EXPLAIN SELECT OUTR.dt FROM t1 AS OUTR WHERE OUTR.dt IN (SELECT INNR.dt FROM t2 AS INNR WHERE OUTR.dt IS NULL );
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY OUTR ALL NULL NULL NULL NULL 2 Using where; Start temporary
1 PRIMARY INNR ALL NULL NULL NULL NULL 2 Using where; End temporary; Using join buffer (flat, BNL join)
1 PRIMARY OUTR ALL NULL NULL NULL NULL 2 Using where
1 PRIMARY INNR ALL NULL NULL NULL NULL 2 Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
flush tables;
SELECT OUTR.dt FROM t1 AS OUTR WHERE OUTR.dt IN (SELECT INNR.dt FROM t2 AS INNR WHERE OUTR.dt IS NULL );
dt
flush tables;
EXPLAIN SELECT OUTR.dt FROM t1 AS OUTR WHERE OUTR.dt IN ( SELECT INNR.dt FROM t2 AS INNR WHERE OUTR.t < '2005-11-13 7:41:31' );
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY OUTR ALL NULL NULL NULL NULL 2 Using where; Start temporary
1 PRIMARY INNR ALL NULL NULL NULL NULL 2 Using where; End temporary; Using join buffer (flat, BNL join)
1 PRIMARY OUTR ALL NULL NULL NULL NULL 2 Using where
1 PRIMARY INNR ALL NULL NULL NULL NULL 2 Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
flush tables;
SELECT OUTR.dt FROM t1 AS OUTR WHERE OUTR.dt IN ( SELECT INNR.dt FROM t2 AS INNR WHERE OUTR.t < '2005-11-13 7:41:31' );
dt
...
...
@@ -67,8 +67,8 @@ explain extended
select * from t1
where id in (select id from t1 as x1 where (t1.cur_date is null));
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t1 ALL NULL NULL NULL NULL 2 100.00 Using where; Start temporary
1 PRIMARY x1 ALL NULL NULL NULL NULL 2 100.00 Using where; End temporary; Using join buffer (flat, BNL join)
1 PRIMARY t1 ALL NULL NULL NULL NULL 2 100.00 Using where
1 PRIMARY x1 ALL NULL NULL NULL NULL 2 100.00 Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
Warnings:
Note 1276 Field or reference 'test.t1.cur_date' of SELECT #2 was resolved in SELECT #1
Note 1003 select `test`.`t1`.`id` AS `id`,`test`.`t1`.`cur_date` AS `cur_date` from `test`.`t1` semi join (`test`.`t1` `x1`) where ((`test`.`x1`.`id` = `test`.`t1`.`id`) and (`test`.`t1`.`cur_date` = 0))
...
...
@@ -79,8 +79,8 @@ explain extended
select * from t2
where id in (select id from t2 as x1 where (t2.cur_date is null));
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t2 ALL NULL NULL NULL NULL 2 100.00 Using where; Start temporary
1 PRIMARY x1 ALL NULL NULL NULL NULL 2 100.00 Using where; End temporary; Using join buffer (flat, BNL join)
1 PRIMARY t2 ALL NULL NULL NULL NULL 2 100.00 Using where
1 PRIMARY x1 ALL NULL NULL NULL NULL 2 100.00 Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
Warnings:
Note 1276 Field or reference 'test.t2.cur_date' of SELECT #2 was resolved in SELECT #1
Note 1003 select `test`.`t2`.`id` AS `id`,`test`.`t2`.`cur_date` AS `cur_date` from `test`.`t2` semi join (`test`.`t2` `x1`) where ((`test`.`x1`.`id` = `test`.`t2`.`id`) and (`test`.`t2`.`cur_date` = 0))
set optimizer_switch='semijoin=on,firstmatch=on,loosescan=on';
set optimizer_switch='mrr=on,mrr_sort_keys=on,index_condition_pushdown=on';
drop table if exists t0, t1, t2, t3;
drop table if exists t0, t1, t2, t3, t4, t5;
drop view if exists v1;
create table t0 (a int);
insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
...
...
@@ -340,8 +340,8 @@ WHERE Language='English' AND Percentage > 10 AND
t2.Population > 100000);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t1 range Population,Country Population 4 NULL 1 Using index condition; Rowid-ordered scan; Start temporary
1 PRIMARY t2 eq_ref PRIMARY,Population PRIMARY 3 test.t1.Country 1 Using where; Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
1 PRIMARY t3 eq_ref PRIMARY,Percentage PRIMARY 33 test.t1.Country,const 1 Using index condition; Using where; End temporary; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
1 PRIMARY t2 eq_ref PRIMARY,Population PRIMARY 3 test.t1.Country 1 Using where; End temporary; Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
1 PRIMARY t3 eq_ref PRIMARY,Percentage PRIMARY 33 test.t1.Country,const 1 Using index condition; Using where; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
set optimizer_switch=@bug35674_save_optimizer_switch;