postgresql/src/include/nodes/nodes.h

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/*-------------------------------------------------------------------------
*
* nodes.h
* Definitions for tagged nodes.
*
*
* Portions Copyright (c) 1996-2015, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
2010-09-20 22:08:53 +02:00
* src/include/nodes/nodes.h
*
*-------------------------------------------------------------------------
*/
#ifndef NODES_H
#define NODES_H
/*
* The first field of every node is NodeTag. Each node created (with makeNode)
* will have one of the following tags as the value of its first field.
*
* Note that the numbers of the node tags are not contiguous. We left holes
* here so that we can add more tags without changing the existing enum's.
* (Since node tag numbers never exist outside backend memory, there's no
* real harm in renumbering, it just costs a full rebuild ...)
*/
typedef enum NodeTag
{
T_Invalid = 0,
/*
* TAGS FOR EXECUTOR NODES (execnodes.h)
*/
T_IndexInfo = 10,
T_ExprContext,
T_ProjectionInfo,
T_JunkFilter,
T_ResultRelInfo,
T_EState,
T_TupleTableSlot,
/*
* TAGS FOR PLAN NODES (plannodes.h)
*/
T_Plan = 100,
T_Result,
T_ModifyTable,
T_Append,
T_MergeAppend,
T_RecursiveUnion,
T_BitmapAnd,
T_BitmapOr,
T_Scan,
T_SeqScan,
T_IndexScan,
T_IndexOnlyScan,
T_BitmapIndexScan,
T_BitmapHeapScan,
T_TidScan,
T_SubqueryScan,
T_FunctionScan,
T_ValuesScan,
T_CteScan,
T_WorkTableScan,
T_ForeignScan,
T_CustomScan,
T_Join,
T_NestLoop,
T_MergeJoin,
T_HashJoin,
T_Material,
T_Sort,
T_Group,
T_Agg,
T_WindowAgg,
T_Unique,
T_Hash,
T_SetOp,
T_LockRows,
T_Limit,
/* these aren't subclasses of Plan: */
T_NestLoopParam,
T_PlanRowMark,
T_PlanInvalItem,
/*
* TAGS FOR PLAN STATE NODES (execnodes.h)
*
* These should correspond one-to-one with Plan node types.
*/
T_PlanState = 200,
T_ResultState,
T_ModifyTableState,
T_AppendState,
T_MergeAppendState,
T_RecursiveUnionState,
T_BitmapAndState,
T_BitmapOrState,
T_ScanState,
T_SeqScanState,
T_IndexScanState,
T_IndexOnlyScanState,
T_BitmapIndexScanState,
T_BitmapHeapScanState,
T_TidScanState,
T_SubqueryScanState,
T_FunctionScanState,
T_ValuesScanState,
T_CteScanState,
T_WorkTableScanState,
T_ForeignScanState,
T_CustomScanState,
T_JoinState,
T_NestLoopState,
T_MergeJoinState,
T_HashJoinState,
T_MaterialState,
T_SortState,
T_GroupState,
T_AggState,
T_WindowAggState,
T_UniqueState,
T_HashState,
T_SetOpState,
T_LockRowsState,
T_LimitState,
/*
* TAGS FOR PRIMITIVE NODES (primnodes.h)
*/
T_Alias = 300,
T_RangeVar,
T_Expr,
T_Var,
T_Const,
T_Param,
T_Aggref,
T_WindowFunc,
T_ArrayRef,
T_FuncExpr,
T_NamedArgExpr,
T_OpExpr,
T_DistinctExpr,
T_NullIfExpr,
T_ScalarArrayOpExpr,
T_BoolExpr,
T_SubLink,
T_SubPlan,
T_AlternativeSubPlan,
T_FieldSelect,
T_FieldStore,
T_RelabelType,
T_CoerceViaIO,
T_ArrayCoerceExpr,
T_ConvertRowtypeExpr,
T_CollateExpr,
T_CaseExpr,
T_CaseWhen,
T_CaseTestExpr,
T_ArrayExpr,
T_RowExpr,
T_RowCompareExpr,
T_CoalesceExpr,
T_MinMaxExpr,
T_XmlExpr,
T_NullTest,
T_BooleanTest,
T_CoerceToDomain,
T_CoerceToDomainValue,
T_SetToDefault,
T_CurrentOfExpr,
T_TargetEntry,
T_RangeTblRef,
T_JoinExpr,
T_FromExpr,
T_IntoClause,
/*
* TAGS FOR EXPRESSION STATE NODES (execnodes.h)
*
* These correspond (not always one-for-one) to primitive nodes derived
* from Expr.
*/
T_ExprState = 400,
T_GenericExprState,
T_WholeRowVarExprState,
T_AggrefExprState,
T_WindowFuncExprState,
T_ArrayRefExprState,
T_FuncExprState,
T_ScalarArrayOpExprState,
T_BoolExprState,
T_SubPlanState,
T_AlternativeSubPlanState,
T_FieldSelectState,
T_FieldStoreState,
T_CoerceViaIOState,
T_ArrayCoerceExprState,
T_ConvertRowtypeExprState,
T_CaseExprState,
T_CaseWhenState,
T_ArrayExprState,
T_RowExprState,
T_RowCompareExprState,
T_CoalesceExprState,
T_MinMaxExprState,
T_XmlExprState,
T_NullTestState,
T_CoerceToDomainState,
T_DomainConstraintState,
/*
* TAGS FOR PLANNER NODES (relation.h)
*/
T_PlannerInfo = 500,
T_PlannerGlobal,
T_RelOptInfo,
T_IndexOptInfo,
Revise parameterized-path mechanism to fix assorted issues. This patch adjusts the treatment of parameterized paths so that all paths with the same parameterization (same set of required outer rels) for the same relation will have the same rowcount estimate. We cache the rowcount estimates to ensure that property, and hopefully save a few cycles too. Doing this makes it practical for add_path_precheck to operate without a rowcount estimate: it need only assume that paths with different parameterizations never dominate each other, which is close enough to true anyway for coarse filtering, because normally a more-parameterized path should yield fewer rows thanks to having more join clauses to apply. In add_path, we do the full nine yards of comparing rowcount estimates along with everything else, so that we can discard parameterized paths that don't actually have an advantage. This fixes some issues I'd found with add_path rejecting parameterized paths on the grounds that they were more expensive than not-parameterized ones, even though they yielded many fewer rows and hence would be cheaper once subsequent joining was considered. To make the same-rowcounts assumption valid, we have to require that any parameterized path enforce *all* join clauses that could be obtained from the particular set of outer rels, even if not all of them are useful for indexing. This is required at both base scans and joins. It's a good thing anyway since the net impact is that join quals are checked at the lowest practical level in the join tree. Hence, discard the original rather ad-hoc mechanism for choosing parameterization joinquals, and build a better one that has a more principled rule for when clauses can be moved. The original rule was actually buggy anyway for lack of knowledge about which relations are part of an outer join's outer side; getting this right requires adding an outer_relids field to RestrictInfo.
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T_ParamPathInfo,
T_Path,
T_IndexPath,
T_BitmapHeapPath,
T_BitmapAndPath,
T_BitmapOrPath,
T_NestPath,
T_MergePath,
T_HashPath,
T_TidPath,
T_ForeignPath,
T_CustomPath,
T_AppendPath,
T_MergeAppendPath,
T_ResultPath,
T_MaterialPath,
T_UniquePath,
T_EquivalenceClass,
T_EquivalenceMember,
T_PathKey,
T_RestrictInfo,
T_PlaceHolderVar,
T_SpecialJoinInfo,
T_LateralJoinInfo,
T_AppendRelInfo,
T_PlaceHolderInfo,
T_MinMaxAggInfo,
T_PlannerParamItem,
/*
* TAGS FOR MEMORY NODES (memnodes.h)
*/
T_MemoryContext = 600,
T_AllocSetContext,
/*
* TAGS FOR VALUE NODES (value.h)
*/
T_Value = 650,
T_Integer,
T_Float,
T_String,
T_BitString,
T_Null,
/*
* TAGS FOR LIST NODES (pg_list.h)
*/
T_List,
T_IntList,
T_OidList,
/*
* TAGS FOR STATEMENT NODES (mostly in parsenodes.h)
*/
T_Query = 700,
T_PlannedStmt,
T_InsertStmt,
T_DeleteStmt,
T_UpdateStmt,
T_SelectStmt,
T_AlterTableStmt,
T_AlterTableCmd,
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T_AlterDomainStmt,
T_SetOperationStmt,
T_GrantStmt,
T_GrantRoleStmt,
T_AlterDefaultPrivilegesStmt,
T_ClosePortalStmt,
T_ClusterStmt,
T_CopyStmt,
T_CreateStmt,
T_DefineStmt,
T_DropStmt,
T_TruncateStmt,
T_CommentStmt,
T_FetchStmt,
T_IndexStmt,
T_CreateFunctionStmt,
T_AlterFunctionStmt,
T_DoStmt,
T_RenameStmt,
T_RuleStmt,
T_NotifyStmt,
T_ListenStmt,
T_UnlistenStmt,
T_TransactionStmt,
T_ViewStmt,
T_LoadStmt,
T_CreateDomainStmt,
T_CreatedbStmt,
T_DropdbStmt,
T_VacuumStmt,
T_ExplainStmt,
T_CreateTableAsStmt,
T_CreateSeqStmt,
T_AlterSeqStmt,
T_VariableSetStmt,
T_VariableShowStmt,
T_DiscardStmt,
T_CreateTrigStmt,
T_CreatePLangStmt,
T_CreateRoleStmt,
T_AlterRoleStmt,
T_DropRoleStmt,
T_LockStmt,
T_ConstraintsSetStmt,
T_ReindexStmt,
T_CheckPointStmt,
T_CreateSchemaStmt,
T_AlterDatabaseStmt,
T_AlterDatabaseSetStmt,
T_AlterRoleSetStmt,
T_CreateConversionStmt,
T_CreateCastStmt,
T_CreateOpClassStmt,
T_CreateOpFamilyStmt,
T_AlterOpFamilyStmt,
T_PrepareStmt,
T_ExecuteStmt,
T_DeallocateStmt,
T_DeclareCursorStmt,
T_CreateTableSpaceStmt,
T_DropTableSpaceStmt,
T_AlterObjectSchemaStmt,
T_AlterOwnerStmt,
T_DropOwnedStmt,
T_ReassignOwnedStmt,
T_CompositeTypeStmt,
T_CreateEnumStmt,
T_CreateRangeStmt,
T_AlterEnumStmt,
T_AlterTSDictionaryStmt,
T_AlterTSConfigurationStmt,
T_CreateFdwStmt,
T_AlterFdwStmt,
T_CreateForeignServerStmt,
T_AlterForeignServerStmt,
T_CreateUserMappingStmt,
T_AlterUserMappingStmt,
T_DropUserMappingStmt,
T_AlterTableSpaceOptionsStmt,
T_AlterTableMoveAllStmt,
T_SecLabelStmt,
T_CreateForeignTableStmt,
T_ImportForeignSchemaStmt,
T_CreateExtensionStmt,
T_AlterExtensionStmt,
T_AlterExtensionContentsStmt,
T_CreateEventTrigStmt,
T_AlterEventTrigStmt,
T_RefreshMatViewStmt,
T_ReplicaIdentityStmt,
T_AlterSystemStmt,
Row-Level Security Policies (RLS) Building on the updatable security-barrier views work, add the ability to define policies on tables to limit the set of rows which are returned from a query and which are allowed to be added to a table. Expressions defined by the policy for filtering are added to the security barrier quals of the query, while expressions defined to check records being added to a table are added to the with-check options of the query. New top-level commands are CREATE/ALTER/DROP POLICY and are controlled by the table owner. Row Security is able to be enabled and disabled by the owner on a per-table basis using ALTER TABLE .. ENABLE/DISABLE ROW SECURITY. Per discussion, ROW SECURITY is disabled on tables by default and must be enabled for policies on the table to be used. If no policies exist on a table with ROW SECURITY enabled, a default-deny policy is used and no records will be visible. By default, row security is applied at all times except for the table owner and the superuser. A new GUC, row_security, is added which can be set to ON, OFF, or FORCE. When set to FORCE, row security will be applied even for the table owner and superusers. When set to OFF, row security will be disabled when allowed and an error will be thrown if the user does not have rights to bypass row security. Per discussion, pg_dump sets row_security = OFF by default to ensure that exports and backups will have all data in the table or will error if there are insufficient privileges to bypass row security. A new option has been added to pg_dump, --enable-row-security, to ask pg_dump to export with row security enabled. A new role capability, BYPASSRLS, which can only be set by the superuser, is added to allow other users to be able to bypass row security using row_security = OFF. Many thanks to the various individuals who have helped with the design, particularly Robert Haas for his feedback. Authors include Craig Ringer, KaiGai Kohei, Adam Brightwell, Dean Rasheed, with additional changes and rework by me. Reviewers have included all of the above, Greg Smith, Jeff McCormick, and Robert Haas.
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T_CreatePolicyStmt,
T_AlterPolicyStmt,
T_CreateTransformStmt,
/*
* TAGS FOR PARSE TREE NODES (parsenodes.h)
*/
T_A_Expr = 900,
T_ColumnRef,
T_ParamRef,
T_A_Const,
T_FuncCall,
T_A_Star,
T_A_Indices,
T_A_Indirection,
T_A_ArrayExpr,
T_ResTarget,
T_MultiAssignRef,
T_TypeCast,
T_CollateClause,
T_SortBy,
T_WindowDef,
T_RangeSubselect,
T_RangeFunction,
T_TypeName,
T_ColumnDef,
T_IndexElem,
T_Constraint,
T_DefElem,
T_RangeTblEntry,
T_RangeTblFunction,
T_WithCheckOption,
T_SortGroupClause,
T_WindowClause,
T_PrivGrantee,
T_FuncWithArgs,
T_AccessPriv,
T_CreateOpClassItem,
T_TableLikeClause,
T_FunctionParameter,
T_LockingClause,
T_RowMarkClause,
T_XmlSerialize,
T_WithClause,
T_CommonTableExpr,
T_RoleSpec,
/*
* TAGS FOR REPLICATION GRAMMAR PARSE NODES (replnodes.h)
*/
T_IdentifySystemCmd,
T_BaseBackupCmd,
T_CreateReplicationSlotCmd,
T_DropReplicationSlotCmd,
T_StartReplicationCmd,
Allow a streaming replication standby to follow a timeline switch. Before this patch, streaming replication would refuse to start replicating if the timeline in the primary doesn't exactly match the standby. The situation where it doesn't match is when you have a master, and two standbys, and you promote one of the standbys to become new master. Promoting bumps up the timeline ID, and after that bump, the other standby would refuse to continue. There's significantly more timeline related logic in streaming replication now. First of all, when a standby connects to primary, it will ask the primary for any timeline history files that are missing from the standby. The missing files are sent using a new replication command TIMELINE_HISTORY, and stored in standby's pg_xlog directory. Using the timeline history files, the standby can follow the latest timeline present in the primary (recovery_target_timeline='latest'), just as it can follow new timelines appearing in an archive directory. START_REPLICATION now takes a TIMELINE parameter, to specify exactly which timeline to stream WAL from. This allows the standby to request the primary to send over WAL that precedes the promotion. The replication protocol is changed slightly (in a backwards-compatible way although there's little hope of streaming replication working across major versions anyway), to allow replication to stop when the end of timeline reached, putting the walsender back into accepting a replication command. Many thanks to Amit Kapila for testing and reviewing various versions of this patch.
2012-12-13 18:00:00 +01:00
T_TimeLineHistoryCmd,
/*
* TAGS FOR RANDOM OTHER STUFF
*
* These are objects that aren't part of parse/plan/execute node tree
* structures, but we give them NodeTags anyway for identification
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* purposes (usually because they are involved in APIs where we want to
* pass multiple object types through the same pointer).
*/
T_TriggerData = 950, /* in commands/trigger.h */
T_EventTriggerData, /* in commands/event_trigger.h */
T_ReturnSetInfo, /* in nodes/execnodes.h */
T_WindowObjectData, /* private in nodeWindowAgg.c */
T_TIDBitmap, /* in nodes/tidbitmap.h */
T_InlineCodeBlock, /* in nodes/parsenodes.h */
T_FdwRoutine /* in foreign/fdwapi.h */
} NodeTag;
/*
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* The first field of a node of any type is guaranteed to be the NodeTag.
* Hence the type of any node can be gotten by casting it to Node. Declaring
* a variable to be of Node * (instead of void *) can also facilitate
* debugging.
*/
typedef struct Node
{
NodeTag type;
} Node;
#define nodeTag(nodeptr) (((const Node*)(nodeptr))->type)
/*
* newNode -
* create a new node of the specified size and tag the node with the
* specified tag.
*
* !WARNING!: Avoid using newNode directly. You should be using the
* macro makeNode. eg. to create a Query node, use makeNode(Query)
*
* Note: the size argument should always be a compile-time constant, so the
* apparent risk of multiple evaluation doesn't matter in practice.
*/
#ifdef __GNUC__
/* With GCC, we can use a compound statement within an expression */
#define newNode(size, tag) \
({ Node *_result; \
AssertMacro((size) >= sizeof(Node)); /* need the tag, at least */ \
_result = (Node *) palloc0fast(size); \
_result->type = (tag); \
_result; \
})
#else
/*
* There is no way to dereference the palloc'ed pointer to assign the
* tag, and also return the pointer itself, so we need a holder variable.
* Fortunately, this macro isn't recursive so we just define
* a global variable for this purpose.
*/
extern PGDLLIMPORT Node *newNodeMacroHolder;
#define newNode(size, tag) \
( \
AssertMacro((size) >= sizeof(Node)), /* need the tag, at least */ \
newNodeMacroHolder = (Node *) palloc0fast(size), \
newNodeMacroHolder->type = (tag), \
newNodeMacroHolder \
)
#endif /* __GNUC__ */
#define makeNode(_type_) ((_type_ *) newNode(sizeof(_type_),T_##_type_))
#define NodeSetTag(nodeptr,t) (((Node*)(nodeptr))->type = (t))
#define IsA(nodeptr,_type_) (nodeTag(nodeptr) == T_##_type_)
/* ----------------------------------------------------------------
* extern declarations follow
* ----------------------------------------------------------------
*/
/*
* nodes/{outfuncs.c,print.c}
*/
extern char *nodeToString(const void *obj);
/*
* nodes/{readfuncs.c,read.c}
*/
extern void *stringToNode(char *str);
/*
* nodes/copyfuncs.c
*/
extern void *copyObject(const void *obj);
/*
* nodes/equalfuncs.c
*/
extern bool equal(const void *a, const void *b);
/*
* Typedefs for identifying qualifier selectivities and plan costs as such.
* These are just plain "double"s, but declaring a variable as Selectivity
* or Cost makes the intent more obvious.
*
* These could have gone into plannodes.h or some such, but many files
* depend on them...
*/
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typedef double Selectivity; /* fraction of tuples a qualifier will pass */
typedef double Cost; /* execution cost (in page-access units) */
/*
* CmdType -
* enums for type of operation represented by a Query or PlannedStmt
*
* This is needed in both parsenodes.h and plannodes.h, so put it here...
*/
typedef enum CmdType
{
CMD_UNKNOWN,
CMD_SELECT, /* select stmt */
CMD_UPDATE, /* update stmt */
CMD_INSERT, /* insert stmt */
CMD_DELETE,
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CMD_UTILITY, /* cmds like create, destroy, copy, vacuum,
* etc. */
CMD_NOTHING /* dummy command for instead nothing rules
* with qual */
} CmdType;
/*
* JoinType -
* enums for types of relation joins
*
* JoinType determines the exact semantics of joining two relations using
* a matching qualification. For example, it tells what to do with a tuple
* that has no match in the other relation.
*
* This is needed in both parsenodes.h and plannodes.h, so put it here...
*/
typedef enum JoinType
{
/*
* The canonical kinds of joins according to the SQL JOIN syntax. Only
* these codes can appear in parser output (e.g., JoinExpr nodes).
*/
JOIN_INNER, /* matching tuple pairs only */
JOIN_LEFT, /* pairs + unmatched LHS tuples */
JOIN_FULL, /* pairs + unmatched LHS + unmatched RHS */
JOIN_RIGHT, /* pairs + unmatched RHS tuples */
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/*
* Semijoins and anti-semijoins (as defined in relational theory) do not
* appear in the SQL JOIN syntax, but there are standard idioms for
* representing them (e.g., using EXISTS). The planner recognizes these
* cases and converts them to joins. So the planner and executor must
* support these codes. NOTE: in JOIN_SEMI output, it is unspecified
* which matching RHS row is joined to. In JOIN_ANTI output, the row is
* guaranteed to be null-extended.
*/
JOIN_SEMI, /* 1 copy of each LHS row that has match(es) */
JOIN_ANTI, /* 1 copy of each LHS row that has no match */
/*
* These codes are used internally in the planner, but are not supported
* by the executor (nor, indeed, by most of the planner).
*/
JOIN_UNIQUE_OUTER, /* LHS path must be made unique */
JOIN_UNIQUE_INNER /* RHS path must be made unique */
/*
* We might need additional join types someday.
*/
} JoinType;
/*
* OUTER joins are those for which pushed-down quals must behave differently
* from the join's own quals. This is in fact everything except INNER and
* SEMI joins. However, this macro must also exclude the JOIN_UNIQUE symbols
* since those are temporary proxies for what will eventually be an INNER
* join.
*
* Note: semijoins are a hybrid case, but we choose to treat them as not
* being outer joins. This is okay principally because the SQL syntax makes
* it impossible to have a pushed-down qual that refers to the inner relation
* of a semijoin; so there is no strong need to distinguish join quals from
* pushed-down quals. This is convenient because for almost all purposes,
* quals attached to a semijoin can be treated the same as innerjoin quals.
*/
#define IS_OUTER_JOIN(jointype) \
(((1 << (jointype)) & \
((1 << JOIN_LEFT) | \
(1 << JOIN_FULL) | \
(1 << JOIN_RIGHT) | \
(1 << JOIN_ANTI))) != 0)
#endif /* NODES_H */