Details
Description
For the following query with SELECT:
select * |
from v1,t3 |
where
|
v1.c2 = t3.c2 and |
v1.c2 in (select max(c2) from t2 where c3 = v1.c3) |
and v1.c1 < 10 and |
v1.c1 in (select c1 from v2); |
EXPLAIN EXTENDED produces messages:
Warnings:
|
Note 1276 Field or reference 'v1.c3' of SELECT #2 was resolved in SELECT #1 |
Note 1003 /* select#1 */ select `test`.`t1`.`c1` AS `c1`,`test`.`t1`.`c2` AS `c2`,`test`.`t1`.`c3` AS `c3`,`test`.`t3`.`c1` AS `c1`,`test`.`t3`.`c2` AS `c2`,`test`.`t3`.`c3` AS `c3` from `test`.`t1` semi join (`test`.`t2`) join `test`.`t3` where `test`.`t1`.`c2` = 2 and `test`.`t3`.`c2` = 2 and `test`.`t2`.`c2` = 2 and <expr_cache><2,`test`.`t1`.`c3`>(<in_optimizer>(2,<exists>(/* select#2 */ select max(`test`.`t2`.`c2`) from `test`.`t2` where `test`.`t2`.`c3` = `test`.`t1`.`c3` having <cache>(`test`.`t1`.`c2`) = <ref_null_helper>(max(`test`.`t2`.`c2`))))) and `test`.`t1`.`c1` < 10 |
For the queries with DELETE and UPDATE based on previous SELECT:
delete
|
from v1 |
using v1,t3
|
where
|
v1.c2 = t3.c2 and |
v1.c2 in (select max(c2) from t2 where c3 = v1.c3) |
and v1.c1 < 10 and |
exists (select 'X' from v2 where c1 = v1.c1); |
update v1,t3 |
set v1.c1 = 15 |
where
|
v1.c2 = t3.c2 and |
v1.c2 in (select max(c2) from t2 where c3 = v1.c3) |
and v1.c1 < 10 and |
exists (select 'X' from v2 where c1 = v1.c1); |
EXPLAIN EXTENDED does not produce message with query after optimization :
Warnings:
|
Note 1276 Field or reference 'v1.c3' of SELECT #2 was resolved in SELECT #1 |
Note 1276 Field or reference 'v1.c1' of SELECT #3 was resolved in SELECT #1 |
Problem with plan in this case will be fixed in MDEV-30538
MTR test case:
--source include/have_innodb.inc
|
|
create table t1 (c1 integer, c2 integer, c3 integer) engine=innodb; |
insert into t1(c1,c2,c3) |
values (1,1,1),(1,2,2),(1,3,3), |
(2,1,4),(2,2,5),(2,3,6),
|
(2,4,7),(2,5,8);
|
create view v1 as select * from t1 where c2=2; |
create index t1_c2 on t1 (c2); |
analyze table t1 persistent for all; |
|
create table t2 (c1 integer, c2 integer, c3 integer) engine=innodb; |
insert into t2(c1,c2,c3) |
values (1,1,1),(1,2,2),(1,3,3), |
(2,1,4),(2,2,5),(2,3,6),
|
(2,4,7),(2,5,8);
|
create view v2 as select * from t2 where c2=2; |
create index t2_c2 on t2 (c2); |
analyze table t2 persistent for all; |
|
create table t3 (c1 integer, c2 integer, c3 integer) engine=innodb; |
insert into t3(c1,c2,c3) |
values (1,1,1),(1,2,2),(1,3,3), |
(2,1,4),(2,2,5),(2,3,6),
|
(2,4,7),(2,5,8);
|
analyze table t3 persistent for all; |
|
EXPLAIN EXTENDED
|
select * |
from v1,t3 |
where
|
v1.c2 = t3.c2 and |
v1.c2 in (select max(c2) from t2 where c3 = v1.c3) |
and v1.c1 < 10 and |
v1.c1 in (select c1 from v2); |
|
|
EXPLAIN EXTENDED
|
delete
|
from v1 |
using v1,t3
|
where
|
v1.c2 = t3.c2 and |
v1.c2 in (select max(c2) from t2 where c3 = v1.c3) |
and v1.c1 < 10 and |
exists (select 'X' from v2 where c1 = v1.c1); |
|
EXPLAIN EXTENDED
|
update v1,t3 |
set v1.c1 = 15 |
where
|
v1.c2 = t3.c2 and |
v1.c2 in (select max(c2) from t2 where c3 = v1.c3) |
and v1.c1 < 10 and |
exists (select 'X' from v2 where c1 = v1.c1); |
|
drop view v1, v2; |
drop table t1, t2, t3; |
Attachments
Issue Links
- causes
-
MDEV-31224 Crash with EXPLAIN EXTENDED for multi-table update of system table
- Closed