Make constraint rename issue relcache invalidation on target relation

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
index 4dfa4a4c49cb8472af6800796a994d2c4056aecb..8893522e1d01b0098134643dbd6a9c938a5dd090 100644 (file)
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -2827,8 +2827,15 @@ 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 address;
 }
 

diff --git a/src/test/regress/expected/alter_table.out b/src/test/regress/expected/alter_table.out
index 70e140039ac911ec757ef2821fd65d4061dd6ac2..37ba3876dca2b9a3c330279277ca5bcfe4235bec 100644 (file)
--- a/src/test/regress/expected/alter_table.out
+++ b/src/test/regress/expected/alter_table.out
@@ -342,6 +342,28 @@ ALTER TABLE IF EXISTS constraint_not_exist RENAME CONSTRAINT con3 TO con3foo; --
 NOTICE:  relation "constraint_not_exist" does not exist, skipping
 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   | Collation | Nullable | Default 
+--------+---------+-----------+----------+---------
+ 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
index e79b402a322865d967c99dce6ce97dc96e32cf35..56033ae631b425be15ff3c7aaec1f136c87158bd 100644 (file)
--- a/src/test/regress/sql/alter_table.sql
+++ b/src/test/regress/sql/alter_table.sql
@@ -251,6 +251,20 @@ DROP TABLE constraint_rename_test;
 ALTER TABLE IF EXISTS constraint_not_exist RENAME CONSTRAINT con3 TO con3foo; -- ok
 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);