diff options
Diffstat (limited to 'src/backend/commands/tablecmds.c')
| -rw-r--r-- | src/backend/commands/tablecmds.c | 27 |
1 files changed, 17 insertions, 10 deletions
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index 946119fa860..73da6c39c22 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -3044,7 +3044,7 @@ rename_constraint_internal(Oid myrelid, || con->contype == CONSTRAINT_UNIQUE || con->contype == CONSTRAINT_EXCLUSION)) /* rename the index; this renames the constraint as well */ - RenameRelationInternal(con->conindid, newconname, false); + RenameRelationInternal(con->conindid, newconname, false, true); else RenameConstraintById(constraintOid, newconname); @@ -3112,6 +3112,7 @@ RenameConstraint(RenameStmt *stmt) ObjectAddress RenameRelation(RenameStmt *stmt) { + bool is_index = stmt->renameType == OBJECT_INDEX; Oid relid; ObjectAddress address; @@ -3123,7 +3124,8 @@ RenameRelation(RenameStmt *stmt) * Lock level used here should match RenameRelationInternal, to avoid lock * escalation. */ - relid = RangeVarGetRelidExtended(stmt->relation, AccessExclusiveLock, + relid = RangeVarGetRelidExtended(stmt->relation, + is_index ? ShareUpdateExclusiveLock : AccessExclusiveLock, stmt->missing_ok ? RVR_MISSING_OK : 0, RangeVarCallbackForAlterRelation, (void *) stmt); @@ -3137,7 +3139,7 @@ RenameRelation(RenameStmt *stmt) } /* Do the work */ - RenameRelationInternal(relid, stmt->newname, false); + RenameRelationInternal(relid, stmt->newname, false, is_index); ObjectAddressSet(address, RelationRelationId, relid); @@ -3148,7 +3150,7 @@ RenameRelation(RenameStmt *stmt) * RenameRelationInternal - change the name of a relation */ void -RenameRelationInternal(Oid myrelid, const char *newrelname, bool is_internal) +RenameRelationInternal(Oid myrelid, const char *newrelname, bool is_internal, bool is_index) { Relation targetrelation; Relation relrelation; /* for RELATION relation */ @@ -3157,11 +3159,16 @@ RenameRelationInternal(Oid myrelid, const char *newrelname, bool is_internal) 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. + * Grab a lock on the target relation, which we will NOT release until end + * of transaction. We need at least a self-exclusive lock so that + * concurrent DDL doesn't overwrite the rename if they start updating + * while still seeing the old version. The lock also guards against + * triggering relcache reloads in concurrent sessions, which might not + * handle this information changing under them. For indexes, we can use a + * reduced lock level because RelationReloadIndexInfo() handles indexes + * specially. */ - targetrelation = relation_open(myrelid, AccessExclusiveLock); + targetrelation = relation_open(myrelid, is_index ? ShareUpdateExclusiveLock : AccessExclusiveLock); namespaceId = RelationGetNamespace(targetrelation); /* @@ -3214,7 +3221,7 @@ RenameRelationInternal(Oid myrelid, const char *newrelname, bool is_internal) } /* - * Close rel, but keep exclusive lock! + * Close rel, but keep lock! */ relation_close(targetrelation, NoLock); } @@ -7076,7 +7083,7 @@ ATExecAddIndexConstraint(AlteredTableInfo *tab, Relation rel, ereport(NOTICE, (errmsg("ALTER TABLE / ADD CONSTRAINT USING INDEX will rename index \"%s\" to \"%s\"", indexName, constraintName))); - RenameRelationInternal(index_oid, constraintName, false); + RenameRelationInternal(index_oid, constraintName, false, true); } /* Extra checks needed if making primary key */ |