database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-07-29 05:21:33 +03:00
Code Activity

MDEV-25441 WITH TIES is not respected with SQL_BUFFER_RESULT and constant in ORDER BY

Browse Source 
Pushing LIMIT to temp aggregation table is possible, but not when WITH
TIES is used. In a degenerate case with constant ORDER BY, the constant
gets removed and the code assumed the limit is push-able.

Ensure that if WITH TIES is present, that this does not happen.
This commit is contained in:
Vicențiu Ciorbaru
2021-04-18 22:58:34 +03:00
parent 44a6af65f5
commit aeccdddedd
3 changed files with 52 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

34
mysql-test/main/fetch_first.result
View File

@ -1334,3 +1334,37 @@ a b sum(a)
1 2 1
1 3 1
drop table t1;
#
# MDEV-25441
# WITH TIES is not respected with SQL_BUFFER_RESULT and constant in ORDER BY
#
CREATE TABLE t1 (a INT);
INSERT INTO t1 values (1), (2), (3), (4), (5), (6), (7), (8), (9), (10);
explain SELECT SQL_BUFFER_RESULT 1 AS f FROM t1 ORDER BY f FETCH NEXT 2 ROW WITH TIES;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 10 Using temporary
SELECT SQL_BUFFER_RESULT 1 AS f FROM t1 ORDER BY f FETCH NEXT 2 ROW WITH TIES;
f
1
1
1
1
1
1
1
1
1
1
SELECT 1 AS f FROM t1 ORDER BY f FETCH NEXT 2 ROW WITH TIES;
f
1
1
1
1
1
1
1
1
1
1
drop table t1;