From 15cbbf81a58fd04479c0e5ff134838492473e935 Mon Sep 17 00:00:00 2001 From: Peter Eisentraut Date: Fri, 13 Mar 2020 11:28:11 +0100 Subject: [PATCH] Preserve replica identity index across ALTER TABLE rewrite If an index was explicitly set as replica identity index, this setting was lost when a table was rewritten by ALTER TABLE. Because this setting is part of pg_index but actually controlled by ALTER TABLE (not part of CREATE INDEX, say), we have to do some extra work to restore it. Based-on-patch-by: Quan Zongliang Reviewed-by: Euler Taveira Discussion: https://www.postgresql.org/message-id/flat/c70fcab2-4866-0d9f-1d01-e75e189db342@gmail.com --- src/backend/commands/tablecmds.c | 42 +++++++++++++++++ src/backend/utils/cache/lsyscache.c | 25 ++++++++++ src/include/utils/lsyscache.h | 1 + .../regress/expected/replica_identity.out | 46 +++++++++++++++++++ src/test/regress/sql/replica_identity.sql | 21 +++++++++ 5 files changed, 135 insertions(+) diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index 38386fb9cf..3a2e2ecc4f 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -175,6 +175,7 @@ typedef struct AlteredTableInfo List *changedConstraintDefs; /* string definitions of same */ List *changedIndexOids; /* OIDs of indexes to rebuild */ List *changedIndexDefs; /* string definitions of same */ + char *replicaIdentityIndex; /* index to reset as REPLICA IDENTITY */ } AlteredTableInfo; /* Struct describing one new constraint to check in Phase 3 scan */ @@ -10314,6 +10315,22 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel, return address; } +/* + * Subroutine for ATExecAlterColumnType: remember that a replica identity + * needs to be reset. + */ +static void +RememberReplicaIdentityForRebuilding(Oid indoid, AlteredTableInfo *tab) +{ + if (!get_index_isreplident(indoid)) + return; + + if (tab->replicaIdentityIndex) + elog(ERROR, "relation %u has multiple indexes marked as replica identity", tab->relid); + + tab->replicaIdentityIndex = get_rel_name(indoid); +} + /* * Subroutine for ATExecAlterColumnType: remember that a constraint needs * to be rebuilt (which we might already know). @@ -10332,11 +10349,16 @@ RememberConstraintForRebuilding(Oid conoid, AlteredTableInfo *tab) { /* OK, capture the constraint's existing definition string */ char *defstring = pg_get_constraintdef_command(conoid); + Oid indoid; tab->changedConstraintOids = lappend_oid(tab->changedConstraintOids, conoid); tab->changedConstraintDefs = lappend(tab->changedConstraintDefs, defstring); + + indoid = get_constraint_index(conoid); + if (OidIsValid(indoid)) + RememberReplicaIdentityForRebuilding(indoid, tab); } } @@ -10379,6 +10401,8 @@ RememberIndexForRebuilding(Oid indoid, AlteredTableInfo *tab) indoid); tab->changedIndexDefs = lappend(tab->changedIndexDefs, defstring); + + RememberReplicaIdentityForRebuilding(indoid, tab); } } } @@ -10593,6 +10617,24 @@ ATPostAlterTypeCleanup(List **wqueue, AlteredTableInfo *tab, LOCKMODE lockmode) add_exact_object_address(&obj, objects); } + /* + * Queue up command to restore replica identity index marking + */ + if (tab->replicaIdentityIndex) + { + AlterTableCmd *cmd = makeNode(AlterTableCmd); + ReplicaIdentityStmt *subcmd = makeNode(ReplicaIdentityStmt); + + subcmd->identity_type = REPLICA_IDENTITY_INDEX; + subcmd->name = tab->replicaIdentityIndex; + cmd->subtype = AT_ReplicaIdentity; + cmd->def = (Node *) subcmd; + + /* do it after indexes and constraints */ + tab->subcmds[AT_PASS_OLD_CONSTR] = + lappend(tab->subcmds[AT_PASS_OLD_CONSTR], cmd); + } + /* * It should be okay to use DROP_RESTRICT here, since nothing else should * be depending on these objects. diff --git a/src/backend/utils/cache/lsyscache.c b/src/backend/utils/cache/lsyscache.c index a4da935371..047a8ced02 100644 --- a/src/backend/utils/cache/lsyscache.c +++ b/src/backend/utils/cache/lsyscache.c @@ -3156,3 +3156,28 @@ get_range_collation(Oid rangeOid) else return InvalidOid; } + +/* ---------- PG_INDEX CACHE ---------- */ + +/* + * get_index_isreplident + * + * Given the index OID, return pg_index.indisreplident. + */ +bool +get_index_isreplident(Oid index_oid) +{ + HeapTuple tuple; + Form_pg_index rd_index; + bool result; + + tuple = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(index_oid)); + if (!HeapTupleIsValid(tuple)) + return false; + + rd_index = (Form_pg_index) GETSTRUCT(tuple); + result = rd_index->indisreplident; + ReleaseSysCache(tuple); + + return result; +} diff --git a/src/include/utils/lsyscache.h b/src/include/utils/lsyscache.h index c97c926992..3832785c0f 100644 --- a/src/include/utils/lsyscache.h +++ b/src/include/utils/lsyscache.h @@ -178,6 +178,7 @@ extern char *get_namespace_name(Oid nspid); extern char *get_namespace_name_or_temp(Oid nspid); extern Oid get_range_subtype(Oid rangeOid); extern Oid get_range_collation(Oid rangeOid); +extern bool get_index_isreplident(Oid index_oid); #define type_is_array(typid) (get_element_type(typid) != InvalidOid) /* type_is_array_domain accepts both plain arrays and domains over arrays */ diff --git a/src/test/regress/expected/replica_identity.out b/src/test/regress/expected/replica_identity.out index 67c34a92a4..65c7c9ac9f 100644 --- a/src/test/regress/expected/replica_identity.out +++ b/src/test/regress/expected/replica_identity.out @@ -186,5 +186,51 @@ SELECT relreplident FROM pg_class WHERE oid = 'test_replica_identity'::regclass; n (1 row) +--- +-- Test that ALTER TABLE rewrite preserves nondefault replica identity +--- +-- constraint variant +CREATE TABLE test_replica_identity2 (id int UNIQUE NOT NULL); +ALTER TABLE test_replica_identity2 REPLICA IDENTITY USING INDEX test_replica_identity2_id_key; +\d test_replica_identity2 + Table "public.test_replica_identity2" + Column | Type | Collation | Nullable | Default +--------+---------+-----------+----------+--------- + id | integer | | not null | +Indexes: + "test_replica_identity2_id_key" UNIQUE CONSTRAINT, btree (id) REPLICA IDENTITY + +ALTER TABLE test_replica_identity2 ALTER COLUMN id TYPE bigint; +\d test_replica_identity2 + Table "public.test_replica_identity2" + Column | Type | Collation | Nullable | Default +--------+--------+-----------+----------+--------- + id | bigint | | not null | +Indexes: + "test_replica_identity2_id_key" UNIQUE CONSTRAINT, btree (id) REPLICA IDENTITY + +-- straight index variant +CREATE TABLE test_replica_identity3 (id int NOT NULL); +CREATE UNIQUE INDEX test_replica_identity3_id_key ON test_replica_identity3 (id); +ALTER TABLE test_replica_identity3 REPLICA IDENTITY USING INDEX test_replica_identity3_id_key; +\d test_replica_identity3 + Table "public.test_replica_identity3" + Column | Type | Collation | Nullable | Default +--------+---------+-----------+----------+--------- + id | integer | | not null | +Indexes: + "test_replica_identity3_id_key" UNIQUE, btree (id) REPLICA IDENTITY + +ALTER TABLE test_replica_identity3 ALTER COLUMN id TYPE bigint; +\d test_replica_identity3 + Table "public.test_replica_identity3" + Column | Type | Collation | Nullable | Default +--------+--------+-----------+----------+--------- + id | bigint | | not null | +Indexes: + "test_replica_identity3_id_key" UNIQUE, btree (id) REPLICA IDENTITY + DROP TABLE test_replica_identity; +DROP TABLE test_replica_identity2; +DROP TABLE test_replica_identity3; DROP TABLE test_replica_identity_othertable; diff --git a/src/test/regress/sql/replica_identity.sql b/src/test/regress/sql/replica_identity.sql index 3d2171c733..5277ff39cd 100644 --- a/src/test/regress/sql/replica_identity.sql +++ b/src/test/regress/sql/replica_identity.sql @@ -79,5 +79,26 @@ SELECT relreplident FROM pg_class WHERE oid = 'test_replica_identity'::regclass; ALTER TABLE test_replica_identity REPLICA IDENTITY NOTHING; SELECT relreplident FROM pg_class WHERE oid = 'test_replica_identity'::regclass; +--- +-- Test that ALTER TABLE rewrite preserves nondefault replica identity +--- + +-- constraint variant +CREATE TABLE test_replica_identity2 (id int UNIQUE NOT NULL); +ALTER TABLE test_replica_identity2 REPLICA IDENTITY USING INDEX test_replica_identity2_id_key; +\d test_replica_identity2 +ALTER TABLE test_replica_identity2 ALTER COLUMN id TYPE bigint; +\d test_replica_identity2 + +-- straight index variant +CREATE TABLE test_replica_identity3 (id int NOT NULL); +CREATE UNIQUE INDEX test_replica_identity3_id_key ON test_replica_identity3 (id); +ALTER TABLE test_replica_identity3 REPLICA IDENTITY USING INDEX test_replica_identity3_id_key; +\d test_replica_identity3 +ALTER TABLE test_replica_identity3 ALTER COLUMN id TYPE bigint; +\d test_replica_identity3 + DROP TABLE test_replica_identity; +DROP TABLE test_replica_identity2; +DROP TABLE test_replica_identity3; DROP TABLE test_replica_identity_othertable;