode); break; case AT_ValidateConstraintRecurse: /* VALIDATE CONSTRAINT with * recursion */ address = ATExecValidateConstraint(rel, cmd->name, true, false, lockmode); break; case AT_DropConstraint: /* DROP CONSTRAINT */ ATExecDropConstraint(rel, cmd->name, cmd->behavior, false, false, cmd->missing_ok, lockmode); break; case AT_DropConstraintRecurse: /* DROP CONSTRAINT with recursion */ ATExecDropConstraint(rel, cmd->name, cmd->behavior, true, false, cmd->missing_ok, lockmode); break; case AT_AlterColumnType: /* ALTER COLUMN TYPE */ address = ATExecAlterColumnType(tab, rel, cmd, lockmode); break; case AT_AlterColumnGenericOptions: /* ALTER COLUMN OPTIONS */ address = ATExecAlterColumnGenericOptions(rel, cmd->name, (List *) cmd->def, lockmode); break; case AT_ChangeOwner: /* ALTER OWNER */ ATExecChangeOwner(RelationGetRelid(rel), get_rolespec_oid(cmd->newowner, false), false, lockmode); break; case AT_ClusterOn: /* CLUSTER ON */ address = ATExecClusterOn(rel, cmd->name, lockmode); break; case AT_DropCluster: /* SET WITHOUT CLUSTER */ ATExecDropCluster(rel, lockmode); break; case AT_SetLogged: /* SET LOGGED */ case AT_SetUnLogged: /* SET UNLOGGED */ break; case AT_AddOids: /* SET WITH OIDS */ /* Use the ADD COLUMN code, unless prep decided to do nothing */ if (cmd->def != NULL) address = ATExecAddColumn(wqueue, tab, rel, (ColumnDef *) cmd->def, true, false, false, cmd->missing_ok, lockmode); break; case AT_AddOidsRecurse: /* SET WITH OIDS */ /* Use the ADD COLUMN code, unless prep decided to do nothing */ if (cmd->def != NULL) address = ATExecAddColumn(wqueue, tab, rel, (ColumnDef *) cmd->def, true, true, false, cmd->missing_ok, lockmode); break; case AT_DropOids: /* SET WITHOUT OIDS */ /* * Nothing to do here; we'll have generated a DropColumn * subcommand to do the real work */ break; case AT_SetTableSpace: /* SET TABLESPACE */ /* * Nothing to do here; Phase 3 does the work */ break; case AT_SetRelOptions: /* SET (...) */ case AT_ResetRelOptions: /* RESET (...) */ case AT_ReplaceRelOptions: /* replace entire option list */ ATExecSetRelOptions(rel, (List *) cmd->def, cmd->subtype, lockmode); break; case AT_EnableTrig: /* ENABLE TRIGGER name */ ATExecEnableDisableTrigger(rel, cmd->name, TRIGGER_FIRES_ON_ORIGIN, false, lockmode); break; case AT_EnableAlwaysTrig: /* ENABLE ALWAYS TRIGGER name */ ATExecEnableDisableTrigger(rel, cmd->name, TRIGGER_FIRES_ALWAYS, false, lockmode); break; case AT_EnableReplicaTrig: /* ENABLE REPLICA TRIGGER name */ ATExecEnableDisableTrigger(rel, cmd->name, TRIGGER_FIRES_ON_REPLICA, false, lockmode); break; case AT_DisableTrig: /* DISABLE TRIGGER name */ ATExecEnableDisableTrigger(rel, cmd->name, TRIGGER_DISABLED, false, lockmode); break; case AT_EnableTrigAll: /* ENABLE TRIGGER ALL */ ATExecEnableDisableTrigger(rel, NULL, TRIGGER_FIRES_ON_ORIGIN, false, lockmode); break; case AT_DisableTrigAll: /* DISABLE TRIGGER ALL */ ATExecEnableDisableTrigger(rel, NULL, TRIGGER_DISABLED, false, lockmode); break; case AT_EnableTrigUser: /* ENABLE TRIGGER USER */ ATExecEnableDisableTrigger(rel, NULL, TRIGGER_FIRES_ON_ORIGIN, true, lockmode); break; case AT_DisableTrigUser: /* DISABLE TRIGGER USER */ ATExecEnableDisableTrigger(rel, NULL, TRIGGER_DISABLED, true, lockmode); break; case AT_EnableRule: /* ENABLE RULE name */ ATExecEnableDisableRule(rel, cmd->name, RULE_FIRES_ON_ORIGIN, lockmode); break; case AT_EnableAlwaysRule: /* ENABLE ALWAYS RULE name */ ATExecEnableDisableRule(rel, cmd->name, RULE_FIRES_ALWAYS, lockmode); break; case AT_EnableReplicaRule: /* ENABLE REPLICA RULE name */ ATExecEnableDisableRule(rel, cmd->name, RULE_FIRES_ON_REPLICA, lockmode); break; case AT_DisableRule: /* DISABLE RULE name */ ATExecEnableDisableRule(rel, cmd->name, RULE_DISABLED, lockmode); break; case AT_AddInherit: address = ATExecAddInherit(rel, (RangeVar *) cmd->def, lockmode); break; case AT_DropInherit: address = ATExecDropInherit(rel, (RangeVar *) cmd->def, lockmode); break; case AT_AddOf: address = ATExecAddOf(rel, (TypeName *) cmd->def, lockmode); break; case AT_DropOf: ATExecDropOf(rel, lockmode); break; case AT_ReplicaIdentity: ATExecReplicaIdentity(rel, (ReplicaIdentityStmt *) cmd->def, lockmode); break; case AT_EnableRowSecurity: ATExecEnableRowSecurity(rel); break; case AT_DisableRowSecurity: ATExecDisableRowSecurity(rel); break; case AT_ForceRowSecurity: ATExecForceNoForceRowSecurity(rel, true); break; case AT_NoForceRowSecurity: ATExecForceNoForceRowSecurity(rel, false); break; case AT_GenericOptions: ATExecGenericOptions(rel, (List *) cmd->def); break; case AT_AttachPartition: ATExecAttachPartition(wqueue, rel, (PartitionCmd *) cmd->def); break; case AT_DetachPartition: ATExecDetachPartition(rel, ((PartitionCmd *) cmd->def)->name); break; default: /* oops */ elog(ERROR, "unrecognized alter table type: %d", (int) cmd->subtype); break; } /* * Report the subcommand to interested event triggers. */ EventTriggerCollectAlterTableSubcmd((Node *) cmd, address); /* * Bump the command counter to ensure the next subcommand in the sequence * can see the changes so far */ CommandCounterIncrement(); } /* * ATRewriteTables: ALTER TABLE phase 3 */ static void ATRewriteTables(AlterTableStmt *parsetree, List **wqueue, LOCKMODE lockmode) { ListCell *ltab; /* Go through each table that needs to be checked or rewritten */ foreach(ltab, *wqueue) { AlteredTableInfo *tab = (AlteredTableInfo *) lfirst(ltab); /* Foreign tables have no storage, nor do partitioned tables. */ if (tab->relkind == RELKIND_FOREIGN_TABLE || tab->relkind == RELKIND_PARTITIONED_TABLE) continue; /* * If we change column data types or add/remove OIDs, the operation * has to be propagated to tables that use this table's rowtype as a * column type. tab->newvals will also be non-NULL in the case where * we're adding a column with a default. We choose to forbid that * case as well, since composite types might eventually support * defaults. * * (Eventually we'll probably need to check for composite type * dependencies even when we're just scanning the table without a * rewrite, but at the moment a composite type does not enforce any * constraints, so it's not necessary/appropriate to enforce them just * during ALTER.) */ if (tab->newvals != NIL || tab->rewrite > 0) { Relation rel; rel = heap_open(tab->relid, NoLock); find_composite_type_dependencies(rel->rd_rel->reltype, rel, NULL); heap_close(rel, NoLock); } /* * We only need to rewrite the table if at least one column needs to * be recomputed, we are adding/removing the OID column, or we are * changing its persistence. * * There are two reasons for requiring a rewrite when changing * persistence: on one hand, we need to ensure that the buffers * belonging to each of the two relations are marked with or without * BM_PERMANENT properly. On the other hand, since rewriting creates * and assigns a new relfilenode, we automatically create or drop an * init fork for the relation as appropriate. */ if (tab->rewrite > 0) { /* Build a temporary relation and copy data */ Relation OldHeap; Oid OIDNewHeap; Oid NewTableSpace; char persistence; OldHeap = heap_open(tab->relid, NoLock); /* * We don't support rewriting of system catalogs; there are too * many corner cases and too little benefit. In particular this * is certainly not going to work for mapped catalogs. */ if (IsSystemRelation(OldHeap)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot rewrite system relation \"%s\"", RelationGetRelationName(OldHeap)))); if (RelationIsUsedAsCatalogTable(OldHeap)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot rewrite table \"%s\" used as a catalog table", RelationGetRelationName(OldHeap)))); /* * Don't allow rewrite on temp tables of other backends ... their * local buffer manager is not going to cope. */ if (RELATION_IS_OTHER_TEMP(OldHeap)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot rewrite temporary tables of other sessions"))); /* * Select destination tablespace (same as original unless user * requested a change) */ if (tab->newTableSpace) NewTableSpace = tab->newTableSpace; else NewTableSpace = OldHeap->rd_rel->reltablespace; /* * Select persistence of transient table (same as original unless * user requested a change) */ persistence = tab->chgPersistence ? tab->newrelpersistence : OldHeap->rd_rel->relpersistence; heap_close(OldHeap, NoLock); /* * Fire off an Event Trigger now, before actually rewriting the * table. * * We don't support Event Trigger for nested commands anywhere, * here included, and parsetree is given NULL when coming from * AlterTableInternal. * * And fire it only once. */ if (parsetree) EventTriggerTableRewrite((Node *) parsetree, tab->relid, tab->rewrite); /* * Create transient table that will receive the modified data. * * Ensure it is marked correctly as logged or unlogged. We have * to do this here so that buffers for the new relfilenode will * have the right persistence set, and at the same time ensure * that the original filenode's buffers will get read in with the * correct setting (i.e. the original one). Otherwise a rollback * after the rewrite would possibly result with buffers for the * original filenode having the wrong persistence setting. * * NB: This relies on swap_relation_files() also swapping the * persistence. That wouldn't work for pg_class, but that can't be * unlogged anyway. */ OIDNewHeap = make_new_heap(tab->relid, NewTableSpace, persistence, lockmode); /* * Copy the heap data into the new table with the desired * modifications, and test the current data within the table * against new constraints generated by ALTER TABLE commands. */ ATRewriteTable(tab, OIDNewHeap, lockmode); /* * Swap the physical files of the old and new heaps, then rebuild * indexes and discard the old heap. We can use RecentXmin for * the table's new relfrozenxid because we rewrote all the tuples * in ATRewriteTable, so no older Xid remains in the table. Also, * we never try to swap toast tables by content, since we have no * interest in letting this code work on system catalogs. */ finish_heap_swap(tab->relid, OIDNewHeap, false, false, true, !OidIsValid(tab->newTableSpace), RecentXmin, ReadNextMultiXactId(), persistence); } else { /* * Test the current data within the table against new constraints * generated by ALTER TABLE commands, but don't rebuild data. */ if (tab->constraints != NIL || tab->new_notnull || tab->partition_constraint != NULL) ATRewriteTable(tab, InvalidOid, lockmode); /* * If we had SET TABLESPACE but no reason to reconstruct tuples, * just do a block-by-block copy. */ if (tab->newTableSpace) ATExecSetTableSpace(tab->relid, tab->newTableSpace, lockmode); } } /* * Foreign key constraints are checked in a final pass, since (a) it's * generally best to examine each one separately, and (b) it's at least * theoretically possible that we have changed both relations of the * foreign key, and we'd better have finished both rewrites before we try * to read the tables. */ foreach(ltab, *wqueue) { AlteredTableInfo *tab = (AlteredTableInfo *) lfirst(ltab); Relation rel = NULL; ListCell *lcon; foreach(lcon, tab->constraints) { NewConstraint *con = lfirst(lcon); if (con->contype == CONSTR_FOREIGN) { Constraint *fkconstraint = (Constraint *) con->qual; Relation refrel; if (rel == NULL) { /* Long since locked, no need for another */ rel = heap_open(tab->relid, NoLock); } refrel = heap_open(con->refrelid, RowShareLock); validateForeignKeyConstraint(fkconstraint->conname, rel, refrel, con->refindid, con->conid); /* * No need to mark the constraint row as validated, we did * that when we inserted the row earlier. */ heap_close(refrel, NoLock); } } if (rel) heap_close(rel, NoLock); } } /* * ATRewriteTable: scan or rewrite one table * * OIDNewHeap is InvalidOid if we don't need to rewrite */ static void ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap, LOCKMODE lockmode) { Relation oldrel; Relation newrel; TupleDesc oldTupDesc; TupleDesc newTupDesc; bool needscan = false; List *notnull_attrs; int i; ListCell *l; EState *estate; CommandId mycid; BulkInsertState bistate; int hi_options; ExprState *partqualstate = NULL; /* * Open the relation(s). We have surely already locked the existing * table. */ oldrel = heap_open(tab->relid, NoLock); oldTupDesc = tab->oldDesc; newTupDesc = RelationGetDescr(oldrel); /* includes all mods */ if (OidIsValid(OIDNewHeap)) newrel = heap_open(OIDNewHeap, lockmode); else newrel = NULL; /* * Prepare a BulkInsertState and options for heap_insert. Because we're * building a new heap, we can skip WAL-logging and fsync it to disk at * the end instead (unless WAL-logging is required for archiving or * streaming replication). The FSM is empty too, so don't bother using it. */ if (newrel) { mycid = GetCurrentCommandId(true); bistate = GetBulkInsertState(); hi_options = HEAP_INSERT_SKIP_FSM; if (!XLogIsNeeded()) hi_options |= HEAP_INSERT_SKIP_WAL; } else { /* keep compiler quiet about using these uninitialized */ mycid = 0; bistate = NULL; hi_options = 0; } /* * Generate the constraint and default execution states */ estate = CreateExecutorState(); /* Build the needed expression execution states */ foreach(l, tab->constraints) { NewConstraint *con = lfirst(l); switch (con->contype) { case CONSTR_CHECK: needscan = true; con->qualstate = ExecPrepareExpr((Expr *) con->qual, estate); break; case CONSTR_FOREIGN: /* Nothing to do here */ break; default: elog(ERROR, "unrecognized constraint type: %d", (int) con->contype); } } /* Build expression execution states for partition check quals */ if (tab->partition_constraint) { needscan = true; partqualstate = ExecPrepareExpr(tab->partition_constraint, estate); } foreach(l, tab->newvals) { NewColumnValue *ex = lfirst(l); /* expr already planned */ ex->exprstate = ExecInitExpr((Expr *) ex->expr, NULL); } notnull_attrs = NIL; if (newrel || tab->new_notnull) { /* * If we are rebuilding the tuples OR if we added any new NOT NULL * constraints, check all not-null constraints. This is a bit of * overkill but it minimizes risk of bugs, and heap_attisnull is a * pretty cheap test anyway. */ for (i = 0; i < newTupDesc->natts; i++) { if (newTupDesc->attrs[i]->attnotnull && !newTupDesc->attrs[i]->attisdropped) notnull_attrs = lappend_int(notnull_attrs, i); } if (notnull_attrs) needscan = true; } if (newrel || needscan) { ExprContext *econtext; Datum *values; bool *isnull; TupleTableSlot *oldslot; TupleTableSlot *newslot; HeapScanDesc scan; HeapTuple tuple; MemoryContext oldCxt; List *dropped_attrs = NIL; ListCell *lc; Snapshot snapshot; if (newrel) ereport(DEBUG1, (errmsg("rewriting table \"%s\"", RelationGetRelationName(oldrel)))); else ereport(DEBUG1, (errmsg("verifying table \"%s\"", RelationGetRelationName(oldrel)))); if (newrel) { /* * All predicate locks on the tuples or pages are about to be made * invalid, because we move tuples around. Promote them to * relation locks. */ TransferPredicateLocksToHeapRelation(oldrel); } econtext = GetPerTupleExprContext(estate); /* * Make tuple slots for old and new tuples. Note that even when the * tuples are the same, the tupDescs might not be (consider ADD COLUMN * without a default). */ oldslot = MakeSingleTupleTableSlot(oldTupDesc); newslot = MakeSingleTupleTableSlot(newTupDesc); /* Preallocate values/isnull arrays */ i = Max(newTupDesc->natts, oldTupDesc->natts); values = (Datum *) palloc(i * sizeof(Datum)); isnull = (bool *) palloc(i * sizeof(bool)); memset(values, 0, i * sizeof(Datum)); memset(isnull, true, i * sizeof(bool)); /* * Any attributes that are dropped according to the new tuple * descriptor can be set to NULL. We precompute the list of dropped * attributes to avoid needing to do so in the per-tuple loop. */ for (i = 0; i < newTupDesc->natts; i++) { if (newTupDesc->attrs[i]->attisdropped) dropped_attrs = lappend_int(dropped_attrs, i); } /* * Scan through the rows, generating a new row if needed and then * checking all the constraints. */ snapshot = RegisterSnapshot(GetLatestSnapshot()); scan = heap_beginscan(oldrel, snapshot, 0, NULL); /* * Switch to per-tuple memory context and reset it for each tuple * produced, so we don't leak memory. */ oldCxt = MemoryContextSwitchTo(GetPerTupleMemoryContext(estate)); while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL) { if (tab->rewrite > 0) { Oid tupOid = InvalidOid; /* Extract data from old tuple */ heap_deform_tuple(tuple, oldTupDesc, values, isnull); if (oldTupDesc->tdhasoid) tupOid = HeapTupleGetOid(tuple); /* Set dropped attributes to null in new tuple */ foreach(lc, dropped_attrs) isnull[lfirst_int(lc)] = true; /* * Process supplied expressions to replace selected columns. * Expression inputs come from the old tuple. */ ExecStoreTuple(tuple, oldslot, InvalidBuffer, false); econtext->ecxt_scantuple = oldslot; foreach(l, tab->newvals) { NewColumnValue *ex = lfirst(l); values[ex->attnum - 1] = ExecEvalExpr(ex->exprstate, econtext, &isnull[ex->attnum - 1]); } /* * Form the new tuple. Note that we don't explicitly pfree it, * since the per-tuple memory context will be reset shortly. */ tuple = heap_form_tuple(newTupDesc, values, isnull); /* Preserve OID, if any */ if (newTupDesc->tdhasoid) HeapTupleSetOid(tuple, tupOid); /* * Constraints might reference the tableoid column, so * initialize t_tableOid before evaluating them. */ tuple->t_tableOid = RelationGetRelid(oldrel); } /* Now check any constraints on the possibly-changed tuple */ ExecStoreTuple(tuple, newslot, InvalidBuffer, false); econtext->ecxt_scantuple = newslot; foreach(l, notnull_attrs) { int attn = lfirst_int(l); if (heap_attisnull(tuple, attn + 1)) ereport(ERROR, (errcode(ERRCODE_NOT_NULL_VIOLATION), errmsg("column \"%s\" contains null values", NameStr(newTupDesc->attrs[attn]->attname)), errtablecol(oldrel, attn + 1))); } foreach(l, tab->constraints) { NewConstraint *con = lfirst(l); switch (con->contype) { case CONSTR_CHECK: if (!ExecCheck(con->qualstate, econtext)) ereport(ERROR, (errcode(ERRCODE_CHECK_VIOLATION), errmsg("check constraint \"%s\" is violated by some row", con->name), errtableconstraint(oldrel, con->name))); break; case CONSTR_FOREIGN: /* Nothing to do here */ break; default: elog(ERROR, "unrecognized constraint type: %d", (int) con->contype); } } if (partqualstate && !ExecCheck(partqualstate, econtext)) ereport(ERROR, (errcode(ERRCODE_CHECK_VIOLATION), errmsg("partition constraint is violated by some row"))); /* Write the tuple out to the new relation */ if (newrel) heap_insert(newrel, tuple, mycid, hi_options, bistate); ResetExprContext(econtext); CHECK_FOR_INTERRUPTS(); } MemoryContextSwitchTo(oldCxt); heap_endscan(scan); UnregisterSnapshot(snapshot); ExecDropSingleTupleTableSlot(oldslot); ExecDropSingleTupleTableSlot(newslot); } FreeExecutorState(estate); heap_close(oldrel, NoLock); if (newrel) { FreeBulkInsertState(bistate); /* If we skipped writing WAL, then we need to sync the heap. */ if (hi_options & HEAP_INSERT_SKIP_WAL) heap_sync(newrel); heap_close(newrel, NoLock); } } /* * ATGetQueueEntry: find or create an entry in the ALTER TABLE work queue */ static AlteredTableInfo * ATGetQueueEntry(List **wqueue, Relation rel) { Oid relid = RelationGetRelid(rel); AlteredTableInfo *tab; ListCell *ltab; foreach(ltab, *wqueue) { tab = (AlteredTableInfo *) lfirst(ltab); if (tab->relid == relid) return tab; } /* * Not there, so add it. Note that we make a copy of the relation's * existing descriptor before anything interesting can happen to it. */ tab = (AlteredTableInfo *) palloc0(sizeof(AlteredTableInfo)); tab->relid = relid; tab->relkind = rel->rd_rel->relkind; tab->oldDesc = CreateTupleDescCopy(RelationGetDescr(rel)); tab->newrelpersistence = RELPERSISTENCE_PERMANENT; tab->chgPersistence = false; *wqueue = lappend(*wqueue, tab); return tab; } /* * ATSimplePermissions * * - Ensure that it is a relation (or possibly a view) * - Ensure this user is the owner * - Ensure that it is not a system table */ static void ATSimplePermissions(Relation rel, int allowed_targets) { int actual_target; switch (rel->rd_rel->relkind) { case RELKIND_RELATION: case RELKIND_PARTITIONED_TABLE: actual_target = ATT_TABLE; break; case RELKIND_VIEW: actual_target = ATT_VIEW; break; case RELKIND_MATVIEW: actual_target = ATT_MATVIEW; break; case RELKIND_INDEX: actual_target = ATT_INDEX; break; case RELKIND_COMPOSITE_TYPE: actual_target = ATT_COMPOSITE_TYPE; break; case RELKIND_FOREIGN_TABLE: actual_target = ATT_FOREIGN_TABLE; break; default: actual_target = 0; break; } /* Wrong target type? */ if ((actual_target & allowed_targets) == 0) ATWrongRelkindError(rel, allowed_targets); /* Permissions checks */ if (!pg_class_ownercheck(RelationGetRelid(rel), GetUserId())) aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS, RelationGetRelationName(rel)); if (!allowSystemTableMods && IsSystemRelation(rel)) ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("permission denied: \"%s\" is a system catalog", RelationGetRelationName(rel)))); } /* * ATWrongRelkindError * * Throw an error when a relation has been determined to be of the wrong * type. */ static void ATWrongRelkindError(Relation rel, int allowed_targets) { char *msg; switch (allowed_targets) { case ATT_TABLE: msg = _("\"%s\" is not a table"); break; case ATT_TABLE | ATT_VIEW: msg = _("\"%s\" is not a table or view"); break; case ATT_TABLE | ATT_VIEW | ATT_FOREIGN_TABLE: msg = _("\"%s\" is not a table, view, or foreign table"); break; case ATT_TABLE | ATT_VIEW | ATT_MATVIEW | ATT_INDEX: msg = _("\"%s\" is not a table, view, materialized view, or index"); break; case ATT_TABLE | ATT_MATVIEW: msg = _("\"%s\" is not a table or materialized view"); break; case ATT_TABLE | ATT_MATVIEW | ATT_INDEX: msg = _("\"%s\" is not a table, materialized view, or index"); break; case ATT_TABLE | ATT_MATVIEW | ATT_FOREIGN_TABLE: msg = _("\"%s\" is not a table, materialized view, or foreign table"); break; case ATT_TABLE | ATT_FOREIGN_TABLE: msg = _("\"%s\" is not a table or foreign table"); break; case ATT_TABLE | ATT_COMPOSITE_TYPE | ATT_FOREIGN_TABLE: msg = _("\"%s\" is not a table, composite type, or foreign table"); break; case ATT_TABLE | ATT_MATVIEW | ATT_INDEX | ATT_FOREIGN_TABLE: msg = _("\"%s\" is not a table, materialized view, index, or foreign table"); break; case ATT_VIEW: msg = _("\"%s\" is not a view"); break; case ATT_FOREIGN_TABLE: msg = _("\"%s\" is not a foreign table"); break; default: /* shouldn't get here, add all necessary cases above */ msg = _("\"%s\" is of the wrong type"); break; } ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg(msg, RelationGetRelationName(rel)))); } /* * ATSimpleRecursion * * Simple table recursion sufficient for most ALTER TABLE operations. * All direct and indirect children are processed in an unspecified order. * Note that if a child inherits from the original table via multiple * inheritance paths, it will be visited just once. */ static void ATSimpleRecursion(List **wqueue, Relation rel, AlterTableCmd *cmd, bool recurse, LOCKMODE lockmode) { /* * Propagate to children if desired. Only plain tables and foreign tables * have children, so no need to search for other relkinds. */ if (recurse && (rel->rd_rel->relkind == RELKIND_RELATION || rel->rd_rel->relkind == RELKIND_FOREIGN_TABLE || rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)) { Oid relid = RelationGetRelid(rel); ListCell *child; List *children; children = find_all_inheritors(relid, lockmode, NULL); /* * find_all_inheritors does the recursive search of the inheritance * hierarchy, so all we have to do is process all of the relids in the * list that it returns. */ foreach(child, children) { Oid childrelid = lfirst_oid(child); Relation childrel; if (childrelid == relid) continue; /* find_all_inheritors already got lock */ childrel = relation_open(childrelid, NoLock); CheckTableNotInUse(childrel, "ALTER TABLE"); ATPrepCmd(wqueue, childrel, cmd, false, true, lockmode); relation_close(childrel, NoLock); } } } /* * ATTypedTableRecursion * * Propagate ALTER TYPE operations to the typed tables of that type. * Also check the RESTRICT/CASCADE behavior. Given CASCADE, also permit * recursion to inheritance children of the typed tables. */ static void ATTypedTableRecursion(List **wqueue, Relation rel, AlterTableCmd *cmd, LOCKMODE lockmode) { ListCell *child; List *children; Assert(rel->rd_rel->relkind == RELKIND_COMPOSITE_TYPE); children = find_typed_table_dependencies(rel->rd_rel->reltype, RelationGetRelationName(rel), cmd->behavior); foreach(child, children) { Oid childrelid = lfirst_oid(child); Relation childrel; childrel = relation_open(childrelid, lockmode); CheckTableNotInUse(childrel, "ALTER TABLE"); ATPrepCmd(wqueue, childrel, cmd, true, true, lockmode); relation_close(childrel, NoLock); } } /* * find_composite_type_dependencies * * Check to see if a composite type is being used as a column in some * other table (possibly nested several levels deep in composite types!). * Eventually, we'd like to propagate the check or rewrite operation * into other such tables, but for now, just error out if we find any. * * Caller should provide either a table name or a type name (not both) to * report in the error message, if any. * * We assume that functions and views depending on the type are not reasons * to reject the ALTER. (How safe is this really?) */ void find_composite_type_dependencies(Oid typeOid, Relation origRelation, const char *origTypeName) { Relation depRel; ScanKeyData key[2]; SysScanDesc depScan; HeapTuple depTup; Oid arrayOid; /* * We scan pg_depend to find those things that depend on the rowtype. (We * assume we can ignore refobjsubid for a rowtype.) */ depRel = heap_open(DependRelationId, AccessShareLock); ScanKeyInit(&key[0], Anum_pg_depend_refclassid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(TypeRelationId)); ScanKeyInit(&key[1], Anum_pg_depend_refobjid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(typeOid)); depScan = systable_beginscan(depRel, DependReferenceIndexId, true, NULL, 2, key); while (HeapTupleIsValid(depTup = systable_getnext(depScan))) { Form_pg_depend pg_depend = (Form_pg_depend) GETSTRUCT(depTup); Relation rel; Form_pg_attribute att; /* Ignore dependees that aren't user columns of relations */ /* (we assume system columns are never of rowtypes) */ if (pg_depend->classid != RelationRelationId || pg_depend->objsubid <= 0) continue; rel = relation_open(pg_depend->objid, AccessShareLock); att = rel->rd_att->attrs[pg_depend->objsubid - 1]; if (rel->rd_rel->relkind == RELKIND_RELATION || rel->rd_rel->relkind == RELKIND_MATVIEW || rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) { if (origTypeName) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter type \"%s\" because column \"%s.%s\" uses it", origTypeName, RelationGetRelationName(rel), NameStr(att->attname)))); else if (origRelation->rd_rel->relkind == RELKIND_COMPOSITE_TYPE) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter type \"%s\" because column \"%s.%s\" uses it", RelationGetRelationName(origRelation), RelationGetRelationName(rel), NameStr(att->attname)))); else if (origRelation->rd_rel->relkind == RELKIND_FOREIGN_TABLE) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter foreign table \"%s\" because column \"%s.%s\" uses its row type", RelationGetRelationName(origRelation), RelationGetRelationName(rel), NameStr(att->attname)))); else ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter table \"%s\" because column \"%s.%s\" uses its row type", RelationGetRelationName(origRelation), RelationGetRelationName(rel), NameStr(att->attname)))); } else if (OidIsValid(rel->rd_rel->reltype)) { /* * A view or composite type itself isn't a problem, but we must * recursively check for indirect dependencies via its rowtype. */ find_composite_type_dependencies(rel->rd_rel->reltype, origRelation, origTypeName); } relation_close(rel, AccessShareLock); } systable_endscan(depScan); relation_close(depRel, AccessShareLock); /* * If there's an array type for the rowtype, must check for uses of it, * too. */ arrayOid = get_array_type(typeOid); if (OidIsValid(arrayOid)) find_composite_type_dependencies(arrayOid, origRelation, origTypeName); } /* * find_typed_table_dependencies * * Check to see if a composite type is being used as the type of a * typed table. Abort if any are found and behavior is RESTRICT. * Else return the list of tables. */ static List * find_typed_table_dependencies(Oid typeOid, const char *typeName, DropBehavior behavior) { Relation classRel; ScanKeyData key[1]; HeapScanDesc scan; HeapTuple tuple; List *result = NIL; classRel = heap_open(RelationRelationId, AccessShareLock); ScanKeyInit(&key[0], Anum_pg_class_reloftype, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(typeOid)); scan = heap_beginscan_catalog(classRel, 1, key); while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL) { if (behavior == DROP_RESTRICT) ereport(ERROR, (errcode(ERRCODE_DEPENDENT_OBJECTS_STILL_EXIST), errmsg("cannot alter type \"%s\" because it is the type of a typed table", typeName), errhint("Use ALTER ... CASCADE to alter the typed tables too."))); else result = lappend_oid(result, HeapTupleGetOid(tuple)); } heap_endscan(scan); heap_close(classRel, AccessShareLock); return result; } /* * check_of_type * * Check whether a type is suitable for CREATE TABLE OF/ALTER TABLE OF. If it * isn't suitable, throw an error. Currently, we require that the type * originated with CREATE TYPE AS. We could support any row type, but doing so * would require handling a number of extra corner cases in the DDL commands. */ void check_of_type(HeapTuple typetuple) { Form_pg_type typ = (Form_pg_type) GETSTRUCT(typetuple); bool typeOk = false; if (typ->typtype == TYPTYPE_COMPOSITE) { Relation typeRelation; Assert(OidIsValid(typ->typrelid)); typeRelation = relation_open(typ->typrelid, AccessShareLock); typeOk = (typeRelation->rd_rel->relkind == RELKIND_COMPOSITE_TYPE); /* * Close the parent rel, but keep our AccessShareLock on it until xact * commit. That will prevent someone else from deleting or ALTERing * the type before the typed table creation/conversion commits. */ relation_close(typeRelation, NoLock); } if (!typeOk) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("type %s is not a composite type", format_type_be(HeapTupleGetOid(typetuple))))); } /* * ALTER TABLE ADD COLUMN * * Adds an additional attribute to a relation making the assumption that * CHECK, NOT NULL, and FOREIGN KEY constraints will be removed from the * AT_AddColumn AlterTableCmd by parse_utilcmd.c and added as independent * AlterTableCmd's. * * ADD COLUMN cannot use the normal ALTER TABLE recursion mechanism, because we * have to decide at runtime whether to recurse or not depending on whether we * actually add a column or merely merge with an existing column. (We can't * check this in a static pre-pass because it won't handle multiple inheritance * situations correctly.) */ static void ATPrepAddColumn(List **wqueue, Relation rel, bool recurse, bool recursing, bool is_view, AlterTableCmd *cmd, LOCKMODE lockmode) { if (rel->rd_rel->reloftype && !recursing) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot add column to typed table"))); if (rel->rd_rel->relkind == RELKIND_COMPOSITE_TYPE) ATTypedTableRecursion(wqueue, rel, cmd, lockmode); if (recurse && !is_view) cmd->subtype = AT_AddColumnRecurse; } /* * Add a column to a table; this handles the AT_AddOids cases as well. The * return value is the address of the new column in the parent relation. */ static ObjectAddress ATExecAddColumn(List **wqueue, AlteredTableInfo *tab, Relation rel, ColumnDef *colDef, bool isOid, bool recurse, bool recursing, bool if_not_exists, LOCKMODE lockmode) { Oid myrelid = RelationGetRelid(rel); Relation pgclass, attrdesc; HeapTuple reltup; FormData_pg_attribute attribute; int newattnum; char relkind; HeapTuple typeTuple; Oid typeOid; int32 typmod; Oid collOid; Form_pg_type tform; Expr *defval; List *children; ListCell *child; AclResult aclresult; ObjectAddress address; /* At top level, permission check was done in ATPrepCmd, else do it */ if (recursing) ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE); if (rel->rd_rel->relispartition && !recursing) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot add column to a partition"))); attrdesc = heap_open(AttributeRelationId, RowExclusiveLock); /* * Are we adding the column to a recursion child? If so, check whether to * merge with an existing definition for the column. If we do merge, we * must not recurse. Children will already have the column, and recursing * into them would mess up attinhcount. */ if (colDef->inhcount > 0) { HeapTuple tuple; /* Does child already have a column by this name? */ tuple = SearchSysCacheCopyAttName(myrelid, colDef->colname); if (HeapTupleIsValid(tuple)) { Form_pg_attribute childatt = (Form_pg_attribute) GETSTRUCT(tuple); Oid ctypeId; int32 ctypmod; Oid ccollid; /* Child column must match on type, typmod, and collation */ typenameTypeIdAndMod(NULL, colDef->typeName, &ctypeId, &ctypmod); if (ctypeId != childatt->atttypid || ctypmod != childatt->atttypmod) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("child table \"%s\" has different type for column \"%s\"", RelationGetRelationName(rel), colDef->colname))); ccollid = GetColumnDefCollation(NULL, colDef, ctypeId); if (ccollid != childatt->attcollation) ereport(ERROR, (errcode(ERRCODE_COLLATION_MISMATCH), errmsg("child table \"%s\" has different collation for column \"%s\"", RelationGetRelationName(rel), colDef->colname), errdetail("\"%s\" versus \"%s\"", get_collation_name(ccollid), get_collation_name(childatt->attcollation)))); /* If it's OID, child column must actually be OID */ if (isOid && childatt->attnum != ObjectIdAttributeNumber) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("child table \"%s\" has a conflicting \"%s\" column", RelationGetRelationName(rel), colDef->colname))); /* Bump the existing child att's inhcount */ childatt->attinhcount++; CatalogTupleUpdate(attrdesc, &tuple->t_self, tuple); heap_freetuple(tuple); /* Inform the user about the merge */ ereport(NOTICE, (errmsg("merging definition of column \"%s\" for child \"%s\"", colDef->colname, RelationGetRelationName(rel)))); heap_close(attrdesc, RowExclusiveLock); return InvalidObjectAddress; } } pgclass = heap_open(RelationRelationId, RowExclusiveLock); reltup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(myrelid)); if (!HeapTupleIsValid(reltup)) elog(ERROR, "cache lookup failed for relation %u", myrelid); relkind = ((Form_pg_class) GETSTRUCT(reltup))->relkind; /* * Cannot add identity column if table has children, because identity does * not inherit. (Adding column and identity separately will work.) */ if (colDef->identity && recurse && find_inheritance_children(myrelid, NoLock) != NIL) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot recursively add identity column to table that has child tables"))); /* skip if the name already exists and if_not_exists is true */ if (!check_for_column_name_collision(rel, colDef->colname, if_not_exists)) { heap_close(attrdesc, RowExclusiveLock); heap_freetuple(reltup); heap_close(pgclass, RowExclusiveLock); return InvalidObjectAddress; } /* Determine the new attribute's number */ if (isOid) newattnum = ObjectIdAttributeNumber; else { newattnum = ((Form_pg_class) GETSTRUCT(reltup))->relnatts + 1; if (newattnum > MaxHeapAttributeNumber) ereport(ERROR, (errcode(ERRCODE_TOO_MANY_COLUMNS), errmsg("tables can have at most %d columns", MaxHeapAttributeNumber))); } typeTuple = typenameType(NULL, colDef->typeName, &typmod); tform = (Form_pg_type) GETSTRUCT(typeTuple); typeOid = HeapTupleGetOid(typeTuple); aclresult = pg_type_aclcheck(typeOid, GetUserId(), ACL_USAGE); if (aclresult != ACLCHECK_OK) aclcheck_error_type(aclresult, typeOid); collOid = GetColumnDefCollation(NULL, colDef, typeOid); /* make sure datatype is legal for a column */ CheckAttributeType(colDef->colname, typeOid, collOid, list_make1_oid(rel->rd_rel->reltype), false); /* construct new attribute's pg_attribute entry */ attribute.attrelid = myrelid; namestrcpy(&(attribute.attname), colDef->colname); attribute.atttypid = typeOid; attribute.attstattarget = (newattnum > 0) ? -1 : 0; attribute.attlen = tform->typlen; attribute.attcacheoff = -1; attribute.atttypmod = typmod; attribute.attnum = newattnum; attribute.attbyval = tform->typbyval; attribute.attndims = list_length(colDef->typeName->arrayBounds); attribute.attstorage = tform->typstorage; attribute.attalign = tform->typalign; attribute.attnotnull = colDef->is_not_null; attribute.atthasdef = false; attribute.attidentity = colDef->identity; attribute.attisdropped = false; attribute.attislocal = colDef->is_local; attribute.attinhcount = colDef->inhcount; attribute.attcollation = collOid; /* attribute.attacl is handled by InsertPgAttributeTuple */ ReleaseSysCache(typeTuple); InsertPgAttributeTuple(attrdesc, &attribute, NULL); heap_close(attrdesc, RowExclusiveLock); /* * Update pg_class tuple as appropriate */ if (isOid) ((Form_pg_class) GETSTRUCT(reltup))->relhasoids = true; else ((Form_pg_class) GETSTRUCT(reltup))->relnatts = newattnum; CatalogTupleUpdate(pgclass, &reltup->t_self, reltup); heap_freetuple(reltup); /* Post creation hook for new attribute */ InvokeObjectPostCreateHook(RelationRelationId, myrelid, newattnum); heap_close(pgclass, RowExclusiveLock); /* Make the attribute's catalog entry visible */ CommandCounterIncrement(); /* * Store the DEFAULT, if any, in the catalogs */ if (colDef->raw_default) { RawColumnDefault *rawEnt; rawEnt = (RawColumnDefault *) palloc(sizeof(RawColumnDefault)); rawEnt->attnum = attribute.attnum; rawEnt->raw_default = copyObject(colDef->raw_default); /* * This function is intended for CREATE TABLE, so it processes a * _list_ of defaults, but we just do one. */ AddRelationNewConstraints(rel, list_make1(rawEnt), NIL, false, true, false); /* Make the additional catalog changes visible */ CommandCounterIncrement(); } /* * Tell Phase 3 to fill in the default expression, if there is one. * * If there is no default, Phase 3 doesn't have to do anything, because * that effectively means that the default is NULL. The heap tuple access * routines always check for attnum > # of attributes in tuple, and return * NULL if so, so without any modification of the tuple data we will get * the effect of NULL values in the new column. * * An exception occurs when the new column is of a domain type: the domain * might have a NOT NULL constraint, or a check constraint that indirectly * rejects nulls. If there are any domain constraints then we construct * an explicit NULL default value that will be passed through * CoerceToDomain processing. (This is a tad inefficient, since it causes * rewriting the table which we really don't have to do, but the present * design of domain processing doesn't offer any simple way of checking * the constraints more directly.) * * Note: we use build_column_default, and not just the cooked default * returned by AddRelationNewConstraints, so that the right thing happens * when a datatype's default applies. * * We skip this step completely for views and foreign tables. For a view, * we can only get here from CREATE OR REPLACE VIEW, which historically * doesn't set up defaults, not even for domain-typed columns. And in any * case we mustn't invoke Phase 3 on a view or foreign table, since they * have no storage. */ if (relkind != RELKIND_VIEW && relkind != RELKIND_COMPOSITE_TYPE && relkind != RELKIND_FOREIGN_TABLE && attribute.attnum > 0) { defval = (Expr *) build_column_default(rel, attribute.attnum); if (!defval && DomainHasConstraints(typeOid)) { Oid baseTypeId; int32 baseTypeMod; Oid baseTypeColl; baseTypeMod = typmod; baseTypeId = getBaseTypeAndTypmod(typeOid, &baseTypeMod); baseTypeColl = get_typcollation(baseTypeId); defval = (Expr *) makeNullConst(baseTypeId, baseTypeMod, baseTypeColl); defval = (Expr *) coerce_to_target_type(NULL, (Node *) defval, baseTypeId, typeOid, typmod, COERCION_ASSIGNMENT, COERCE_IMPLICIT_CAST, -1); if (defval == NULL) /* should not happen */ elog(ERROR, "failed to coerce base type to domain"); } if (defval) { NewColumnValue *newval; newval = (NewColumnValue *) palloc0(sizeof(NewColumnValue)); newval->attnum = attribute.attnum; newval->expr = expression_planner(defval); tab->newvals = lappend(tab->newvals, newval); tab->rewrite |= AT_REWRITE_DEFAULT_VAL; } /* * If the new column is NOT NULL, tell Phase 3 it needs to test that. * (Note we don't do this for an OID column. OID will be marked not * null, but since it's filled specially, there's no need to test * anything.) */ tab->new_notnull |= colDef->is_not_null; } /* * If we are adding an OID column, we have to tell Phase 3 to rewrite the * table to fix that. */ if (isOid) tab->rewrite |= AT_REWRITE_ALTER_OID; /* * Add needed dependency entries for the new column. */ add_column_datatype_dependency(myrelid, newattnum, attribute.atttypid); add_column_collation_dependency(myrelid, newattnum, attribute.attcollation); /* * Propagate to children as appropriate. Unlike most other ALTER * routines, we have to do this one level of recursion at a time; we can't * use find_all_inheritors to do it in one pass. */ children = find_inheritance_children(RelationGetRelid(rel), lockmode); /* * If we are told not to recurse, there had better not be any child * tables; else the addition would put them out of step. */ if (children && !recurse) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("column must be added to child tables too"))); /* Children should see column as singly inherited */ if (!recursing) { colDef = copyObject(colDef); colDef->inhcount = 1; colDef->is_local = false; } foreach(child, children) { Oid childrelid = lfirst_oid(child); Relation childrel; AlteredTableInfo *childtab; /* find_inheritance_children already got lock */ childrel = heap_open(childrelid, NoLock); CheckTableNotInUse(childrel, "ALTER TABLE"); /* Find or create work queue entry for this table */ childtab = ATGetQueueEntry(wqueue, childrel); /* Recurse to child; return value is ignored */ ATExecAddColumn(wqueue, childtab, childrel, colDef, isOid, recurse, true, if_not_exists, lockmode); heap_close(childrel, NoLock); } ObjectAddressSubSet(address, RelationRelationId, myrelid, newattnum); return address; } /* * If a new or renamed column will collide with the name of an existing * column and if_not_exists is false then error out, else do nothing. */ static bool check_for_column_name_collision(Relation rel, const char *colname, bool if_not_exists) { HeapTuple attTuple; int attnum; /* * this test is deliberately not attisdropped-aware, since if one tries to * add a column matching a dropped column name, it's gonna fail anyway. */ attTuple = SearchSysCache2(ATTNAME, ObjectIdGetDatum(RelationGetRelid(rel)), PointerGetDatum(colname)); if (!HeapTupleIsValid(attTuple)) return true; attnum = ((Form_pg_attribute) GETSTRUCT(attTuple))->attnum; ReleaseSysCache(attTuple); /* * We throw a different error message for conflicts with system column * names, since they are normally not shown and the user might otherwise * be confused about the reason for the conflict. */ if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_DUPLICATE_COLUMN), errmsg("column name \"%s\" conflicts with a system column name", colname))); else { if (if_not_exists) { ereport(NOTICE, (errcode(ERRCODE_DUPLICATE_COLUMN), errmsg("column \"%s\" of relation \"%s\" already exists, skipping", colname, RelationGetRelationName(rel)))); return false; } ereport(ERROR, (errcode(ERRCODE_DUPLICATE_COLUMN), errmsg("column \"%s\" of relation \"%s\" already exists", colname, RelationGetRelationName(rel)))); } return true; } /* * Install a column's dependency on its datatype. */ static void add_column_datatype_dependency(Oid relid, int32 attnum, Oid typid) { ObjectAddress myself, referenced; myself.classId = RelationRelationId; myself.objectId = relid; myself.objectSubId = attnum; referenced.classId = TypeRelationId; referenced.objectId = typid; referenced.objectSubId = 0; recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL); } /* * Install a column's dependency on its collation. */ static void add_column_collation_dependency(Oid relid, int32 attnum, Oid collid) { ObjectAddress myself, referenced; /* We know the default collation is pinned, so don't bother recording it */ if (OidIsValid(collid) && collid != DEFAULT_COLLATION_OID) { myself.classId = RelationRelationId; myself.objectId = relid; myself.objectSubId = attnum; referenced.classId = CollationRelationId; referenced.objectId = collid; referenced.objectSubId = 0; recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL); } } /* * ALTER TABLE SET WITH OIDS * * Basically this is an ADD COLUMN for the special OID column. We have * to cons up a ColumnDef node because the ADD COLUMN code needs one. */ static void ATPrepAddOids(List **wqueue, Relation rel, bool recurse, AlterTableCmd *cmd, LOCKMODE lockmode) { /* If we're recursing to a child table, the ColumnDef is already set up */ if (cmd->def == NULL) { ColumnDef *cdef = makeNode(ColumnDef); cdef->colname = pstrdup("oid"); cdef->typeName = makeTypeNameFromOid(OIDOID, -1); cdef->inhcount = 0; cdef->is_local = true; cdef->is_not_null = true; cdef->storage = 0; cdef->location = -1; cmd->def = (Node *) cdef; } ATPrepAddColumn(wqueue, rel, recurse, false, false, cmd, lockmode); if (recurse) cmd->subtype = AT_AddOidsRecurse; } /* * ALTER TABLE ALTER COLUMN DROP NOT NULL * * Return the address of the modified column. If the column was already * nullable, InvalidObjectAddress is returned. */ static void ATPrepDropNotNull(Relation rel, bool recurse, bool recursing) { /* * If the parent is a partitioned table, like check constraints, NOT NULL * constraints must be dropped from child tables. */ if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE && !recurse && !recursing) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("constraint must be dropped from child tables too"))); } static ObjectAddress ATExecDropNotNull(Relation rel, const char *colName, LOCKMODE lockmode) { HeapTuple tuple; AttrNumber attnum; Relation attr_rel; List *indexoidlist; ListCell *indexoidscan; ObjectAddress address; /* * lookup the attribute */ attr_rel = heap_open(AttributeRelationId, RowExclusiveLock); tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(rel)))); attnum = ((Form_pg_attribute) GETSTRUCT(tuple))->attnum; /* Prevent them from altering a system attribute */ if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter system column \"%s\"", colName))); if (get_attidentity(RelationGetRelid(rel), attnum)) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("column \"%s\" of relation \"%s\" is an identity column", colName, RelationGetRelationName(rel)))); /* * Check that the attribute is not in a primary key * * Note: we'll throw error even if the pkey index is not valid. */ /* Loop over all indexes on the relation */ indexoidlist = RelationGetIndexList(rel); foreach(indexoidscan, indexoidlist) { Oid indexoid = lfirst_oid(indexoidscan); HeapTuple indexTuple; Form_pg_index indexStruct; int i; indexTuple = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(indexoid)); if (!HeapTupleIsValid(indexTuple)) elog(ERROR, "cache lookup failed for index %u", indexoid); indexStruct = (Form_pg_index) GETSTRUCT(indexTuple); /* If the index is not a primary key, skip the check */ if (indexStruct->indisprimary) { /* * Loop over each attribute in the primary key and see if it * matches the to-be-altered attribute */ for (i = 0; i < indexStruct->indnatts; i++) { if (indexStruct->indkey.values[i] == attnum) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("column \"%s\" is in a primary key", colName))); } } ReleaseSysCache(indexTuple); } list_free(indexoidlist); /* If rel is partition, shouldn't drop NOT NULL if parent has the same */ if (rel->rd_rel->relispartition) { Oid parentId = get_partition_parent(RelationGetRelid(rel)); Relation parent = heap_open(parentId, AccessShareLock); TupleDesc tupDesc = RelationGetDescr(parent); AttrNumber parent_attnum; parent_attnum = get_attnum(parentId, colName); if (tupDesc->attrs[parent_attnum - 1]->attnotnull) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("column \"%s\" is marked NOT NULL in parent table", colName))); heap_close(parent, AccessShareLock); } /* * If the table is a range partitioned table, check that the column is not * in the partition key. */ if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) { PartitionKey key = RelationGetPartitionKey(rel); if (get_partition_strategy(key) == PARTITION_STRATEGY_RANGE) { int partnatts = get_partition_natts(key), i; for (i = 0; i < partnatts; i++) { AttrNumber partattnum = get_partition_col_attnum(key, i); if (partattnum == attnum) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("column \"%s\" is in range partition key", colName))); } } } /* * Okay, actually perform the catalog change ... if needed */ if (((Form_pg_attribute) GETSTRUCT(tuple))->attnotnull) { ((Form_pg_attribute) GETSTRUCT(tuple))->attnotnull = FALSE; CatalogTupleUpdate(attr_rel, &tuple->t_self, tuple); ObjectAddressSubSet(address, RelationRelationId, RelationGetRelid(rel), attnum); } else address = InvalidObjectAddress; InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), attnum); heap_close(attr_rel, RowExclusiveLock); return address; } /* * ALTER TABLE ALTER COLUMN SET NOT NULL * * Return the address of the modified column. If the column was already NOT * NULL, InvalidObjectAddress is returned. */ static void ATPrepSetNotNull(Relation rel, bool recurse, bool recursing) { /* * If the parent is a partitioned table, like check constraints, NOT NULL * constraints must be added to the child tables. */ if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE && !recurse && !recursing) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("constraint must be added to child tables too"))); } static ObjectAddress ATExecSetNotNull(AlteredTableInfo *tab, Relation rel, const char *colName, LOCKMODE lockmode) { HeapTuple tuple; AttrNumber attnum; Relation attr_rel; ObjectAddress address; /* * lookup the attribute */ attr_rel = heap_open(AttributeRelationId, RowExclusiveLock); tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(rel)))); attnum = ((Form_pg_attribute) GETSTRUCT(tuple))->attnum; /* Prevent them from altering a system attribute */ if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter system column \"%s\"", colName))); /* * Okay, actually perform the catalog change ... if needed */ if (!((Form_pg_attribute) GETSTRUCT(tuple))->attnotnull) { ((Form_pg_attribute) GETSTRUCT(tuple))->attnotnull = TRUE; CatalogTupleUpdate(attr_rel, &tuple->t_self, tuple); /* Tell Phase 3 it needs to test the constraint */ tab->new_notnull = true; ObjectAddressSubSet(address, RelationRelationId, RelationGetRelid(rel), attnum); } else address = InvalidObjectAddress; InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), attnum); heap_close(attr_rel, RowExclusiveLock); return address; } /* * ALTER TABLE ALTER COLUMN SET/DROP DEFAULT * * Return the address of the affected column. */ static ObjectAddress ATExecColumnDefault(Relation rel, const char *colName, Node *newDefault, LOCKMODE lockmode) { AttrNumber attnum; ObjectAddress address; /* * get the number of the attribute */ attnum = get_attnum(RelationGetRelid(rel), colName); if (attnum == InvalidAttrNumber) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(rel)))); /* Prevent them from altering a system attribute */ if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter system column \"%s\"", colName))); if (get_attidentity(RelationGetRelid(rel), attnum)) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("column \"%s\" of relation \"%s\" is an identity column", colName, RelationGetRelationName(rel)), newDefault ? 0 : errhint("Use ALTER TABLE ... ALTER COLUMN ... DROP IDENTITY instead."))); /* * Remove any old default for the column. We use RESTRICT here for * safety, but at present we do not expect anything to depend on the * default. * * We treat removing the existing default as an internal operation when it * is preparatory to adding a new default, but as a user-initiated * operation when the user asked for a drop. */ RemoveAttrDefault(RelationGetRelid(rel), attnum, DROP_RESTRICT, false, newDefault == NULL ? false : true); if (newDefault) { /* SET DEFAULT */ RawColumnDefault *rawEnt; rawEnt = (RawColumnDefault *) palloc(sizeof(RawColumnDefault)); rawEnt->attnum = attnum; rawEnt->raw_default = newDefault; /* * This function is intended for CREATE TABLE, so it processes a * _list_ of defaults, but we just do one. */ AddRelationNewConstraints(rel, list_make1(rawEnt), NIL, false, true, false); } ObjectAddressSubSet(address, RelationRelationId, RelationGetRelid(rel), attnum); return address; } /* * ALTER TABLE ALTER COLUMN ADD IDENTITY * * Return the address of the affected column. */ static ObjectAddress ATExecAddIdentity(Relation rel, const char *colName, Node *def, LOCKMODE lockmode) { Relation attrelation; HeapTuple tuple; Form_pg_attribute attTup; AttrNumber attnum; ObjectAddress address; ColumnDef *cdef = castNode(ColumnDef, def); attrelation = heap_open(AttributeRelationId, RowExclusiveLock); tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(rel)))); attTup = (Form_pg_attribute) GETSTRUCT(tuple); attnum = attTup->attnum; /* Can't alter a system attribute */ if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter system column \"%s\"", colName))); /* * Creating a column as identity implies NOT NULL, so adding the identity * to an existing column that is not NOT NULL would create a state that * cannot be reproduced without contortions. */ if (!attTup->attnotnull) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("column \"%s\" of relation \"%s\" must be declared NOT NULL before identity can be added", colName, RelationGetRelationName(rel)))); if (attTup->attidentity) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("column \"%s\" of relation \"%s\" is already an identity column", colName, RelationGetRelationName(rel)))); if (attTup->atthasdef) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("column \"%s\" of relation \"%s\" already has a default value", colName, RelationGetRelationName(rel)))); attTup->attidentity = cdef->identity; CatalogTupleUpdate(attrelation, &tuple->t_self, tuple); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), attTup->attnum); ObjectAddressSubSet(address, RelationRelationId, RelationGetRelid(rel), attnum); heap_freetuple(tuple); heap_close(attrelation, RowExclusiveLock); return address; } /* * ALTER TABLE ALTER COLUMN SET { GENERATED or sequence options } * * Return the address of the affected column. */ static ObjectAddress ATExecSetIdentity(Relation rel, const char *colName, Node *def, LOCKMODE lockmode) { ListCell *option; DefElem *generatedEl = NULL; HeapTuple tuple; Form_pg_attribute attTup; AttrNumber attnum; Relation attrelation; ObjectAddress address; foreach(option, castNode(List, def)) { DefElem *defel = castNode(DefElem, lfirst(option)); if (strcmp(defel->defname, "generated") == 0) { if (generatedEl) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("conflicting or redundant options"))); generatedEl = defel; } else elog(ERROR, "option \"%s\" not recognized", defel->defname); } /* * Even if there is nothing to change here, we run all the checks. There * will be a subsequent ALTER SEQUENCE that relies on everything being * there. */ attrelation = heap_open(AttributeRelationId, RowExclusiveLock); tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(rel)))); attTup = (Form_pg_attribute) GETSTRUCT(tuple); attnum = attTup->attnum; if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter system column \"%s\"", colName))); if (!attTup->attidentity) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("column \"%s\" of relation \"%s\" is not an identity column", colName, RelationGetRelationName(rel)))); if (generatedEl) { attTup->attidentity = defGetInt32(generatedEl); CatalogTupleUpdate(attrelation, &tuple->t_self, tuple); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), attTup->attnum); ObjectAddressSubSet(address, RelationRelationId, RelationGetRelid(rel), attnum); } else address = InvalidObjectAddress; heap_freetuple(tuple); heap_close(attrelation, RowExclusiveLock); return address; } /* * ALTER TABLE ALTER COLUMN DROP IDENTITY * * Return the address of the affected column. */ static ObjectAddress ATExecDropIdentity(Relation rel, const char *colName, bool missing_ok, LOCKMODE lockmode) { HeapTuple tuple; Form_pg_attribute attTup; AttrNumber attnum; Relation attrelation; ObjectAddress address; Oid seqid; ObjectAddress seqaddress; attrelation = heap_open(AttributeRelationId, RowExclusiveLock); tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(rel)))); attTup = (Form_pg_attribute) GETSTRUCT(tuple); attnum = attTup->attnum; if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter system column \"%s\"", colName))); if (!attTup->attidentity) { if (!missing_ok) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("column \"%s\" of relation \"%s\" is not an identity column", colName, RelationGetRelationName(rel)))); else { ereport(NOTICE, (errmsg("column \"%s\" of relation \"%s\" is not an identity column, skipping", colName, RelationGetRelationName(rel)))); heap_freetuple(tuple); heap_close(attrelation, RowExclusiveLock); return InvalidObjectAddress; } } attTup->attidentity = '\0'; CatalogTupleUpdate(attrelation, &tuple->t_self, tuple); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), attTup->attnum); ObjectAddressSubSet(address, RelationRelationId, RelationGetRelid(rel), attnum); heap_freetuple(tuple); heap_close(attrelation, RowExclusiveLock); /* drop the internal sequence */ seqid = getOwnedSequence(RelationGetRelid(rel), attnum); deleteDependencyRecordsForClass(RelationRelationId, seqid, RelationRelationId, DEPENDENCY_INTERNAL); CommandCounterIncrement(); seqaddress.classId = RelationRelationId; seqaddress.objectId = seqid; seqaddress.objectSubId = 0; performDeletion(&seqaddress, DROP_RESTRICT, PERFORM_DELETION_INTERNAL); return address; } /* * ALTER TABLE ALTER COLUMN SET STATISTICS */ static void ATPrepSetStatistics(Relation rel, const char *colName, Node *newValue, LOCKMODE lockmode) { /* * We do our own permission checking because (a) we want to allow SET * STATISTICS on indexes (for expressional index columns), and (b) we want * to allow SET STATISTICS on system catalogs without requiring * allowSystemTableMods to be turned on. */ if (rel->rd_rel->relkind != RELKIND_RELATION && rel->rd_rel->relkind != RELKIND_MATVIEW && rel->rd_rel->relkind != RELKIND_INDEX && rel->rd_rel->relkind != RELKIND_FOREIGN_TABLE && rel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is not a table, materialized view, index, or foreign table", RelationGetRelationName(rel)))); /* Permissions checks */ if (!pg_class_ownercheck(RelationGetRelid(rel), GetUserId())) aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS, RelationGetRelationName(rel)); } /* * Return value is the address of the modified column */ static ObjectAddress ATExecSetStatistics(Relation rel, const char *colName, Node *newValue, LOCKMODE lockmode) { int newtarget; Relation attrelation; HeapTuple tuple; Form_pg_attribute attrtuple; AttrNumber attnum; ObjectAddress address; Assert(IsA(newValue, Integer)); newtarget = intVal(newValue); /* * Limit target to a sane range */ if (newtarget < -1) { ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("statistics target %d is too low", newtarget))); } else if (newtarget > 10000) { newtarget = 10000; ereport(WARNING, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("lowering statistics target to %d", newtarget))); } attrelation = heap_open(AttributeRelationId, RowExclusiveLock); tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(rel)))); attrtuple = (Form_pg_attribute) GETSTRUCT(tuple); attnum = attrtuple->attnum; if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter system column \"%s\"", colName))); attrtuple->attstattarget = newtarget; CatalogTupleUpdate(attrelation, &tuple->t_self, tuple); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), attrtuple->attnum); ObjectAddressSubSet(address, RelationRelationId, RelationGetRelid(rel), attnum); heap_freetuple(tuple); heap_close(attrelation, RowExclusiveLock); return address; } /* * Return value is the address of the modified column */ static ObjectAddress ATExecSetOptions(Relation rel, const char *colName, Node *options, bool isReset, LOCKMODE lockmode) { Relation attrelation; HeapTuple tuple, newtuple; Form_pg_attribute attrtuple; AttrNumber attnum; Datum datum, newOptions; bool isnull; ObjectAddress address; Datum repl_val[Natts_pg_attribute]; bool repl_null[Natts_pg_attribute]; bool repl_repl[Natts_pg_attribute]; attrelation = heap_open(AttributeRelationId, RowExclusiveLock); tuple = SearchSysCacheAttName(RelationGetRelid(rel), colName); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(rel)))); attrtuple = (Form_pg_attribute) GETSTRUCT(tuple); attnum = attrtuple->attnum; if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter system column \"%s\"", colName))); /* Generate new proposed attoptions (text array) */ datum = SysCacheGetAttr(ATTNAME, tuple, Anum_pg_attribute_attoptions, &isnull); newOptions = transformRelOptions(isnull ? (Datum) 0 : datum, castNode(List, options), NULL, NULL, false, isReset); /* Validate new options */ (void) attribute_reloptions(newOptions, true); /* Build new tuple. */ memset(repl_null, false, sizeof(repl_null)); memset(repl_repl, false, sizeof(repl_repl)); if (newOptions != (Datum) 0) repl_val[Anum_pg_attribute_attoptions - 1] = newOptions; else repl_null[Anum_pg_attribute_attoptions - 1] = true; repl_repl[Anum_pg_attribute_attoptions - 1] = true; newtuple = heap_modify_tuple(tuple, RelationGetDescr(attrelation), repl_val, repl_null, repl_repl); /* Update system catalog. */ CatalogTupleUpdate(attrelation, &newtuple->t_self, newtuple); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), attrtuple->attnum); ObjectAddressSubSet(address, RelationRelationId, RelationGetRelid(rel), attnum); heap_freetuple(newtuple); ReleaseSysCache(tuple); heap_close(attrelation, RowExclusiveLock); return address; } /* * ALTER TABLE ALTER COLUMN SET STORAGE * * Return value is the address of the modified column */ static ObjectAddress ATExecSetStorage(Relation rel, const char *colName, Node *newValue, LOCKMODE lockmode) { char *storagemode; char newstorage; Relation attrelation; HeapTuple tuple; Form_pg_attribute attrtuple; AttrNumber attnum; ObjectAddress address; Assert(IsA(newValue, String)); storagemode = strVal(newValue); if (pg_strcasecmp(storagemode, "plain") == 0) newstorage = 'p'; else if (pg_strcasecmp(storagemode, "external") == 0) newstorage = 'e'; else if (pg_strcasecmp(storagemode, "extended") == 0) newstorage = 'x'; else if (pg_strcasecmp(storagemode, "main") == 0) newstorage = 'm'; else { ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("invalid storage type \"%s\"", storagemode))); newstorage = 0; /* keep compiler quiet */ } attrelation = heap_open(AttributeRelationId, RowExclusiveLock); tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(rel)))); attrtuple = (Form_pg_attribute) GETSTRUCT(tuple); attnum = attrtuple->attnum; if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter system column \"%s\"", colName))); /* * safety check: do not allow toasted storage modes unless column datatype * is TOAST-aware. */ if (newstorage == 'p' || TypeIsToastable(attrtuple->atttypid)) attrtuple->attstorage = newstorage; else ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("column data type %s can only have storage PLAIN", format_type_be(attrtuple->atttypid)))); CatalogTupleUpdate(attrelation, &tuple->t_self, tuple); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), attrtuple->attnum); heap_freetuple(tuple); heap_close(attrelation, RowExclusiveLock); ObjectAddressSubSet(address, RelationRelationId, RelationGetRelid(rel), attnum); return address; } /* * ALTER TABLE DROP COLUMN * * DROP COLUMN cannot use the normal ALTER TABLE recursion mechanism, * because we have to decide at runtime whether to recurse or not depending * on whether attinhcount goes to zero or not. (We can't check this in a * static pre-pass because it won't handle multiple inheritance situations * correctly.) */ static void ATPrepDropColumn(List **wqueue, Relation rel, bool recurse, bool recursing, AlterTableCmd *cmd, LOCKMODE lockmode) { if (rel->rd_rel->reloftype && !recursing) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot drop column from typed table"))); if (rel->rd_rel->relkind == RELKIND_COMPOSITE_TYPE) ATTypedTableRecursion(wqueue, rel, cmd, lockmode); if (recurse) cmd->subtype = AT_DropColumnRecurse; } /* * Checks if attnum is a partition attribute for rel * * Sets *used_in_expr if attnum is found to be referenced in some partition * key expression. It's possible for a column to be both used directly and * as part of an expression; if that happens, *used_in_expr may end up as * either true or false. That's OK for current uses of this function, because * *used_in_expr is only used to tailor the error message text. */ static bool is_partition_attr(Relation rel, AttrNumber attnum, bool *used_in_expr) { PartitionKey key; int partnatts; List *partexprs; ListCell *partexprs_item; int i; if (rel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE) return false; key = RelationGetPartitionKey(rel); partnatts = get_partition_natts(key); partexprs = get_partition_exprs(key); partexprs_item = list_head(partexprs); for (i = 0; i < partnatts; i++) { AttrNumber partattno = get_partition_col_attnum(key, i); if (partattno != 0) { if (attnum == partattno) { if (used_in_expr) *used_in_expr = false; return true; } } else { /* Arbitrary expression */ Node *expr = (Node *) lfirst(partexprs_item); Bitmapset *expr_attrs = NULL; /* Find all attributes referenced */ pull_varattnos(expr, 1, &expr_attrs); partexprs_item = lnext(partexprs_item); if (bms_is_member(attnum - FirstLowInvalidHeapAttributeNumber, expr_attrs)) { if (used_in_expr) *used_in_expr = true; return true; } } } return false; } /* * Return value is the address of the dropped column. */ static ObjectAddress ATExecDropColumn(List **wqueue, Relation rel, const char *colName, DropBehavior behavior, bool recurse, bool recursing, bool missing_ok, LOCKMODE lockmode) { HeapTuple tuple; Form_pg_attribute targetatt; AttrNumber attnum; List *children; ObjectAddress object; bool is_expr; /* At top level, permission check was done in ATPrepCmd, else do it */ if (recursing) ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE); /* * get the number of the attribute */ tuple = SearchSysCacheAttName(RelationGetRelid(rel), colName); if (!HeapTupleIsValid(tuple)) { if (!missing_ok) { ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(rel)))); } else { ereport(NOTICE, (errmsg("column \"%s\" of relation \"%s\" does not exist, skipping", colName, RelationGetRelationName(rel)))); return InvalidObjectAddress; } } targetatt = (Form_pg_attribute) GETSTRUCT(tuple); attnum = targetatt->attnum; /* Can't drop a system attribute, except OID */ if (attnum <= 0 && attnum != ObjectIdAttributeNumber) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot drop system column \"%s\"", colName))); /* Don't drop inherited columns */ if (targetatt->attinhcount > 0 && !recursing) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot drop inherited column \"%s\"", colName))); /* Don't drop columns used in the partition key */ if (is_partition_attr(rel, attnum, &is_expr)) { if (!is_expr) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot drop column named in partition key"))); else ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot drop column referenced in partition key expression"))); } ReleaseSysCache(tuple); /* * Propagate to children as appropriate. Unlike most other ALTER * routines, we have to do this one level of recursion at a time; we can't * use find_all_inheritors to do it in one pass. */ children = find_inheritance_children(RelationGetRelid(rel), lockmode); if (children) { Relation attr_rel; ListCell *child; /* * In case of a partitioned table, the column must be dropped from the * partitions as well. */ if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE && !recurse) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("column must be dropped from child tables too"))); attr_rel = heap_open(AttributeRelationId, RowExclusiveLock); foreach(child, children) { Oid childrelid = lfirst_oid(child); Relation childrel; Form_pg_attribute childatt; /* find_inheritance_children already got lock */ childrel = heap_open(childrelid, NoLock); CheckTableNotInUse(childrel, "ALTER TABLE"); tuple = SearchSysCacheCopyAttName(childrelid, colName); if (!HeapTupleIsValid(tuple)) /* shouldn't happen */ elog(ERROR, "cache lookup failed for attribute \"%s\" of relation %u", colName, childrelid); childatt = (Form_pg_attribute) GETSTRUCT(tuple); if (childatt->attinhcount <= 0) /* shouldn't happen */ elog(ERROR, "relation %u has non-inherited attribute \"%s\"", childrelid, colName); if (recurse) { /* * If the child column has other definition sources, just * decrement its inheritance count; if not, recurse to delete * it. */ if (childatt->attinhcount == 1 && !childatt->attislocal) { /* Time to delete this child column, too */ ATExecDropColumn(wqueue, childrel, colName, behavior, true, true, false, lockmode); } else { /* Child column must survive my deletion */ childatt->attinhcount--; CatalogTupleUpdate(attr_rel, &tuple->t_self, tuple); /* Make update visible */ CommandCounterIncrement(); } } else { /* * If we were told to drop ONLY in this table (no recursion), * we need to mark the inheritors' attributes as locally * defined rather than inherited. */ childatt->attinhcount--; childatt->attislocal = true; CatalogTupleUpdate(attr_rel, &tuple->t_self, tuple); /* Make update visible */ CommandCounterIncrement(); } heap_freetuple(tuple); heap_close(childrel, NoLock); } heap_close(attr_rel, RowExclusiveLock); } /* * Perform the actual column deletion */ object.classId = RelationRelationId; object.objectId = RelationGetRelid(rel); object.objectSubId = attnum; performDeletion(&object, behavior, 0); /* * If we dropped the OID column, must adjust pg_class.relhasoids and tell * Phase 3 to physically get rid of the column. We formerly left the * column in place physically, but this caused subtle problems. See * http://archives.postgresql.org/pgsql-hackers/2009-02/msg00363.php */ if (attnum == ObjectIdAttributeNumber) { Relation class_rel; Form_pg_class tuple_class; AlteredTableInfo *tab; class_rel = heap_open(RelationRelationId, RowExclusiveLock); tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(RelationGetRelid(rel))); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for relation %u", RelationGetRelid(rel)); tuple_class = (Form_pg_class) GETSTRUCT(tuple); tuple_class->relhasoids = false; CatalogTupleUpdate(class_rel, &tuple->t_self, tuple); heap_close(class_rel, RowExclusiveLock); /* Find or create work queue entry for this table */ tab = ATGetQueueEntry(wqueue, rel); /* Tell Phase 3 to physically remove the OID column */ tab->rewrite |= AT_REWRITE_ALTER_OID; } return object; } /* * ALTER TABLE ADD INDEX * * There is no such command in the grammar, but parse_utilcmd.c converts * UNIQUE and PRIMARY KEY constraints into AT_AddIndex subcommands. This lets * us schedule creation of the index at the appropriate time during ALTER. * * Return value is the address of the new index. */ static ObjectAddress ATExecAddIndex(AlteredTableInfo *tab, Relation rel, IndexStmt *stmt, bool is_rebuild, LOCKMODE lockmode) { bool check_rights; bool skip_build; bool quiet; ObjectAddress address; Assert(IsA(stmt, IndexStmt)); Assert(!stmt->concurrent); /* The IndexStmt has already been through transformIndexStmt */ Assert(stmt->transformed); /* suppress schema rights check when rebuilding existing index */ check_rights = !is_rebuild; /* skip index build if phase 3 will do it or we're reusing an old one */ skip_build = tab->rewrite > 0 || OidIsValid(stmt->oldNode); /* suppress notices when rebuilding existing index */ quiet = is_rebuild; address = DefineIndex(RelationGetRelid(rel), stmt, InvalidOid, /* no predefined OID */ true, /* is_alter_table */ check_rights, skip_build, quiet); /* * If TryReuseIndex() stashed a relfilenode for us, we used it for the new * index instead of building from scratch. The DROP of the old edition of * this index will have scheduled the storage for deletion at commit, so * cancel that pending deletion. */ if (OidIsValid(stmt->oldNode)) { Relation irel = index_open(address.objectId, NoLock); RelationPreserveStorage(irel->rd_node, true); index_close(irel, NoLock); } return address; } /* * ALTER TABLE ADD CONSTRAINT USING INDEX * * Returns the address of the new constraint. */ static ObjectAddress ATExecAddIndexConstraint(AlteredTableInfo *tab, Relation rel, IndexStmt *stmt, LOCKMODE lockmode) { Oid index_oid = stmt->indexOid; Relation indexRel; char *indexName; IndexInfo *indexInfo; char *constraintName; char constraintType; ObjectAddress address; Assert(IsA(stmt, IndexStmt)); Assert(OidIsValid(index_oid)); Assert(stmt->isconstraint); indexRel = index_open(index_oid, AccessShareLock); indexName = pstrdup(RelationGetRelationName(indexRel)); indexInfo = BuildIndexInfo(indexRel); /* this should have been checked at parse time */ if (!indexInfo->ii_Unique) elog(ERROR, "index \"%s\" is not unique", indexName); /* * Determine name to assign to constraint. We require a constraint to * have the same name as the underlying index; therefore, use the index's * existing name as the default constraint name, and if the user * explicitly gives some other name for the constraint, rename the index * to match. */ constraintName = stmt->idxname; if (constraintName == NULL) constraintName = indexName; else if (strcmp(constraintName, indexName) != 0) { ereport(NOTICE, (errmsg("ALTER TABLE / ADD CONSTRAINT USING INDEX will rename index \"%s\" to \"%s\"", indexName, constraintName))); RenameRelationInternal(index_oid, constraintName, false); } /* Extra checks needed if making primary key */ if (stmt->primary) index_check_primary_key(rel, indexInfo, true); /* Note we currently don't support EXCLUSION constraints here */ if (stmt->primary) constraintType = CONSTRAINT_PRIMARY; else constraintType = CONSTRAINT_UNIQUE; /* Create the catalog entries for the constraint */ address = index_constraint_create(rel, index_oid, indexInfo, constraintName, constraintType, stmt->deferrable, stmt->initdeferred, stmt->primary, true, /* update pg_index */ true, /* remove old dependencies */ allowSystemTableMods, false); /* is_internal */ index_close(indexRel, NoLock); return address; } /* * ALTER TABLE ADD CONSTRAINT * * Return value is the address of the new constraint; if no constraint was * added, InvalidObjectAddress is returned. */ static ObjectAddress ATExecAddConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel, Constraint *newConstraint, bool recurse, bool is_readd, LOCKMODE lockmode) { ObjectAddress address = InvalidObjectAddress; Assert(IsA(newConstraint, Constraint)); /* * Currently, we only expect to see CONSTR_CHECK and CONSTR_FOREIGN nodes * arriving here (see the preprocessing done in parse_utilcmd.c). Use a * switch anyway to make it easier to add more code later. */ switch (newConstraint->contype) { case CONSTR_CHECK: address = ATAddCheckConstraint(wqueue, tab, rel, newConstraint, recurse, false, is_readd, lockmode); break; case CONSTR_FOREIGN: /* * Note that we currently never recurse for FK constraints, so the * "recurse" flag is silently ignored. * * Assign or validate constraint name */ if (newConstraint->conname) { if (ConstraintNameIsUsed(CONSTRAINT_RELATION, RelationGetRelid(rel), RelationGetNamespace(rel), newConstraint->conname)) ereport(ERROR, (errcode(ERRCODE_DUPLICATE_OBJECT), errmsg("constraint \"%s\" for relation \"%s\" already exists", newConstraint->conname, RelationGetRelationName(rel)))); } else newConstraint->conname = ChooseConstraintName(RelationGetRelationName(rel), strVal(linitial(newConstraint->fk_attrs)), "fkey", RelationGetNamespace(rel), NIL); address = ATAddForeignKeyConstraint(tab, rel, newConstraint, lockmode); break; default: elog(ERROR, "unrecognized constraint type: %d", (int) newConstraint->contype); } return address; } /* * Add a check constraint to a single table and its children. Returns the * address of the constraint added to the parent relation, if one gets added, * or InvalidObjectAddress otherwise. * * Subroutine for ATExecAddConstraint. * * We must recurse to child tables during execution, rather than using * ALTER TABLE's normal prep-time recursion. The reason is that all the * constraints *must* be given the same name, else they won't be seen as * related later. If the user didn't explicitly specify a name, then * AddRelationNewConstraints would normally assign different names to the * child constraints. To fix that, we must capture the name assigned at * the parent table and pass that down. */ static ObjectAddress ATAddCheckConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel, Constraint *constr, bool recurse, bool recursing, bool is_readd, LOCKMODE lockmode) { List *newcons; ListCell *lcon; List *children; ListCell *child; ObjectAddress address = InvalidObjectAddress; /* At top level, permission check was done in ATPrepCmd, else do it */ if (recursing) ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE); /* * Call AddRelationNewConstraints to do the work, making sure it works on * a copy of the Constraint so transformExpr can't modify the original. It * returns a list of cooked constraints. * * If the constraint ends up getting merged with a pre-existing one, it's * omitted from the returned list, which is what we want: we do not need * to do any validation work. That can only happen at child tables, * though, since we disallow merging at the top level. */ newcons = AddRelationNewConstraints(rel, NIL, list_make1(copyObject(constr)), recursing | is_readd, /* allow_merge */ !recursing, /* is_local */ is_readd); /* is_internal */ /* we don't expect more than one constraint here */ Assert(list_length(newcons) <= 1); /* Add each to-be-validated constraint to Phase 3's queue */ foreach(lcon, newcons) { CookedConstraint *ccon = (CookedConstraint *) lfirst(lcon); if (!ccon->skip_validation) { NewConstraint *newcon; newcon = (NewConstraint *) palloc0(sizeof(NewConstraint)); newcon->name = ccon->name; newcon->contype = ccon->contype; newcon->qual = ccon->expr; tab->constraints = lappend(tab->constraints, newcon); } /* Save the actually assigned name if it was defaulted */ if (constr->conname == NULL) constr->conname = ccon->name; ObjectAddressSet(address, ConstraintRelationId, ccon->conoid); } /* At this point we must have a locked-down name to use */ Assert(constr->conname != NULL); /* Advance command counter in case same table is visited multiple times */ CommandCounterIncrement(); /* * If the constraint got merged with an existing constraint, we're done. * We mustn't recurse to child tables in this case, because they've * already got the constraint, and visiting them again would lead to an * incorrect value for coninhcount. */ if (newcons == NIL) return address; /* * If adding a NO INHERIT constraint, no need to find our children. */ if (constr->is_no_inherit) return address; /* * Propagate to children as appropriate. Unlike most other ALTER * routines, we have to do this one level of recursion at a time; we can't * use find_all_inheritors to do it in one pass. */ children = find_inheritance_children(RelationGetRelid(rel), lockmode); /* * Check if ONLY was specified with ALTER TABLE. If so, allow the * constraint creation only if there are no children currently. Error out * otherwise. */ if (!recurse && children != NIL) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("constraint must be added to child tables too"))); foreach(child, children) { Oid childrelid = lfirst_oid(child); Relation childrel; AlteredTableInfo *childtab; /* find_inheritance_children already got lock */ childrel = heap_open(childrelid, NoLock); CheckTableNotInUse(childrel, "ALTER TABLE"); /* Find or create work queue entry for this table */ childtab = ATGetQueueEntry(wqueue, childrel); /* Recurse to child */ ATAddCheckConstraint(wqueue, childtab, childrel, constr, recurse, true, is_readd, lockmode); heap_close(childrel, NoLock); } return address; } /* * Add a foreign-key constraint to a single table; return the new constraint's * address. * * Subroutine for ATExecAddConstraint. Must already hold exclusive * lock on the rel, and have done appropriate validity checks for it. * We do permissions checks here, however. */ static ObjectAddress ATAddForeignKeyConstraint(AlteredTableInfo *tab, Relation rel, Constraint *fkconstraint, LOCKMODE lockmode) { Relation pkrel; int16 pkattnum[INDEX_MAX_KEYS]; int16 fkattnum[INDEX_MAX_KEYS]; Oid pktypoid[INDEX_MAX_KEYS]; Oid fktypoid[INDEX_MAX_KEYS]; Oid opclasses[INDEX_MAX_KEYS]; Oid pfeqoperators[INDEX_MAX_KEYS]; Oid ppeqoperators[INDEX_MAX_KEYS]; Oid ffeqoperators[INDEX_MAX_KEYS]; int i; int numfks, numpks; Oid indexOid; Oid constrOid; bool old_check_ok; ObjectAddress address; ListCell *old_pfeqop_item = list_head(fkconstraint->old_conpfeqop); /* * Grab ShareRowExclusiveLock on the pk table, so that someone doesn't * delete rows out from under us. */ if (OidIsValid(fkconstraint->old_pktable_oid)) pkrel = heap_open(fkconstraint->old_pktable_oid, ShareRowExclusiveLock); else pkrel = heap_openrv(fkconstraint->pktable, ShareRowExclusiveLock); /* * Validity checks (permission checks wait till we have the column * numbers) */ if (pkrel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot reference partitioned table \"%s\"", RelationGetRelationName(pkrel)))); if (pkrel->rd_rel->relkind != RELKIND_RELATION) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("referenced relation \"%s\" is not a table", RelationGetRelationName(pkrel)))); if (!allowSystemTableMods && IsSystemRelation(pkrel)) ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("permission denied: \"%s\" is a system catalog", RelationGetRelationName(pkrel)))); /* * References from permanent or unlogged tables to temp tables, and from * permanent tables to unlogged tables, are disallowed because the * referenced data can vanish out from under us. References from temp * tables to any other table type are also disallowed, because other * backends might need to run the RI triggers on the perm table, but they * can't reliably see tuples in the local buffers of other backends. */ switch (rel->rd_rel->relpersistence) { case RELPERSISTENCE_PERMANENT: if (pkrel->rd_rel->relpersistence != RELPERSISTENCE_PERMANENT) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("constraints on permanent tables may reference only permanent tables"))); break; case RELPERSISTENCE_UNLOGGED: if (pkrel->rd_rel->relpersistence != RELPERSISTENCE_PERMANENT && pkrel->rd_rel->relpersistence != RELPERSISTENCE_UNLOGGED) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("constraints on unlogged tables may reference only permanent or unlogged tables"))); break; case RELPERSISTENCE_TEMP: if (pkrel->rd_rel->relpersistence != RELPERSISTENCE_TEMP) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("constraints on temporary tables may reference only temporary tables"))); if (!pkrel->rd_islocaltemp || !rel->rd_islocaltemp) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("constraints on temporary tables must involve temporary tables of this session"))); break; } /* * Look up the referencing attributes to make sure they exist, and record * their attnums and type OIDs. */ MemSet(pkattnum, 0, sizeof(pkattnum)); MemSet(fkattnum, 0, sizeof(fkattnum)); MemSet(pktypoid, 0, sizeof(pktypoid)); MemSet(fktypoid, 0, sizeof(fktypoid)); MemSet(opclasses, 0, sizeof(opclasses)); MemSet(pfeqoperators, 0, sizeof(pfeqoperators)); MemSet(ppeqoperators, 0, sizeof(ppeqoperators)); MemSet(ffeqoperators, 0, sizeof(ffeqoperators)); numfks = transformColumnNameList(RelationGetRelid(rel), fkconstraint->fk_attrs, fkattnum, fktypoid); /* * If the attribute list for the referenced table was omitted, lookup the * definition of the primary key and use it. Otherwise, validate the * supplied attribute list. In either case, discover the index OID and * index opclasses, and the attnums and type OIDs of the attributes. */ if (fkconstraint->pk_attrs == NIL) { numpks = transformFkeyGetPrimaryKey(pkrel, &indexOid, &fkconstraint->pk_attrs, pkattnum, pktypoid, opclasses); } else { numpks = transformColumnNameList(RelationGetRelid(pkrel), fkconstraint->pk_attrs, pkattnum, pktypoid); /* Look for an index matching the column list */ indexOid = transformFkeyCheckAttrs(pkrel, numpks, pkattnum, opclasses); } /* * Now we can check permissions. */ checkFkeyPermissions(pkrel, pkattnum, numpks); /* * Look up the equality operators to use in the constraint. * * Note that we have to be careful about the difference between the actual * PK column type and the opclass' declared input type, which might be * only binary-compatible with it. The declared opcintype is the right * thing to probe pg_amop with. */ if (numfks != numpks) ereport(ERROR, (errcode(ERRCODE_INVALID_FOREIGN_KEY), errmsg("number of referencing and referenced columns for foreign key disagree"))); /* * On the strength of a previous constraint, we might avoid scanning * tables to validate this one. See below. */ old_check_ok = (fkconstraint->old_conpfeqop != NIL); Assert(!old_check_ok || numfks == list_length(fkconstraint->old_conpfeqop)); for (i = 0; i < numpks; i++) { Oid pktype = pktypoid[i]; Oid fktype = fktypoid[i]; Oid fktyped; HeapTuple cla_ht; Form_pg_opclass cla_tup; Oid amid; Oid opfamily; Oid opcintype; Oid pfeqop; Oid ppeqop; Oid ffeqop; int16 eqstrategy; Oid pfeqop_right; /* We need several fields out of the pg_opclass entry */ cla_ht = SearchSysCache1(CLAOID, ObjectIdGetDatum(opclasses[i])); if (!HeapTupleIsValid(cla_ht)) elog(ERROR, "cache lookup failed for opclass %u", opclasses[i]); cla_tup = (Form_pg_opclass) GETSTRUCT(cla_ht); amid = cla_tup->opcmethod; opfamily = cla_tup->opcfamily; opcintype = cla_tup->opcintype; ReleaseSysCache(cla_ht); /* * Check it's a btree; currently this can never fail since no other * index AMs support unique indexes. If we ever did have other types * of unique indexes, we'd need a way to determine which operator * strategy number is equality. (Is it reasonable to insist that * every such index AM use btree's number for equality?) */ if (amid != BTREE_AM_OID) elog(ERROR, "only b-tree indexes are supported for foreign keys"); eqstrategy = BTEqualStrategyNumber; /* * There had better be a primary equality operator for the index. * We'll use it for PK = PK comparisons. */ ppeqop = get_opfamily_member(opfamily, opcintype, opcintype, eqstrategy); if (!OidIsValid(ppeqop)) elog(ERROR, "missing operator %d(%u,%u) in opfamily %u", eqstrategy, opcintype, opcintype, opfamily); /* * Are there equality operators that take exactly the FK type? Assume * we should look through any domain here. */ fktyped = getBaseType(fktype); pfeqop = get_opfamily_member(opfamily, opcintype, fktyped, eqstrategy); if (OidIsValid(pfeqop)) { pfeqop_right = fktyped; ffeqop = get_opfamily_member(opfamily, fktyped, fktyped, eqstrategy); } else { /* keep compiler quiet */ pfeqop_right = InvalidOid; ffeqop = InvalidOid; } if (!(OidIsValid(pfeqop) && OidIsValid(ffeqop))) { /* * Otherwise, look for an implicit cast from the FK type to the * opcintype, and if found, use the primary equality operator. * This is a bit tricky because opcintype might be a polymorphic * type such as ANYARRAY or ANYENUM; so what we have to test is * whether the two actual column types can be concurrently cast to * that type. (Otherwise, we'd fail to reject combinations such * as int[] and point[].) */ Oid input_typeids[2]; Oid target_typeids[2]; input_typeids[0] = pktype; input_typeids[1] = fktype; target_typeids[0] = opcintype; target_typeids[1] = opcintype; if (can_coerce_type(2, input_typeids, target_typeids, COERCION_IMPLICIT)) { pfeqop = ffeqop = ppeqop; pfeqop_right = opcintype; } } if (!(OidIsValid(pfeqop) && OidIsValid(ffeqop))) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("foreign key constraint \"%s\" " "cannot be implemented", fkconstraint->conname), errdetail("Key columns \"%s\" and \"%s\" " "are of incompatible types: %s and %s.", strVal(list_nth(fkconstraint->fk_attrs, i)), strVal(list_nth(fkconstraint->pk_attrs, i)), format_type_be(fktype), format_type_be(pktype)))); if (old_check_ok) { /* * When a pfeqop changes, revalidate the constraint. We could * permit intra-opfamily changes, but that adds subtle complexity * without any concrete benefit for core types. We need not * assess ppeqop or ffeqop, which RI_Initial_Check() does not use. */ old_check_ok = (pfeqop == lfirst_oid(old_pfeqop_item)); old_pfeqop_item = lnext(old_pfeqop_item); } if (old_check_ok) { Oid old_fktype; Oid new_fktype; CoercionPathType old_pathtype; CoercionPathType new_pathtype; Oid old_castfunc; Oid new_castfunc; /* * Identify coercion pathways from each of the old and new FK-side * column types to the right (foreign) operand type of the pfeqop. * We may assume that pg_constraint.conkey is not changing. */ old_fktype = tab->oldDesc->attrs[fkattnum[i] - 1]->atttypid; new_fktype = fktype; old_pathtype = findFkeyCast(pfeqop_right, old_fktype, &old_castfunc); new_pathtype = findFkeyCast(pfeqop_right, new_fktype, &new_castfunc); /* * Upon a change to the cast from the FK column to its pfeqop * operand, revalidate the constraint. For this evaluation, a * binary coercion cast is equivalent to no cast at all. While * type implementors should design implicit casts with an eye * toward consistency of operations like equality, we cannot * assume here that they have done so. * * A function with a polymorphic argument could change behavior * arbitrarily in response to get_fn_expr_argtype(). Therefore, * when the cast destination is polymorphic, we only avoid * revalidation if the input type has not changed at all. Given * just the core data types and operator classes, this requirement * prevents no would-be optimizations. * * If the cast converts from a base type to a domain thereon, then * that domain type must be the opcintype of the unique index. * Necessarily, the primary key column must then be of the domain * type. Since the constraint was previously valid, all values on * the foreign side necessarily exist on the primary side and in * turn conform to the domain. Consequently, we need not treat * domains specially here. * * Since we require that all collations share the same notion of * equality (which they do, because texteq reduces to bitwise * equality), we don't compare collation here. * * We need not directly consider the PK type. It's necessarily * binary coercible to the opcintype of the unique index column, * and ri_triggers.c will only deal with PK datums in terms of * that opcintype. Changing the opcintype also changes pfeqop. */ old_check_ok = (new_pathtype == old_pathtype && new_castfunc == old_castfunc && (!IsPolymorphicType(pfeqop_right) || new_fktype == old_fktype)); } pfeqoperators[i] = pfeqop; ppeqoperators[i] = ppeqop; ffeqoperators[i] = ffeqop; } /* * Record the FK constraint in pg_constraint. */ constrOid = CreateConstraintEntry(fkconstraint->conname, RelationGetNamespace(rel), CONSTRAINT_FOREIGN, fkconstraint->deferrable, fkconstraint->initdeferred, fkconstraint->initially_valid, RelationGetRelid(rel), fkattnum, numfks, InvalidOid, /* not a domain * constraint */ indexOid, RelationGetRelid(pkrel), pkattnum, pfeqoperators, ppeqoperators, ffeqoperators, numpks, fkconstraint->fk_upd_action, fkconstraint->fk_del_action, fkconstraint->fk_matchtype, NULL, /* no exclusion constraint */ NULL, /* no check constraint */ NULL, NULL, true, /* islocal */ 0, /* inhcount */ true, /* isnoinherit */ false); /* is_internal */ ObjectAddressSet(address, ConstraintRelationId, constrOid); /* * Create the triggers that will enforce the constraint. */ createForeignKeyTriggers(rel, RelationGetRelid(pkrel), fkconstraint, constrOid, indexOid); /* * Tell Phase 3 to check that the constraint is satisfied by existing * rows. We can skip this during table creation, when requested explicitly * by specifying NOT VALID in an ADD FOREIGN KEY command, and when we're * recreating a constraint following a SET DATA TYPE operation that did * not impugn its validity. */ if (!old_check_ok && !fkconstraint->skip_validation) { NewConstraint *newcon; newcon = (NewConstraint *) palloc0(sizeof(NewConstraint)); newcon->name = fkconstraint->conname; newcon->contype = CONSTR_FOREIGN; newcon->refrelid = RelationGetRelid(pkrel); newcon->refindid = indexOid; newcon->conid = constrOid; newcon->qual = (Node *) fkconstraint; tab->constraints = lappend(tab->constraints, newcon); } /* * Close pk table, but keep lock until we've committed. */ heap_close(pkrel, NoLock); return address; } /* * ALTER TABLE ALTER CONSTRAINT * * Update the attributes of a constraint. * * Currently only works for Foreign Key constraints. * Foreign keys do not inherit, so we purposely ignore the * recursion bit here, but we keep the API the same for when * other constraint types are supported. * * If the constraint is modified, returns its address; otherwise, return * InvalidObjectAddress. */ static ObjectAddress ATExecAlterConstraint(Relation rel, AlterTableCmd *cmd, bool recurse, bool recursing, LOCKMODE lockmode) { Constraint *cmdcon; Relation conrel; SysScanDesc scan; ScanKeyData key; HeapTuple contuple; Form_pg_constraint currcon = NULL; bool found = false; ObjectAddress address; cmdcon = castNode(Constraint, cmd->def); conrel = heap_open(ConstraintRelationId, RowExclusiveLock); /* * Find and check the target constraint */ ScanKeyInit(&key, Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel))); scan = systable_beginscan(conrel, ConstraintRelidIndexId, true, NULL, 1, &key); while (HeapTupleIsValid(contuple = systable_getnext(scan))) { currcon = (Form_pg_constraint) GETSTRUCT(contuple); if (strcmp(NameStr(currcon->conname), cmdcon->conname) == 0) { found = true; break; } } if (!found) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("constraint \"%s\" of relation \"%s\" does not exist", cmdcon->conname, RelationGetRelationName(rel)))); if (currcon->contype != CONSTRAINT_FOREIGN) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("constraint \"%s\" of relation \"%s\" is not a foreign key constraint", cmdcon->conname, RelationGetRelationName(rel)))); if (currcon->condeferrable != cmdcon->deferrable || currcon->condeferred != cmdcon->initdeferred) { HeapTuple copyTuple; HeapTuple tgtuple; Form_pg_constraint copy_con; List *otherrelids = NIL; ScanKeyData tgkey; SysScanDesc tgscan; Relation tgrel; ListCell *lc; /* * Now update the catalog, while we have the door open. */ copyTuple = heap_copytuple(contuple); copy_con = (Form_pg_constraint) GETSTRUCT(copyTuple); copy_con->condeferrable = cmdcon->deferrable; copy_con->condeferred = cmdcon->initdeferred; CatalogTupleUpdate(conrel, ©Tuple->t_self, copyTuple); InvokeObjectPostAlterHook(ConstraintRelationId, HeapTupleGetOid(contuple), 0); heap_freetuple(copyTuple); /* * Now we need to update the multiple entries in pg_trigger that * implement the constraint. */ tgrel = heap_open(TriggerRelationId, RowExclusiveLock); ScanKeyInit(&tgkey, Anum_pg_trigger_tgconstraint, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(HeapTupleGetOid(contuple))); tgscan = systable_beginscan(tgrel, TriggerConstraintIndexId, true, NULL, 1, &tgkey); while (HeapTupleIsValid(tgtuple = systable_getnext(tgscan))) { Form_pg_trigger tgform = (Form_pg_trigger) GETSTRUCT(tgtuple); Form_pg_trigger copy_tg; /* * Remember OIDs of other relation(s) involved in FK constraint. * (Note: it's likely that we could skip forcing a relcache inval * for other rels that don't have a trigger whose properties * change, but let's be conservative.) */ if (tgform->tgrelid != RelationGetRelid(rel)) otherrelids = list_append_unique_oid(otherrelids, tgform->tgrelid); /* * Update deferrability of RI_FKey_noaction_del, * RI_FKey_noaction_upd, RI_FKey_check_ins and RI_FKey_check_upd * triggers, but not others; see createForeignKeyTriggers and * CreateFKCheckTrigger. */ if (tgform->tgfoid != F_RI_FKEY_NOACTION_DEL && tgform->tgfoid != F_RI_FKEY_NOACTION_UPD && tgform->tgfoid != F_RI_FKEY_CHECK_INS && tgform->tgfoid != F_RI_FKEY_CHECK_UPD) continue; copyTuple = heap_copytuple(tgtuple); copy_tg = (Form_pg_trigger) GETSTRUCT(copyTuple); copy_tg->tgdeferrable = cmdcon->deferrable; copy_tg->tginitdeferred = cmdcon->initdeferred; CatalogTupleUpdate(tgrel, ©Tuple->t_self, copyTuple); InvokeObjectPostAlterHook(TriggerRelationId, HeapTupleGetOid(tgtuple), 0); heap_freetuple(copyTuple); } systable_endscan(tgscan); heap_close(tgrel, RowExclusiveLock); /* * Invalidate relcache so that others see the new attributes. We must * inval both the named rel and any others having relevant triggers. * (At present there should always be exactly one other rel, but * there's no need to hard-wire such an assumption here.) */ CacheInvalidateRelcache(rel); foreach(lc, otherrelids) { CacheInvalidateRelcacheByRelid(lfirst_oid(lc)); } ObjectAddressSet(address, ConstraintRelationId, HeapTupleGetOid(contuple)); } else address = InvalidObjectAddress; systable_endscan(scan); heap_close(conrel, RowExclusiveLock); return address; } /* * ALTER TABLE VALIDATE CONSTRAINT * * XXX The reason we handle recursion here rather than at Phase 1 is because * there's no good way to skip recursing when handling foreign keys: there is * no need to lock children in that case, yet we wouldn't be able to avoid * doing so at that level. * * Return value is the address of the validated constraint. If the constraint * was already validated, InvalidObjectAddress is returned. */ static ObjectAddress ATExecValidateConstraint(Relation rel, char *constrName, bool recurse, bool recursing, LOCKMODE lockmode) { Relation conrel; SysScanDesc scan; ScanKeyData key; HeapTuple tuple; Form_pg_constraint con = NULL; bool found = false; ObjectAddress address; conrel = heap_open(ConstraintRelationId, RowExclusiveLock); /* * Find and check the target constraint */ ScanKeyInit(&key, Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel))); scan = systable_beginscan(conrel, ConstraintRelidIndexId, true, NULL, 1, &key); while (HeapTupleIsValid(tuple = systable_getnext(scan))) { con = (Form_pg_constraint) GETSTRUCT(tuple); if (strcmp(NameStr(con->conname), constrName) == 0) { found = true; break; } } if (!found) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("constraint \"%s\" of relation \"%s\" does not exist", constrName, RelationGetRelationName(rel)))); if (con->contype != CONSTRAINT_FOREIGN && con->contype != CONSTRAINT_CHECK) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("constraint \"%s\" of relation \"%s\" is not a foreign key or check constraint", constrName, RelationGetRelationName(rel)))); if (!con->convalidated) { HeapTuple copyTuple; Form_pg_constraint copy_con; if (con->contype == CONSTRAINT_FOREIGN) { Relation refrel; /* * Triggers are already in place on both tables, so a concurrent * write that alters the result here is not possible. Normally we * can run a query here to do the validation, which would only * require AccessShareLock. In some cases, it is possible that we * might need to fire triggers to perform the check, so we take a * lock at RowShareLock level just in case. */ refrel = heap_open(con->confrelid, RowShareLock); validateForeignKeyConstraint(constrName, rel, refrel, con->conindid, HeapTupleGetOid(tuple)); heap_close(refrel, NoLock); /* * Foreign keys do not inherit, so we purposely ignore the * recursion bit here */ } else if (con->contype == CONSTRAINT_CHECK) { List *children = NIL; ListCell *child; /* * If we're recursing, the parent has already done this, so skip * it. */ if (!recursing) children = find_all_inheritors(RelationGetRelid(rel), lockmode, NULL); /* * For CHECK constraints, we must ensure that we only mark the * constraint as validated on the parent if it's already validated * on the children. * * We recurse before validating on the parent, to reduce risk of * deadlocks. */ foreach(child, children) { Oid childoid = lfirst_oid(child); Relation childrel; if (childoid == RelationGetRelid(rel)) continue; /* * If we are told not to recurse, there had better not be any * child tables, because we can't mark the constraint on the * parent valid unless it is valid for all child tables. */ if (!recurse) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("constraint must be validated on child tables too"))); /* find_all_inheritors already got lock */ childrel = heap_open(childoid, NoLock); ATExecValidateConstraint(childrel, constrName, false, true, lockmode); heap_close(childrel, NoLock); } validateCheckConstraint(rel, tuple); /* * Invalidate relcache so that others see the new validated * constraint. */ CacheInvalidateRelcache(rel); } /* * Now update the catalog, while we have the door open. */ copyTuple = heap_copytuple(tuple); copy_con = (Form_pg_constraint) GETSTRUCT(copyTuple); copy_con->convalidated = true; CatalogTupleUpdate(conrel, ©Tuple->t_self, copyTuple); InvokeObjectPostAlterHook(ConstraintRelationId, HeapTupleGetOid(tuple), 0); heap_freetuple(copyTuple); ObjectAddressSet(address, ConstraintRelationId, HeapTupleGetOid(tuple)); } else address = InvalidObjectAddress; /* already validated */ systable_endscan(scan); heap_close(conrel, RowExclusiveLock); return address; } /* * transformColumnNameList - transform list of column names * * Lookup each name and return its attnum and type OID */ static int transformColumnNameList(Oid relId, List *colList, int16 *attnums, Oid *atttypids) { ListCell *l; int attnum; attnum = 0; foreach(l, colList) { char *attname = strVal(lfirst(l)); HeapTuple atttuple; atttuple = SearchSysCacheAttName(relId, attname); if (!HeapTupleIsValid(atttuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" referenced in foreign key constraint does not exist", attname))); if (attnum >= INDEX_MAX_KEYS) ereport(ERROR, (errcode(ERRCODE_TOO_MANY_COLUMNS), errmsg("cannot have more than %d keys in a foreign key", INDEX_MAX_KEYS))); attnums[attnum] = ((Form_pg_attribute) GETSTRUCT(atttuple))->attnum; atttypids[attnum] = ((Form_pg_attribute) GETSTRUCT(atttuple))->atttypid; ReleaseSysCache(atttuple); attnum++; } return attnum; } /* * transformFkeyGetPrimaryKey - * * Look up the names, attnums, and types of the primary key attributes * for the pkrel. Also return the index OID and index opclasses of the * index supporting the primary key. * * All parameters except pkrel are output parameters. Also, the function * return value is the number of attributes in the primary key. * * Used when the column list in the REFERENCES specification is omitted. */ static int transformFkeyGetPrimaryKey(Relation pkrel, Oid *indexOid, List **attnamelist, int16 *attnums, Oid *atttypids, Oid *opclasses) { List *indexoidlist; ListCell *indexoidscan; HeapTuple indexTuple = NULL; Form_pg_index indexStruct = NULL; Datum indclassDatum; bool isnull; oidvector *indclass; int i; /* * Get the list of index OIDs for the table from the relcache, and look up * each one in the pg_index syscache until we find one marked primary key * (hopefully there isn't more than one such). Insist it's valid, too. */ *indexOid = InvalidOid; indexoidlist = RelationGetIndexList(pkrel); foreach(indexoidscan, indexoidlist) { Oid indexoid = lfirst_oid(indexoidscan); indexTuple = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(indexoid)); if (!HeapTupleIsValid(indexTuple)) elog(ERROR, "cache lookup failed for index %u", indexoid); indexStruct = (Form_pg_index) GETSTRUCT(indexTuple); if (indexStruct->indisprimary && IndexIsValid(indexStruct)) { /* * Refuse to use a deferrable primary key. This is per SQL spec, * and there would be a lot of interesting semantic problems if we * tried to allow it. */ if (!indexStruct->indimmediate) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("cannot use a deferrable primary key for referenced table \"%s\"", RelationGetRelationName(pkrel)))); *indexOid = indexoid; break; } ReleaseSysCache(indexTuple); } list_free(indexoidlist); /* * Check that we found it */ if (!OidIsValid(*indexOid)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("there is no primary key for referenced table \"%s\"", RelationGetRelationName(pkrel)))); /* Must get indclass the hard way */ indclassDatum = SysCacheGetAttr(INDEXRELID, indexTuple, Anum_pg_index_indclass, &isnull); Assert(!isnull); indclass = (oidvector *) DatumGetPointer(indclassDatum); /* * Now build the list of PK attributes from the indkey definition (we * assume a primary key cannot have expressional elements) */ *attnamelist = NIL; for (i = 0; i < indexStruct->indnatts; i++) { int pkattno = indexStruct->indkey.values[i]; attnums[i] = pkattno; atttypids[i] = attnumTypeId(pkrel, pkattno); opclasses[i] = indclass->values[i]; *attnamelist = lappend(*attnamelist, makeString(pstrdup(NameStr(*attnumAttName(pkrel, pkattno))))); } ReleaseSysCache(indexTuple); return i; } /* * transformFkeyCheckAttrs - * * Make sure that the attributes of a referenced table belong to a unique * (or primary key) constraint. Return the OID of the index supporting * the constraint, as well as the opclasses associated with the index * columns. */ static Oid transformFkeyCheckAttrs(Relation pkrel, int numattrs, int16 *attnums, Oid *opclasses) /* output parameter */ { Oid indexoid = InvalidOid; bool found = false; bool found_deferrable = false; List *indexoidlist; ListCell *indexoidscan; int i, j; /* * Reject duplicate appearances of columns in the referenced-columns list. * Such a case is forbidden by the SQL standard, and even if we thought it * useful to allow it, there would be ambiguity about how to match the * list to unique indexes (in particular, it'd be unclear which index * opclass goes with which FK column). */ for (i = 0; i < numattrs; i++) { for (j = i + 1; j < numattrs; j++) { if (attnums[i] == attnums[j]) ereport(ERROR, (errcode(ERRCODE_INVALID_FOREIGN_KEY), errmsg("foreign key referenced-columns list must not contain duplicates"))); } } /* * Get the list of index OIDs for the table from the relcache, and look up * each one in the pg_index syscache, and match unique indexes to the list * of attnums we are given. */ indexoidlist = RelationGetIndexList(pkrel); foreach(indexoidscan, indexoidlist) { HeapTuple indexTuple; Form_pg_index indexStruct; indexoid = lfirst_oid(indexoidscan); indexTuple = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(indexoid)); if (!HeapTupleIsValid(indexTuple)) elog(ERROR, "cache lookup failed for index %u", indexoid); indexStruct = (Form_pg_index) GETSTRUCT(indexTuple); /* * Must have the right number of columns; must be unique and not a * partial index; forget it if there are any expressions, too. Invalid * indexes are out as well. */ if (indexStruct->indnatts == numattrs && indexStruct->indisunique && IndexIsValid(indexStruct) && heap_attisnull(indexTuple, Anum_pg_index_indpred) && heap_attisnull(indexTuple, Anum_pg_index_indexprs)) { Datum indclassDatum; bool isnull; oidvector *indclass; /* Must get indclass the hard way */ indclassDatum = SysCacheGetAttr(INDEXRELID, indexTuple, Anum_pg_index_indclass, &isnull); Assert(!isnull); indclass = (oidvector *) DatumGetPointer(indclassDatum); /* * The given attnum list may match the index columns in any order. * Check for a match, and extract the appropriate opclasses while * we're at it. * * We know that attnums[] is duplicate-free per the test at the * start of this function, and we checked above that the number of * index columns agrees, so if we find a match for each attnums[] * entry then we must have a one-to-one match in some order. */ for (i = 0; i < numattrs; i++) { found = false; for (j = 0; j < numattrs; j++) { if (attnums[i] == indexStruct->indkey.values[j]) { opclasses[i] = indclass->values[j]; found = true; break; } } if (!found) break; } /* * Refuse to use a deferrable unique/primary key. This is per SQL * spec, and there would be a lot of interesting semantic problems * if we tried to allow it. */ if (found && !indexStruct->indimmediate) { /* * Remember that we found an otherwise matching index, so that * we can generate a more appropriate error message. */ found_deferrable = true; found = false; } } ReleaseSysCache(indexTuple); if (found) break; } if (!found) { if (found_deferrable) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("cannot use a deferrable unique constraint for referenced table \"%s\"", RelationGetRelationName(pkrel)))); else ereport(ERROR, (errcode(ERRCODE_INVALID_FOREIGN_KEY), errmsg("there is no unique constraint matching given keys for referenced table \"%s\"", RelationGetRelationName(pkrel)))); } list_free(indexoidlist); return indexoid; } /* * findFkeyCast - * * Wrapper around find_coercion_pathway() for ATAddForeignKeyConstraint(). * Caller has equal regard for binary coercibility and for an exact match. */ static CoercionPathType findFkeyCast(Oid targetTypeId, Oid sourceTypeId, Oid *funcid) { CoercionPathType ret; if (targetTypeId == sourceTypeId) { ret = COERCION_PATH_RELABELTYPE; *funcid = InvalidOid; } else { ret = find_coercion_pathway(targetTypeId, sourceTypeId, COERCION_IMPLICIT, funcid); if (ret == COERCION_PATH_NONE) /* A previously-relied-upon cast is now gone. */ elog(ERROR, "could not find cast from %u to %u", sourceTypeId, targetTypeId); } return ret; } /* * Permissions checks on the referenced table for ADD FOREIGN KEY * * Note: we have already checked that the user owns the referencing table, * else we'd have failed much earlier; no additional checks are needed for it. */ static void checkFkeyPermissions(Relation rel, int16 *attnums, int natts) { Oid roleid = GetUserId(); AclResult aclresult; int i; /* Okay if we have relation-level REFERENCES permission */ aclresult = pg_class_aclcheck(RelationGetRelid(rel), roleid, ACL_REFERENCES); if (aclresult == ACLCHECK_OK) return; /* Else we must have REFERENCES on each column */ for (i = 0; i < natts; i++) { aclresult = pg_attribute_aclcheck(RelationGetRelid(rel), attnums[i], roleid, ACL_REFERENCES); if (aclresult != ACLCHECK_OK) aclcheck_error(aclresult, ACL_KIND_CLASS, RelationGetRelationName(rel)); } } /* * Scan the existing rows in a table to verify they meet a proposed * CHECK constraint. * * The caller must have opened and locked the relation appropriately. */ static void validateCheckConstraint(Relation rel, HeapTuple constrtup) { EState *estate; Datum val; char *conbin; Expr *origexpr; ExprState *exprstate; TupleDesc tupdesc; HeapScanDesc scan; HeapTuple tuple; ExprContext *econtext; MemoryContext oldcxt; TupleTableSlot *slot; Form_pg_constraint constrForm; bool isnull; Snapshot snapshot; /* VALIDATE CONSTRAINT is a no-op for foreign tables */ if (rel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) return; constrForm = (Form_pg_constraint) GETSTRUCT(constrtup); estate = CreateExecutorState(); /* * XXX this tuple doesn't really come from a syscache, but this doesn't * matter to SysCacheGetAttr, because it only wants to be able to fetch * the tupdesc */ val = SysCacheGetAttr(CONSTROID, constrtup, Anum_pg_constraint_conbin, &isnull); if (isnull) elog(ERROR, "null conbin for constraint %u", HeapTupleGetOid(constrtup)); conbin = TextDatumGetCString(val); origexpr = (Expr *) stringToNode(conbin); exprstate = ExecPrepareExpr(origexpr, estate); econtext = GetPerTupleExprContext(estate); tupdesc = RelationGetDescr(rel); slot = MakeSingleTupleTableSlot(tupdesc); econtext->ecxt_scantuple = slot; snapshot = RegisterSnapshot(GetLatestSnapshot()); scan = heap_beginscan(rel, snapshot, 0, NULL); /* * Switch to per-tuple memory context and reset it for each tuple * produced, so we don't leak memory. */ oldcxt = MemoryContextSwitchTo(GetPerTupleMemoryContext(estate)); while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL) { ExecStoreTuple(tuple, slot, InvalidBuffer, false); if (!ExecCheck(exprstate, econtext)) ereport(ERROR, (errcode(ERRCODE_CHECK_VIOLATION), errmsg("check constraint \"%s\" is violated by some row", NameStr(constrForm->conname)), errtableconstraint(rel, NameStr(constrForm->conname)))); ResetExprContext(econtext); } MemoryContextSwitchTo(oldcxt); heap_endscan(scan); UnregisterSnapshot(snapshot); ExecDropSingleTupleTableSlot(slot); FreeExecutorState(estate); } /* * Scan the existing rows in a table to verify they meet a proposed FK * constraint. * * Caller must have opened and locked both relations appropriately. */ static void validateForeignKeyConstraint(char *conname, Relation rel, Relation pkrel, Oid pkindOid, Oid constraintOid) { HeapScanDesc scan; HeapTuple tuple; Trigger trig; Snapshot snapshot; ereport(DEBUG1, (errmsg("validating foreign key constraint \"%s\"", conname))); /* * Build a trigger call structure; we'll need it either way. */ MemSet(&trig, 0, sizeof(trig)); trig.tgoid = InvalidOid; trig.tgname = conname; trig.tgenabled = TRIGGER_FIRES_ON_ORIGIN; trig.tgisinternal = TRUE; trig.tgconstrrelid = RelationGetRelid(pkrel); trig.tgconstrindid = pkindOid; trig.tgconstraint = constraintOid; trig.tgdeferrable = FALSE; trig.tginitdeferred = FALSE; /* we needn't fill in remaining fields */ /* * See if we can do it with a single LEFT JOIN query. A FALSE result * indicates we must proceed with the fire-the-trigger method. */ if (RI_Initial_Check(&trig, rel, pkrel)) return; /* * Scan through each tuple, calling RI_FKey_check_ins (insert trigger) as * if that tuple had just been inserted. If any of those fail, it should * ereport(ERROR) and that's that. */ snapshot = RegisterSnapshot(GetLatestSnapshot()); scan = heap_beginscan(rel, snapshot, 0, NULL); while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL) { FunctionCallInfoData fcinfo; TriggerData trigdata; /* * Make a call to the trigger function * * No parameters are passed, but we do set a context */ MemSet(&fcinfo, 0, sizeof(fcinfo)); /* * We assume RI_FKey_check_ins won't look at flinfo... */ trigdata.type = T_TriggerData; trigdata.tg_event = TRIGGER_EVENT_INSERT | TRIGGER_EVENT_ROW; trigdata.tg_relation = rel; trigdata.tg_trigtuple = tuple; trigdata.tg_newtuple = NULL; trigdata.tg_trigger = &trig; trigdata.tg_trigtuplebuf = scan->rs_cbuf; trigdata.tg_newtuplebuf = InvalidBuffer; fcinfo.context = (Node *) &trigdata; RI_FKey_check_ins(&fcinfo); } heap_endscan(scan); UnregisterSnapshot(snapshot); } static void CreateFKCheckTrigger(Oid myRelOid, Oid refRelOid, Constraint *fkconstraint, Oid constraintOid, Oid indexOid, bool on_insert) { CreateTrigStmt *fk_trigger; /* * Note: for a self-referential FK (referencing and referenced tables are * the same), it is important that the ON UPDATE action fires before the * CHECK action, since both triggers will fire on the same row during an * UPDATE event; otherwise the CHECK trigger will be checking a non-final * state of the row. Triggers fire in name order, so we ensure this by * using names like "RI_ConstraintTrigger_a_NNNN" for the action triggers * and "RI_ConstraintTrigger_c_NNNN" for the check triggers. */ fk_trigger = makeNode(CreateTrigStmt); fk_trigger->trigname = "RI_ConstraintTrigger_c"; fk_trigger->relation = NULL; fk_trigger->row = true; fk_trigger->timing = TRIGGER_TYPE_AFTER; /* Either ON INSERT or ON UPDATE */ if (on_insert) { fk_trigger->funcname = SystemFuncName("RI_FKey_check_ins"); fk_trigger->events = TRIGGER_TYPE_INSERT; } else { fk_trigger->funcname = SystemFuncName("RI_FKey_check_upd"); fk_trigger->events = TRIGGER_TYPE_UPDATE; } fk_trigger->columns = NIL; fk_trigger->transitionRels = NIL; fk_trigger->whenClause = NULL; fk_trigger->isconstraint = true; fk_trigger->deferrable = fkconstraint->deferrable; fk_trigger->initdeferred = fkconstraint->initdeferred; fk_trigger->constrrel = NULL; fk_trigger->args = NIL; (void) CreateTrigger(fk_trigger, NULL, myRelOid, refRelOid, constraintOid, indexOid, true); /* Make changes-so-far visible */ CommandCounterIncrement(); } /* * Create the triggers that implement an FK constraint. * * NB: if you change any trigger properties here, see also * ATExecAlterConstraint. */ static void createForeignKeyTriggers(Relation rel, Oid refRelOid, Constraint *fkconstraint, Oid constraintOid, Oid indexOid) { Oid myRelOid; CreateTrigStmt *fk_trigger; myRelOid = RelationGetRelid(rel); /* Make changes-so-far visible */ CommandCounterIncrement(); /* * Build and execute a CREATE CONSTRAINT TRIGGER statement for the ON * DELETE action on the referenced table. */ fk_trigger = makeNode(CreateTrigStmt); fk_trigger->trigname = "RI_ConstraintTrigger_a"; fk_trigger->relation = NULL; fk_trigger->row = true; fk_trigger->timing = TRIGGER_TYPE_AFTER; fk_trigger->events = TRIGGER_TYPE_DELETE; fk_trigger->columns = NIL; fk_trigger->transitionRels = NIL; fk_trigger->whenClause = NULL; fk_trigger->isconstraint = true; fk_trigger->constrrel = NULL; switch (fkconstraint->fk_del_action) { case FKCONSTR_ACTION_NOACTION: fk_trigger->deferrable = fkconstraint->deferrable; fk_trigger->initdeferred = fkconstraint->initdeferred; fk_trigger->funcname = SystemFuncName("RI_FKey_noaction_del"); break; case FKCONSTR_ACTION_RESTRICT: fk_trigger->deferrable = false; fk_trigger->initdeferred = false; fk_trigger->funcname = SystemFuncName("RI_FKey_restrict_del"); break; case FKCONSTR_ACTION_CASCADE: fk_trigger->deferrable = false; fk_trigger->initdeferred = false; fk_trigger->funcname = SystemFuncName("RI_FKey_cascade_del"); break; case FKCONSTR_ACTION_SETNULL: fk_trigger->deferrable = false; fk_trigger->initdeferred = false; fk_trigger->funcname = SystemFuncName("RI_FKey_setnull_del"); break; case FKCONSTR_ACTION_SETDEFAULT: fk_trigger->deferrable = false; fk_trigger->initdeferred = false; fk_trigger->funcname = SystemFuncName("RI_FKey_setdefault_del"); break; default: elog(ERROR, "unrecognized FK action type: %d", (int) fkconstraint->fk_del_action); break; } fk_trigger->args = NIL; (void) CreateTrigger(fk_trigger, NULL, refRelOid, myRelOid, constraintOid, indexOid, true); /* Make changes-so-far visible */ CommandCounterIncrement(); /* * Build and execute a CREATE CONSTRAINT TRIGGER statement for the ON * UPDATE action on the referenced table. */ fk_trigger = makeNode(CreateTrigStmt); fk_trigger->trigname = "RI_ConstraintTrigger_a"; fk_trigger->relation = NULL; fk_trigger->row = true; fk_trigger->timing = TRIGGER_TYPE_AFTER; fk_trigger->events = TRIGGER_TYPE_UPDATE; fk_trigger->columns = NIL; fk_trigger->transitionRels = NIL; fk_trigger->whenClause = NULL; fk_trigger->isconstraint = true; fk_trigger->constrrel = NULL; switch (fkconstraint->fk_upd_action) { case FKCONSTR_ACTION_NOACTION: fk_trigger->deferrable = fkconstraint->deferrable; fk_trigger->initdeferred = fkconstraint->initdeferred; fk_trigger->funcname = SystemFuncName("RI_FKey_noaction_upd"); break; case FKCONSTR_ACTION_RESTRICT: fk_trigger->deferrable = false; fk_trigger->initdeferred = false; fk_trigger->funcname = SystemFuncName("RI_FKey_restrict_upd"); break; case FKCONSTR_ACTION_CASCADE: fk_trigger->deferrable = false; fk_trigger->initdeferred = false; fk_trigger->funcname = SystemFuncName("RI_FKey_cascade_upd"); break; case FKCONSTR_ACTION_SETNULL: fk_trigger->deferrable = false; fk_trigger->initdeferred = false; fk_trigger->funcname = SystemFuncName("RI_FKey_setnull_upd"); break; case FKCONSTR_ACTION_SETDEFAULT: fk_trigger->deferrable = false; fk_trigger->initdeferred = false; fk_trigger->funcname = SystemFuncName("RI_FKey_setdefault_upd"); break; default: elog(ERROR, "unrecognized FK action type: %d", (int) fkconstraint->fk_upd_action); break; } fk_trigger->args = NIL; (void) CreateTrigger(fk_trigger, NULL, refRelOid, myRelOid, constraintOid, indexOid, true); /* Make changes-so-far visible */ CommandCounterIncrement(); /* * Build and execute CREATE CONSTRAINT TRIGGER statements for the CHECK * action for both INSERTs and UPDATEs on the referencing table. */ CreateFKCheckTrigger(myRelOid, refRelOid, fkconstraint, constraintOid, indexOid, true); CreateFKCheckTrigger(myRelOid, refRelOid, fkconstraint, constraintOid, indexOid, false); } /* * ALTER TABLE DROP CONSTRAINT * * Like DROP COLUMN, we can't use the normal ALTER TABLE recursion mechanism. */ static void ATExecDropConstraint(Relation rel, const char *constrName, DropBehavior behavior, bool recurse, bool recursing, bool missing_ok, LOCKMODE lockmode) { List *children; ListCell *child; Relation conrel; Form_pg_constraint con; SysScanDesc scan; ScanKeyData key; HeapTuple tuple; bool found = false; bool is_no_inherit_constraint = false; /* At top level, permission check was done in ATPrepCmd, else do it */ if (recursing) ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE); conrel = heap_open(ConstraintRelationId, RowExclusiveLock); /* * Find and drop the target constraint */ ScanKeyInit(&key, Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel))); scan = systable_beginscan(conrel, ConstraintRelidIndexId, true, NULL, 1, &key); while (HeapTupleIsValid(tuple = systable_getnext(scan))) { ObjectAddress conobj; con = (Form_pg_constraint) GETSTRUCT(tuple); if (strcmp(NameStr(con->conname), constrName) != 0) continue; /* Don't drop inherited constraints */ if (con->coninhcount > 0 && !recursing) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot drop inherited constraint \"%s\" of relation \"%s\"", constrName, RelationGetRelationName(rel)))); is_no_inherit_constraint = con->connoinherit; /* * If it's a foreign-key constraint, we'd better lock the referenced * table and check that that's not in use, just as we've already done * for the constrained table (else we might, eg, be dropping a trigger * that has unfired events). But we can/must skip that in the * self-referential case. */ if (con->contype == CONSTRAINT_FOREIGN && con->confrelid != RelationGetRelid(rel)) { Relation frel; /* Must match lock taken by RemoveTriggerById: */ frel = heap_open(con->confrelid, AccessExclusiveLock); CheckTableNotInUse(frel, "ALTER TABLE"); heap_close(frel, NoLock); } /* * Perform the actual constraint deletion */ conobj.classId = ConstraintRelationId; conobj.objectId = HeapTupleGetOid(tuple); conobj.objectSubId = 0; performDeletion(&conobj, behavior, 0); found = true; /* constraint found and dropped -- no need to keep looping */ break; } systable_endscan(scan); if (!found) { if (!missing_ok) { ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("constraint \"%s\" of relation \"%s\" does not exist", constrName, RelationGetRelationName(rel)))); } else { ereport(NOTICE, (errmsg("constraint \"%s\" of relation \"%s\" does not exist, skipping", constrName, RelationGetRelationName(rel)))); heap_close(conrel, RowExclusiveLock); return; } } /* * In case of a partitioned table, the constraint must be dropped from the * partitions too. There is no such thing as NO INHERIT constraints in * case of partitioned tables. */ if (!recurse && rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("constraint must be dropped from child tables too"))); /* * Propagate to children as appropriate. Unlike most other ALTER * routines, we have to do this one level of recursion at a time; we can't * use find_all_inheritors to do it in one pass. */ if (!is_no_inherit_constraint) children = find_inheritance_children(RelationGetRelid(rel), lockmode); else children = NIL; foreach(child, children) { Oid childrelid = lfirst_oid(child); Relation childrel; HeapTuple copy_tuple; /* find_inheritance_children already got lock */ childrel = heap_open(childrelid, NoLock); CheckTableNotInUse(childrel, "ALTER TABLE"); ScanKeyInit(&key, Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(childrelid)); scan = systable_beginscan(conrel, ConstraintRelidIndexId, true, NULL, 1, &key); /* scan for matching tuple - there should only be one */ while (HeapTupleIsValid(tuple = systable_getnext(scan))) { con = (Form_pg_constraint) GETSTRUCT(tuple); /* Right now only CHECK constraints can be inherited */ if (con->contype != CONSTRAINT_CHECK) continue; if (strcmp(NameStr(con->conname), constrName) == 0) break; } if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("constraint \"%s\" of relation \"%s\" does not exist", constrName, RelationGetRelationName(childrel)))); copy_tuple = heap_copytuple(tuple); systable_endscan(scan); con = (Form_pg_constraint) GETSTRUCT(copy_tuple); if (con->coninhcount <= 0) /* shouldn't happen */ elog(ERROR, "relation %u has non-inherited constraint \"%s\"", childrelid, constrName); if (recurse) { /* * If the child constraint has other definition sources, just * decrement its inheritance count; if not, recurse to delete it. */ if (con->coninhcount == 1 && !con->conislocal) { /* Time to delete this child constraint, too */ ATExecDropConstraint(childrel, constrName, behavior, true, true, false, lockmode); } else { /* Child constraint must survive my deletion */ con->coninhcount--; CatalogTupleUpdate(conrel, ©_tuple->t_self, copy_tuple); /* Make update visible */ CommandCounterIncrement(); } } else { /* * If we were told to drop ONLY in this table (no recursion), we * need to mark the inheritors' constraints as locally defined * rather than inherited. */ con->coninhcount--; con->conislocal = true; CatalogTupleUpdate(conrel, ©_tuple->t_self, copy_tuple); /* Make update visible */ CommandCounterIncrement(); } heap_freetuple(copy_tuple); heap_close(childrel, NoLock); } heap_close(conrel, RowExclusiveLock); } /* * ALTER COLUMN TYPE */ static void ATPrepAlterColumnType(List **wqueue, AlteredTableInfo *tab, Relation rel, bool recurse, bool recursing, AlterTableCmd *cmd, LOCKMODE lockmode) { char *colName = cmd->name; ColumnDef *def = (ColumnDef *) cmd->def; TypeName *typeName = def->typeName; Node *transform = def->cooked_default; HeapTuple tuple; Form_pg_attribute attTup; AttrNumber attnum; Oid targettype; int32 targettypmod; Oid targetcollid; NewColumnValue *newval; ParseState *pstate = make_parsestate(NULL); AclResult aclresult; bool is_expr; if (rel->rd_rel->reloftype && !recursing) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot alter column type of typed table"))); /* lookup the attribute so we can check inheritance status */ tuple = SearchSysCacheAttName(RelationGetRelid(rel), colName); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(rel)))); attTup = (Form_pg_attribute) GETSTRUCT(tuple); attnum = attTup->attnum; /* Can't alter a system attribute */ if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter system column \"%s\"", colName))); /* Don't alter inherited columns */ if (attTup->attinhcount > 0 && !recursing) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot alter inherited column \"%s\"", colName))); /* Don't alter columns used in the partition key */ if (is_partition_attr(rel, attnum, &is_expr)) { if (!is_expr) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot alter type of column named in partition key"))); else ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot alter type of column referenced in partition key expression"))); } /* Look up the target type */ typenameTypeIdAndMod(NULL, typeName, &targettype, &targettypmod); aclresult = pg_type_aclcheck(targettype, GetUserId(), ACL_USAGE); if (aclresult != ACLCHECK_OK) aclcheck_error_type(aclresult, targettype); /* And the collation */ targetcollid = GetColumnDefCollation(NULL, def, targettype); /* make sure datatype is legal for a column */ CheckAttributeType(colName, targettype, targetcollid, list_make1_oid(rel->rd_rel->reltype), false); if (tab->relkind == RELKIND_RELATION || tab->relkind == RELKIND_PARTITIONED_TABLE) { /* * Set up an expression to transform the old data value to the new * type. If a USING option was given, use the expression as * transformed by transformAlterTableStmt, else just take the old * value and try to coerce it. We do this first so that type * incompatibility can be detected before we waste effort, and because * we need the expression to be parsed against the original table row * type. */ if (!transform) { transform = (Node *) makeVar(1, attnum, attTup->atttypid, attTup->atttypmod, attTup->attcollation, 0); } transform = coerce_to_target_type(pstate, transform, exprType(transform), targettype, targettypmod, COERCION_ASSIGNMENT, COERCE_IMPLICIT_CAST, -1); if (transform == NULL) { /* error text depends on whether USING was specified or not */ if (def->cooked_default != NULL) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("result of USING clause for column \"%s\"" " cannot be cast automatically to type %s", colName, format_type_be(targettype)), errhint("You might need to add an explicit cast."))); else ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("column \"%s\" cannot be cast automatically to type %s", colName, format_type_be(targettype)), /* translator: USING is SQL, don't translate it */ errhint("You might need to specify \"USING %s::%s\".", quote_identifier(colName), format_type_with_typemod(targettype, targettypmod)))); } /* Fix collations after all else */ assign_expr_collations(pstate, transform); /* Plan the expr now so we can accurately assess the need to rewrite. */ transform = (Node *) expression_planner((Expr *) transform); /* * Add a work queue item to make ATRewriteTable update the column * contents. */ newval = (NewColumnValue *) palloc0(sizeof(NewColumnValue)); newval->attnum = attnum; newval->expr = (Expr *) transform; tab->newvals = lappend(tab->newvals, newval); if (ATColumnChangeRequiresRewrite(transform, attnum)) tab->rewrite |= AT_REWRITE_COLUMN_REWRITE; } else if (transform) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is not a table", RelationGetRelationName(rel)))); if (tab->relkind == RELKIND_COMPOSITE_TYPE || tab->relkind == RELKIND_FOREIGN_TABLE) { /* * For composite types, do this check now. Tables will check it later * when the table is being rewritten. */ find_composite_type_dependencies(rel->rd_rel->reltype, rel, NULL); } ReleaseSysCache(tuple); /* * Recurse manually by queueing a new command for each child, if * necessary. We cannot apply ATSimpleRecursion here because we need to * remap attribute numbers in the USING expression, if any. * * If we are told not to recurse, there had better not be any child * tables; else the alter would put them out of step. */ if (recurse) { Oid relid = RelationGetRelid(rel); ListCell *child; List *children; children = find_all_inheritors(relid, lockmode, NULL); /* * find_all_inheritors does the recursive search of the inheritance * hierarchy, so all we have to do is process all of the relids in the * list that it returns. */ foreach(child, children) { Oid childrelid = lfirst_oid(child); Relation childrel; if (childrelid == relid) continue; /* find_all_inheritors already got lock */ childrel = relation_open(childrelid, NoLock); CheckTableNotInUse(childrel, "ALTER TABLE"); /* * Remap the attribute numbers. If no USING expression was * specified, there is no need for this step. */ if (def->cooked_default) { AttrNumber *attmap; bool found_whole_row; /* create a copy to scribble on */ cmd = copyObject(cmd); attmap = convert_tuples_by_name_map(RelationGetDescr(childrel), RelationGetDescr(rel), gettext_noop("could not convert row type")); ((ColumnDef *) cmd->def)->cooked_default = map_variable_attnos(def->cooked_default, 1, 0, attmap, RelationGetDescr(rel)->natts, &found_whole_row); if (found_whole_row) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot convert whole-row table reference"), errdetail("USING expression contains a whole-row table reference."))); pfree(attmap); } ATPrepCmd(wqueue, childrel, cmd, false, true, lockmode); relation_close(childrel, NoLock); } } else if (!recursing && find_inheritance_children(RelationGetRelid(rel), NoLock) != NIL) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("type of inherited column \"%s\" must be changed in child tables too", colName))); if (tab->relkind == RELKIND_COMPOSITE_TYPE) ATTypedTableRecursion(wqueue, rel, cmd, lockmode); } /* * When the data type of a column is changed, a rewrite might not be required * if the new type is sufficiently identical to the old one, and the USING * clause isn't trying to insert some other value. It's safe to skip the * rewrite if the old type is binary coercible to the new type, or if the * new type is an unconstrained domain over the old type. In the case of a * constrained domain, we could get by with scanning the table and checking * the constraint rather than actually rewriting it, but we don't currently * try to do that. */ static bool ATColumnChangeRequiresRewrite(Node *expr, AttrNumber varattno) { Assert(expr != NULL); for (;;) { /* only one varno, so no need to check that */ if (IsA(expr, Var) &&((Var *) expr)->varattno == varattno) return false; else if (IsA(expr, RelabelType)) expr = (Node *) ((RelabelType *) expr)->arg; else if (IsA(expr, CoerceToDomain)) { CoerceToDomain *d = (CoerceToDomain *) expr; if (DomainHasConstraints(d->resulttype)) return true; expr = (Node *) d->arg; } else return true; } } /* * ALTER COLUMN .. SET DATA TYPE * * Return the address of the modified column. */ static ObjectAddress ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel, AlterTableCmd *cmd, LOCKMODE lockmode) { char *colName = cmd->name; ColumnDef *def = (ColumnDef *) cmd->def; TypeName *typeName = def->typeName; HeapTuple heapTup; Form_pg_attribute attTup; AttrNumber attnum; HeapTuple typeTuple; Form_pg_type tform; Oid targettype; int32 targettypmod; Oid targetcollid; Node *defaultexpr; Relation attrelation; Relation depRel; ScanKeyData key[3]; SysScanDesc scan; HeapTuple depTup; ObjectAddress address; attrelation = heap_open(AttributeRelationId, RowExclusiveLock); /* Look up the target column */ heapTup = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName); if (!HeapTupleIsValid(heapTup)) /* shouldn't happen */ ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(rel)))); attTup = (Form_pg_attribute) GETSTRUCT(heapTup); attnum = attTup->attnum; /* Check for multiple ALTER TYPE on same column --- can't cope */ if (attTup->atttypid != tab->oldDesc->attrs[attnum - 1]->atttypid || attTup->atttypmod != tab->oldDesc->attrs[attnum - 1]->atttypmod) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter type of column \"%s\" twice", colName))); /* Look up the target type (should not fail, since prep found it) */ typeTuple = typenameType(NULL, typeName, &targettypmod); tform = (Form_pg_type) GETSTRUCT(typeTuple); targettype = HeapTupleGetOid(typeTuple); /* And the collation */ targetcollid = GetColumnDefCollation(NULL, def, targettype); /* * If there is a default expression for the column, get it and ensure we * can coerce it to the new datatype. (We must do this before changing * the column type, because build_column_default itself will try to * coerce, and will not issue the error message we want if it fails.) * * We remove any implicit coercion steps at the top level of the old * default expression; this has been agreed to satisfy the principle of * least surprise. (The conversion to the new column type should act like * it started from what the user sees as the stored expression, and the * implicit coercions aren't going to be shown.) */ if (attTup->atthasdef) { defaultexpr = build_column_default(rel, attnum); Assert(defaultexpr); defaultexpr = strip_implicit_coercions(defaultexpr); defaultexpr = coerce_to_target_type(NULL, /* no UNKNOWN params */ defaultexpr, exprType(defaultexpr), targettype, targettypmod, COERCION_ASSIGNMENT, COERCE_IMPLICIT_CAST, -1); if (defaultexpr == NULL) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("default for column \"%s\" cannot be cast automatically to type %s", colName, format_type_be(targettype)))); } else defaultexpr = NULL; /* * Find everything that depends on the column (constraints, indexes, etc), * and record enough information to let us recreate the objects. * * The actual recreation does not happen here, but only after we have * performed all the individual ALTER TYPE operations. We have to save * the info before executing ALTER TYPE, though, else the deparser will * get confused. * * There could be multiple entries for the same object, so we must check * to ensure we process each one only once. Note: we assume that an index * that implements a constraint will not show a direct dependency on the * column. */ depRel = heap_open(DependRelationId, RowExclusiveLock); ScanKeyInit(&key[0], Anum_pg_depend_refclassid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationRelationId)); ScanKeyInit(&key[1], Anum_pg_depend_refobjid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel))); ScanKeyInit(&key[2], Anum_pg_depend_refobjsubid, BTEqualStrategyNumber, F_INT4EQ, Int32GetDatum((int32) attnum)); scan = systable_beginscan(depRel, DependReferenceIndexId, true, NULL, 3, key); while (HeapTupleIsValid(depTup = systable_getnext(scan))) { Form_pg_depend foundDep = (Form_pg_depend) GETSTRUCT(depTup); ObjectAddress foundObject; /* We don't expect any PIN dependencies on columns */ if (foundDep->deptype == DEPENDENCY_PIN) elog(ERROR, "cannot alter type of a pinned column"); foundObject.classId = foundDep->classid; foundObject.objectId = foundDep->objid; foundObject.objectSubId = foundDep->objsubid; switch (getObjectClass(&foundObject)) { case OCLASS_CLASS: { char relKind = get_rel_relkind(foundObject.objectId); if (relKind == RELKIND_INDEX) { Assert(foundObject.objectSubId == 0); if (!list_member_oid(tab->changedIndexOids, foundObject.objectId)) { tab->changedIndexOids = lappend_oid(tab->changedIndexOids, foundObject.objectId); tab->changedIndexDefs = lappend(tab->changedIndexDefs, pg_get_indexdef_string(foundObject.objectId)); } } else if (relKind == RELKIND_SEQUENCE) { /* * This must be a SERIAL column's sequence. We need * not do anything to it. */ Assert(foundObject.objectSubId == 0); } else { /* Not expecting any other direct dependencies... */ elog(ERROR, "unexpected object depending on column: %s", getObjectDescription(&foundObject)); } break; } case OCLASS_CONSTRAINT: Assert(foundObject.objectSubId == 0); if (!list_member_oid(tab->changedConstraintOids, foundObject.objectId)) { char *defstring = pg_get_constraintdef_command(foundObject.objectId); /* * Put NORMAL dependencies at the front of the list and * AUTO dependencies at the back. This makes sure that * foreign-key constraints depending on this column will * be dropped before unique or primary-key constraints of * the column; which we must have because the FK * constraints depend on the indexes belonging to the * unique constraints. */ if (foundDep->deptype == DEPENDENCY_NORMAL) { tab->changedConstraintOids = lcons_oid(foundObject.objectId, tab->changedConstraintOids); tab->changedConstraintDefs = lcons(defstring, tab->changedConstraintDefs); } else { tab->changedConstraintOids = lappend_oid(tab->changedConstraintOids, foundObject.objectId); tab->changedConstraintDefs = lappend(tab->changedConstraintDefs, defstring); } } break; case OCLASS_REWRITE: /* XXX someday see if we can cope with revising views */ ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter type of a column used by a view or rule"), errdetail("%s depends on column \"%s\"", getObjectDescription(&foundObject), colName))); break; case OCLASS_TRIGGER: /* * A trigger can depend on a column because the column is * specified as an update target, or because the column is * used in the trigger's WHEN condition. The first case would * not require any extra work, but the second case would * require updating the WHEN expression, which will take a * significant amount of new code. Since we can't easily tell * which case applies, we punt for both. FIXME someday. */ ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter type of a column used in a trigger definition"), errdetail("%s depends on column \"%s\"", getObjectDescription(&foundObject), colName))); break; case OCLASS_POLICY: /* * A policy can depend on a column because the column is * specified in the policy's USING or WITH CHECK qual * expressions. It might be possible to rewrite and recheck * the policy expression, but punt for now. It's certainly * easy enough to remove and recreate the policy; still, FIXME * someday. */ ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter type of a column used in a policy definition"), errdetail("%s depends on column \"%s\"", getObjectDescription(&foundObject), colName))); break; case OCLASS_DEFAULT: /* * Ignore the column's default expression, since we will fix * it below. */ Assert(defaultexpr); break; case OCLASS_PROC: case OCLASS_TYPE: case OCLASS_CAST: case OCLASS_COLLATION: case OCLASS_CONVERSION: case OCLASS_LANGUAGE: case OCLASS_LARGEOBJECT: case OCLASS_OPERATOR: case OCLASS_OPCLASS: case OCLASS_OPFAMILY: case OCLASS_AMOP: case OCLASS_AMPROC: case OCLASS_SCHEMA: case OCLASS_TSPARSER: case OCLASS_TSDICT: case OCLASS_TSTEMPLATE: case OCLASS_TSCONFIG: case OCLASS_ROLE: case OCLASS_DATABASE: case OCLASS_TBLSPACE: case OCLASS_FDW: case OCLASS_FOREIGN_SERVER: case OCLASS_USER_MAPPING: case OCLASS_DEFACL: case OCLASS_EXTENSION: /* * We don't expect any of these sorts of objects to depend on * a column. */ elog(ERROR, "unexpected object depending on column: %s", getObjectDescription(&foundObject)); break; default: elog(ERROR, "unrecognized object class: %u", foundObject.classId); } } systable_endscan(scan); /* * Now scan for dependencies of this column on other things. The only * thing we should find is the dependency on the column datatype, which we * want to remove, and possibly a collation dependency. */ ScanKeyInit(&key[0], Anum_pg_depend_classid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationRelationId)); ScanKeyInit(&key[1], Anum_pg_depend_objid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel))); ScanKeyInit(&key[2], Anum_pg_depend_objsubid, BTEqualStrategyNumber, F_INT4EQ, Int32GetDatum((int32) attnum)); scan = systable_beginscan(depRel, DependDependerIndexId, true, NULL, 3, key); while (HeapTupleIsValid(depTup = systable_getnext(scan))) { Form_pg_depend foundDep = (Form_pg_depend) GETSTRUCT(depTup); if (foundDep->deptype != DEPENDENCY_NORMAL) elog(ERROR, "found unexpected dependency type '%c'", foundDep->deptype); if (!(foundDep->refclassid == TypeRelationId && foundDep->refobjid == attTup->atttypid) && !(foundDep->refclassid == CollationRelationId && foundDep->refobjid == attTup->attcollation)) elog(ERROR, "found unexpected dependency for column"); CatalogTupleDelete(depRel, &depTup->t_self); } systable_endscan(scan); heap_close(depRel, RowExclusiveLock); /* * Here we go --- change the recorded column type and collation. (Note * heapTup is a copy of the syscache entry, so okay to scribble on.) */ attTup->atttypid = targettype; attTup->atttypmod = targettypmod; attTup->attcollation = targetcollid; attTup->attndims = list_length(typeName->arrayBounds); attTup->attlen = tform->typlen; attTup->attbyval = tform->typbyval; attTup->attalign = tform->typalign; attTup->attstorage = tform->typstorage; ReleaseSysCache(typeTuple); CatalogTupleUpdate(attrelation, &heapTup->t_self, heapTup); heap_close(attrelation, RowExclusiveLock); /* Install dependencies on new datatype and collation */ add_column_datatype_dependency(RelationGetRelid(rel), attnum, targettype); add_column_collation_dependency(RelationGetRelid(rel), attnum, targetcollid); /* * Drop any pg_statistic entry for the column, since it's now wrong type */ RemoveStatistics(RelationGetRelid(rel), attnum); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), attnum); /* * Update the default, if present, by brute force --- remove and re-add * the default. Probably unsafe to take shortcuts, since the new version * may well have additional dependencies. (It's okay to do this now, * rather than after other ALTER TYPE commands, since the default won't * depend on other column types.) */ if (defaultexpr) { /* Must make new row visible since it will be updated again */ CommandCounterIncrement(); /* * We use RESTRICT here for safety, but at present we do not expect * anything to depend on the default. */ RemoveAttrDefault(RelationGetRelid(rel), attnum, DROP_RESTRICT, true, true); StoreAttrDefault(rel, attnum, defaultexpr, true); } ObjectAddressSubSet(address, RelationRelationId, RelationGetRelid(rel), attnum); /* Cleanup */ heap_freetuple(heapTup); return address; } /* * Returns the address of the modified column */ static ObjectAddress ATExecAlterColumnGenericOptions(Relation rel, const char *colName, List *options, LOCKMODE lockmode) { Relation ftrel; Relation attrel; ForeignServer *server; ForeignDataWrapper *fdw; HeapTuple tuple; HeapTuple newtuple; bool isnull; Datum repl_val[Natts_pg_attribute]; bool repl_null[Natts_pg_attribute]; bool repl_repl[Natts_pg_attribute]; Datum datum; Form_pg_foreign_table fttableform; Form_pg_attribute atttableform; AttrNumber attnum; ObjectAddress address; if (options == NIL) return InvalidObjectAddress; /* First, determine FDW validator associated to the foreign table. */ ftrel = heap_open(ForeignTableRelationId, AccessShareLock); tuple = SearchSysCache1(FOREIGNTABLEREL, rel->rd_id); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("foreign table \"%s\" does not exist", RelationGetRelationName(rel)))); fttableform = (Form_pg_foreign_table) GETSTRUCT(tuple); server = GetForeignServer(fttableform->ftserver); fdw = GetForeignDataWrapper(server->fdwid); heap_close(ftrel, AccessShareLock); ReleaseSysCache(tuple); attrel = heap_open(AttributeRelationId, RowExclusiveLock); tuple = SearchSysCacheAttName(RelationGetRelid(rel), colName); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(rel)))); /* Prevent them from altering a system attribute */ atttableform = (Form_pg_attribute) GETSTRUCT(tuple); attnum = atttableform->attnum; if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter system column \"%s\"", colName))); /* Initialize buffers for new tuple values */ memset(repl_val, 0, sizeof(repl_val)); memset(repl_null, false, sizeof(repl_null)); memset(repl_repl, false, sizeof(repl_repl)); /* Extract the current options */ datum = SysCacheGetAttr(ATTNAME, tuple, Anum_pg_attribute_attfdwoptions, &isnull); if (isnull) datum = PointerGetDatum(NULL); /* Transform the options */ datum = transformGenericOptions(AttributeRelationId, datum, options, fdw->fdwvalidator); if (PointerIsValid(DatumGetPointer(datum))) repl_val[Anum_pg_attribute_attfdwoptions - 1] = datum; else repl_null[Anum_pg_attribute_attfdwoptions - 1] = true; repl_repl[Anum_pg_attribute_attfdwoptions - 1] = true; /* Everything looks good - update the tuple */ newtuple = heap_modify_tuple(tuple, RelationGetDescr(attrel), repl_val, repl_null, repl_repl); CatalogTupleUpdate(attrel, &newtuple->t_self, newtuple); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), atttableform->attnum); ObjectAddressSubSet(address, RelationRelationId, RelationGetRelid(rel), attnum); ReleaseSysCache(tuple); heap_close(attrel, RowExclusiveLock); heap_freetuple(newtuple); return address; } /* * Cleanup after we've finished all the ALTER TYPE operations for a * particular relation. We have to drop and recreate all the indexes * and constraints that depend on the altered columns. */ static void ATPostAlterTypeCleanup(List **wqueue, AlteredTableInfo *tab, LOCKMODE lockmode) { ObjectAddress obj; ListCell *def_item; ListCell *oid_item; /* * Re-parse the index and constraint definitions, and attach them to the * appropriate work queue entries. We do this before dropping because in * the case of a FOREIGN KEY constraint, we might not yet have exclusive * lock on the table the constraint is attached to, and we need to get * that before dropping. It's safe because the parser won't actually look * at the catalogs to detect the existing entry. * * We can't rely on the output of deparsing to tell us which relation to * operate on, because concurrent activity might have made the name * resolve differently. Instead, we've got to use the OID of the * constraint or index we're processing to figure out which relation to * operate on. */ forboth(oid_item, tab->changedConstraintOids, def_item, tab->changedConstraintDefs) { Oid oldId = lfirst_oid(oid_item); HeapTuple tup; Form_pg_constraint con; Oid relid; Oid confrelid; bool conislocal; tup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(oldId)); if (!HeapTupleIsValid(tup)) /* should not happen */ elog(ERROR, "cache lookup failed for constraint %u", oldId); con = (Form_pg_constraint) GETSTRUCT(tup); relid = con->conrelid; confrelid = con->confrelid; conislocal = con->conislocal; ReleaseSysCache(tup); /* * If the constraint is inherited (only), we don't want to inject a * new definition here; it'll get recreated when ATAddCheckConstraint * recurses from adding the parent table's constraint. But we had to * carry the info this far so that we can drop the constraint below. */ if (!conislocal) continue; ATPostAlterTypeParse(oldId, relid, confrelid, (char *) lfirst(def_item), wqueue, lockmode, tab->rewrite); } forboth(oid_item, tab->changedIndexOids, def_item, tab->changedIndexDefs) { Oid oldId = lfirst_oid(oid_item); Oid relid; relid = IndexGetRelation(oldId, false); ATPostAlterTypeParse(oldId, relid, InvalidOid, (char *) lfirst(def_item), wqueue, lockmode, tab->rewrite); } /* * Now we can drop the existing constraints and indexes --- constraints * first, since some of them might depend on the indexes. In fact, we * have to delete FOREIGN KEY constraints before UNIQUE constraints, but * we already ordered the constraint list to ensure that would happen. It * should be okay to use DROP_RESTRICT here, since nothing else should be * depending on these objects. */ foreach(oid_item, tab->changedConstraintOids) { obj.classId = ConstraintRelationId; obj.objectId = lfirst_oid(oid_item); obj.objectSubId = 0; performDeletion(&obj, DROP_RESTRICT, PERFORM_DELETION_INTERNAL); } foreach(oid_item, tab->changedIndexOids) { obj.classId = RelationRelationId; obj.objectId = lfirst_oid(oid_item); obj.objectSubId = 0; performDeletion(&obj, DROP_RESTRICT, PERFORM_DELETION_INTERNAL); } /* * The objects will get recreated during subsequent passes over the work * queue. */ } static void ATPostAlterTypeParse(Oid oldId, Oid oldRelId, Oid refRelId, char *cmd, List **wqueue, LOCKMODE lockmode, bool rewrite) { List *raw_parsetree_list; List *querytree_list; ListCell *list_item; Relation rel; /* * We expect that we will get only ALTER TABLE and CREATE INDEX * statements. Hence, there is no need to pass them through * parse_analyze() or the rewriter, but instead we need to pass them * through parse_utilcmd.c to make them ready for execution. */ raw_parsetree_list = raw_parser(cmd); querytree_list = NIL; foreach(list_item, raw_parsetree_list) { RawStmt *rs = castNode(RawStmt, lfirst(list_item)); Node *stmt = rs->stmt; if (IsA(stmt, IndexStmt)) querytree_list = lappend(querytree_list, transformIndexStmt(oldRelId, (IndexStmt *) stmt, cmd)); else if (IsA(stmt, AlterTableStmt)) querytree_list = list_concat(querytree_list, transformAlterTableStmt(oldRelId, (AlterTableStmt *) stmt, cmd)); else querytree_list = lappend(querytree_list, stmt); } /* Caller should already have acquired whatever lock we need. */ rel = relation_open(oldRelId, NoLock); /* * Attach each generated command to the proper place in the work queue. * Note this could result in creation of entirely new work-queue entries. * * Also note that we have to tweak the command subtypes, because it turns * out that re-creation of indexes and constraints has to act a bit * differently from initial creation. */ foreach(list_item, querytree_list) { Node *stm = (Node *) lfirst(list_item); AlteredTableInfo *tab; tab = ATGetQueueEntry(wqueue, rel); if (IsA(stm, IndexStmt)) { IndexStmt *stmt = (IndexStmt *) stm; AlterTableCmd *newcmd; if (!rewrite) TryReuseIndex(oldId, stmt); /* keep the index's comment */ stmt->idxcomment = GetComment(oldId, RelationRelationId, 0); newcmd = makeNode(AlterTableCmd); newcmd->subtype = AT_ReAddIndex; newcmd->def = (Node *) stmt; tab->subcmds[AT_PASS_OLD_INDEX] = lappend(tab->subcmds[AT_PASS_OLD_INDEX], newcmd); } else if (IsA(stm, AlterTableStmt)) { AlterTableStmt *stmt = (AlterTableStmt *) stm; ListCell *lcmd; foreach(lcmd, stmt->cmds) { AlterTableCmd *cmd = (AlterTableCmd *) lfirst(lcmd); if (cmd->subtype == AT_AddIndex) { IndexStmt *indstmt; Oid indoid; indstmt = castNode(IndexStmt, cmd->def); indoid = get_constraint_index(oldId); if (!rewrite) TryReuseIndex(indoid, indstmt); /* keep any comment on the index */ indstmt->idxcomment = GetComment(indoid, RelationRelationId, 0); cmd->subtype = AT_ReAddIndex; tab->subcmds[AT_PASS_OLD_INDEX] = lappend(tab->subcmds[AT_PASS_OLD_INDEX], cmd); /* recreate any comment on the constraint */ RebuildConstraintComment(tab, AT_PASS_OLD_INDEX, oldId, rel, indstmt->idxname); } else if (cmd->subtype == AT_AddConstraint) { Constraint *con; con = castNode(Constraint, cmd->def); con->old_pktable_oid = refRelId; /* rewriting neither side of a FK */ if (con->contype == CONSTR_FOREIGN && !rewrite && tab->rewrite == 0) TryReuseForeignKey(oldId, con); cmd->subtype = AT_ReAddConstraint; tab->subcmds[AT_PASS_OLD_CONSTR] = lappend(tab->subcmds[AT_PASS_OLD_CONSTR], cmd); /* recreate any comment on the constraint */ RebuildConstraintComment(tab, AT_PASS_OLD_CONSTR, oldId, rel, con->conname); } else elog(ERROR, "unexpected statement subtype: %d", (int) cmd->subtype); } } else elog(ERROR, "unexpected statement type: %d", (int) nodeTag(stm)); } relation_close(rel, NoLock); } /* * Subroutine for ATPostAlterTypeParse() to recreate a comment entry for * a constraint that is being re-added. */ static void RebuildConstraintComment(AlteredTableInfo *tab, int pass, Oid objid, Relation rel, char *conname) { CommentStmt *cmd; char *comment_str; AlterTableCmd *newcmd; /* Look for comment for object wanted, and leave if none */ comment_str = GetComment(objid, ConstraintRelationId, 0); if (comment_str == NULL) return; /* Build node CommentStmt */ cmd = makeNode(CommentStmt); cmd->objtype = OBJECT_TABCONSTRAINT; cmd->object = (Node *) list_make3(makeString(get_namespace_name(RelationGetNamespace(rel))), makeString(RelationGetRelationName(rel)), makeString(conname)); cmd->comment = comment_str; /* Append it to list of commands */ newcmd = makeNode(AlterTableCmd); newcmd->subtype = AT_ReAddComment; newcmd->def = (Node *) cmd; tab->subcmds[pass] = lappend(tab->subcmds[pass], newcmd); } /* * Subroutine for ATPostAlterTypeParse(). Calls out to CheckIndexCompatible() * for the real analysis, then mutates the IndexStmt based on that verdict. */ static void TryReuseIndex(Oid oldId, IndexStmt *stmt) { if (CheckIndexCompatible(oldId, stmt->accessMethod, stmt->indexParams, stmt->excludeOpNames)) { Relation irel = index_open(oldId, NoLock); stmt->oldNode = irel->rd_node.relNode; index_close(irel, NoLock); } } /* * Subroutine for ATPostAlterTypeParse(). * * Stash the old P-F equality operator into the Constraint node, for possible * use by ATAddForeignKeyConstraint() in determining whether revalidation of * this constraint can be skipped. */ static void TryReuseForeignKey(Oid oldId, Constraint *con) { HeapTuple tup; Datum adatum; bool isNull; ArrayType *arr; Oid *rawarr; int numkeys; int i; Assert(con->contype == CONSTR_FOREIGN); Assert(con->old_conpfeqop == NIL); /* already prepared this node */ tup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(oldId)); if (!HeapTupleIsValid(tup)) /* should not happen */ elog(ERROR, "cache lookup failed for constraint %u", oldId); adatum = SysCacheGetAttr(CONSTROID, tup, Anum_pg_constraint_conpfeqop, &isNull); if (isNull) elog(ERROR, "null conpfeqop for constraint %u", oldId); arr = DatumGetArrayTypeP(adatum); /* ensure not toasted */ numkeys = ARR_DIMS(arr)[0]; /* test follows the one in ri_FetchConstraintInfo() */ if (ARR_NDIM(arr) != 1 || ARR_HASNULL(arr) || ARR_ELEMTYPE(arr) != OIDOID) elog(ERROR, "conpfeqop is not a 1-D Oid array"); rawarr = (Oid *) ARR_DATA_PTR(arr); /* stash a List of the operator Oids in our Constraint node */ for (i = 0; i < numkeys; i++) con->old_conpfeqop = lcons_oid(rawarr[i], con->old_conpfeqop); ReleaseSysCache(tup); } /* * ALTER TABLE OWNER * * recursing is true if we are recursing from a table to its indexes, * sequences, or toast table. We don't allow the ownership of those things to * be changed separately from the parent table. Also, we can skip permission * checks (this is necessary not just an optimization, else we'd fail to * handle toast tables properly). * * recursing is also true if ALTER TYPE OWNER is calling us to fix up a * free-standing composite type. */ void ATExecChangeOwner(Oid relationOid, Oid newOwnerId, bool recursing, LOCKMODE lockmode) { Relation target_rel; Relation class_rel; HeapTuple tuple; Form_pg_class tuple_class; /* * Get exclusive lock till end of transaction on the target table. Use * relation_open so that we can work on indexes and sequences. */ target_rel = relation_open(relationOid, lockmode); /* Get its pg_class tuple, too */ class_rel = heap_open(RelationRelationId, RowExclusiveLock); tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relationOid)); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for relation %u", relationOid); tuple_class = (Form_pg_class) GETSTRUCT(tuple); /* Can we change the ownership of this tuple? */ switch (tuple_class->relkind) { case RELKIND_RELATION: case RELKIND_VIEW: case RELKIND_MATVIEW: case RELKIND_FOREIGN_TABLE: case RELKIND_PARTITIONED_TABLE: /* ok to change owner */ break; case RELKIND_INDEX: if (!recursing) { /* * Because ALTER INDEX OWNER used to be allowed, and in fact * is generated by old versions of pg_dump, we give a warning * and do nothing rather than erroring out. Also, to avoid * unnecessary chatter while restoring those old dumps, say * nothing at all if the command would be a no-op anyway. */ if (tuple_class->relowner != newOwnerId) ereport(WARNING, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot change owner of index \"%s\"", NameStr(tuple_class->relname)), errhint("Change the ownership of the index's table, instead."))); /* quick hack to exit via the no-op path */ newOwnerId = tuple_class->relowner; } break; case RELKIND_SEQUENCE: if (!recursing && tuple_class->relowner != newOwnerId) { /* if it's an owned sequence, disallow changing it by itself */ Oid tableId; int32 colId; if (sequenceIsOwned(relationOid, DEPENDENCY_AUTO, &tableId, &colId) || sequenceIsOwned(relationOid, DEPENDENCY_INTERNAL, &tableId, &colId)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot change owner of sequence \"%s\"", NameStr(tuple_class->relname)), errdetail("Sequence \"%s\" is linked to table \"%s\".", NameStr(tuple_class->relname), get_rel_name(tableId)))); } break; case RELKIND_COMPOSITE_TYPE: if (recursing) break; ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is a composite type", NameStr(tuple_class->relname)), errhint("Use ALTER TYPE instead."))); break; case RELKIND_TOASTVALUE: if (recursing) break; /* FALL THRU */ default: ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is not a table, view, sequence, or foreign table", NameStr(tuple_class->relname)))); } /* * If the new owner is the same as the existing owner, consider the * command to have succeeded. This is for dump restoration purposes. */ if (tuple_class->relowner != newOwnerId) { Datum repl_val[Natts_pg_class]; bool repl_null[Natts_pg_class]; bool repl_repl[Natts_pg_class]; Acl *newAcl; Datum aclDatum; bool isNull; HeapTuple newtuple; /* skip permission checks when recursing to index or toast table */ if (!recursing) { /* Superusers can always do it */ if (!superuser()) { Oid namespaceOid = tuple_class->relnamespace; AclResult aclresult; /* Otherwise, must be owner of the existing object */ if (!pg_class_ownercheck(relationOid, GetUserId())) aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS, RelationGetRelationName(target_rel)); /* Must be able to become new owner */ check_is_member_of_role(GetUserId(), newOwnerId); /* New owner must have CREATE privilege on namespace */ aclresult = pg_namespace_aclcheck(namespaceOid, newOwnerId, ACL_CREATE); if (aclresult != ACLCHECK_OK) aclcheck_error(aclresult, ACL_KIND_NAMESPACE, get_namespace_name(namespaceOid)); } } memset(repl_null, false, sizeof(repl_null)); memset(repl_repl, false, sizeof(repl_repl)); repl_repl[Anum_pg_class_relowner - 1] = true; repl_val[Anum_pg_class_relowner - 1] = ObjectIdGetDatum(newOwnerId); /* * Determine the modified ACL for the new owner. This is only * necessary when the ACL is non-null. */ aclDatum = SysCacheGetAttr(RELOID, tuple, Anum_pg_class_relacl, &isNull); if (!isNull) { newAcl = aclnewowner(DatumGetAclP(aclDatum), tuple_class->relowner, newOwnerId); repl_repl[Anum_pg_class_relacl - 1] = true; repl_val[Anum_pg_class_relacl - 1] = PointerGetDatum(newAcl); } newtuple = heap_modify_tuple(tuple, RelationGetDescr(class_rel), repl_val, repl_null, repl_repl); CatalogTupleUpdate(class_rel, &newtuple->t_self, newtuple); heap_freetuple(newtuple); /* * We must similarly update any per-column ACLs to reflect the new * owner; for neatness reasons that's split out as a subroutine. */ change_owner_fix_column_acls(relationOid, tuple_class->relowner, newOwnerId); /* * Update owner dependency reference, if any. A composite type has * none, because it's tracked for the pg_type entry instead of here; * indexes and TOAST tables don't have their own entries either. */ if (tuple_class->relkind != RELKIND_COMPOSITE_TYPE && tuple_class->relkind != RELKIND_INDEX && tuple_class->relkind != RELKIND_TOASTVALUE) changeDependencyOnOwner(RelationRelationId, relationOid, newOwnerId); /* * Also change the ownership of the table's row type, if it has one */ if (tuple_class->relkind != RELKIND_INDEX) AlterTypeOwnerInternal(tuple_class->reltype, newOwnerId); /* * If we are operating on a table or materialized view, also change * the ownership of any indexes and sequences that belong to the * relation, as well as its toast table (if it has one). */ if (tuple_class->relkind == RELKIND_RELATION || tuple_class->relkind == RELKIND_MATVIEW || tuple_class->relkind == RELKIND_TOASTVALUE) { List *index_oid_list; ListCell *i; /* Find all the indexes belonging to this relation */ index_oid_list = RelationGetIndexList(target_rel); /* For each index, recursively change its ownership */ foreach(i, index_oid_list) ATExecChangeOwner(lfirst_oid(i), newOwnerId, true, lockmode); list_free(index_oid_list); } if (tuple_class->relkind == RELKIND_RELATION || tuple_class->relkind == RELKIND_MATVIEW) { /* If it has a toast table, recurse to change its ownership */ if (tuple_class->reltoastrelid != InvalidOid) ATExecChangeOwner(tuple_class->reltoastrelid, newOwnerId, true, lockmode); /* If it has dependent sequences, recurse to change them too */ change_owner_recurse_to_sequences(relationOid, newOwnerId, lockmode); } } InvokeObjectPostAlterHook(RelationRelationId, relationOid, 0); ReleaseSysCache(tuple); heap_close(class_rel, RowExclusiveLock); relation_close(target_rel, NoLock); } /* * change_owner_fix_column_acls * * Helper function for ATExecChangeOwner. Scan the columns of the table * and fix any non-null column ACLs to reflect the new owner. */ static void change_owner_fix_column_acls(Oid relationOid, Oid oldOwnerId, Oid newOwnerId) { Relation attRelation; SysScanDesc scan; ScanKeyData key[1]; HeapTuple attributeTuple; attRelation = heap_open(AttributeRelationId, RowExclusiveLock); ScanKeyInit(&key[0], Anum_pg_attribute_attrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relationOid)); scan = systable_beginscan(attRelation, AttributeRelidNumIndexId, true, NULL, 1, key); while (HeapTupleIsValid(attributeTuple = systable_getnext(scan))) { Form_pg_attribute att = (Form_pg_attribute) GETSTRUCT(attributeTuple); Datum repl_val[Natts_pg_attribute]; bool repl_null[Natts_pg_attribute]; bool repl_repl[Natts_pg_attribute]; Acl *newAcl; Datum aclDatum; bool isNull; HeapTuple newtuple; /* Ignore dropped columns */ if (att->attisdropped) continue; aclDatum = heap_getattr(attributeTuple, Anum_pg_attribute_attacl, RelationGetDescr(attRelation), &isNull); /* Null ACLs do not require changes */ if (isNull) continue; memset(repl_null, false, sizeof(repl_null)); memset(repl_repl, false, sizeof(repl_repl)); newAcl = aclnewowner(DatumGetAclP(aclDatum), oldOwnerId, newOwnerId); repl_repl[Anum_pg_attribute_attacl - 1] = true; repl_val[Anum_pg_attribute_attacl - 1] = PointerGetDatum(newAcl); newtuple = heap_modify_tuple(attributeTuple, RelationGetDescr(attRelation), repl_val, repl_null, repl_repl); CatalogTupleUpdate(attRelation, &newtuple->t_self, newtuple); heap_freetuple(newtuple); } systable_endscan(scan); heap_close(attRelation, RowExclusiveLock); } /* * change_owner_recurse_to_sequences * * Helper function for ATExecChangeOwner. Examines pg_depend searching * for sequences that are dependent on serial columns, and changes their * ownership. */ static void change_owner_recurse_to_sequences(Oid relationOid, Oid newOwnerId, LOCKMODE lockmode) { Relation depRel; SysScanDesc scan; ScanKeyData key[2]; HeapTuple tup; /* * SERIAL sequences are those having an auto dependency on one of the * table's columns (we don't care *which* column, exactly). */ depRel = heap_open(DependRelationId, AccessShareLock); ScanKeyInit(&key[0], Anum_pg_depend_refclassid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationRelationId)); ScanKeyInit(&key[1], Anum_pg_depend_refobjid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relationOid)); /* we leave refobjsubid unspecified */ scan = systable_beginscan(depRel, DependReferenceIndexId, true, NULL, 2, key); while (HeapTupleIsValid(tup = systable_getnext(scan))) { Form_pg_depend depForm = (Form_pg_depend) GETSTRUCT(tup); Relation seqRel; /* skip dependencies other than auto dependencies on columns */ if (depForm->refobjsubid == 0 || depForm->classid != RelationRelationId || depForm->objsubid != 0 || !(depForm->deptype == DEPENDENCY_AUTO || depForm->deptype == DEPENDENCY_INTERNAL)) continue; /* Use relation_open just in case it's an index */ seqRel = relation_open(depForm->objid, lockmode); /* skip non-sequence relations */ if (RelationGetForm(seqRel)->relkind != RELKIND_SEQUENCE) { /* No need to keep the lock */ relation_close(seqRel, lockmode); continue; } /* We don't need to close the sequence while we alter it. */ ATExecChangeOwner(depForm->objid, newOwnerId, true, lockmode); /* Now we can close it. Keep the lock till end of transaction. */ relation_close(seqRel, NoLock); } systable_endscan(scan); relation_close(depRel, AccessShareLock); } /* * ALTER TABLE CLUSTER ON * * The only thing we have to do is to change the indisclustered bits. * * Return the address of the new clustering index. */ static ObjectAddress ATExecClusterOn(Relation rel, const char *indexName, LOCKMODE lockmode) { Oid indexOid; ObjectAddress address; indexOid = get_relname_relid(indexName, rel->rd_rel->relnamespace); if (!OidIsValid(indexOid)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("index \"%s\" for table \"%s\" does not exist", indexName, RelationGetRelationName(rel)))); /* Check index is valid to cluster on */ check_index_is_clusterable(rel, indexOid, false, lockmode); /* And do the work */ mark_index_clustered(rel, indexOid, false); ObjectAddressSet(address, RelationRelationId, indexOid); return address; } /* * ALTER TABLE SET WITHOUT CLUSTER * * We have to find any indexes on the table that have indisclustered bit * set and turn it off. */ static void ATExecDropCluster(Relation rel, LOCKMODE lockmode) { mark_index_clustered(rel, InvalidOid, false); } /* * ALTER TABLE SET TABLESPACE */ static void ATPrepSetTableSpace(AlteredTableInfo *tab, Relation rel, char *tablespacename, LOCKMODE lockmode) { Oid tablespaceId; /* Check that the tablespace exists */ tablespaceId = get_tablespace_oid(tablespacename, false); /* Check permissions except when moving to database's default */ if (OidIsValid(tablespaceId) && tablespaceId != MyDatabaseTableSpace) { AclResult aclresult; aclresult = pg_tablespace_aclcheck(tablespaceId, GetUserId(), ACL_CREATE); if (aclresult != ACLCHECK_OK) aclcheck_error(aclresult, ACL_KIND_TABLESPACE, tablespacename); } /* Save info for Phase 3 to do the real work */ if (OidIsValid(tab->newTableSpace)) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("cannot have multiple SET TABLESPACE subcommands"))); tab->newTableSpace = tablespaceId; } /* * Set, reset, or replace reloptions. */ static void ATExecSetRelOptions(Relation rel, List *defList, AlterTableType operation, LOCKMODE lockmode) { Oid relid; Relation pgclass; HeapTuple tuple; HeapTuple newtuple; Datum datum; bool isnull; Datum newOptions; Datum repl_val[Natts_pg_class]; bool repl_null[Natts_pg_class]; bool repl_repl[Natts_pg_class]; static char *validnsps[] = HEAP_RELOPT_NAMESPACES; if (defList == NIL && operation != AT_ReplaceRelOptions) return; /* nothing to do */ pgclass = heap_open(RelationRelationId, RowExclusiveLock); /* Fetch heap tuple */ relid = RelationGetRelid(rel); tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid)); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for relation %u", relid); if (operation == AT_ReplaceRelOptions) { /* * If we're supposed to replace the reloptions list, we just pretend * there were none before. */ datum = (Datum) 0; isnull = true; } else { /* Get the old reloptions */ datum = SysCacheGetAttr(RELOID, tuple, Anum_pg_class_reloptions, &isnull); } /* Generate new proposed reloptions (text array) */ newOptions = transformRelOptions(isnull ? (Datum) 0 : datum, defList, NULL, validnsps, false, operation == AT_ResetRelOptions); /* Validate */ switch (rel->rd_rel->relkind) { case RELKIND_RELATION: case RELKIND_TOASTVALUE: case RELKIND_MATVIEW: case RELKIND_PARTITIONED_TABLE: (void) heap_reloptions(rel->rd_rel->relkind, newOptions, true); break; case RELKIND_VIEW: (void) view_reloptions(newOptions, true); break; case RELKIND_INDEX: (void) index_reloptions(rel->rd_amroutine->amoptions, newOptions, true); break; default: ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is not a table, view, materialized view, index, or TOAST table", RelationGetRelationName(rel)))); break; } /* Special-case validation of view options */ if (rel->rd_rel->relkind == RELKIND_VIEW) { Query *view_query = get_view_query(rel); List *view_options = untransformRelOptions(newOptions); ListCell *cell; bool check_option = false; foreach(cell, view_options) { DefElem *defel = (DefElem *) lfirst(cell); if (pg_strcasecmp(defel->defname, "check_option") == 0) check_option = true; } /* * If the check option is specified, look to see if the view is * actually auto-updatable or not. */ if (check_option) { const char *view_updatable_error = view_query_is_auto_updatable(view_query, true); if (view_updatable_error) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("WITH CHECK OPTION is supported only on automatically updatable views"), errhint("%s", view_updatable_error))); } } /* * All we need do here is update the pg_class row; the new options will be * propagated into relcaches during post-commit cache inval. */ memset(repl_val, 0, sizeof(repl_val)); memset(repl_null, false, sizeof(repl_null)); memset(repl_repl, false, sizeof(repl_repl)); if (newOptions != (Datum) 0) repl_val[Anum_pg_class_reloptions - 1] = newOptions; else repl_null[Anum_pg_class_reloptions - 1] = true; repl_repl[Anum_pg_class_reloptions - 1] = true; newtuple = heap_modify_tuple(tuple, RelationGetDescr(pgclass), repl_val, repl_null, repl_repl); CatalogTupleUpdate(pgclass, &newtuple->t_self, newtuple); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), 0); heap_freetuple(newtuple); ReleaseSysCache(tuple); /* repeat the whole exercise for the toast table, if there's one */ if (OidIsValid(rel->rd_rel->reltoastrelid)) { Relation toastrel; Oid toastid = rel->rd_rel->reltoastrelid; toastrel = heap_open(toastid, lockmode); /* Fetch heap tuple */ tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(toastid)); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for relation %u", toastid); if (operation == AT_ReplaceRelOptions) { /* * If we're supposed to replace the reloptions list, we just * pretend there were none before. */ datum = (Datum) 0; isnull = true; } else { /* Get the old reloptions */ datum = SysCacheGetAttr(RELOID, tuple, Anum_pg_class_reloptions, &isnull); } newOptions = transformRelOptions(isnull ? (Datum) 0 : datum, defList, "toast", validnsps, false, operation == AT_ResetRelOptions); (void) heap_reloptions(RELKIND_TOASTVALUE, newOptions, true); memset(repl_val, 0, sizeof(repl_val)); memset(repl_null, false, sizeof(repl_null)); memset(repl_repl, false, sizeof(repl_repl)); if (newOptions != (Datum) 0) repl_val[Anum_pg_class_reloptions - 1] = newOptions; else repl_null[Anum_pg_class_reloptions - 1] = true; repl_repl[Anum_pg_class_reloptions - 1] = true; newtuple = heap_modify_tuple(tuple, RelationGetDescr(pgclass), repl_val, repl_null, repl_repl); CatalogTupleUpdate(pgclass, &newtuple->t_self, newtuple); InvokeObjectPostAlterHookArg(RelationRelationId, RelationGetRelid(toastrel), 0, InvalidOid, true); heap_freetuple(newtuple); ReleaseSysCache(tuple); heap_close(toastrel, NoLock); } heap_close(pgclass, RowExclusiveLock); } /* * Execute ALTER TABLE SET TABLESPACE for cases where there is no tuple * rewriting to be done, so we just want to copy the data as fast as possible. */ static void ATExecSetTableSpace(Oid tableOid, Oid newTableSpace, LOCKMODE lockmode) { Relation rel; Oid oldTableSpace; Oid reltoastrelid; Oid newrelfilenode; RelFileNode newrnode; SMgrRelation dstrel; Relation pg_class; HeapTuple tuple; Form_pg_class rd_rel; ForkNumber forkNum; List *reltoastidxids = NIL; ListCell *lc; /* * Need lock here in case we are recursing to toast table or index */ rel = relation_open(tableOid, lockmode); /* * No work if no change in tablespace. */ oldTableSpace = rel->rd_rel->reltablespace; if (newTableSpace == oldTableSpace || (newTableSpace == MyDatabaseTableSpace && oldTableSpace == 0)) { InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), 0); relation_close(rel, NoLock); return; } /* * We cannot support moving mapped relations into different tablespaces. * (In particular this eliminates all shared catalogs.) */ if (RelationIsMapped(rel)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot move system relation \"%s\"", RelationGetRelationName(rel)))); /* Can't move a non-shared relation into pg_global */ if (newTableSpace == GLOBALTABLESPACE_OID) ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("only shared relations can be placed in pg_global tablespace"))); /* * Don't allow moving temp tables of other backends ... their local buffer * manager is not going to cope. */ if (RELATION_IS_OTHER_TEMP(rel)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot move temporary tables of other sessions"))); reltoastrelid = rel->rd_rel->reltoastrelid; /* Fetch the list of indexes on toast relation if necessary */ if (OidIsValid(reltoastrelid)) { Relation toastRel = relation_open(reltoastrelid, lockmode); reltoastidxids = RelationGetIndexList(toastRel); relation_close(toastRel, lockmode); } /* Get a modifiable copy of the relation's pg_class row */ pg_class = heap_open(RelationRelationId, RowExclusiveLock); tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(tableOid)); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for relation %u", tableOid); rd_rel = (Form_pg_class) GETSTRUCT(tuple); /* * Since we copy the file directly without looking at the shared buffers, * we'd better first flush out any pages of the source relation that are * in shared buffers. We assume no new changes will be made while we are * holding exclusive lock on the rel. */ FlushRelationBuffers(rel); /* * Relfilenodes are not unique in databases across tablespaces, so we need * to allocate a new one in the new tablespace. */ newrelfilenode = GetNewRelFileNode(newTableSpace, NULL, rel->rd_rel->relpersistence); /* Open old and new relation */ newrnode = rel->rd_node; newrnode.relNode = newrelfilenode; newrnode.spcNode = newTableSpace; dstrel = smgropen(newrnode, rel->rd_backend); RelationOpenSmgr(rel); /* * Create and copy all forks of the relation, and schedule unlinking of * old physical files. * * NOTE: any conflict in relfilenode value will be caught in * RelationCreateStorage(). */ RelationCreateStorage(newrnode, rel->rd_rel->relpersistence); /* copy main fork */ copy_relation_data(rel->rd_smgr, dstrel, MAIN_FORKNUM, rel->rd_rel->relpersistence); /* copy those extra forks that exist */ for (forkNum = MAIN_FORKNUM + 1; forkNum <= MAX_FORKNUM; forkNum++) { if (smgrexists(rel->rd_smgr, forkNum)) { smgrcreate(dstrel, forkNum, false); /* * WAL log creation if the relation is persistent, or this is the * init fork of an unlogged relation. */ if (rel->rd_rel->relpersistence == RELPERSISTENCE_PERMANENT || (rel->rd_rel->relpersistence == RELPERSISTENCE_UNLOGGED && forkNum == INIT_FORKNUM)) log_smgrcreate(&newrnode, forkNum); copy_relation_data(rel->rd_smgr, dstrel, forkNum, rel->rd_rel->relpersistence); } } /* drop old relation, and close new one */ RelationDropStorage(rel); smgrclose(dstrel); /* update the pg_class row */ rd_rel->reltablespace = (newTableSpace == MyDatabaseTableSpace) ? InvalidOid : newTableSpace; rd_rel->relfilenode = newrelfilenode; CatalogTupleUpdate(pg_class, &tuple->t_self, tuple); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), 0); heap_freetuple(tuple); heap_close(pg_class, RowExclusiveLock); relation_close(rel, NoLock); /* Make sure the reltablespace change is visible */ CommandCounterIncrement(); /* Move associated toast relation and/or indexes, too */ if (OidIsValid(reltoastrelid)) ATExecSetTableSpace(reltoastrelid, newTableSpace, lockmode); foreach(lc, reltoastidxids) ATExecSetTableSpace(lfirst_oid(lc), newTableSpace, lockmode); /* Clean up */ list_free(reltoastidxids); } /* * Alter Table ALL ... SET TABLESPACE * * Allows a user to move all objects of some type in a given tablespace in the * current database to another tablespace. Objects can be chosen based on the * owner of the object also, to allow users to move only their objects. * The user must have CREATE rights on the new tablespace, as usual. The main * permissions handling is done by the lower-level table move function. * * All to-be-moved objects are locked first. If NOWAIT is specified and the * lock can't be acquired then we ereport(ERROR). */ Oid AlterTableMoveAll(AlterTableMoveAllStmt *stmt) { List *relations = NIL; ListCell *l; ScanKeyData key[1]; Relation rel; HeapScanDesc scan; HeapTuple tuple; Oid orig_tablespaceoid; Oid new_tablespaceoid; List *role_oids = roleSpecsToIds(stmt->roles); /* Ensure we were not asked to move something we can't */ if (stmt->objtype != OBJECT_TABLE && stmt->objtype != OBJECT_INDEX && stmt->objtype != OBJECT_MATVIEW) ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("only tables, indexes, and materialized views exist in tablespaces"))); /* Get the orig and new tablespace OIDs */ orig_tablespaceoid = get_tablespace_oid(stmt->orig_tablespacename, false); new_tablespaceoid = get_tablespace_oid(stmt->new_tablespacename, false); /* Can't move shared relations in to or out of pg_global */ /* This is also checked by ATExecSetTableSpace, but nice to stop earlier */ if (orig_tablespaceoid == GLOBALTABLESPACE_OID || new_tablespaceoid == GLOBALTABLESPACE_OID) ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("cannot move relations in to or out of pg_global tablespace"))); /* * Must have CREATE rights on the new tablespace, unless it is the * database default tablespace (which all users implicitly have CREATE * rights on). */ if (OidIsValid(new_tablespaceoid) && new_tablespaceoid != MyDatabaseTableSpace) { AclResult aclresult; aclresult = pg_tablespace_aclcheck(new_tablespaceoid, GetUserId(), ACL_CREATE); if (aclresult != ACLCHECK_OK) aclcheck_error(aclresult, ACL_KIND_TABLESPACE, get_tablespace_name(new_tablespaceoid)); } /* * Now that the checks are done, check if we should set either to * InvalidOid because it is our database's default tablespace. */ if (orig_tablespaceoid == MyDatabaseTableSpace) orig_tablespaceoid = InvalidOid; if (new_tablespaceoid == MyDatabaseTableSpace) new_tablespaceoid = InvalidOid; /* no-op */ if (orig_tablespaceoid == new_tablespaceoid) return new_tablespaceoid; /* * Walk the list of objects in the tablespace and move them. This will * only find objects in our database, of course. */ ScanKeyInit(&key[0], Anum_pg_class_reltablespace, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(orig_tablespaceoid)); rel = heap_open(RelationRelationId, AccessShareLock); scan = heap_beginscan_catalog(rel, 1, key); while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL) { Oid relOid = HeapTupleGetOid(tuple); Form_pg_class relForm; relForm = (Form_pg_class) GETSTRUCT(tuple); /* * Do not move objects in pg_catalog as part of this, if an admin * really wishes to do so, they can issue the individual ALTER * commands directly. * * Also, explicitly avoid any shared tables, temp tables, or TOAST * (TOAST will be moved with the main table). */ if (IsSystemNamespace(relForm->relnamespace) || relForm->relisshared || isAnyTempNamespace(relForm->relnamespace) || relForm->relnamespace == PG_TOAST_NAMESPACE) continue; /* Only move the object type requested */ if ((stmt->objtype == OBJECT_TABLE && relForm->relkind != RELKIND_RELATION && relForm->relkind != RELKIND_PARTITIONED_TABLE) || (stmt->objtype == OBJECT_INDEX && relForm->relkind != RELKIND_INDEX) || (stmt->objtype == OBJECT_MATVIEW && relForm->relkind != RELKIND_MATVIEW)) continue; /* Check if we are only moving objects owned by certain roles */ if (role_oids != NIL && !list_member_oid(role_oids, relForm->relowner)) continue; /* * Handle permissions-checking here since we are locking the tables * and also to avoid doing a bunch of work only to fail part-way. Note * that permissions will also be checked by AlterTableInternal(). * * Caller must be considered an owner on the table to move it. */ if (!pg_class_ownercheck(relOid, GetUserId())) aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS, NameStr(relForm->relname)); if (stmt->nowait && !ConditionalLockRelationOid(relOid, AccessExclusiveLock)) ereport(ERROR, (errcode(ERRCODE_OBJECT_IN_USE), errmsg("aborting because lock on relation \"%s.%s\" is not available", get_namespace_name(relForm->relnamespace), NameStr(relForm->relname)))); else LockRelationOid(relOid, AccessExclusiveLock); /* Add to our list of objects to move */ relations = lappend_oid(relations, relOid); } heap_endscan(scan); heap_close(rel, AccessShareLock); if (relations == NIL) ereport(NOTICE, (errcode(ERRCODE_NO_DATA_FOUND), errmsg("no matching relations in tablespace \"%s\" found", orig_tablespaceoid == InvalidOid ? "(database default)" : get_tablespace_name(orig_tablespaceoid)))); /* Everything is locked, loop through and move all of the relations. */ foreach(l, relations) { List *cmds = NIL; AlterTableCmd *cmd = makeNode(AlterTableCmd); cmd->subtype = AT_SetTableSpace; cmd->name = stmt->new_tablespacename; cmds = lappend(cmds, cmd); EventTriggerAlterTableStart((Node *) stmt); /* OID is set by AlterTableInternal */ AlterTableInternal(lfirst_oid(l), cmds, false); EventTriggerAlterTableEnd(); } return new_tablespaceoid; } /* * Copy data, block by block */ static void copy_relation_data(SMgrRelation src, SMgrRelation dst, ForkNumber forkNum, char relpersistence) { char *buf; Page page; bool use_wal; bool copying_initfork; BlockNumber nblocks; BlockNumber blkno; /* * palloc the buffer so that it's MAXALIGN'd. If it were just a local * char[] array, the compiler might align it on any byte boundary, which * can seriously hurt transfer speed to and from the kernel; not to * mention possibly making log_newpage's accesses to the page header fail. */ buf = (char *) palloc(BLCKSZ); page = (Page) buf; /* * The init fork for an unlogged relation in many respects has to be * treated the same as normal relation, changes need to be WAL logged and * it needs to be synced to disk. */ copying_initfork = relpersistence == RELPERSISTENCE_UNLOGGED && forkNum == INIT_FORKNUM; /* * We need to log the copied data in WAL iff WAL archiving/streaming is * enabled AND it's a permanent relation. */ use_wal = XLogIsNeeded() && (relpersistence == RELPERSISTENCE_PERMANENT || copying_initfork); nblocks = smgrnblocks(src, forkNum); for (blkno = 0; blkno < nblocks; blkno++) { /* If we got a cancel signal during the copy of the data, quit */ CHECK_FOR_INTERRUPTS(); smgrread(src, forkNum, blkno, buf); if (!PageIsVerified(page, blkno)) ereport(ERROR, (errcode(ERRCODE_DATA_CORRUPTED), errmsg("invalid page in block %u of relation %s", blkno, relpathbackend(src->smgr_rnode.node, src->smgr_rnode.backend, forkNum)))); /* * WAL-log the copied page. Unfortunately we don't know what kind of a * page this is, so we have to log the full page including any unused * space. */ if (use_wal) log_newpage(&dst->smgr_rnode.node, forkNum, blkno, page, false); PageSetChecksumInplace(page, blkno); /* * Now write the page. We say isTemp = true even if it's not a temp * rel, because there's no need for smgr to schedule an fsync for this * write; we'll do it ourselves below. */ smgrextend(dst, forkNum, blkno, buf, true); } pfree(buf); /* * If the rel is WAL-logged, must fsync before commit. We use heap_sync * to ensure that the toast table gets fsync'd too. (For a temp or * unlogged rel we don't care since the data will be gone after a crash * anyway.) * * It's obvious that we must do this when not WAL-logging the copy. It's * less obvious that we have to do it even if we did WAL-log the copied * pages. The reason is that since we're copying outside shared buffers, a * CHECKPOINT occurring during the copy has no way to flush the previously * written data to disk (indeed it won't know the new rel even exists). A * crash later on would replay WAL from the checkpoint, therefore it * wouldn't replay our earlier WAL entries. If we do not fsync those pages * here, they might still not be on disk when the crash occurs. */ if (relpersistence == RELPERSISTENCE_PERMANENT || copying_initfork) smgrimmedsync(dst, forkNum); } /* * ALTER TABLE ENABLE/DISABLE TRIGGER * * We just pass this off to trigger.c. */ static void ATExecEnableDisableTrigger(Relation rel, char *trigname, char fires_when, bool skip_system, LOCKMODE lockmode) { EnableDisableTrigger(rel, trigname, fires_when, skip_system); } /* * ALTER TABLE ENABLE/DISABLE RULE * * We just pass this off to rewriteDefine.c. */ static void ATExecEnableDisableRule(Relation rel, char *rulename, char fires_when, LOCKMODE lockmode) { EnableDisableRule(rel, rulename, fires_when); } /* * ALTER TABLE INHERIT * * Add a parent to the child's parents. This verifies that all the columns and * check constraints of the parent appear in the child and that they have the * same data types and expressions. */ static void ATPrepAddInherit(Relation child_rel) { if (child_rel->rd_rel->reloftype) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot change inheritance of typed table"))); if (child_rel->rd_rel->relispartition) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot change inheritance of a partition"))); if (child_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot change inheritance of partitioned table"))); } /* * Return the address of the new parent relation. */ static ObjectAddress ATExecAddInherit(Relation child_rel, RangeVar *parent, LOCKMODE lockmode) { Relation parent_rel; List *children; ObjectAddress address; /* * A self-exclusive lock is needed here. See the similar case in * MergeAttributes() for a full explanation. */ parent_rel = heap_openrv(parent, ShareUpdateExclusiveLock); /* * Must be owner of both parent and child -- child was checked by * ATSimplePermissions call in ATPrepCmd */ ATSimplePermissions(parent_rel, ATT_TABLE | ATT_FOREIGN_TABLE); /* Permanent rels cannot inherit from temporary ones */ if (parent_rel->rd_rel->relpersistence == RELPERSISTENCE_TEMP && child_rel->rd_rel->relpersistence != RELPERSISTENCE_TEMP) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot inherit from temporary relation \"%s\"", RelationGetRelationName(parent_rel)))); /* If parent rel is temp, it must belong to this session */ if (parent_rel->rd_rel->relpersistence == RELPERSISTENCE_TEMP && !parent_rel->rd_islocaltemp) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot inherit from temporary relation of another session"))); /* Ditto for the child */ if (child_rel->rd_rel->relpersistence == RELPERSISTENCE_TEMP && !child_rel->rd_islocaltemp) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot inherit to temporary relation of another session"))); /* Prevent partitioned tables from becoming inheritance parents */ if (parent_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot inherit from partitioned table \"%s\"", parent->relname))); /* Likewise for partitions */ if (parent_rel->rd_rel->relispartition) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot inherit from a partition"))); /* * Prevent circularity by seeing if proposed parent inherits from child. * (In particular, this disallows making a rel inherit from itself.) * * This is not completely bulletproof because of race conditions: in * multi-level inheritance trees, someone else could concurrently be * making another inheritance link that closes the loop but does not join * either of the rels we have locked. Preventing that seems to require * exclusive locks on the entire inheritance tree, which is a cure worse * than the disease. find_all_inheritors() will cope with circularity * anyway, so don't sweat it too much. * * We use weakest lock we can on child's children, namely AccessShareLock. */ children = find_all_inheritors(RelationGetRelid(child_rel), AccessShareLock, NULL); if (list_member_oid(children, RelationGetRelid(parent_rel))) ereport(ERROR, (errcode(ERRCODE_DUPLICATE_TABLE), errmsg("circular inheritance not allowed"), errdetail("\"%s\" is already a child of \"%s\".", parent->relname, RelationGetRelationName(child_rel)))); /* If parent has OIDs then child must have OIDs */ if (parent_rel->rd_rel->relhasoids && !child_rel->rd_rel->relhasoids) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("table \"%s\" without OIDs cannot inherit from table \"%s\" with OIDs", RelationGetRelationName(child_rel), RelationGetRelationName(parent_rel)))); /* OK to create inheritance */ CreateInheritance(child_rel, parent_rel); ObjectAddressSet(address, RelationRelationId, RelationGetRelid(parent_rel)); /* keep our lock on the parent relation until commit */ heap_close(parent_rel, NoLock); return address; } /* * CreateInheritance * Catalog manipulation portion of creating inheritance between a child * table and a parent table. * * Common to ATExecAddInherit() and ATExecAttachPartition(). */ static void CreateInheritance(Relation child_rel, Relation parent_rel) { Relation catalogRelation; SysScanDesc scan; ScanKeyData key; HeapTuple inheritsTuple; int32 inhseqno; /* Note: get RowExclusiveLock because we will write pg_inherits below. */ catalogRelation = heap_open(InheritsRelationId, RowExclusiveLock); /* * Check for duplicates in the list of parents, and determine the highest * inhseqno already present; we'll use the next one for the new parent. * Also, if proposed child is a partition, it cannot already be * inheriting. * * Note: we do not reject the case where the child already inherits from * the parent indirectly; CREATE TABLE doesn't reject comparable cases. */ ScanKeyInit(&key, Anum_pg_inherits_inhrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(child_rel))); scan = systable_beginscan(catalogRelation, InheritsRelidSeqnoIndexId, true, NULL, 1, &key); /* inhseqno sequences start at 1 */ inhseqno = 0; while (HeapTupleIsValid(inheritsTuple = systable_getnext(scan))) { Form_pg_inherits inh = (Form_pg_inherits) GETSTRUCT(inheritsTuple); if (inh->inhparent == RelationGetRelid(parent_rel)) ereport(ERROR, (errcode(ERRCODE_DUPLICATE_TABLE), errmsg("relation \"%s\" would be inherited from more than once", RelationGetRelationName(parent_rel)))); if (inh->inhseqno > inhseqno) inhseqno = inh->inhseqno; } systable_endscan(scan); /* Match up the columns and bump attinhcount as needed */ MergeAttributesIntoExisting(child_rel, parent_rel); /* Match up the constraints and bump coninhcount as needed */ MergeConstraintsIntoExisting(child_rel, parent_rel); /* * OK, it looks valid. Make the catalog entries that show inheritance. */ StoreCatalogInheritance1(RelationGetRelid(child_rel), RelationGetRelid(parent_rel), inhseqno + 1, catalogRelation, parent_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE); /* Now we're done with pg_inherits */ heap_close(catalogRelation, RowExclusiveLock); } /* * Obtain the source-text form of the constraint expression for a check * constraint, given its pg_constraint tuple */ static char * decompile_conbin(HeapTuple contup, TupleDesc tupdesc) { Form_pg_constraint con; bool isnull; Datum attr; Datum expr; con = (Form_pg_constraint) GETSTRUCT(contup); attr = heap_getattr(contup, Anum_pg_constraint_conbin, tupdesc, &isnull); if (isnull) elog(ERROR, "null conbin for constraint %u", HeapTupleGetOid(contup)); expr = DirectFunctionCall2(pg_get_expr, attr, ObjectIdGetDatum(con->conrelid)); return TextDatumGetCString(expr); } /* * Determine whether two check constraints are functionally equivalent * * The test we apply is to see whether they reverse-compile to the same * source string. This insulates us from issues like whether attributes * have the same physical column numbers in parent and child relations. */ static bool constraints_equivalent(HeapTuple a, HeapTuple b, TupleDesc tupleDesc) { Form_pg_constraint acon = (Form_pg_constraint) GETSTRUCT(a); Form_pg_constraint bcon = (Form_pg_constraint) GETSTRUCT(b); if (acon->condeferrable != bcon->condeferrable || acon->condeferred != bcon->condeferred || strcmp(decompile_conbin(a, tupleDesc), decompile_conbin(b, tupleDesc)) != 0) return false; else return true; } /* * Check columns in child table match up with columns in parent, and increment * their attinhcount. * * Called by CreateInheritance * * Currently all parent columns must be found in child. Missing columns are an * error. One day we might consider creating new columns like CREATE TABLE * does. However, that is widely unpopular --- in the common use case of * partitioned tables it's a foot-gun. * * The data type must match exactly. If the parent column is NOT NULL then * the child must be as well. Defaults are not compared, however. */ static void MergeAttributesIntoExisting(Relation child_rel, Relation parent_rel) { Relation attrrel; AttrNumber parent_attno; int parent_natts; TupleDesc tupleDesc; HeapTuple tuple; bool child_is_partition = false; attrrel = heap_open(AttributeRelationId, RowExclusiveLock); tupleDesc = RelationGetDescr(parent_rel); parent_natts = tupleDesc->natts; /* If parent_rel is a partitioned table, child_rel must be a partition */ if (parent_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) child_is_partition = true; for (parent_attno = 1; parent_attno <= parent_natts; parent_attno++) { Form_pg_attribute attribute = tupleDesc->attrs[parent_attno - 1]; char *attributeName = NameStr(attribute->attname); /* Ignore dropped columns in the parent. */ if (attribute->attisdropped) continue; /* Find same column in child (matching on column name). */ tuple = SearchSysCacheCopyAttName(RelationGetRelid(child_rel), attributeName); if (HeapTupleIsValid(tuple)) { /* Check they are same type, typmod, and collation */ Form_pg_attribute childatt = (Form_pg_attribute) GETSTRUCT(tuple); if (attribute->atttypid != childatt->atttypid || attribute->atttypmod != childatt->atttypmod) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("child table \"%s\" has different type for column \"%s\"", RelationGetRelationName(child_rel), attributeName))); if (attribute->attcollation != childatt->attcollation) ereport(ERROR, (errcode(ERRCODE_COLLATION_MISMATCH), errmsg("child table \"%s\" has different collation for column \"%s\"", RelationGetRelationName(child_rel), attributeName))); /* * Check child doesn't discard NOT NULL property. (Other * constraints are checked elsewhere.) */ if (attribute->attnotnull && !childatt->attnotnull) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("column \"%s\" in child table must be marked NOT NULL", attributeName))); /* * OK, bump the child column's inheritance count. (If we fail * later on, this change will just roll back.) */ childatt->attinhcount++; /* * In case of partitions, we must enforce that value of attislocal * is same in all partitions. (Note: there are only inherited * attributes in partitions) */ if (child_is_partition) { Assert(childatt->attinhcount == 1); childatt->attislocal = false; } CatalogTupleUpdate(attrrel, &tuple->t_self, tuple); heap_freetuple(tuple); } else { ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("child table is missing column \"%s\"", attributeName))); } } /* * If the parent has an OID column, so must the child, and we'd better * update the child's attinhcount and attislocal the same as for normal * columns. We needn't check data type or not-nullness though. */ if (tupleDesc->tdhasoid) { /* * Here we match by column number not name; the match *must* be the * system column, not some random column named "oid". */ tuple = SearchSysCacheCopy2(ATTNUM, ObjectIdGetDatum(RelationGetRelid(child_rel)), Int16GetDatum(ObjectIdAttributeNumber)); if (HeapTupleIsValid(tuple)) { Form_pg_attribute childatt = (Form_pg_attribute) GETSTRUCT(tuple); /* See comments above; these changes should be the same */ childatt->attinhcount++; if (child_is_partition) { Assert(childatt->attinhcount == 1); childatt->attislocal = false; } CatalogTupleUpdate(attrrel, &tuple->t_self, tuple); heap_freetuple(tuple); } else { ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("child table is missing column \"%s\"", "oid"))); } } heap_close(attrrel, RowExclusiveLock); } /* * Check constraints in child table match up with constraints in parent, * and increment their coninhcount. * * Constraints that are marked ONLY in the parent are ignored. * * Called by CreateInheritance * * Currently all constraints in parent must be present in the child. One day we * may consider adding new constraints like CREATE TABLE does. * * XXX This is O(N^2) which may be an issue with tables with hundreds of * constraints. As long as tables have more like 10 constraints it shouldn't be * a problem though. Even 100 constraints ought not be the end of the world. * * XXX See MergeWithExistingConstraint too if you change this code. */ static void MergeConstraintsIntoExisting(Relation child_rel, Relation parent_rel) { Relation catalog_relation; TupleDesc tuple_desc; SysScanDesc parent_scan; ScanKeyData parent_key; HeapTuple parent_tuple; bool child_is_partition = false; catalog_relation = heap_open(ConstraintRelationId, RowExclusiveLock); tuple_desc = RelationGetDescr(catalog_relation); /* If parent_rel is a partitioned table, child_rel must be a partition */ if (parent_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) child_is_partition = true; /* Outer loop scans through the parent's constraint definitions */ ScanKeyInit(&parent_key, Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(parent_rel))); parent_scan = systable_beginscan(catalog_relation, ConstraintRelidIndexId, true, NULL, 1, &parent_key); while (HeapTupleIsValid(parent_tuple = systable_getnext(parent_scan))) { Form_pg_constraint parent_con = (Form_pg_constraint) GETSTRUCT(parent_tuple); SysScanDesc child_scan; ScanKeyData child_key; HeapTuple child_tuple; bool found = false; if (parent_con->contype != CONSTRAINT_CHECK) continue; /* if the parent's constraint is marked NO INHERIT, it's not inherited */ if (parent_con->connoinherit) continue; /* Search for a child constraint matching this one */ ScanKeyInit(&child_key, Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(child_rel))); child_scan = systable_beginscan(catalog_relation, ConstraintRelidIndexId, true, NULL, 1, &child_key); while (HeapTupleIsValid(child_tuple = systable_getnext(child_scan))) { Form_pg_constraint child_con = (Form_pg_constraint) GETSTRUCT(child_tuple); HeapTuple child_copy; if (child_con->contype != CONSTRAINT_CHECK) continue; if (strcmp(NameStr(parent_con->conname), NameStr(child_con->conname)) != 0) continue; if (!constraints_equivalent(parent_tuple, child_tuple, tuple_desc)) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("child table \"%s\" has different definition for check constraint \"%s\"", RelationGetRelationName(child_rel), NameStr(parent_con->conname)))); /* If the child constraint is "no inherit" then cannot merge */ if (child_con->connoinherit) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("constraint \"%s\" conflicts with non-inherited constraint on child table \"%s\"", NameStr(child_con->conname), RelationGetRelationName(child_rel)))); /* * If the child constraint is "not valid" then cannot merge with a * valid parent constraint */ if (parent_con->convalidated && !child_con->convalidated) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("constraint \"%s\" conflicts with NOT VALID constraint on child table \"%s\"", NameStr(child_con->conname), RelationGetRelationName(child_rel)))); /* * OK, bump the child constraint's inheritance count. (If we fail * later on, this change will just roll back.) */ child_copy = heap_copytuple(child_tuple); child_con = (Form_pg_constraint) GETSTRUCT(child_copy); child_con->coninhcount++; /* * In case of partitions, an inherited constraint must be * inherited only once since it cannot have multiple parents and * it is never considered local. */ if (child_is_partition) { Assert(child_con->coninhcount == 1); child_con->conislocal = false; } CatalogTupleUpdate(catalog_relation, &child_copy->t_self, child_copy); heap_freetuple(child_copy); found = true; break; } systable_endscan(child_scan); if (!found) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("child table is missing constraint \"%s\"", NameStr(parent_con->conname)))); } systable_endscan(parent_scan); heap_close(catalog_relation, RowExclusiveLock); } /* * ALTER TABLE NO INHERIT * * Return value is the address of the relation that is no longer parent. */ static ObjectAddress ATExecDropInherit(Relation rel, RangeVar *parent, LOCKMODE lockmode) { ObjectAddress address; Relation parent_rel; if (rel->rd_rel->relispartition) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot change inheritance of a partition"))); /* * AccessShareLock on the parent is probably enough, seeing that DROP * TABLE doesn't lock parent tables at all. We need some lock since we'll * be inspecting the parent's schema. */ parent_rel = heap_openrv(parent, AccessShareLock); /* * We don't bother to check ownership of the parent table --- ownership of * the child is presumed enough rights. */ /* Off to RemoveInheritance() where most of the work happens */ RemoveInheritance(rel, parent_rel); /* keep our lock on the parent relation until commit */ heap_close(parent_rel, NoLock); ObjectAddressSet(address, RelationRelationId, RelationGetRelid(parent_rel)); return address; } /* * RemoveInheritance * * Drop a parent from the child's parents. This just adjusts the attinhcount * and attislocal of the columns and removes the pg_inherit and pg_depend * entries. * * If attinhcount goes to 0 then attislocal gets set to true. If it goes back * up attislocal stays true, which means if a child is ever removed from a * parent then its columns will never be automatically dropped which may * surprise. But at least we'll never surprise by dropping columns someone * isn't expecting to be dropped which would actually mean data loss. * * coninhcount and conislocal for inherited constraints are adjusted in * exactly the same way. * * Common to ATExecDropInherit() and ATExecDetachPartition(). */ static void RemoveInheritance(Relation child_rel, Relation parent_rel) { Relation catalogRelation; SysScanDesc scan; ScanKeyData key[3]; HeapTuple inheritsTuple, attributeTuple, constraintTuple; List *connames; bool found = false; bool child_is_partition = false; /* If parent_rel is a partitioned table, child_rel must be a partition */ if (parent_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) child_is_partition = true; /* * Find and destroy the pg_inherits entry linking the two, or error out if * there is none. */ catalogRelation = heap_open(InheritsRelationId, RowExclusiveLock); ScanKeyInit(&key[0], Anum_pg_inherits_inhrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(child_rel))); scan = systable_beginscan(catalogRelation, InheritsRelidSeqnoIndexId, true, NULL, 1, key); while (HeapTupleIsValid(inheritsTuple = systable_getnext(scan))) { Oid inhparent; inhparent = ((Form_pg_inherits) GETSTRUCT(inheritsTuple))->inhparent; if (inhparent == RelationGetRelid(parent_rel)) { CatalogTupleDelete(catalogRelation, &inheritsTuple->t_self); found = true; break; } } systable_endscan(scan); heap_close(catalogRelation, RowExclusiveLock); if (!found) { if (child_is_partition) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_TABLE), errmsg("relation \"%s\" is not a partition of relation \"%s\"", RelationGetRelationName(child_rel), RelationGetRelationName(parent_rel)))); else ereport(ERROR, (errcode(ERRCODE_UNDEFINED_TABLE), errmsg("relation \"%s\" is not a parent of relation \"%s\"", RelationGetRelationName(parent_rel), RelationGetRelationName(child_rel)))); } /* * Search through child columns looking for ones matching parent rel */ catalogRelation = heap_open(AttributeRelationId, RowExclusiveLock); ScanKeyInit(&key[0], Anum_pg_attribute_attrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(child_rel))); scan = systable_beginscan(catalogRelation, AttributeRelidNumIndexId, true, NULL, 1, key); while (HeapTupleIsValid(attributeTuple = systable_getnext(scan))) { Form_pg_attribute att = (Form_pg_attribute) GETSTRUCT(attributeTuple); /* Ignore if dropped or not inherited */ if (att->attisdropped) continue; if (att->attinhcount <= 0) continue; if (SearchSysCacheExistsAttName(RelationGetRelid(parent_rel), NameStr(att->attname))) { /* Decrement inhcount and possibly set islocal to true */ HeapTuple copyTuple = heap_copytuple(attributeTuple); Form_pg_attribute copy_att = (Form_pg_attribute) GETSTRUCT(copyTuple); copy_att->attinhcount--; if (copy_att->attinhcount == 0) copy_att->attislocal = true; CatalogTupleUpdate(catalogRelation, ©Tuple->t_self, copyTuple); heap_freetuple(copyTuple); } } systable_endscan(scan); heap_close(catalogRelation, RowExclusiveLock); /* * Likewise, find inherited check constraints and disinherit them. To do * this, we first need a list of the names of the parent's check * constraints. (We cheat a bit by only checking for name matches, * assuming that the expressions will match.) */ catalogRelation = heap_open(ConstraintRelationId, RowExclusiveLock); ScanKeyInit(&key[0], Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(parent_rel))); scan = systable_beginscan(catalogRelation, ConstraintRelidIndexId, true, NULL, 1, key); connames = NIL; while (HeapTupleIsValid(constraintTuple = systable_getnext(scan))) { Form_pg_constraint con = (Form_pg_constraint) GETSTRUCT(constraintTuple); if (con->contype == CONSTRAINT_CHECK) connames = lappend(connames, pstrdup(NameStr(con->conname))); } systable_endscan(scan); /* Now scan the child's constraints */ ScanKeyInit(&key[0], Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(child_rel))); scan = systable_beginscan(catalogRelation, ConstraintRelidIndexId, true, NULL, 1, key); while (HeapTupleIsValid(constraintTuple = systable_getnext(scan))) { Form_pg_constraint con = (Form_pg_constraint) GETSTRUCT(constraintTuple); bool match; ListCell *lc; if (con->contype != CONSTRAINT_CHECK) continue; match = false; foreach(lc, connames) { if (strcmp(NameStr(con->conname), (char *) lfirst(lc)) == 0) { match = true; break; } } if (match) { /* Decrement inhcount and possibly set islocal to true */ HeapTuple copyTuple = heap_copytuple(constraintTuple); Form_pg_constraint copy_con = (Form_pg_constraint) GETSTRUCT(copyTuple); if (copy_con->coninhcount <= 0) /* shouldn't happen */ elog(ERROR, "relation %u has non-inherited constraint \"%s\"", RelationGetRelid(child_rel), NameStr(copy_con->conname)); copy_con->coninhcount--; if (copy_con->coninhcount == 0) copy_con->conislocal = true; CatalogTupleUpdate(catalogRelation, ©Tuple->t_self, copyTuple); heap_freetuple(copyTuple); } } systable_endscan(scan); heap_close(catalogRelation, RowExclusiveLock); drop_parent_dependency(RelationGetRelid(child_rel), RelationRelationId, RelationGetRelid(parent_rel)); /* * Post alter hook of this inherits. Since object_access_hook doesn't take * multiple object identifiers, we relay oid of parent relation using * auxiliary_id argument. */ InvokeObjectPostAlterHookArg(InheritsRelationId, RelationGetRelid(child_rel), 0, RelationGetRelid(parent_rel), false); } /* * Drop the dependency created by StoreCatalogInheritance1 (CREATE TABLE * INHERITS/ALTER TABLE INHERIT -- refclassid will be RelationRelationId) or * heap_create_with_catalog (CREATE TABLE OF/ALTER TABLE OF -- refclassid will * be TypeRelationId). There's no convenient way to do this, so go trawling * through pg_depend. */ static void drop_parent_dependency(Oid relid, Oid refclassid, Oid refobjid) { Relation catalogRelation; SysScanDesc scan; ScanKeyData key[3]; HeapTuple depTuple; catalogRelation = heap_open(DependRelationId, RowExclusiveLock); ScanKeyInit(&key[0], Anum_pg_depend_classid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationRelationId)); ScanKeyInit(&key[1], Anum_pg_depend_objid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relid)); ScanKeyInit(&key[2], Anum_pg_depend_objsubid, BTEqualStrategyNumber, F_INT4EQ, Int32GetDatum(0)); scan = systable_beginscan(catalogRelation, DependDependerIndexId, true, NULL, 3, key); while (HeapTupleIsValid(depTuple = systable_getnext(scan))) { Form_pg_depend dep = (Form_pg_depend) GETSTRUCT(depTuple); if (dep->refclassid == refclassid && dep->refobjid == refobjid && dep->refobjsubid == 0 && dep->deptype == DEPENDENCY_NORMAL) CatalogTupleDelete(catalogRelation, &depTuple->t_self); } systable_endscan(scan); heap_close(catalogRelation, RowExclusiveLock); } /* * ALTER TABLE OF * * Attach a table to a composite type, as though it had been created with CREATE * TABLE OF. All attname, atttypid, atttypmod and attcollation must match. The * subject table must not have inheritance parents. These restrictions ensure * that you cannot create a configuration impossible with CREATE TABLE OF alone. * * The address of the type is returned. */ static ObjectAddress ATExecAddOf(Relation rel, const TypeName *ofTypename, LOCKMODE lockmode) { Oid relid = RelationGetRelid(rel); Type typetuple; Oid typeid; Relation inheritsRelation, relationRelation; SysScanDesc scan; ScanKeyData key; AttrNumber table_attno, type_attno; TupleDesc typeTupleDesc, tableTupleDesc; ObjectAddress tableobj, typeobj; HeapTuple classtuple; /* Validate the type. */ typetuple = typenameType(NULL, ofTypename, NULL); check_of_type(typetuple); typeid = HeapTupleGetOid(typetuple); /* Fail if the table has any inheritance parents. */ inheritsRelation = heap_open(InheritsRelationId, AccessShareLock); ScanKeyInit(&key, Anum_pg_inherits_inhrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relid)); scan = systable_beginscan(inheritsRelation, InheritsRelidSeqnoIndexId, true, NULL, 1, &key); if (HeapTupleIsValid(systable_getnext(scan))) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("typed tables cannot inherit"))); systable_endscan(scan); heap_close(inheritsRelation, AccessShareLock); /* * Check the tuple descriptors for compatibility. Unlike inheritance, we * require that the order also match. However, attnotnull need not match. * Also unlike inheritance, we do not require matching relhasoids. */ typeTupleDesc = lookup_rowtype_tupdesc(typeid, -1); tableTupleDesc = RelationGetDescr(rel); table_attno = 1; for (type_attno = 1; type_attno <= typeTupleDesc->natts; type_attno++) { Form_pg_attribute type_attr, table_attr; const char *type_attname, *table_attname; /* Get the next non-dropped type attribute. */ type_attr = typeTupleDesc->attrs[type_attno - 1]; if (type_attr->attisdropped) continue; type_attname = NameStr(type_attr->attname); /* Get the next non-dropped table attribute. */ do { if (table_attno > tableTupleDesc->natts) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("table is missing column \"%s\"", type_attname))); table_attr = tableTupleDesc->attrs[table_attno++ - 1]; } while (table_attr->attisdropped); table_attname = NameStr(table_attr->attname); /* Compare name. */ if (strncmp(table_attname, type_attname, NAMEDATALEN) != 0) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("table has column \"%s\" where type requires \"%s\"", table_attname, type_attname))); /* Compare type. */ if (table_attr->atttypid != type_attr->atttypid || table_attr->atttypmod != type_attr->atttypmod || table_attr->attcollation != type_attr->attcollation) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("table \"%s\" has different type for column \"%s\"", RelationGetRelationName(rel), type_attname))); } DecrTupleDescRefCount(typeTupleDesc); /* Any remaining columns at the end of the table had better be dropped. */ for (; table_attno <= tableTupleDesc->natts; table_attno++) { Form_pg_attribute table_attr = tableTupleDesc->attrs[table_attno - 1]; if (!table_attr->attisdropped) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("table has extra column \"%s\"", NameStr(table_attr->attname)))); } /* If the table was already typed, drop the existing dependency. */ if (rel->rd_rel->reloftype) drop_parent_dependency(relid, TypeRelationId, rel->rd_rel->reloftype); /* Record a dependency on the new type. */ tableobj.classId = RelationRelationId; tableobj.objectId = relid; tableobj.objectSubId = 0; typeobj.classId = TypeRelationId; typeobj.objectId = typeid; typeobj.objectSubId = 0; recordDependencyOn(&tableobj, &typeobj, DEPENDENCY_NORMAL); /* Update pg_class.reloftype */ relationRelation = heap_open(RelationRelationId, RowExclusiveLock); classtuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid)); if (!HeapTupleIsValid(classtuple)) elog(ERROR, "cache lookup failed for relation %u", relid); ((Form_pg_class) GETSTRUCT(classtuple))->reloftype = typeid; CatalogTupleUpdate(relationRelation, &classtuple->t_self, classtuple); InvokeObjectPostAlterHook(RelationRelationId, relid, 0); heap_freetuple(classtuple); heap_close(relationRelation, RowExclusiveLock); ReleaseSysCache(typetuple); return typeobj; } /* * ALTER TABLE NOT OF * * Detach a typed table from its originating type. Just clear reloftype and * remove the dependency. */ static void ATExecDropOf(Relation rel, LOCKMODE lockmode) { Oid relid = RelationGetRelid(rel); Relation relationRelation; HeapTuple tuple; if (!OidIsValid(rel->rd_rel->reloftype)) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is not a typed table", RelationGetRelationName(rel)))); /* * We don't bother to check ownership of the type --- ownership of the * table is presumed enough rights. No lock required on the type, either. */ drop_parent_dependency(relid, TypeRelationId, rel->rd_rel->reloftype); /* Clear pg_class.reloftype */ relationRelation = heap_open(RelationRelationId, RowExclusiveLock); tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid)); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for relation %u", relid); ((Form_pg_class) GETSTRUCT(tuple))->reloftype = InvalidOid; CatalogTupleUpdate(relationRelation, &tuple->t_self, tuple); InvokeObjectPostAlterHook(RelationRelationId, relid, 0); heap_freetuple(tuple); heap_close(relationRelation, RowExclusiveLock); } /* * relation_mark_replica_identity: Update a table's replica identity * * Iff ri_type = REPLICA_IDENTITY_INDEX, indexOid must be the Oid of a suitable * index. Otherwise, it should be InvalidOid. */ static void relation_mark_replica_identity(Relation rel, char ri_type, Oid indexOid, bool is_internal) { Relation pg_index; Relation pg_class; HeapTuple pg_class_tuple; HeapTuple pg_index_tuple; Form_pg_class pg_class_form; Form_pg_index pg_index_form; ListCell *index; /* * Check whether relreplident has changed, and update it if so. */ pg_class = heap_open(RelationRelationId, RowExclusiveLock); pg_class_tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(RelationGetRelid(rel))); if (!HeapTupleIsValid(pg_class_tuple)) elog(ERROR, "cache lookup failed for relation \"%s\"", RelationGetRelationName(rel)); pg_class_form = (Form_pg_class) GETSTRUCT(pg_class_tuple); if (pg_class_form->relreplident != ri_type) { pg_class_form->relreplident = ri_type; CatalogTupleUpdate(pg_class, &pg_class_tuple->t_self, pg_class_tuple); } heap_close(pg_class, RowExclusiveLock); heap_freetuple(pg_class_tuple); /* * Check whether the correct index is marked indisreplident; if so, we're * done. */ if (OidIsValid(indexOid)) { Assert(ri_type == REPLICA_IDENTITY_INDEX); pg_index_tuple = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(indexOid)); if (!HeapTupleIsValid(pg_index_tuple)) elog(ERROR, "cache lookup failed for index %u", indexOid); pg_index_form = (Form_pg_index) GETSTRUCT(pg_index_tuple); if (pg_index_form->indisreplident) { ReleaseSysCache(pg_index_tuple); return; } ReleaseSysCache(pg_index_tuple); } /* * Clear the indisreplident flag from any index that had it previously, * and set it for any index that should have it now. */ pg_index = heap_open(IndexRelationId, RowExclusiveLock); foreach(index, RelationGetIndexList(rel)) { Oid thisIndexOid = lfirst_oid(index); bool dirty = false; pg_index_tuple = SearchSysCacheCopy1(INDEXRELID, ObjectIdGetDatum(thisIndexOid)); if (!HeapTupleIsValid(pg_index_tuple)) elog(ERROR, "cache lookup failed for index %u", thisIndexOid); pg_index_form = (Form_pg_index) GETSTRUCT(pg_index_tuple); /* * Unset the bit if set. We know it's wrong because we checked this * earlier. */ if (pg_index_form->indisreplident) { dirty = true; pg_index_form->indisreplident = false; } else if (thisIndexOid == indexOid) { dirty = true; pg_index_form->indisreplident = true; } if (dirty) { CatalogTupleUpdate(pg_index, &pg_index_tuple->t_self, pg_index_tuple); InvokeObjectPostAlterHookArg(IndexRelationId, thisIndexOid, 0, InvalidOid, is_internal); } heap_freetuple(pg_index_tuple); } heap_close(pg_index, RowExclusiveLock); } /* * ALTER TABLE REPLICA IDENTITY ... */ static void ATExecReplicaIdentity(Relation rel, ReplicaIdentityStmt *stmt, LOCKMODE lockmode) { Oid indexOid; Relation indexRel; int key; if (stmt->identity_type == REPLICA_IDENTITY_DEFAULT) { relation_mark_replica_identity(rel, stmt->identity_type, InvalidOid, true); return; } else if (stmt->identity_type == REPLICA_IDENTITY_FULL) { relation_mark_replica_identity(rel, stmt->identity_type, InvalidOid, true); return; } else if (stmt->identity_type == REPLICA_IDENTITY_NOTHING) { relation_mark_replica_identity(rel, stmt->identity_type, InvalidOid, true); return; } else if (stmt->identity_type == REPLICA_IDENTITY_INDEX) { /* fallthrough */ ; } else elog(ERROR, "unexpected identity type %u", stmt->identity_type); /* Check that the index exists */ indexOid = get_relname_relid(stmt->name, rel->rd_rel->relnamespace); if (!OidIsValid(indexOid)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("index \"%s\" for table \"%s\" does not exist", stmt->name, RelationGetRelationName(rel)))); indexRel = index_open(indexOid, ShareLock); /* Check that the index is on the relation we're altering. */ if (indexRel->rd_index == NULL || indexRel->rd_index->indrelid != RelationGetRelid(rel)) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is not an index for table \"%s\"", RelationGetRelationName(indexRel), RelationGetRelationName(rel)))); /* The AM must support uniqueness, and the index must in fact be unique. */ if (!indexRel->rd_amroutine->amcanunique || !indexRel->rd_index->indisunique) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot use non-unique index \"%s\" as replica identity", RelationGetRelationName(indexRel)))); /* Deferred indexes are not guaranteed to be always unique. */ if (!indexRel->rd_index->indimmediate) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot use non-immediate index \"%s\" as replica identity", RelationGetRelationName(indexRel)))); /* Expression indexes aren't supported. */ if (RelationGetIndexExpressions(indexRel) != NIL) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot use expression index \"%s\" as replica identity", RelationGetRelationName(indexRel)))); /* Predicate indexes aren't supported. */ if (RelationGetIndexPredicate(indexRel) != NIL) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot use partial index \"%s\" as replica identity", RelationGetRelationName(indexRel)))); /* And neither are invalid indexes. */ if (!IndexIsValid(indexRel->rd_index)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot use invalid index \"%s\" as replica identity", RelationGetRelationName(indexRel)))); /* Check index for nullable columns. */ for (key = 0; key < indexRel->rd_index->indnatts; key++) { int16 attno = indexRel->rd_index->indkey.values[key]; Form_pg_attribute attr; /* Allow OID column to be indexed; it's certainly not nullable */ if (attno == ObjectIdAttributeNumber) continue; /* * Reject any other system columns. (Going forward, we'll disallow * indexes containing such columns in the first place, but they might * exist in older branches.) */ if (attno <= 0) ereport(ERROR, (errcode(ERRCODE_INVALID_COLUMN_REFERENCE), errmsg("index \"%s\" cannot be used as replica identity because column %d is a system column", RelationGetRelationName(indexRel), attno))); attr = rel->rd_att->attrs[attno - 1]; if (!attr->attnotnull) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("index \"%s\" cannot be used as replica identity because column \"%s\" is nullable", RelationGetRelationName(indexRel), NameStr(attr->attname)))); } /* This index is suitable for use as a replica identity. Mark it. */ relation_mark_replica_identity(rel, stmt->identity_type, indexOid, true); index_close(indexRel, NoLock); } /* * ALTER TABLE ENABLE/DISABLE ROW LEVEL SECURITY */ static void ATExecEnableRowSecurity(Relation rel) { Relation pg_class; Oid relid; HeapTuple tuple; relid = RelationGetRelid(rel); pg_class = heap_open(RelationRelationId, RowExclusiveLock); tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid)); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for relation %u", relid); ((Form_pg_class) GETSTRUCT(tuple))->relrowsecurity = true; CatalogTupleUpdate(pg_class, &tuple->t_self, tuple); heap_close(pg_class, RowExclusiveLock); heap_freetuple(tuple); } static void ATExecDisableRowSecurity(Relation rel) { Relation pg_class; Oid relid; HeapTuple tuple; relid = RelationGetRelid(rel); /* Pull the record for this relation and update it */ pg_class = heap_open(RelationRelationId, RowExclusiveLock); tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid)); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for relation %u", relid); ((Form_pg_class) GETSTRUCT(tuple))->relrowsecurity = false; CatalogTupleUpdate(pg_class, &tuple->t_self, tuple); heap_close(pg_class, RowExclusiveLock); heap_freetuple(tuple); } /* * ALTER TABLE FORCE/NO FORCE ROW LEVEL SECURITY */ static void ATExecForceNoForceRowSecurity(Relation rel, bool force_rls) { Relation pg_class; Oid relid; HeapTuple tuple; relid = RelationGetRelid(rel); pg_class = heap_open(RelationRelationId, RowExclusiveLock); tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid)); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for relation %u", relid); ((Form_pg_class) GETSTRUCT(tuple))->relforcerowsecurity = force_rls; CatalogTupleUpdate(pg_class, &tuple->t_self, tuple); heap_close(pg_class, RowExclusiveLock); heap_freetuple(tuple); } /* * ALTER FOREIGN TABLE OPTIONS (...) */ static void ATExecGenericOptions(Relation rel, List *options) { Relation ftrel; ForeignServer *server; ForeignDataWrapper *fdw; HeapTuple tuple; bool isnull; Datum repl_val[Natts_pg_foreign_table]; bool repl_null[Natts_pg_foreign_table]; bool repl_repl[Natts_pg_foreign_table]; Datum datum; Form_pg_foreign_table tableform; if (options == NIL) return; ftrel = heap_open(ForeignTableRelationId, RowExclusiveLock); tuple = SearchSysCacheCopy1(FOREIGNTABLEREL, rel->rd_id); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("foreign table \"%s\" does not exist", RelationGetRelationName(rel)))); tableform = (Form_pg_foreign_table) GETSTRUCT(tuple); server = GetForeignServer(tableform->ftserver); fdw = GetForeignDataWrapper(server->fdwid); memset(repl_val, 0, sizeof(repl_val)); memset(repl_null, false, sizeof(repl_null)); memset(repl_repl, false, sizeof(repl_repl)); /* Extract the current options */ datum = SysCacheGetAttr(FOREIGNTABLEREL, tuple, Anum_pg_foreign_table_ftoptions, &isnull); if (isnull) datum = PointerGetDatum(NULL); /* Transform the options */ datum = transformGenericOptions(ForeignTableRelationId, datum, options, fdw->fdwvalidator); if (PointerIsValid(DatumGetPointer(datum))) repl_val[Anum_pg_foreign_table_ftoptions - 1] = datum; else repl_null[Anum_pg_foreign_table_ftoptions - 1] = true; repl_repl[Anum_pg_foreign_table_ftoptions - 1] = true; /* Everything looks good - update the tuple */ tuple = heap_modify_tuple(tuple, RelationGetDescr(ftrel), repl_val, repl_null, repl_repl); CatalogTupleUpdate(ftrel, &tuple->t_self, tuple); /* * Invalidate relcache so that all sessions will refresh any cached plans * that might depend on the old options. */ CacheInvalidateRelcache(rel); InvokeObjectPostAlterHook(ForeignTableRelationId, RelationGetRelid(rel), 0); heap_close(ftrel, RowExclusiveLock); heap_freetuple(tuple); } /* * Preparation phase for SET LOGGED/UNLOGGED * * This verifies that we're not trying to change a temp table. Also, * existing foreign key constraints are checked to avoid ending up with * permanent tables referencing unlogged tables. * * Return value is false if the operation is a no-op (in which case the * checks are skipped), otherwise true. */ static bool ATPrepChangePersistence(Relation rel, bool toLogged) { Relation pg_constraint; HeapTuple tuple; SysScanDesc scan; ScanKeyData skey[1]; /* * Disallow changing status for a temp table. Also verify whether we can * get away with doing nothing; in such cases we don't need to run the * checks below, either. */ switch (rel->rd_rel->relpersistence) { case RELPERSISTENCE_TEMP: ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot change logged status of table \"%s\" because it is temporary", RelationGetRelationName(rel)), errtable(rel))); break; case RELPERSISTENCE_PERMANENT: if (toLogged) /* nothing to do */ return false; break; case RELPERSISTENCE_UNLOGGED: if (!toLogged) /* nothing to do */ return false; break; } /* * Check that the table is not part any publication when changing to * UNLOGGED as UNLOGGED tables can't be published. */ if (!toLogged && list_length(GetRelationPublications(RelationGetRelid(rel))) > 0) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("cannot change table \"%s\" to unlogged because it is part of a publication", RelationGetRelationName(rel)), errdetail("Unlogged relations cannot be replicated."))); /* * Check existing foreign key constraints to preserve the invariant that * permanent tables cannot reference unlogged ones. Self-referencing * foreign keys can safely be ignored. */ pg_constraint = heap_open(ConstraintRelationId, AccessShareLock); /* * Scan conrelid if changing to permanent, else confrelid. This also * determines whether a useful index exists. */ ScanKeyInit(&skey[0], toLogged ? Anum_pg_constraint_conrelid : Anum_pg_constraint_confrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel))); scan = systable_beginscan(pg_constraint, toLogged ? ConstraintRelidIndexId : InvalidOid, true, NULL, 1, skey); while (HeapTupleIsValid(tuple = systable_getnext(scan))) { Form_pg_constraint con = (Form_pg_constraint) GETSTRUCT(tuple); if (con->contype == CONSTRAINT_FOREIGN) { Oid foreignrelid; Relation foreignrel; /* the opposite end of what we used as scankey */ foreignrelid = toLogged ? con->confrelid : con->conrelid; /* ignore if self-referencing */ if (RelationGetRelid(rel) == foreignrelid) continue; foreignrel = relation_open(foreignrelid, AccessShareLock); if (toLogged) { if (foreignrel->rd_rel->relpersistence != RELPERSISTENCE_PERMANENT) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("could not change table \"%s\" to logged because it references unlogged table \"%s\"", RelationGetRelationName(rel), RelationGetRelationName(foreignrel)), errtableconstraint(rel, NameStr(con->conname)))); } else { if (foreignrel->rd_rel->relpersistence == RELPERSISTENCE_PERMANENT) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("could not change table \"%s\" to unlogged because it references logged table \"%s\"", RelationGetRelationName(rel), RelationGetRelationName(foreignrel)), errtableconstraint(rel, NameStr(con->conname)))); } relation_close(foreignrel, AccessShareLock); } } systable_endscan(scan); heap_close(pg_constraint, AccessShareLock); return true; } /* * Execute ALTER TABLE SET SCHEMA */ ObjectAddress AlterTableNamespace(AlterObjectSchemaStmt *stmt, Oid *oldschema) { Relation rel; Oid relid; Oid oldNspOid; Oid nspOid; RangeVar *newrv; ObjectAddresses *objsMoved; ObjectAddress myself; relid = RangeVarGetRelidExtended(stmt->relation, AccessExclusiveLock, stmt->missing_ok, false, RangeVarCallbackForAlterRelation, (void *) stmt); if (!OidIsValid(relid)) { ereport(NOTICE, (errmsg("relation \"%s\" does not exist, skipping", stmt->relation->relname))); return InvalidObjectAddress; } rel = relation_open(relid, NoLock); oldNspOid = RelationGetNamespace(rel); /* If it's an owned sequence, disallow moving it by itself. */ if (rel->rd_rel->relkind == RELKIND_SEQUENCE) { Oid tableId; int32 colId; if (sequenceIsOwned(relid, DEPENDENCY_AUTO, &tableId, &colId) || sequenceIsOwned(relid, DEPENDENCY_INTERNAL, &tableId, &colId)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot move an owned sequence into another schema"), errdetail("Sequence \"%s\" is linked to table \"%s\".", RelationGetRelationName(rel), get_rel_name(tableId)))); } /* Get and lock schema OID and check its permissions. */ newrv = makeRangeVar(stmt->newschema, RelationGetRelationName(rel), -1); nspOid = RangeVarGetAndCheckCreationNamespace(newrv, NoLock, NULL); /* common checks on switching namespaces */ CheckSetNamespace(oldNspOid, nspOid); objsMoved = new_object_addresses(); AlterTableNamespaceInternal(rel, oldNspOid, nspOid, objsMoved); free_object_addresses(objsMoved); ObjectAddressSet(myself, RelationRelationId, relid); if (oldschema) *oldschema = oldNspOid; /* close rel, but keep lock until commit */ relation_close(rel, NoLock); return myself; } /* * The guts of relocating a table or materialized view to another namespace: * besides moving the relation itself, its dependent objects are relocated to * the new schema. */ void AlterTableNamespaceInternal(Relation rel, Oid oldNspOid, Oid nspOid, ObjectAddresses *objsMoved) { Relation classRel; Assert(objsMoved != NULL); /* OK, modify the pg_class row and pg_depend entry */ classRel = heap_open(RelationRelationId, RowExclusiveLock); AlterRelationNamespaceInternal(classRel, RelationGetRelid(rel), oldNspOid, nspOid, true, objsMoved); /* Fix the table's row type too */ AlterTypeNamespaceInternal(rel->rd_rel->reltype, nspOid, false, false, objsMoved); /* Fix other dependent stuff */ if (rel->rd_rel->relkind == RELKIND_RELATION || rel->rd_rel->relkind == RELKIND_MATVIEW || rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) { AlterIndexNamespaces(classRel, rel, oldNspOid, nspOid, objsMoved); AlterSeqNamespaces(classRel, rel, oldNspOid, nspOid, objsMoved, AccessExclusiveLock); AlterConstraintNamespaces(RelationGetRelid(rel), oldNspOid, nspOid, false, objsMoved); } heap_close(classRel, RowExclusiveLock); } /* * The guts of relocating a relation to another namespace: fix the pg_class * entry, and the pg_depend entry if any. Caller must already have * opened and write-locked pg_class. */ void AlterRelationNamespaceInternal(Relation classRel, Oid relOid, Oid oldNspOid, Oid newNspOid, bool hasDependEntry, ObjectAddresses *objsMoved) { HeapTuple classTup; Form_pg_class classForm; ObjectAddress thisobj; bool already_done = false; classTup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relOid)); if (!HeapTupleIsValid(classTup)) elog(ERROR, "cache lookup failed for relation %u", relOid); classForm = (Form_pg_class) GETSTRUCT(classTup); Assert(classForm->relnamespace == oldNspOid); thisobj.classId = RelationRelationId; thisobj.objectId = relOid; thisobj.objectSubId = 0; /* * If the object has already been moved, don't move it again. If it's * already in the right place, don't move it, but still fire the object * access hook. */ already_done = object_address_present(&thisobj, objsMoved); if (!already_done && oldNspOid != newNspOid) { /* check for duplicate name (more friendly than unique-index failure) */ if (get_relname_relid(NameStr(classForm->relname), newNspOid) != InvalidOid) ereport(ERROR, (errcode(ERRCODE_DUPLICATE_TABLE), errmsg("relation \"%s\" already exists in schema \"%s\"", NameStr(classForm->relname), get_namespace_name(newNspOid)))); /* classTup is a copy, so OK to scribble on */ classForm->relnamespace = newNspOid; CatalogTupleUpdate(classRel, &classTup->t_self, classTup); /* Update dependency on schema if caller said so */ if (hasDependEntry && changeDependencyFor(RelationRelationId, relOid, NamespaceRelationId, oldNspOid, newNspOid) != 1) elog(ERROR, "failed to change schema dependency for relation \"%s\"", NameStr(classForm->relname)); } if (!already_done) { add_exact_object_address(&thisobj, objsMoved); InvokeObjectPostAlterHook(RelationRelationId, relOid, 0); } heap_freetuple(classTup); } /* * Move all indexes for the specified relation to another namespace. * * Note: we assume adequate permission checking was done by the caller, * and that the caller has a suitable lock on the owning relation. */ static void AlterIndexNamespaces(Relation classRel, Relation rel, Oid oldNspOid, Oid newNspOid, ObjectAddresses *objsMoved) { List *indexList; ListCell *l; indexList = RelationGetIndexList(rel); foreach(l, indexList) { Oid indexOid = lfirst_oid(l); ObjectAddress thisobj; thisobj.classId = RelationRelationId; thisobj.objectId = indexOid; thisobj.objectSubId = 0; /* * Note: currently, the index will not have its own dependency on the * namespace, so we don't need to do changeDependencyFor(). There's no * row type in pg_type, either. * * XXX this objsMoved test may be pointless -- surely we have a single * dependency link from a relation to each index? */ if (!object_address_present(&thisobj, objsMoved)) { AlterRelationNamespaceInternal(classRel, indexOid, oldNspOid, newNspOid, false, objsMoved); add_exact_object_address(&thisobj, objsMoved); } } list_free(indexList); } /* * Move all identity and SERIAL-column sequences of the specified relation to another * namespace. * * Note: we assume adequate permission checking was done by the caller, * and that the caller has a suitable lock on the owning relation. */ static void AlterSeqNamespaces(Relation classRel, Relation rel, Oid oldNspOid, Oid newNspOid, ObjectAddresses *objsMoved, LOCKMODE lockmode) { Relation depRel; SysScanDesc scan; ScanKeyData key[2]; HeapTuple tup; /* * SERIAL sequences are those having an auto dependency on one of the * table's columns (we don't care *which* column, exactly). */ depRel = heap_open(DependRelationId, AccessShareLock); ScanKeyInit(&key[0], Anum_pg_depend_refclassid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationRelationId)); ScanKeyInit(&key[1], Anum_pg_depend_refobjid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel))); /* we leave refobjsubid unspecified */ scan = systable_beginscan(depRel, DependReferenceIndexId, true, NULL, 2, key); while (HeapTupleIsValid(tup = systable_getnext(scan))) { Form_pg_depend depForm = (Form_pg_depend) GETSTRUCT(tup); Relation seqRel; /* skip dependencies other than auto dependencies on columns */ if (depForm->refobjsubid == 0 || depForm->classid != RelationRelationId || depForm->objsubid != 0 || !(depForm->deptype == DEPENDENCY_AUTO || depForm->deptype == DEPENDENCY_INTERNAL)) continue; /* Use relation_open just in case it's an index */ seqRel = relation_open(depForm->objid, lockmode); /* skip non-sequence relations */ if (RelationGetForm(seqRel)->relkind != RELKIND_SEQUENCE) { /* No need to keep the lock */ relation_close(seqRel, lockmode); continue; } /* Fix the pg_class and pg_depend entries */ AlterRelationNamespaceInternal(classRel, depForm->objid, oldNspOid, newNspOid, true, objsMoved); /* * Sequences have entries in pg_type. We need to be careful to move * them to the new namespace, too. */ AlterTypeNamespaceInternal(RelationGetForm(seqRel)->reltype, newNspOid, false, false, objsMoved); /* Now we can close it. Keep the lock till end of transaction. */ relation_close(seqRel, NoLock); } systable_endscan(scan); relation_close(depRel, AccessShareLock); } /* * This code supports * CREATE TEMP TABLE ... ON COMMIT { DROP | PRESERVE ROWS | DELETE ROWS } * * Because we only support this for TEMP tables, it's sufficient to remember * the state in a backend-local data structure. */ /* * Register a newly-created relation's ON COMMIT action. */ void register_on_commit_action(Oid relid, OnCommitAction action) { OnCommitItem *oc; MemoryContext oldcxt; /* * We needn't bother registering the relation unless there is an ON COMMIT * action we need to take. */ if (action == ONCOMMIT_NOOP || action == ONCOMMIT_PRESERVE_ROWS) return; oldcxt = MemoryContextSwitchTo(CacheMemoryContext); oc = (OnCommitItem *) palloc(sizeof(OnCommitItem)); oc->relid = relid; oc->oncommit = action; oc->creating_subid = GetCurrentSubTransactionId(); oc->deleting_subid = InvalidSubTransactionId; on_commits = lcons(oc, on_commits); MemoryContextSwitchTo(oldcxt); } /* * Unregister any ON COMMIT action when a relation is deleted. * * Actually, we only mark the OnCommitItem entry as to be deleted after commit. */ void remove_on_commit_action(Oid relid) { ListCell *l; foreach(l, on_commits) { OnCommitItem *oc = (OnCommitItem *) lfirst(l); if (oc->relid == relid) { oc->deleting_subid = GetCurrentSubTransactionId(); break; } } } /* * Perform ON COMMIT actions. * * This is invoked just before actually committing, since it's possible * to encounter errors. */ void PreCommit_on_commit_actions(void) { ListCell *l; List *oids_to_truncate = NIL; foreach(l, on_commits) { OnCommitItem *oc = (OnCommitItem *) lfirst(l); /* Ignore entry if already dropped in this xact */ if (oc->deleting_subid != InvalidSubTransactionId) continue; switch (oc->oncommit) { case ONCOMMIT_NOOP: case ONCOMMIT_PRESERVE_ROWS: /* Do nothing (there shouldn't be such entries, actually) */ break; case ONCOMMIT_DELETE_ROWS: /* * If this transaction hasn't accessed any temporary * relations, we can skip truncating ON COMMIT DELETE ROWS * tables, as they must still be empty. */ if ((MyXactFlags & XACT_FLAGS_ACCESSEDTEMPREL)) oids_to_truncate = lappend_oid(oids_to_truncate, oc->relid); break; case ONCOMMIT_DROP: { ObjectAddress object; object.classId = RelationRelationId; object.objectId = oc->relid; object.objectSubId = 0; /* * Since this is an automatic drop, rather than one * directly initiated by the user, we pass the * PERFORM_DELETION_INTERNAL flag. */ performDeletion(&object, DROP_CASCADE, PERFORM_DELETION_INTERNAL); /* * Note that table deletion will call * remove_on_commit_action, so the entry should get marked * as deleted. */ Assert(oc->deleting_subid != InvalidSubTransactionId); break; } } } if (oids_to_truncate != NIL) { heap_truncate(oids_to_truncate); CommandCounterIncrement(); /* XXX needed? */ } } /* * Post-commit or post-abort cleanup for ON COMMIT management. * * All we do here is remove no-longer-needed OnCommitItem entries. * * During commit, remove entries that were deleted during this transaction; * during abort, remove those created during this transaction. */ void AtEOXact_on_commit_actions(bool isCommit) { ListCell *cur_item; ListCell *prev_item; prev_item = NULL; cur_item = list_head(on_commits); while (cur_item != NULL) { OnCommitItem *oc = (OnCommitItem *) lfirst(cur_item); if (isCommit ? oc->deleting_subid != InvalidSubTransactionId : oc->creating_subid != InvalidSubTransactionId) { /* cur_item must be removed */ on_commits = list_delete_cell(on_commits, cur_item, prev_item); pfree(oc); if (prev_item) cur_item = lnext(prev_item); else cur_item = list_head(on_commits); } else { /* cur_item must be preserved */ oc->creating_subid = InvalidSubTransactionId; oc->deleting_subid = InvalidSubTransactionId; prev_item = cur_item; cur_item = lnext(prev_item); } } } /* * Post-subcommit or post-subabort cleanup for ON COMMIT management. * * During subabort, we can immediately remove entries created during this * subtransaction. During subcommit, just relabel entries marked during * this subtransaction as being the parent's responsibility. */ void AtEOSubXact_on_commit_actions(bool isCommit, SubTransactionId mySubid, SubTransactionId parentSubid) { ListCell *cur_item; ListCell *prev_item; prev_item = NULL; cur_item = list_head(on_commits); while (cur_item != NULL) { OnCommitItem *oc = (OnCommitItem *) lfirst(cur_item); if (!isCommit && oc->creating_subid == mySubid) { /* cur_item must be removed */ on_commits = list_delete_cell(on_commits, cur_item, prev_item); pfree(oc); if (prev_item) cur_item = lnext(prev_item); else cur_item = list_head(on_commits); } else { /* cur_item must be preserved */ if (oc->creating_subid == mySubid) oc->creating_subid = parentSubid; if (oc->deleting_subid == mySubid) oc->deleting_subid = isCommit ? parentSubid : InvalidSubTransactionId; prev_item = cur_item; cur_item = lnext(prev_item); } } } /* * This is intended as a callback for RangeVarGetRelidExtended(). It allows * the relation to be locked only if (1) it's a plain table, materialized * view, or TOAST table and (2) the current user is the owner (or the * superuser). This meets the permission-checking needs of CLUSTER, REINDEX * TABLE, and REFRESH MATERIALIZED VIEW; we expose it here so that it can be * used by all. */ void RangeVarCallbackOwnsTable(const RangeVar *relation, Oid relId, Oid oldRelId, void *arg) { char relkind; /* Nothing to do if the relation was not found. */ if (!OidIsValid(relId)) return; /* * If the relation does exist, check whether it's an index. But note that * the relation might have been dropped between the time we did the name * lookup and now. In that case, there's nothing to do. */ relkind = get_rel_relkind(relId); if (!relkind) return; if (relkind != RELKIND_RELATION && relkind != RELKIND_TOASTVALUE && relkind != RELKIND_MATVIEW && relkind != RELKIND_PARTITIONED_TABLE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is not a table or materialized view", relation->relname))); /* Check permissions */ if (!pg_class_ownercheck(relId, GetUserId())) aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS, relation->relname); } /* * Callback to RangeVarGetRelidExtended(), similar to * RangeVarCallbackOwnsTable() but without checks on the type of the relation. */ void RangeVarCallbackOwnsRelation(const RangeVar *relation, Oid relId, Oid oldRelId, void *arg) { HeapTuple tuple; /* Nothing to do if the relation was not found. */ if (!OidIsValid(relId)) return; tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relId)); if (!HeapTupleIsValid(tuple)) /* should not happen */ elog(ERROR, "cache lookup failed for relation %u", relId); if (!pg_class_ownercheck(relId, GetUserId())) aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS, relation->relname); if (!allowSystemTableMods && IsSystemClass(relId, (Form_pg_class) GETSTRUCT(tuple))) ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("permission denied: \"%s\" is a system catalog", relation->relname))); ReleaseSysCache(tuple); } /* * Common RangeVarGetRelid callback for rename, set schema, and alter table * processing. */ static void RangeVarCallbackForAlterRelation(const RangeVar *rv, Oid relid, Oid oldrelid, void *arg) { Node *stmt = (Node *) arg; ObjectType reltype; HeapTuple tuple; Form_pg_class classform; AclResult aclresult; char relkind; tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid)); if (!HeapTupleIsValid(tuple)) return; /* concurrently dropped */ classform = (Form_pg_class) GETSTRUCT(tuple); relkind = classform->relkind; /* Must own relation. */ if (!pg_class_ownercheck(relid, GetUserId())) aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS, rv->relname); /* No system table modifications unless explicitly allowed. */ if (!allowSystemTableMods && IsSystemClass(relid, classform)) ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("permission denied: \"%s\" is a system catalog", rv->relname))); /* * Extract the specified relation type from the statement parse tree. * * Also, for ALTER .. RENAME, check permissions: the user must (still) * have CREATE rights on the containing namespace. */ if (IsA(stmt, RenameStmt)) { aclresult = pg_namespace_aclcheck(classform->relnamespace, GetUserId(), ACL_CREATE); if (aclresult != ACLCHECK_OK) aclcheck_error(aclresult, ACL_KIND_NAMESPACE, get_namespace_name(classform->relnamespace)); reltype = ((RenameStmt *) stmt)->renameType; } else if (IsA(stmt, AlterObjectSchemaStmt)) reltype = ((AlterObjectSchemaStmt *) stmt)->objectType; else if (IsA(stmt, AlterTableStmt)) reltype = ((AlterTableStmt *) stmt)->relkind; else { reltype = OBJECT_TABLE; /* placate compiler */ elog(ERROR, "unrecognized node type: %d", (int) nodeTag(stmt)); } /* * For compatibility with prior releases, we allow ALTER TABLE to be used * with most other types of relations (but not composite types). We allow * similar flexibility for ALTER INDEX in the case of RENAME, but not * otherwise. Otherwise, the user must select the correct form of the * command for the relation at issue. */ if (reltype == OBJECT_SEQUENCE && relkind != RELKIND_SEQUENCE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is not a sequence", rv->relname))); if (reltype == OBJECT_VIEW && relkind != RELKIND_VIEW) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is not a view", rv->relname))); if (reltype == OBJECT_MATVIEW && relkind != RELKIND_MATVIEW) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is not a materialized view", rv->relname))); if (reltype == OBJECT_FOREIGN_TABLE && relkind != RELKIND_FOREIGN_TABLE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is not a foreign table", rv->relname))); if (reltype == OBJECT_TYPE && relkind != RELKIND_COMPOSITE_TYPE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is not a composite type", rv->relname))); if (reltype == OBJECT_INDEX && relkind != RELKIND_INDEX && !IsA(stmt, RenameStmt)) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is not an index", rv->relname))); /* * Don't allow ALTER TABLE on composite types. We want people to use ALTER * TYPE for that. */ if (reltype != OBJECT_TYPE && relkind == RELKIND_COMPOSITE_TYPE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is a composite type", rv->relname), errhint("Use ALTER TYPE instead."))); /* * Don't allow ALTER TABLE .. SET SCHEMA on relations that can't be moved * to a different schema, such as indexes and TOAST tables. */ if (IsA(stmt, AlterObjectSchemaStmt) && relkind != RELKIND_RELATION && relkind != RELKIND_VIEW && relkind != RELKIND_MATVIEW && relkind != RELKIND_SEQUENCE && relkind != RELKIND_FOREIGN_TABLE && relkind != RELKIND_PARTITIONED_TABLE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is not a table, view, materialized view, sequence, or foreign table", rv->relname))); ReleaseSysCache(tuple); } /* * Transform any expressions present in the partition key */ static PartitionSpec * transformPartitionSpec(Relation rel, PartitionSpec *partspec, char *strategy) { PartitionSpec *newspec; ParseState *pstate; RangeTblEntry *rte; ListCell *l; newspec = makeNode(PartitionSpec); newspec->strategy = partspec->strategy; newspec->location = partspec->location; newspec->partParams = NIL; /* Parse partitioning strategy name */ if (!pg_strcasecmp(partspec->strategy, "list")) *strategy = PARTITION_STRATEGY_LIST; else if (!pg_strcasecmp(partspec->strategy, "range")) *strategy = PARTITION_STRATEGY_RANGE; else ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("unrecognized partitioning strategy \"%s\"", partspec->strategy))); /* * Create a dummy ParseState and insert the target relation as its sole * rangetable entry. We need a ParseState for transformExpr. */ pstate = make_parsestate(NULL); rte = addRangeTableEntryForRelation(pstate, rel, NULL, false, true); addRTEtoQuery(pstate, rte, true, true, true); /* take care of any partition expressions */ foreach(l, partspec->partParams) { ListCell *lc; PartitionElem *pelem = (PartitionElem *) lfirst(l); /* Check for PARTITION BY ... (foo, foo) */ foreach(lc, newspec->partParams) { PartitionElem *pparam = (PartitionElem *) lfirst(lc); if (pelem->name && pparam->name && !strcmp(pelem->name, pparam->name)) ereport(ERROR, (errcode(ERRCODE_DUPLICATE_COLUMN), errmsg("column \"%s\" appears more than once in partition key", pelem->name), parser_errposition(pstate, pelem->location))); } if (pelem->expr) { /* Now do parse transformation of the expression */ pelem->expr = transformExpr(pstate, pelem->expr, EXPR_KIND_PARTITION_EXPRESSION); /* we have to fix its collations too */ assign_expr_collations(pstate, pelem->expr); } newspec->partParams = lappend(newspec->partParams, pelem); } return newspec; } /* * Compute per-partition-column information from a list of PartitionElem's */ static void ComputePartitionAttrs(Relation rel, List *partParams, AttrNumber *partattrs, List **partexprs, Oid *partopclass, Oid *partcollation) { int attn; ListCell *lc; attn = 0; foreach(lc, partParams) { PartitionElem *pelem = (PartitionElem *) lfirst(lc); Oid atttype; Oid attcollation; if (pelem->name != NULL) { /* Simple attribute reference */ HeapTuple atttuple; Form_pg_attribute attform; atttuple = SearchSysCacheAttName(RelationGetRelid(rel), pelem->name); if (!HeapTupleIsValid(atttuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" named in partition key does not exist", pelem->name))); attform = (Form_pg_attribute) GETSTRUCT(atttuple); if (attform->attnum <= 0) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("cannot use system column \"%s\" in partition key", pelem->name))); partattrs[attn] = attform->attnum; atttype = attform->atttypid; attcollation = attform->attcollation; ReleaseSysCache(atttuple); /* Note that whole-row references can't happen here; see below */ } else { /* Expression */ Node *expr = pelem->expr; Assert(expr != NULL); atttype = exprType(expr); attcollation = exprCollation(expr); /* * Strip any top-level COLLATE clause. This ensures that we treat * "x COLLATE y" and "(x COLLATE y)" alike. */ while (IsA(expr, CollateExpr)) expr = (Node *) ((CollateExpr *) expr)->arg; if (IsA(expr, Var) && ((Var *) expr)->varattno != InvalidAttrNumber) { /* * User wrote "(column)" or "(column COLLATE something)". * Treat it like simple attribute anyway. */ partattrs[attn] = ((Var *) expr)->varattno; } else { Bitmapset *expr_attrs = NULL; partattrs[attn] = 0; /* marks the column as expression */ *partexprs = lappend(*partexprs, expr); /* * Note that expression_planner does not change the passed in * expression destructively and we have already saved the * expression to be stored into the catalog above. */ expr = (Node *) expression_planner((Expr *) expr); /* * Partition expression cannot contain mutable functions, * because a given row must always map to the same partition * as long as there is no change in the partition boundary * structure. */ if (contain_mutable_functions(expr)) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("functions in partition key expression must be marked IMMUTABLE"))); /* * While it is not exactly *wrong* for an expression to be a * constant value, it seems better to prevent such input. */ if (IsA(expr, Const)) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("cannot use constant expression as partition key"))); /* * transformPartitionSpec() should have already rejected * subqueries, aggregates, window functions, and SRFs, based * on the EXPR_KIND_ for partition expressions. */ /* Cannot have expressions containing whole-row references */ pull_varattnos(expr, 1, &expr_attrs); if (bms_is_member(0 - FirstLowInvalidHeapAttributeNumber, expr_attrs)) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("partition key expressions cannot contain whole-row references"))); } } /* * Apply collation override if any */ if (pelem->collation) attcollation = get_collation_oid(pelem->collation, false); /* * Check we have a collation iff it's a collatable type. The only * expected failures here are (1) COLLATE applied to a noncollatable * type, or (2) partition expression had an unresolved collation. But * we might as well code this to be a complete consistency check. */ if (type_is_collatable(atttype)) { if (!OidIsValid(attcollation)) ereport(ERROR, (errcode(ERRCODE_INDETERMINATE_COLLATION), errmsg("could not determine which collation to use for partition expression"), errhint("Use the COLLATE clause to set the collation explicitly."))); } else { if (OidIsValid(attcollation)) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("collations are not supported by type %s", format_type_be(atttype)))); } partcollation[attn] = attcollation; /* * Identify a btree opclass to use. Currently, we use only btree * operators, which seems enough for list and range partitioning. */ if (!pelem->opclass) { partopclass[attn] = GetDefaultOpClass(atttype, BTREE_AM_OID); if (!OidIsValid(partopclass[attn])) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("data type %s has no default btree operator class", format_type_be(atttype)), errhint("You must specify a btree operator class or define a default btree operator class for the data type."))); } else partopclass[attn] = ResolveOpClass(pelem->opclass, atttype, "btree", BTREE_AM_OID); attn++; } } /* * ALTER TABLE ATTACH PARTITION FOR VALUES * * Return the address of the newly attached partition. */ static ObjectAddress ATExecAttachPartition(List **wqueue, Relation rel, PartitionCmd *cmd) { PartitionKey key = RelationGetPartitionKey(rel); Relation attachRel, catalog; List *childrels; TupleConstr *attachRel_constr; List *partConstraint, *existConstraint; SysScanDesc scan; ScanKeyData skey; AttrNumber attno; int natts; TupleDesc tupleDesc; bool skip_validate = false; ObjectAddress address; attachRel = heap_openrv(cmd->name, AccessExclusiveLock); /* * Must be owner of both parent and source table -- parent was checked by * ATSimplePermissions call in ATPrepCmd */ ATSimplePermissions(attachRel, ATT_TABLE | ATT_FOREIGN_TABLE); /* A partition can only have one parent */ if (attachRel->rd_rel->relispartition) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is already a partition", RelationGetRelationName(attachRel)))); if (OidIsValid(attachRel->rd_rel->reloftype)) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot attach a typed table as partition"))); /* * Table being attached should not already be part of inheritance; either * as a child table... */ catalog = heap_open(InheritsRelationId, AccessShareLock); ScanKeyInit(&skey, Anum_pg_inherits_inhrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(attachRel))); scan = systable_beginscan(catalog, InheritsRelidSeqnoIndexId, true, NULL, 1, &skey); if (HeapTupleIsValid(systable_getnext(scan))) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot attach inheritance child as partition"))); systable_endscan(scan); /* ...or as a parent table (except the case when it is partitioned) */ ScanKeyInit(&skey, Anum_pg_inherits_inhparent, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(attachRel))); scan = systable_beginscan(catalog, InheritsParentIndexId, true, NULL, 1, &skey); if (HeapTupleIsValid(systable_getnext(scan)) && attachRel->rd_rel->relkind == RELKIND_RELATION) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot attach inheritance parent as partition"))); systable_endscan(scan); heap_close(catalog, AccessShareLock); /* * Prevent circularity by seeing if rel is a partition of attachRel. (In * particular, this disallows making a rel a partition of itself.) */ childrels = find_all_inheritors(RelationGetRelid(attachRel), AccessShareLock, NULL); if (list_member_oid(childrels, RelationGetRelid(rel))) ereport(ERROR, (errcode(ERRCODE_DUPLICATE_TABLE), errmsg("circular inheritance not allowed"), errdetail("\"%s\" is already a child of \"%s\".", RelationGetRelationName(rel), RelationGetRelationName(attachRel)))); /* Temp parent cannot have a partition that is itself not a temp */ if (rel->rd_rel->relpersistence == RELPERSISTENCE_TEMP && attachRel->rd_rel->relpersistence != RELPERSISTENCE_TEMP) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot attach a permanent relation as partition of temporary relation \"%s\"", RelationGetRelationName(rel)))); /* If the parent is temp, it must belong to this session */ if (rel->rd_rel->relpersistence == RELPERSISTENCE_TEMP && !rel->rd_islocaltemp) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot attach as partition of temporary relation of another session"))); /* Ditto for the partition */ if (attachRel->rd_rel->relpersistence == RELPERSISTENCE_TEMP && !attachRel->rd_islocaltemp) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot attach temporary relation of another session as partition"))); /* If parent has OIDs then child must have OIDs */ if (rel->rd_rel->relhasoids && !attachRel->rd_rel->relhasoids) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot attach table \"%s\" without OIDs as partition of" " table \"%s\" with OIDs", RelationGetRelationName(attachRel), RelationGetRelationName(rel)))); /* OTOH, if parent doesn't have them, do not allow in attachRel either */ if (attachRel->rd_rel->relhasoids && !rel->rd_rel->relhasoids) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot attach table \"%s\" with OIDs as partition of table" " \"%s\" without OIDs", RelationGetRelationName(attachRel), RelationGetRelationName(rel)))); /* Check if there are any columns in attachRel that aren't in the parent */ tupleDesc = RelationGetDescr(attachRel); natts = tupleDesc->natts; for (attno = 1; attno <= natts; attno++) { Form_pg_attribute attribute = tupleDesc->attrs[attno - 1]; char *attributeName = NameStr(attribute->attname); /* Ignore dropped */ if (attribute->attisdropped) continue; /* Try to find the column in parent (matching on column name) */ if (!SearchSysCacheExists2(ATTNAME, ObjectIdGetDatum(RelationGetRelid(rel)), CStringGetDatum(attributeName))) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("table \"%s\" contains column \"%s\" not found in parent \"%s\"", RelationGetRelationName(attachRel), attributeName, RelationGetRelationName(rel)), errdetail("New partition should contain only the columns present in parent."))); } /* OK to create inheritance. Rest of the checks performed there */ CreateInheritance(attachRel, rel); /* * Check that the new partition's bound is valid and does not overlap any * of existing partitions of the parent - note that it does not return on * error. */ check_new_partition_bound(RelationGetRelationName(attachRel), rel, cmd->bound); /* Update the pg_class entry. */ StorePartitionBound(attachRel, rel, cmd->bound); /* * Generate partition constraint from the partition bound specification. * If the parent itself is a partition, make sure to include its * constraint as well. */ partConstraint = list_concat(get_qual_from_partbound(attachRel, rel, cmd->bound), RelationGetPartitionQual(rel)); partConstraint = (List *) eval_const_expressions(NULL, (Node *) partConstraint); partConstraint = (List *) canonicalize_qual((Expr *) partConstraint); partConstraint = list_make1(make_ands_explicit(partConstraint)); /* * Check if we can do away with having to scan the table being attached to * validate the partition constraint, by *proving* that the existing * constraints of the table *imply* the partition predicate. We include * the table's check constraints and NOT NULL constraints in the list of * clauses passed to predicate_implied_by(). * * There is a case in which we cannot rely on just the result of the * proof. */ attachRel_constr = tupleDesc->constr; existConstraint = NIL; if (attachRel_constr != NULL) { int num_check = attachRel_constr->num_check; int i; Bitmapset *not_null_attrs = NULL; List *part_constr; ListCell *lc; bool partition_accepts_null = true; int partnatts; if (attachRel_constr->has_not_null) { int natts = attachRel->rd_att->natts; for (i = 1; i <= natts; i++) { Form_pg_attribute att = attachRel->rd_att->attrs[i - 1]; if (att->attnotnull && !att->attisdropped) { NullTest *ntest = makeNode(NullTest); ntest->arg = (Expr *) makeVar(1, i, att->atttypid, att->atttypmod, att->attcollation, 0); ntest->nulltesttype = IS_NOT_NULL; /* * argisrow=false is correct even for a composite column, * because attnotnull does not represent a SQL-spec IS NOT * NULL test in such a case, just IS DISTINCT FROM NULL. */ ntest->argisrow = false; ntest->location = -1; existConstraint = lappend(existConstraint, ntest); not_null_attrs = bms_add_member(not_null_attrs, i); } } } for (i = 0; i < num_check; i++) { Node *cexpr; /* * If this constraint hasn't been fully validated yet, we must * ignore it here. */ if (!attachRel_constr->check[i].ccvalid) continue; cexpr = stringToNode(attachRel_constr->check[i].ccbin); /* * Run each expression through const-simplification and * canonicalization. It is necessary, because we will be * comparing it to similarly-processed qual clauses, and may fail * to detect valid matches without this. */ cexpr = eval_const_expressions(NULL, cexpr); cexpr = (Node *) canonicalize_qual((Expr *) cexpr); existConstraint = list_concat(existConstraint, make_ands_implicit((Expr *) cexpr)); } existConstraint = list_make1(make_ands_explicit(existConstraint)); /* And away we go ... */ if (predicate_implied_by(partConstraint, existConstraint)) skip_validate = true; /* * We choose to err on the safer side, i.e., give up on skipping the * validation scan, if the partition key column doesn't have the NOT * NULL constraint and the table is to become a list partition that * does not accept nulls. In this case, the partition predicate * (partConstraint) does include an 'key IS NOT NULL' expression, * however, because of the way predicate_implied_by_simple_clause() is * designed to handle IS NOT NULL predicates in the absence of a IS * NOT NULL clause, we cannot rely on just the above proof. * * That is not an issue in case of a range partition, because if there * were no NOT NULL constraint defined on the key columns, an error * would be thrown before we get here anyway. That is not true, * however, if any of the partition keys is an expression, which is * handled below. */ part_constr = linitial(partConstraint); part_constr = make_ands_implicit((Expr *) part_constr); /* * part_constr contains an IS NOT NULL expression, if this is a list * partition that does not accept nulls (in fact, also if this is a * range partition and some partition key is an expression, but we * never skip validation in that case anyway; see below) */ foreach(lc, part_constr) { Node *expr = lfirst(lc); if (IsA(expr, NullTest) && ((NullTest *) expr)->nulltesttype == IS_NOT_NULL) { partition_accepts_null = false; break; } } partnatts = get_partition_natts(key); for (i = 0; i < partnatts; i++) { AttrNumber partattno; partattno = get_partition_col_attnum(key, i); /* If partition key is an expression, must not skip validation */ if (!partition_accepts_null && (partattno == 0 || !bms_is_member(partattno, not_null_attrs))) skip_validate = false; } } /* It's safe to skip the validation scan after all */ if (skip_validate) ereport(INFO, (errmsg("partition constraint for table \"%s\" is implied by existing constraints", RelationGetRelationName(attachRel)))); /* * Set up to have the table be scanned to validate the partition * constraint (see partConstraint above). If it's a partitioned table, we * instead schedule its leaf partitions to be scanned. */ if (!skip_validate) { List *all_parts; ListCell *lc; /* Take an exclusive lock on the partitions to be checked */ if (attachRel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) all_parts = find_all_inheritors(RelationGetRelid(attachRel), AccessExclusiveLock, NULL); else all_parts = list_make1_oid(RelationGetRelid(attachRel)); foreach(lc, all_parts) { AlteredTableInfo *tab; Oid part_relid = lfirst_oid(lc); Relation part_rel; Expr *constr; /* Lock already taken */ if (part_relid != RelationGetRelid(attachRel)) part_rel = heap_open(part_relid, NoLock); else part_rel = attachRel; /* * Skip if it's a partitioned table. Only RELKIND_RELATION * relations (ie, leaf partitions) need to be scanned. */ if (part_rel != attachRel && part_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) { heap_close(part_rel, NoLock); continue; } /* Grab a work queue entry */ tab = ATGetQueueEntry(wqueue, part_rel); /* Adjust constraint to match this partition */ constr = linitial(partConstraint); tab->partition_constraint = (Expr *) map_partition_varattnos((List *) constr, 1, part_rel, rel); /* keep our lock until commit */ if (part_rel != attachRel) heap_close(part_rel, NoLock); } } ObjectAddressSet(address, RelationRelationId, RelationGetRelid(attachRel)); /* keep our lock until commit */ heap_close(attachRel, NoLock); return address; } /* * ALTER TABLE DETACH PARTITION * * Return the address of the relation that is no longer a partition of rel. */ static ObjectAddress ATExecDetachPartition(Relation rel, RangeVar *name) { Relation partRel, classRel; HeapTuple tuple, newtuple; Datum new_val[Natts_pg_class]; bool isnull, new_null[Natts_pg_class], new_repl[Natts_pg_class]; ObjectAddress address; partRel = heap_openrv(name, AccessShareLock); /* All inheritance related checks are performed within the function */ RemoveInheritance(partRel, rel); /* Update pg_class tuple */ classRel = heap_open(RelationRelationId, RowExclusiveLock); tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(RelationGetRelid(partRel))); Assert(((Form_pg_class) GETSTRUCT(tuple))->relispartition); (void) SysCacheGetAttr(RELOID, tuple, Anum_pg_class_relpartbound, &isnull); Assert(!isnull); /* Clear relpartbound and reset relispartition */ memset(new_val, 0, sizeof(new_val)); memset(new_null, false, sizeof(new_null)); memset(new_repl, false, sizeof(new_repl)); new_val[Anum_pg_class_relpartbound - 1] = (Datum) 0; new_null[Anum_pg_class_relpartbound - 1] = true; new_repl[Anum_pg_class_relpartbound - 1] = true; newtuple = heap_modify_tuple(tuple, RelationGetDescr(classRel), new_val, new_null, new_repl); ((Form_pg_class) GETSTRUCT(newtuple))->relispartition = false; CatalogTupleUpdate(classRel, &newtuple->t_self, newtuple); heap_freetuple(newtuple); heap_close(classRel, RowExclusiveLock); /* * Invalidate the parent's relcache so that the partition is no longer * included in its partition descriptor. */ CacheInvalidateRelcache(rel); ObjectAddressSet(address, RelationRelationId, RelationGetRelid(partRel)); /* keep our lock until commit */ heap_close(partRel, NoLock); return address; }