database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-07-30 16:24:05 +03:00
Code Activity

Fixed bug #26963: invalid optimization of the pushdown conditions

Browse Source 
after single-row table substitution could lead to a wrong result set.
The bug happened because the function Item_field::replace_equal_field
erroniously assumed that any field included in a multiple equality
with a constant has been already substituted for this constant.
This not true for fields becoming constant after row substitutions
for constant tables.
This commit is contained in:
igor@olga.mysql.com
2007-03-11 23:34:40 -07:00
parent f3e56b5adb
commit e7284ace4f
3 changed files with 98 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

38
mysql-test/r/select.result
View File

@ -3933,4 +3933,42 @@ cc cc 7
aa aa 2
aa aa 2
DROP TABLE t1,t2;
CREATE TABLE t1 (
access_id int NOT NULL default '0',
name varchar(20) default NULL,
rank int NOT NULL default '0',
KEY idx (access_id)
);
CREATE TABLE t2 (
faq_group_id int NOT NULL default '0',
faq_id int NOT NULL default '0',
access_id int default NULL,
UNIQUE KEY idx1 (faq_id),
KEY idx2 (faq_group_id,faq_id)
);
INSERT INTO t1 VALUES
(1,'Everyone',2),(2,'Help',3),(3,'Technical Support',1),(4,'Chat User',4);
INSERT INTO t2 VALUES
(261,265,1),(490,494,1);
SELECT t2.faq_id
FROM t1 INNER JOIN t2 IGNORE INDEX (idx1)
ON (t1.access_id = t2.access_id)
LEFT JOIN t2 t
ON (t.faq_group_id = t2.faq_group_id AND
find_in_set(t.access_id, '1,4') < find_in_set(t2.access_id, '1,4'))
WHERE
t2.access_id IN (1,4) AND t.access_id IS NULL AND t2.faq_id in (265);
faq_id
265
SELECT t2.faq_id
FROM t1 INNER JOIN t2
ON (t1.access_id = t2.access_id)
LEFT JOIN t2 t
ON (t.faq_group_id = t2.faq_group_id AND
find_in_set(t.access_id, '1,4') < find_in_set(t2.access_id, '1,4'))
WHERE
t2.access_id IN (1,4) AND t.access_id IS NULL AND t2.faq_id in (265);
faq_id
265
DROP TABLE t1,t2;
End of 5.0 tests