Fix tablespace handling for partitioned indexes

When creating partitioned indexes, the tablespace was not being saved
for the parent index. This meant that subsequently created partitions
would not use the right tablespace for their indexes.

ALTER INDEX SET TABLESPACE and ALTER INDEX ALL IN TABLESPACE raised
errors when tried; fix them too.  This requires bespoke code for
ATExecCmd() that applies to the special case when the tablespace move is
just a catalog change.

Discussion: https://postgr.es/m/20181102003138.uxpaca6qfxzskepi@alvherre.pgsql

Author: alvherre

src/backend/catalog/heap.c

@@ -297,7 +297,6 @@ heap_create(const char *relname,
 		case RELKIND_COMPOSITE_TYPE:
 		case RELKIND_FOREIGN_TABLE:
 		case RELKIND_PARTITIONED_TABLE:
-		case RELKIND_PARTITIONED_INDEX:
 			create_storage = false;
 
 			/*
@@ -306,6 +305,15 @@ heap_create(const char *relname,
 			 */
 			reltablespace = InvalidOid;
 			break;
+
+		case RELKIND_PARTITIONED_INDEX:
+			/*
+			 * Preserve tablespace so that it's used as tablespace for indexes
+			 * on future partitions.
+			 */
+			create_storage = false;
+			break;
+
 		case RELKIND_SEQUENCE:
 			create_storage = true;
 

src/backend/commands/tablecmds.c

@@ -446,6 +446,7 @@ static bool ATPrepChangePersistence(Relation rel, bool toLogged);
 static void ATPrepSetTableSpace(AlteredTableInfo *tab, Relation rel,
 					const char *tablespacename, LOCKMODE lockmode);
 static void ATExecSetTableSpace(Oid tableOid, Oid newTableSpace, LOCKMODE lockmode);
+static void ATExecPartedIdxSetTableSpace(Relation rel, Oid newTableSpace);
 static void ATExecSetRelOptions(Relation rel, List *defList,
 					AlterTableType operation,
 					LOCKMODE lockmode);
@@ -3845,7 +3846,8 @@ ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd,
 			pass = AT_PASS_DROP;
 			break;
 		case AT_SetTableSpace:	/* SET TABLESPACE */
-			ATSimplePermissions(rel, ATT_TABLE | ATT_MATVIEW | ATT_INDEX);
+			ATSimplePermissions(rel, ATT_TABLE | ATT_MATVIEW | ATT_INDEX |
+								ATT_PARTITIONED_INDEX);
 			/* This command never recurses */
 			ATPrepSetTableSpace(tab, rel, cmd->name, lockmode);
 			pass = AT_PASS_MISC;	/* doesn't actually matter */
@@ -4181,10 +4183,13 @@ ATExecCmd(List **wqueue, AlteredTableInfo *tab, Relation rel,
 			 */
 			break;
 		case AT_SetTableSpace:	/* SET TABLESPACE */
-
 			/*
-			 * Nothing to do here; Phase 3 does the work
+			 * Only do this for partitioned indexes, for which this is just
+			 * a catalog change.  Other relation types are handled by Phase 3.
 			 */
+			if (rel->rd_rel->relkind == RELKIND_PARTITIONED_INDEX)
+				ATExecPartedIdxSetTableSpace(rel, tab->newTableSpace);
+
 			break;
 		case AT_SetRelOptions:	/* SET (...) */
 		case AT_ResetRelOptions:	/* RESET (...) */
@@ -11049,6 +11054,55 @@ ATExecSetTableSpace(Oid tableOid, Oid newTableSpace, LOCKMODE lockmode)
 	list_free(reltoastidxids);
 }
 
+/*
+ * Special handling of ALTER TABLE SET TABLESPACE for partitioned indexes,
+ * which have no storage (so not handled in Phase 3 like other relation types)
+ */
+static void
+ATExecPartedIdxSetTableSpace(Relation rel, Oid newTableSpace)
+{
+	HeapTuple	tuple;
+	Oid			oldTableSpace;
+	Relation	pg_class;
+	Form_pg_class rd_rel;
+	Oid			indexOid = RelationGetRelid(rel);
+
+	Assert(rel->rd_rel->relkind == RELKIND_PARTITIONED_INDEX);
+
+	/*
+	 * No work if no change in tablespace.
+	 */
+	oldTableSpace = rel->rd_rel->reltablespace;
+	if (newTableSpace == oldTableSpace ||
+		(newTableSpace == MyDatabaseTableSpace && oldTableSpace == 0))
+	{
+		InvokeObjectPostAlterHook(RelationRelationId,
+								  indexOid, 0);
+		return;
+	}
+
+	/* Get a modifiable copy of the relation's pg_class row */
+	pg_class = heap_open(RelationRelationId, RowExclusiveLock);
+
+	tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(indexOid));
+	if (!HeapTupleIsValid(tuple))
+		elog(ERROR, "cache lookup failed for relation %u", indexOid);
+	rd_rel = (Form_pg_class) GETSTRUCT(tuple);
+
+	/* update the pg_class row */
+	rd_rel->reltablespace = (newTableSpace == MyDatabaseTableSpace) ? InvalidOid : newTableSpace;
+	CatalogTupleUpdate(pg_class, &tuple->t_self, tuple);
+
+	InvokeObjectPostAlterHook(RelationRelationId, indexOid, 0);
+
+	heap_freetuple(tuple);
+
+	heap_close(pg_class, RowExclusiveLock);
+
+	/* Make sure the reltablespace change is visible */
+	CommandCounterIncrement();
+}
+
 /*
  * Alter Table ALL ... SET TABLESPACE
  *

src/test/regress/input/tablespace.source

@@ -44,6 +44,14 @@ CREATE INDEX foo_idx on testschema.foo(i) TABLESPACE regress_tblspace;
 SELECT relname, spcname FROM pg_catalog.pg_tablespace t, pg_catalog.pg_class c
     where c.reltablespace = t.oid AND c.relname = 'foo_idx';
 
+-- partitioned index
+CREATE TABLE testschema.part (a int) PARTITION BY LIST (a);
+CREATE TABLE testschema.part1 PARTITION OF testschema.part FOR VALUES IN (1);
+CREATE INDEX part_a_idx ON testschema.part (a) TABLESPACE regress_tblspace;
+CREATE TABLE testschema.part2 PARTITION OF testschema.part FOR VALUES IN (2);
+SELECT relname, spcname FROM pg_catalog.pg_tablespace t, pg_catalog.pg_class c
+    where c.reltablespace = t.oid AND c.relname LIKE 'part%_idx';
+
 -- check that default_tablespace doesn't affect ALTER TABLE index rebuilds
 CREATE TABLE testschema.test_default_tab(id bigint) TABLESPACE regress_tblspace;
 INSERT INTO testschema.test_default_tab VALUES (1);
@@ -93,6 +101,8 @@ CREATE UNIQUE INDEX anindex ON testschema.atable(column1);
 
 ALTER TABLE testschema.atable SET TABLESPACE regress_tblspace;
 ALTER INDEX testschema.anindex SET TABLESPACE regress_tblspace;
+ALTER INDEX testschema.part_a_idx SET TABLESPACE pg_default;
+ALTER INDEX testschema.part_a_idx SET TABLESPACE regress_tblspace;
 
 INSERT INTO testschema.atable VALUES(3);	-- ok
 INSERT INTO testschema.atable VALUES(1);	-- fail (checks index)

src/test/regress/output/tablespace.source

@@ -61,6 +61,20 @@ SELECT relname, spcname FROM pg_catalog.pg_tablespace t, pg_catalog.pg_class c
  foo_idx | regress_tblspace
 (1 row)
 
+-- partitioned index
+CREATE TABLE testschema.part (a int) PARTITION BY LIST (a);
+CREATE TABLE testschema.part1 PARTITION OF testschema.part FOR VALUES IN (1);
+CREATE INDEX part_a_idx ON testschema.part (a) TABLESPACE regress_tblspace;
+CREATE TABLE testschema.part2 PARTITION OF testschema.part FOR VALUES IN (2);
+SELECT relname, spcname FROM pg_catalog.pg_tablespace t, pg_catalog.pg_class c
+    where c.reltablespace = t.oid AND c.relname LIKE 'part%_idx';
+   relname   |     spcname      
+-------------+------------------
+ part1_a_idx | regress_tblspace
+ part2_a_idx | regress_tblspace
+ part_a_idx  | regress_tblspace
+(3 rows)
+
 -- check that default_tablespace doesn't affect ALTER TABLE index rebuilds
 CREATE TABLE testschema.test_default_tab(id bigint) TABLESPACE regress_tblspace;
 INSERT INTO testschema.test_default_tab VALUES (1);
@@ -200,6 +214,8 @@ CREATE TABLE testschema.atable AS VALUES (1), (2);
 CREATE UNIQUE INDEX anindex ON testschema.atable(column1);
 ALTER TABLE testschema.atable SET TABLESPACE regress_tblspace;
 ALTER INDEX testschema.anindex SET TABLESPACE regress_tblspace;
+ALTER INDEX testschema.part_a_idx SET TABLESPACE pg_default;
+ALTER INDEX testschema.part_a_idx SET TABLESPACE regress_tblspace;
 INSERT INTO testschema.atable VALUES(3);	-- ok
 INSERT INTO testschema.atable VALUES(1);	-- fail (checks index)
 ERROR:  duplicate key value violates unique constraint "anindex"
@@ -241,10 +257,11 @@ NOTICE:  no matching relations in tablespace "regress_tblspace_renamed" found
 -- Should succeed
 DROP TABLESPACE regress_tblspace_renamed;
 DROP SCHEMA testschema CASCADE;
-NOTICE:  drop cascades to 5 other objects
+NOTICE:  drop cascades to 6 other objects
 DETAIL:  drop cascades to table testschema.foo
 drop cascades to table testschema.asselect
 drop cascades to table testschema.asexecute
+drop cascades to table testschema.part
 drop cascades to table testschema.atable
 drop cascades to table testschema.tablespace_acl
 DROP ROLE regress_tablespace_user1;