SKIP LOCKED assert triggered
Started by Simon Riggsabout 4 years ago9 messages
The combination of these two statements in a transaction hits an
Assert in heapam.c at line 4770 on REL_14_STABLE
BEGIN;
SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
...
UPDATE queue SET status = 'UPDATED' WHERE id = :id;
COMMIT;
pgbench reliably finds this, running from inside a PL/pgSQL function.
Alvaro suggests we just ignore the Assert, which on testing appears to
be the right approach. Patch attached, which solves it for me.
There is no formal test that does lock then update, so I have
attempted to create one, but this has not successfully reproduced it
(attached anyway), but this code is different from the pgbench test.
--
Simon Riggs http://www.EnterpriseDB.com/
Attachments:
skip_locked_assert.v1.patchapplication/octet-stream; name=skip_locked_assert.v1.patchDownload
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index 5945559a1e..f11b1b44f6 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -4770,7 +4770,7 @@ failed:
{
Assert(result == TM_SelfModified || result == TM_Updated ||
result == TM_Deleted || result == TM_WouldBlock);
- Assert(!(tuple->t_data->t_infomask & HEAP_XMAX_INVALID));
+ Assert(TM_WouldBlock || !(tuple->t_data->t_infomask & HEAP_XMAX_INVALID));
Assert(result != TM_Updated ||
!ItemPointerEquals(&tuple->t_self, &tuple->t_data->t_ctid));
tmfd->ctid = tuple->t_data->t_ctid;
skip_locked_then_update_test.v1.patchapplication/octet-stream; name=skip_locked_then_update_test.v1.patchDownload
diff --git a/src/test/isolation/expected/skip-locked.out b/src/test/isolation/expected/skip-locked.out
index 3dc5768384..c243a0d8f2 100644
--- a/src/test/isolation/expected/skip-locked.out
+++ b/src/test/isolation/expected/skip-locked.out
@@ -1,561 +1,1541 @@
Parsed test spec with 2 sessions
-starting permutation: s1a s1b s1c s2a s2b s2c
-step s1a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+starting permutation: s1dc s1f s1u s1c s2dc s2f s2u s2c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s1b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+
+starting permutation: s1dc s1f s1u s2dc s1c s2f s2u s2c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
step s1c: COMMIT;
-step s2a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+
+starting permutation: s1dc s1f s1u s2dc s2f s1c s2u s2c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s2b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
+step s1c: COMMIT;
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
step s2c: COMMIT;
-starting permutation: s1a s1b s2a s1c s2b s2c
-step s1a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+starting permutation: s1dc s1f s1u s2dc s2f s2u s1c s2c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s1b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s2a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+step s2c: COMMIT;
+
+starting permutation: s1dc s1f s1u s2dc s2f s2u s2c s1c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
id|data|status
--+----+------
- 2|bar |NEW
+ 1|foo |NEW
+(1 row)
+
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+step s1c: COMMIT;
+
+starting permutation: s1dc s1f s2dc s1u s1c s2f s2u s2c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
(1 row)
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
step s1c: COMMIT;
-step s2b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+
+starting permutation: s1dc s1f s2dc s1u s2f s1c s2u s2c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s1c: COMMIT;
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+
+starting permutation: s1dc s1f s2dc s1u s2f s2u s1c s2c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
step s2c: COMMIT;
-starting permutation: s1a s1b s2a s2b s1c s2c
-step s1a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+starting permutation: s1dc s1f s2dc s1u s2f s2u s2c s1c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s1b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s2a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+step s1c: COMMIT;
+
+starting permutation: s1dc s1f s2dc s2f s1u s1c s2u s2c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
id|data|status
--+----+------
2|bar |NEW
(1 row)
-step s2b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+
+starting permutation: s1dc s1f s2dc s2f s1u s2u s1c s2c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
id|data|status
--+----+------
2|bar |NEW
(1 row)
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
step s1c: COMMIT;
step s2c: COMMIT;
-starting permutation: s1a s1b s2a s2b s2c s1c
-step s1a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+starting permutation: s1dc s1f s2dc s2f s1u s2u s2c s1c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s1b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 2|bar |NEW
+(1 row)
+
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+step s1c: COMMIT;
+
+starting permutation: s1dc s1f s2dc s2f s2u s1u s1c s2c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s2a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
id|data|status
--+----+------
2|bar |NEW
(1 row)
-step s2b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+step s2c: COMMIT;
+
+starting permutation: s1dc s1f s2dc s2f s2u s1u s2c s1c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
id|data|status
--+----+------
2|bar |NEW
(1 row)
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
step s2c: COMMIT;
step s1c: COMMIT;
-starting permutation: s1a s2a s1b s1c s2b s2c
-step s1a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+starting permutation: s1dc s1f s2dc s2f s2u s2c s1u s1c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s2a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
id|data|status
--+----+------
2|bar |NEW
(1 row)
-step s1b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+
+starting permutation: s1dc s2dc s1f s1u s1c s2f s2u s2c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
step s1c: COMMIT;
-step s2b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
step s2c: COMMIT;
-starting permutation: s1a s2a s1b s2b s1c s2c
-step s1a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+starting permutation: s1dc s2dc s1f s1u s2f s1c s2u s2c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s2a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s1c: COMMIT;
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+
+starting permutation: s1dc s2dc s1f s1u s2f s2u s1c s2c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+step s2c: COMMIT;
+
+starting permutation: s1dc s2dc s1f s1u s2f s2u s2c s1c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+step s1c: COMMIT;
+
+starting permutation: s1dc s2dc s1f s2f s1u s1c s2u s2c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s2f: FETCH curs;
id|data|status
--+----+------
2|bar |NEW
(1 row)
-step s1b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+
+starting permutation: s1dc s2dc s1f s2f s1u s2u s1c s2c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s2b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2f: FETCH curs;
id|data|status
--+----+------
2|bar |NEW
(1 row)
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
step s1c: COMMIT;
step s2c: COMMIT;
-starting permutation: s1a s2a s1b s2b s2c s1c
-step s1a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+starting permutation: s1dc s2dc s1f s2f s1u s2u s2c s1c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 2|bar |NEW
+(1 row)
+
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+step s1c: COMMIT;
+
+starting permutation: s1dc s2dc s1f s2f s2u s1u s1c s2c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s2a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2f: FETCH curs;
id|data|status
--+----+------
2|bar |NEW
(1 row)
-step s1b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+step s2c: COMMIT;
+
+starting permutation: s1dc s2dc s1f s2f s2u s1u s2c s1c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s2b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2f: FETCH curs;
id|data|status
--+----+------
2|bar |NEW
(1 row)
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
step s2c: COMMIT;
step s1c: COMMIT;
-starting permutation: s1a s2a s2b s1b s1c s2c
-step s1a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+starting permutation: s1dc s2dc s1f s2f s2u s2c s1u s1c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s2a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2f: FETCH curs;
id|data|status
--+----+------
2|bar |NEW
(1 row)
-step s2b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+
+starting permutation: s1dc s2dc s2f s1f s1u s1c s2u s2c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s1f: FETCH curs;
id|data|status
--+----+------
2|bar |NEW
(1 row)
-step s1b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+
+starting permutation: s1dc s2dc s2f s1f s1u s2u s1c s2c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 2|bar |NEW
+(1 row)
+
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
step s1c: COMMIT;
step s2c: COMMIT;
-starting permutation: s1a s2a s2b s1b s2c s1c
-step s1a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+starting permutation: s1dc s2dc s2f s1f s1u s2u s2c s1c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s2a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s1f: FETCH curs;
id|data|status
--+----+------
2|bar |NEW
(1 row)
-step s2b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+step s1c: COMMIT;
+
+starting permutation: s1dc s2dc s2f s1f s2u s1u s1c s2c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s1f: FETCH curs;
id|data|status
--+----+------
2|bar |NEW
(1 row)
-step s1b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+step s2c: COMMIT;
+
+starting permutation: s1dc s2dc s2f s1f s2u s1u s2c s1c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 2|bar |NEW
+(1 row)
+
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
step s2c: COMMIT;
step s1c: COMMIT;
-starting permutation: s1a s2a s2b s2c s1b s1c
-step s1a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+starting permutation: s1dc s2dc s2f s1f s2u s2c s1u s1c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s2a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s1f: FETCH curs;
id|data|status
--+----+------
2|bar |NEW
(1 row)
-step s2b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+
+starting permutation: s1dc s2dc s2f s2u s1f s1u s1c s2c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
id|data|status
--+----+------
- 2|bar |NEW
+ 1|foo |NEW
(1 row)
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
step s2c: COMMIT;
-step s1b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+
+starting permutation: s1dc s2dc s2f s2u s1f s1u s2c s1c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
step s1c: COMMIT;
-starting permutation: s2a s1a s1b s1c s2b s2c
-step s2a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+starting permutation: s1dc s2dc s2f s2u s1f s2c s1u s1c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s1a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1f: FETCH curs;
id|data|status
--+----+------
- 2|bar |NEW
+ 1|foo |NEW
(1 row)
-step s1b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2c: COMMIT;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+
+starting permutation: s1dc s2dc s2f s2u s2c s1f s1u s1c
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
id|data|status
--+----+------
- 2|bar |NEW
+ 1|foo |NEW
+(1 row)
+
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+
+starting permutation: s2dc s1dc s1f s1u s1c s2f s2u s2c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
(1 row)
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
step s1c: COMMIT;
-step s2b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
step s2c: COMMIT;
-starting permutation: s2a s1a s1b s2b s1c s2c
-step s2a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+starting permutation: s2dc s1dc s1f s1u s2f s1c s2u s2c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s1a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2f: FETCH curs;
id|data|status
--+----+------
- 2|bar |NEW
+ 1|foo |NEW
+(1 row)
+
+step s1c: COMMIT;
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+
+starting permutation: s2dc s1dc s1f s1u s2f s2u s1c s2c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+step s2c: COMMIT;
+
+starting permutation: s2dc s1dc s1f s1u s2f s2u s2c s1c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
(1 row)
-step s1b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+step s1c: COMMIT;
+
+starting permutation: s2dc s1dc s1f s2f s1u s1c s2u s2c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s2f: FETCH curs;
id|data|status
--+----+------
2|bar |NEW
(1 row)
-step s2b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+
+starting permutation: s2dc s1dc s1f s2f s1u s2u s1c s2c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 2|bar |NEW
+(1 row)
+
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
step s1c: COMMIT;
step s2c: COMMIT;
-starting permutation: s2a s1a s1b s2b s2c s1c
-step s2a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+starting permutation: s2dc s1dc s1f s2f s1u s2u s2c s1c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s1a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2f: FETCH curs;
id|data|status
--+----+------
2|bar |NEW
(1 row)
-step s1b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+step s1c: COMMIT;
+
+starting permutation: s2dc s1dc s1f s2f s2u s1u s1c s2c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s2f: FETCH curs;
id|data|status
--+----+------
2|bar |NEW
(1 row)
-step s2b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+step s2c: COMMIT;
+
+starting permutation: s2dc s1dc s1f s2f s2u s1u s2c s1c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 2|bar |NEW
+(1 row)
+
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+step s1c: COMMIT;
+
+starting permutation: s2dc s1dc s1f s2f s2u s2c s1u s1c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 2|bar |NEW
+(1 row)
+
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
step s2c: COMMIT;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
step s1c: COMMIT;
-starting permutation: s2a s1a s2b s1b s1c s2c
-step s2a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+starting permutation: s2dc s1dc s2f s1f s1u s1c s2u s2c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s1a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s1f: FETCH curs;
id|data|status
--+----+------
2|bar |NEW
(1 row)
-step s2b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+
+starting permutation: s2dc s1dc s2f s1f s1u s2u s1c s2c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s1b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s1f: FETCH curs;
id|data|status
--+----+------
2|bar |NEW
(1 row)
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
step s1c: COMMIT;
step s2c: COMMIT;
-starting permutation: s2a s1a s2b s1b s2c s1c
-step s2a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+starting permutation: s2dc s1dc s2f s1f s1u s2u s2c s1c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s1a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s1f: FETCH curs;
id|data|status
--+----+------
2|bar |NEW
(1 row)
-step s2b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+step s1c: COMMIT;
+
+starting permutation: s2dc s1dc s2f s1f s2u s1u s1c s2c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s1b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s1f: FETCH curs;
id|data|status
--+----+------
2|bar |NEW
(1 row)
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+step s2c: COMMIT;
+
+starting permutation: s2dc s1dc s2f s1f s2u s1u s2c s1c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 2|bar |NEW
+(1 row)
+
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
step s2c: COMMIT;
step s1c: COMMIT;
-starting permutation: s2a s1a s2b s2c s1b s1c
-step s2a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+starting permutation: s2dc s1dc s2f s1f s2u s2c s1u s1c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s1a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s1f: FETCH curs;
id|data|status
--+----+------
2|bar |NEW
(1 row)
-step s2b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+
+starting permutation: s2dc s1dc s2f s2u s1f s1u s1c s2c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
step s2c: COMMIT;
-step s1b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+
+starting permutation: s2dc s1dc s2f s2u s1f s1u s2c s1c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
step s1c: COMMIT;
-starting permutation: s2a s2b s1a s1b s1c s2c
-step s2a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+starting permutation: s2dc s1dc s2f s2u s1f s2c s1u s1c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s2b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s1a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2c: COMMIT;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+
+starting permutation: s2dc s1dc s2f s2u s2c s1f s1u s1c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+
+starting permutation: s2dc s2f s1dc s1f s1u s1c s2u s2c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
id|data|status
--+----+------
2|bar |NEW
(1 row)
-step s1b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+
+starting permutation: s2dc s2f s1dc s1f s1u s2u s1c s2c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
id|data|status
--+----+------
2|bar |NEW
(1 row)
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
step s1c: COMMIT;
step s2c: COMMIT;
-starting permutation: s2a s2b s1a s1b s2c s1c
-step s2a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+starting permutation: s2dc s2f s1dc s1f s1u s2u s2c s1c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s2b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 2|bar |NEW
+(1 row)
+
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+step s1c: COMMIT;
+
+starting permutation: s2dc s2f s1dc s1f s2u s1u s1c s2c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s1a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
id|data|status
--+----+------
2|bar |NEW
(1 row)
-step s1b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+step s2c: COMMIT;
+
+starting permutation: s2dc s2f s1dc s1f s2u s1u s2c s1c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
id|data|status
--+----+------
2|bar |NEW
(1 row)
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
step s2c: COMMIT;
step s1c: COMMIT;
-starting permutation: s2a s2b s1a s2c s1b s1c
-step s2a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+starting permutation: s2dc s2f s1dc s1f s2u s2c s1u s1c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s2b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 2|bar |NEW
+(1 row)
+
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+
+starting permutation: s2dc s2f s1dc s2u s1f s1u s1c s2c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s1a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1f: FETCH curs;
id|data|status
--+----+------
- 2|bar |NEW
+ 1|foo |NEW
(1 row)
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
step s2c: COMMIT;
-step s1b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+
+starting permutation: s2dc s2f s1dc s2u s1f s1u s2c s1c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
step s1c: COMMIT;
-starting permutation: s2a s2b s2c s1a s1b s1c
-step s2a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+starting permutation: s2dc s2f s1dc s2u s1f s2c s1u s1c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s2b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s2c: COMMIT;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+
+starting permutation: s2dc s2f s1dc s2u s2c s1f s1u s1c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
step s2c: COMMIT;
-step s1a: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s1f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
-step s1b: SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+
+starting permutation: s2dc s2f s2u s1dc s1f s1u s1c s2c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+step s2c: COMMIT;
+
+starting permutation: s2dc s2f s2u s1dc s1f s1u s2c s1c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+step s1c: COMMIT;
+
+starting permutation: s2dc s2f s2u s1dc s1f s2c s1u s1c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s2c: COMMIT;
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+
+starting permutation: s2dc s2f s2u s1dc s2c s1f s1u s1c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2c: COMMIT;
+step s1f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s1c: COMMIT;
+
+starting permutation: s2dc s2f s2u s2c s1dc s1f s1u s1c
+step s2dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s2f: FETCH curs;
+id|data|status
+--+----+------
+ 1|foo |NEW
+(1 row)
+
+step s2u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
+step s2c: COMMIT;
+step s1dc: DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED;
+step s1f: FETCH curs;
id|data|status
--+----+------
1|foo |NEW
(1 row)
+step s1u: UPDATE queue SET status = status + 1 WHERE CURRENT OF curs;
+ERROR: operator does not exist: text + integer
step s1c: COMMIT;
diff --git a/src/test/isolation/specs/skip-locked.spec b/src/test/isolation/specs/skip-locked.spec
index 12168f8f8a..b035f17b8a 100644
--- a/src/test/isolation/specs/skip-locked.spec
+++ b/src/test/isolation/specs/skip-locked.spec
@@ -17,12 +17,14 @@ teardown
session s1
setup { BEGIN; }
-step s1a { SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1; }
-step s1b { SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1; }
+step s1dc { DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED; }
+step s1f { FETCH curs; }
+step s1u { UPDATE queue SET status = status + 1 WHERE CURRENT OF curs; }
step s1c { COMMIT; }
session s2
setup { BEGIN; }
-step s2a { SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1; }
-step s2b { SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1; }
+step s2dc { DECLARE curs CURSOR FOR SELECT * FROM queue LIMIT 1 FOR UPDATE SKIP LOCKED; }
+step s2f { FETCH curs; }
+step s2u { UPDATE queue SET status = status + 1 WHERE CURRENT OF curs; }
step s2c { COMMIT; }
Re: SKIP LOCKED assert triggered
On 11/12/21, 8:56 AM, "Simon Riggs" <simon.riggs@enterprisedb.com> wrote:
The combination of these two statements in a transaction hits an
Assert in heapam.c at line 4770 on REL_14_STABLE
I've been unable to reproduce this. Do you have any tips for how to
do so? Does there need to be some sort of concurrent workload?
Nathan
Re: SKIP LOCKED assert triggered
On Wed, 1 Dec 2021 at 14:33, Bossart, Nathan <bossartn@amazon.com> wrote:
On 11/12/21, 8:56 AM, "Simon Riggs" <simon.riggs@enterprisedb.com> wrote:
The combination of these two statements in a transaction hits an
Assert in heapam.c at line 4770 on REL_14_STABLEI've been unable to reproduce this. Do you have any tips for how to
do so? Does there need to be some sort of concurrent workload?
That path is only ever taken when there are multiple sessions, and as
I said, pgbench finds this reliably. I guess I didn't say "use -c 2"
--
Simon Riggs http://www.EnterpriseDB.com/
Re: SKIP LOCKED assert triggered
On 2021-Dec-01, Simon Riggs wrote:
On Wed, 1 Dec 2021 at 14:33, Bossart, Nathan <bossartn@amazon.com> wrote:
On 11/12/21, 8:56 AM, "Simon Riggs" <simon.riggs@enterprisedb.com> wrote:
The combination of these two statements in a transaction hits an
Assert in heapam.c at line 4770 on REL_14_STABLEI've been unable to reproduce this. Do you have any tips for how to
do so? Does there need to be some sort of concurrent workload?That path is only ever taken when there are multiple sessions, and as
I said, pgbench finds this reliably. I guess I didn't say "use -c 2"
Simon had sent me the pgbench scripts earlier, so I attach them here.
I don't actually get a crash with -c2 or -c3, but I do get almost
immediate crashes with -c4 and above. If I run it under "rr", it
doesn't occur either. I suspect the rr framework kills concurrency in
some way that hides the problem. I didn't find a way to reproduce it
with isolationtester. (If somebody wants to play with a debugger, I
find that it's much easier to reproduce by adding a short sleep after
the UpdateXmaxHintBits() call in line 4735; but that sleep occurs in a
session *other* than the one that dies. And under rr I still don't see
a crash with a sleep there; in fact the sleep doesn't seem to occur at
all, which is weird.)
The patch does fix the crasher under pgbench, and I think it makes sense
that you can get WouldBlock and yet have the tuple marked with
XMAX_INVALID: if transaction A is writing the tuple, and transaction B
is acquiring the tuple lock, then transaction C also tries to acquire
the tuple lock but that returns nay (because of B), then transaction A
completes, then transaction B could set the XMAX_INVALID flag in time
for C to have a seizure in its way out. So patching the assertion to
allow the case is correct.
What I don't understand is why hasn't this been reported already: this
bug is pretty old. My only explanation is that nobody runs sufficiently-
concurrent load with SKIP LOCKED in assert-enabled builds.
[1]: /messages/by-id/CADLWmXUvd5Z+cFczi6Zj1WcTrXzipgP-wj0pZOWSaRUy=F0omQ@mail.gmail.com
--
Álvaro Herrera Valdivia, Chile — https://www.EnterpriseDB.com/
Re: SKIP LOCKED assert triggered
On 2022-Jan-03, Alvaro Herrera wrote:
What I don't understand is why hasn't this been reported already: this
bug is pretty old. My only explanation is that nobody runs sufficiently-
concurrent load with SKIP LOCKED in assert-enabled builds.
Pushed, thanks Simon for reporting this problem.
[1] /messages/by-id/CADLWmXUvd5Z+cFczi6Zj1WcTrXzipgP-wj0pZOWSaRUy=F0omQ@mail.gmail.com
Heh, I deleted a paragraph from my previous email and forgot to remove
the footnote that it referenced.
--
Álvaro Herrera Valdivia, Chile — https://www.EnterpriseDB.com/
"I love the Postgres community. It's all about doing things _properly_. :-)"
(David Garamond)
Re: SKIP LOCKED assert triggered
On 2022-Jan-04, Alvaro Herrera wrote:
On 2022-Jan-03, Alvaro Herrera wrote:
What I don't understand is why hasn't this been reported already: this
bug is pretty old. My only explanation is that nobody runs sufficiently-
concurrent load with SKIP LOCKED in assert-enabled builds.Pushed, thanks Simon for reporting this problem.
Wow, what an embarrassing problem this fix has.
--
Álvaro Herrera 39°49'30"S 73°17'W — https://www.EnterpriseDB.com/
"Pensar que el espectro que vemos es ilusorio no lo despoja de espanto,
sólo le suma el nuevo terror de la locura" (Perelandra, C.S. Lewis)
Re: SKIP LOCKED assert triggered
Alvaro Herrera <alvherre@alvh.no-ip.org> writes:
Pushed, thanks Simon for reporting this problem.
Umm ...
Assert(TM_WouldBlock || !(tuple->t_data->t_infomask & HEAP_XMAX_INVALID));
AFAICS, this assertion condition is constant-true,
because TM_WouldBlock is a nonzero constant. Perhaps you meant
Assert(result == TM_WouldBlock || !(tuple->t_data->t_infomask & HEAP_XMAX_INVALID));
?
I'd be inclined to format it more like the adjacent Assert, too.
regards, tom lane
Re: SKIP LOCKED assert triggered
On Tue, Jan 04, 2022 at 11:15:30AM -0500, Tom Lane wrote:
Alvaro Herrera <alvherre@alvh.no-ip.org> writes:
Pushed, thanks Simon for reporting this problem.
Umm ...
Assert(TM_WouldBlock || !(tuple->t_data->t_infomask & HEAP_XMAX_INVALID));
AFAICS, this assertion condition is constant-true,
The new cfbot was failing like this
https://cirrus-ci.com/github/postgresql-cfbot/postgresql/commitfest/36/3423
https://cirrus-ci.com/build/5839382107127808
[22:52:27.978] heapam.c:4754:24: error: converting the enum constant to a boolean [-Werror,-Wint-in-bool-context]
Re: SKIP LOCKED assert triggered
On Tue, 4 Jan 2022 at 16:15, Tom Lane <tgl@sss.pgh.pa.us> wrote:
Alvaro Herrera <alvherre@alvh.no-ip.org> writes:
Pushed, thanks Simon for reporting this problem.
And causing another; my bad, apologies.
Umm ...
Assert(TM_WouldBlock || !(tuple->t_data->t_infomask & HEAP_XMAX_INVALID));
AFAICS, this assertion condition is constant-true,
because TM_WouldBlock is a nonzero constant. Perhaps you meantAssert(result == TM_WouldBlock || !(tuple->t_data->t_infomask & HEAP_XMAX_INVALID));
Yes, I think that's what I meant.
--
Simon Riggs http://www.EnterpriseDB.com/