Fix possible crash in ALTER TABLE ... REPLICA IDENTITY USING INDEX.

Careless coding added by commit 07cacba983ef79be could result in a crash
or a bizarre error message if someone tried to select an index on the
OID column as the replica identity index for a table.  Back-patch to 9.4
where the feature was introduced.

Discussion: CAKJS1f8TQYgTRDyF1_u9PVCKWRWz+DkieH=U7954HeHVPJKaKg@mail.gmail.com

David Rowley

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index eaf76d2b902b99cc91254c54c9e06f163b2d59b9..45a5144643432b651925bd736f48e90eb8d13d4b 100644 (file)
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -11052,10 +11052,20 @@ ATExecReplicaIdentity(Relation rel, ReplicaIdentityStmt *stmt, LOCKMODE lockmode
                int16           attno = indexRel->rd_index->indkey.values[key];
                Form_pg_attribute attr;
 
-               /* Of the system columns, only oid is indexable. */
-               if (attno <= 0 && attno != ObjectIdAttributeNumber)
-                       elog(ERROR, "internal column %u in unique index \"%s\"",
-                                attno, RelationGetRelationName(indexRel));
+               /* Allow OID column to be indexed; it's certainly not nullable */
+               if (attno == ObjectIdAttributeNumber)
+                       continue;
+
+               /*
+                * Reject any other system columns.  (Going forward, we'll disallow
+                * indexes containing such columns in the first place, but they might
+                * exist in older branches.)
+                */
+               if (attno <= 0)
+                       ereport(ERROR,
+                                       (errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
+                                        errmsg("index \"%s\" cannot be used as replica identity because column %d is a system column",
+                                                       RelationGetRelationName(indexRel), attno)));
 
                attr = rel->rd_att->attrs[attno - 1];
                if (!attr->attnotnull)

diff --git a/src/test/regress/expected/replica_identity.out b/src/test/regress/expected/replica_identity.out
index 60d9a424a1b7ae701951aaa2b73bf411e5eb8229..39a60a56191b77da4d4ea478b6be159e234a6bf5 100644 (file)
--- a/src/test/regress/expected/replica_identity.out
+++ b/src/test/regress/expected/replica_identity.out
@@ -5,10 +5,11 @@ CREATE TABLE test_replica_identity (
        nonkey text,
        CONSTRAINT test_replica_identity_unique_defer UNIQUE (keya, keyb) DEFERRABLE,
        CONSTRAINT test_replica_identity_unique_nondefer UNIQUE (keya, keyb)
-);
+) WITH OIDS;
 CREATE TABLE test_replica_identity_othertable (id serial primary key);
 CREATE INDEX test_replica_identity_keyab ON test_replica_identity (keya, keyb);
 CREATE UNIQUE INDEX test_replica_identity_keyab_key ON test_replica_identity (keya, keyb);
+CREATE UNIQUE INDEX test_replica_identity_oid_idx ON test_replica_identity (oid);
 CREATE UNIQUE INDEX test_replica_identity_nonkey ON test_replica_identity (keya, nonkey);
 CREATE INDEX test_replica_identity_hash ON test_replica_identity USING hash (nonkey);
 WARNING:  hash indexes are not WAL-logged and their use is discouraged
@@ -88,12 +89,15 @@ Indexes:
     "test_replica_identity_expr" UNIQUE, btree (keya, keyb, (3))
     "test_replica_identity_keyab_key" UNIQUE, btree (keya, keyb)
     "test_replica_identity_nonkey" UNIQUE, btree (keya, nonkey)
+    "test_replica_identity_oid_idx" UNIQUE, btree (oid)
     "test_replica_identity_partial" UNIQUE, btree (keya, keyb) WHERE keyb <> '3'::text
     "test_replica_identity_unique_defer" UNIQUE CONSTRAINT, btree (keya, keyb) DEFERRABLE
     "test_replica_identity_unique_nondefer" UNIQUE CONSTRAINT, btree (keya, keyb)
     "test_replica_identity_hash" hash (nonkey)
     "test_replica_identity_keyab" btree (keya, keyb)
 
+-- succeed, oid unique index
+ALTER TABLE test_replica_identity REPLICA IDENTITY USING INDEX test_replica_identity_oid_idx;
 -- succeed, nondeferrable unique constraint over nonullable cols
 ALTER TABLE test_replica_identity REPLICA IDENTITY USING INDEX test_replica_identity_unique_nondefer;
 -- succeed unique index over nonnullable cols
@@ -118,6 +122,7 @@ Indexes:
     "test_replica_identity_expr" UNIQUE, btree (keya, keyb, (3))
     "test_replica_identity_keyab_key" UNIQUE, btree (keya, keyb) REPLICA IDENTITY
     "test_replica_identity_nonkey" UNIQUE, btree (keya, nonkey)
+    "test_replica_identity_oid_idx" UNIQUE, btree (oid)
     "test_replica_identity_partial" UNIQUE, btree (keya, keyb) WHERE keyb <> '3'::text
     "test_replica_identity_unique_defer" UNIQUE CONSTRAINT, btree (keya, keyb) DEFERRABLE
     "test_replica_identity_unique_nondefer" UNIQUE CONSTRAINT, btree (keya, keyb)
@@ -166,12 +171,14 @@ Indexes:
     "test_replica_identity_expr" UNIQUE, btree (keya, keyb, (3))
     "test_replica_identity_keyab_key" UNIQUE, btree (keya, keyb)
     "test_replica_identity_nonkey" UNIQUE, btree (keya, nonkey)
+    "test_replica_identity_oid_idx" UNIQUE, btree (oid)
     "test_replica_identity_partial" UNIQUE, btree (keya, keyb) WHERE keyb <> '3'::text
     "test_replica_identity_unique_defer" UNIQUE CONSTRAINT, btree (keya, keyb) DEFERRABLE
     "test_replica_identity_unique_nondefer" UNIQUE CONSTRAINT, btree (keya, keyb)
     "test_replica_identity_hash" hash (nonkey)
     "test_replica_identity_keyab" btree (keya, keyb)
 Replica Identity: FULL
+Has OIDs: yes
 
 ALTER TABLE test_replica_identity REPLICA IDENTITY NOTHING;
 SELECT relreplident FROM pg_class WHERE oid = 'test_replica_identity'::regclass;

diff --git a/src/test/regress/sql/replica_identity.sql b/src/test/regress/sql/replica_identity.sql
index 20b682685e9d34c7c8ba322d751c566b80279150..68824a3aa7aa6fc4d9776834a44a63b3384757e3 100644 (file)
--- a/src/test/regress/sql/replica_identity.sql
+++ b/src/test/regress/sql/replica_identity.sql
@@ -5,12 +5,13 @@ CREATE TABLE test_replica_identity (
        nonkey text,
        CONSTRAINT test_replica_identity_unique_defer UNIQUE (keya, keyb) DEFERRABLE,
        CONSTRAINT test_replica_identity_unique_nondefer UNIQUE (keya, keyb)
-);
+) WITH OIDS;
 
 CREATE TABLE test_replica_identity_othertable (id serial primary key);
 
 CREATE INDEX test_replica_identity_keyab ON test_replica_identity (keya, keyb);
 CREATE UNIQUE INDEX test_replica_identity_keyab_key ON test_replica_identity (keya, keyb);
+CREATE UNIQUE INDEX test_replica_identity_oid_idx ON test_replica_identity (oid);
 CREATE UNIQUE INDEX test_replica_identity_nonkey ON test_replica_identity (keya, nonkey);
 CREATE INDEX test_replica_identity_hash ON test_replica_identity USING hash (nonkey);
 CREATE UNIQUE INDEX test_replica_identity_expr ON test_replica_identity (keya, keyb, (3));
@@ -52,6 +53,9 @@ ALTER TABLE test_replica_identity REPLICA IDENTITY USING INDEX test_replica_iden
 SELECT relreplident FROM pg_class WHERE oid = 'test_replica_identity'::regclass;
 \d test_replica_identity
 
+-- succeed, oid unique index
+ALTER TABLE test_replica_identity REPLICA IDENTITY USING INDEX test_replica_identity_oid_idx;
+
 -- succeed, nondeferrable unique constraint over nonullable cols
 ALTER TABLE test_replica_identity REPLICA IDENTITY USING INDEX test_replica_identity_unique_nondefer;