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 bc83a9a4a0709481575b2953eb9cd2db81c1db3d..0747f90c3414f84f2b5c3c7d49b386cbba849c45 100644 (file)
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -2494,8 +2494,15 @@ 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 abce3c5653c47e64e893aa3e62e393cf0e6979f8..b860caadf636b77f469e084e5d6fc3651b166971 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   | 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
index 168d95ec4efbbd19cebaf6a6e87265d945be1f5d..522e96c01191b670fc25d011dccb1f8f915a9767 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);