Fix assorted bugs related to identity column in partitioned tables

When changing the data type of a column of a partitioned table, craft
the ALTER SEQUENCE command only once.  Partitions do not have identity
sequences of their own and thus do not need a ALTER SEQUENCE command
for each partition.

Fix getIdentitySequence() to fetch the identity sequence associated
with the top-level partitioned table when a Relation of a partition is
passed to it.  While doing so, translate the attribute number of the
partition into the attribute number of the partitioned table.

Author: Ashutosh Bapat <[email protected]>
Reported-by: Alexander Lakhin <[email protected]>
Reviewed-by: Dmitry Dolgov <[email protected]>
Discussion: https://www.postgresql.org/message-id/[email protected]

1 files changed, 1 insertions, 18 deletions

diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c
index 9fd05b15e73..8a29fbbc465 100644
--- a/src/backend/rewrite/rewriteHandler.c
+++ b/src/backend/rewrite/rewriteHandler.c
@@ -24,7 +24,6 @@
 #include "access/sysattr.h"
 #include "access/table.h"
 #include "catalog/dependency.h"
-#include "catalog/partition.h"
 #include "commands/trigger.h"
 #include "executor/executor.h"
 #include "foreign/fdwapi.h"
@@ -1233,24 +1232,8 @@ build_column_default(Relation rel, int attrno)
 	if (att_tup->attidentity)
 	{
 		NextValueExpr *nve = makeNode(NextValueExpr);
-		Oid			reloid;
 
-		/*
-		 * The identity sequence is associated with the topmost partitioned
-		 * table.
-		 */
-		if (rel->rd_rel->relispartition)
-		{
-			List	   *ancestors =
-				get_partition_ancestors(RelationGetRelid(rel));
-
-			reloid = llast_oid(ancestors);
-			list_free(ancestors);
-		}
-		else
-			reloid = RelationGetRelid(rel);
-
-		nve->seqid = getIdentitySequence(reloid, attrno, false);
+		nve->seqid = getIdentitySequence(rel, attrno, false);
 		nve->typeId = att_tup->atttypid;
 
 		return (Node *) nve;