Make constraint rename issue relcache invalidation on target relation

michaelpq · michaelpq · commit d5d86e2cd6b8 · 2018-12-17T10:37:24.000+09:00
When a constraint gets renamed, it may have associated with it a target relation (for example domain constraints don't have one). Not invalidating the target relation cache when issuing the renaming can result in issues with subsequent commands that refer to the old constraint name using the relation cache, causing various failures. One pattern spotted was using CREATE TABLE LIKE after a constraint renaming. Reported-by: Stuart <sfbarbee@gmail.com> Author: Amit Langote Reviewed-by: Michael Paquier Discussion: https://postgr.es/m/2047094.V130LYfLq4@station53.ousa.org
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
@@ -2428,8 +2428,15 @@ rename_constraint_internal(Oid myrelid,
 	ReleaseSysCache(tuple);
 
 	if (targetrelation)
+	{
 		relation_close(targetrelation, NoLock); /* close rel but keep lock */
 
+		/*
+		 * Invalidate relcache so as others can see the new constraint name.
+		 */
+		CacheInvalidateRelcache(targetrelation);
+	}
+
 	return constraintOid;
 }
 
diff --git a/src/test/regress/expected/alter_table.out b/src/test/regress/expected/alter_table.out
@@ -340,6 +340,28 @@ DROP TABLE constraint_rename_test2;
 DROP TABLE constraint_rename_test;
 ALTER TABLE IF EXISTS constraint_rename_test ADD CONSTRAINT con4 UNIQUE (a);
 NOTICE:  relation "constraint_rename_test" does not exist, skipping
+-- renaming constraints with cache reset of target relation
+CREATE TABLE constraint_rename_cache (a int,
+  CONSTRAINT chk_a CHECK (a > 0),
+  PRIMARY KEY (a));
+ALTER TABLE constraint_rename_cache
+  RENAME CONSTRAINT chk_a TO chk_a_new;
+ALTER TABLE constraint_rename_cache
+  RENAME CONSTRAINT constraint_rename_cache_pkey TO chk_a_gt_zero;
+CREATE TABLE like_constraint_rename_cache
+  (LIKE constraint_rename_cache INCLUDING ALL);
+\d like_constraint_rename_cache
+Table "public.like_constraint_rename_cache"
+ Column |  Type   | Modifiers 
+--------+---------+-----------
+ a      | integer | not null
+Indexes:
+    "like_constraint_rename_cache_pkey" PRIMARY KEY, btree (a)
+Check constraints:
+    "chk_a_new" CHECK (a > 0)
+
+DROP TABLE constraint_rename_cache;
+DROP TABLE like_constraint_rename_cache;
 -- FOREIGN KEY CONSTRAINT adding TEST
 CREATE TABLE tmp2 (a int primary key);
 CREATE TABLE tmp3 (a int, b int);
diff --git a/src/test/regress/sql/alter_table.sql b/src/test/regress/sql/alter_table.sql
@@ -250,6 +250,20 @@ DROP TABLE constraint_rename_test2;
 DROP TABLE constraint_rename_test;
 ALTER TABLE IF EXISTS constraint_rename_test ADD CONSTRAINT con4 UNIQUE (a);
 
+-- renaming constraints with cache reset of target relation
+CREATE TABLE constraint_rename_cache (a int,
+  CONSTRAINT chk_a CHECK (a > 0),
+  PRIMARY KEY (a));
+ALTER TABLE constraint_rename_cache
+  RENAME CONSTRAINT chk_a TO chk_a_new;
+ALTER TABLE constraint_rename_cache
+  RENAME CONSTRAINT constraint_rename_cache_pkey TO chk_a_gt_zero;
+CREATE TABLE like_constraint_rename_cache
+  (LIKE constraint_rename_cache INCLUDING ALL);
+\d like_constraint_rename_cache
+DROP TABLE constraint_rename_cache;
+DROP TABLE like_constraint_rename_cache;
+
 -- FOREIGN KEY CONSTRAINT adding TEST
 
 CREATE TABLE tmp2 (a int primary key);
