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MDEV-28246 Optimizer uses all partitions after upgrade to 10.3

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Cause: a copy of the joined TABLE_LIST is created during multi_update::prepare
and TABLE::pos_in_table_list of the tables are set to point to the new
TABLE_LIST object. This prevents some optimization steps to perform correctly.
Solution: do not update pos_in_table_list during multi_update::prepare
This commit is contained in:
Oleg Smirnov
2022-05-13 18:10:11 +04:00
parent 8881c0100e
commit 40d9dbb28f
3 changed files with 122 additions and 2 deletions
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31
mysql-test/main/multi_update.test
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@ -1098,3 +1098,34 @@ select a from t1 where a= (select 2 from t1 having (a = 3));
--error ER_SUBQUERY_NO_1_ROW
update t1 set a= (select 2 from t1 having (a = 3));
drop tables t1;
--echo #
--echo # MDEV-28246 Optimizer uses all partitions during an update in MariaDB 10.6.x but not in 10.2.x
--echo #
--source include/have_partition.inc
CREATE TABLE t1 (
part INT(1),
a INT(1),
b INT(1),
PRIMARY KEY (a,part),
INDEX b (b,part)
) PARTITION BY LIST (part) (
PARTITION Current VALUES IN (0),
PARTITION Relevant VALUES IN (1),
PARTITION Archive VALUES IN (2)
);
CREATE TABLE t2 LIKE t1;
INSERT INTO t1 (part,a,b) VALUES (0,0,0),(1,1,1),(2,2,2);
INSERT INTO t2 (part,a,b) VALUES (0,0,0),(1,1,1),(2,2,2);
--echo # Expecting partition "Current"
EXPLAIN FORMAT=JSON UPDATE t2 JOIN t1 USING(a) SET t2.part=3 WHERE t2.part=0 AND t1.part=0;
--echo # Expecting partition "Relevant"
EXPLAIN FORMAT=JSON UPDATE t2 JOIN t1 USING(a) SET t2.part=2 WHERE t2.part=1 AND t1.part=1;
--echo # Expecting partition "Archive"
EXPLAIN FORMAT=JSON UPDATE t2 JOIN t1 USING(a) SET t2.part=3 WHERE t2.part=2 AND t1.part=2;
DROP TABLES t1, t2;