Allow owner change of continuous aggregate

Implements support for changing the owner of the continuous aggregate.
This will change the owner of both the materialized hypertable and the
user view.

Fixes #2414
Fixes #1277

src/process_utility.c

@@ -2814,6 +2814,19 @@ process_altertable_start_matview(ProcessUtilityArgs *args)
 				process_altercontinuousagg_set_with(cagg, view_relid, (List *) cmd->def);
 				break;
 
+			case AT_ChangeOwner:
+				/* Change owner of view */
+				AlterTableInternal(view_relid, list_make1(cmd), false);
+				hcache = ts_hypertable_cache_pin();
+				ht = ts_hypertable_cache_get_entry_by_id(hcache, cagg->data.mat_hypertable_id);
+				Assert(ht); /* Broken continuous aggregate */
+				ts_hypertable_permissions_check_by_id(ht->fd.id);
+				check_alter_table_allowed_on_ht_with_compression(ht, stmt);
+				relation_not_only(stmt->relation);
+				AlterTableInternal(ht->main_table_relid, list_make1(cmd), false);
+				ts_cache_release(hcache);
+				break;
+
 			case AT_SetTableSpace:
 				hcache = ts_hypertable_cache_pin();
 				ht = ts_hypertable_cache_get_entry_by_id(hcache, cagg->data.mat_hypertable_id);

tsl/test/expected/continuous_aggs_ddl.out

@@ -1061,5 +1061,43 @@ FROM metrics_int8
 GROUP BY 1;
 ERROR:  first argument to time_bucket function should be an immutable expression for continuous aggregate query
 \set ON_ERROR_STOP 1
+-- Test various ALTER MATERIALIZED VIEW statements.
+SET ROLE :ROLE_DEFAULT_PERM_USER;
+CREATE MATERIALIZED VIEW owner_check WITH (timescaledb.continuous) AS
+SELECT time_bucket(1 + 2, time)
+FROM metrics_int8
+GROUP BY 1
+WITH NO DATA;
+SELECT relname AS "name",
+       pg_get_userbyid(relowner) AS "owner"
+FROM pg_class, cagg_info 
+WHERE (oid = user_view OR relname = mat_table)
+AND user_view::text = 'owner_check';
+            name             |       owner       
+-----------------------------+-------------------
+ owner_check                 | default_perm_user
+ _materialized_hypertable_24 | default_perm_user
+(2 rows)
+
+-- This should not work since the target user has the wrong role, but
+-- we test that the normal checks are done when changing the owner.
+\set ON_ERROR_STOP 0
+ALTER MATERIALIZED VIEW owner_check OWNER TO :ROLE_1;
+ERROR:  must be member of role "test_role_1"
+\set ON_ERROR_STOP 1
+-- Superuser can always change owner 
+SET ROLE :ROLE_SUPERUSER;
+ALTER MATERIALIZED VIEW owner_check OWNER TO :ROLE_1;
+SELECT relname AS "name",
+       pg_get_userbyid(relowner) AS "owner"
+FROM pg_class, cagg_info 
+WHERE (oid = user_view OR relname = mat_table)
+AND user_view::text = 'owner_check';
+            name             |    owner    
+-----------------------------+-------------
+ owner_check                 | test_role_1
+ _materialized_hypertable_24 | test_role_1
+(2 rows)
+
 DROP TABLESPACE tablespace1;
 DROP TABLESPACE tablespace2;

tsl/test/sql/continuous_aggs_ddl.sql

@@ -695,8 +695,39 @@ CREATE MATERIALIZED VIEW width_expr WITH (timescaledb.continuous) AS
 SELECT time_bucket(extract(year FROM now())::int, time)
 FROM metrics_int8
 GROUP BY 1;
+\set ON_ERROR_STOP 1
+
+-- Test various ALTER MATERIALIZED VIEW statements.
+
+SET ROLE :ROLE_DEFAULT_PERM_USER;
 
+CREATE MATERIALIZED VIEW owner_check WITH (timescaledb.continuous) AS
+SELECT time_bucket(1 + 2, time)
+FROM metrics_int8
+GROUP BY 1
+WITH NO DATA;
+
+SELECT relname AS "name",
+       pg_get_userbyid(relowner) AS "owner"
+FROM pg_class, cagg_info 
+WHERE (oid = user_view OR relname = mat_table)
+AND user_view::text = 'owner_check';
+
+-- This should not work since the target user has the wrong role, but
+-- we test that the normal checks are done when changing the owner.
+\set ON_ERROR_STOP 0
+ALTER MATERIALIZED VIEW owner_check OWNER TO :ROLE_1;
 \set ON_ERROR_STOP 1
 
+-- Superuser can always change owner 
+SET ROLE :ROLE_SUPERUSER;
+ALTER MATERIALIZED VIEW owner_check OWNER TO :ROLE_1;
+
+SELECT relname AS "name",
+       pg_get_userbyid(relowner) AS "owner"
+FROM pg_class, cagg_info 
+WHERE (oid = user_view OR relname = mat_table)
+AND user_view::text = 'owner_check';
+
 DROP TABLESPACE tablespace1;
 DROP TABLESPACE tablespace2;