1 PRIMARY <subquery2> eq_ref distinct_key distinct_key 20 func 1 100.00 Using where
2 SUBQUERY t2_16 ALL NULL NULL NULL NULL 3 100.00 Using where
2 SUBQUERY t2_16 ALL NULL NULL NULL NULL 3 100.00 Using where
Warnings:
Warnings:
Note 1003 select left(`test`.`t1_16`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_16`.`a2`,7) AS `left(a2,7)` from `test`.`t1_16` semi join (`test`.`t2_16`) where ((`test`.`t2_16`.`b1` > '0') and (`test`.`t1_16`.`a1` = substr(`test`.`t2_16`.`b1`,1,16)))
Note 1003 select left(`test`.`t1_16`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_16`.`a2`,7) AS `left(a2,7)` from `test`.`t1_16` semi join (`test`.`t2_16`) where ((`test`.`t2_16`.`b1` > '0') and (`test`.`t1_16`.`a1` = substr(`test`.`t2_16`.`b1`,1,16)))
...
@@ -761,7 +761,7 @@ from t1_512
...
@@ -761,7 +761,7 @@ from t1_512
where a1 in (select substring(b1,1,512) from t2_512 where b1 > '0');
where a1 in (select substring(b1,1,512) from t2_512 where b1 > '0');
id select_type table type possible_keys key key_len ref rows filtered Extra
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY <subquery2> eq_ref distinct_key distinct_key 517 func 1 100.00 Using where
2 SUBQUERY t2_512 ALL NULL NULL NULL NULL 3 100.00 Using where
2 SUBQUERY t2_512 ALL NULL NULL NULL NULL 3 100.00 Using where
Warnings:
Warnings:
Note 1003 select left(`test`.`t1_512`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_512`.`a2`,7) AS `left(a2,7)` from `test`.`t1_512` semi join (`test`.`t2_512`) where ((`test`.`t2_512`.`b1` > '0') and (`test`.`t1_512`.`a1` = substr(`test`.`t2_512`.`b1`,1,512)))
Note 1003 select left(`test`.`t1_512`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_512`.`a2`,7) AS `left(a2,7)` from `test`.`t1_512` semi join (`test`.`t2_512`) where ((`test`.`t2_512`.`b1` > '0') and (`test`.`t1_512`.`a1` = substr(`test`.`t2_512`.`b1`,1,512)))
...
@@ -1237,7 +1237,7 @@ insert into t1 values ('aa', 'aaaa');
...
@@ -1237,7 +1237,7 @@ insert into t1 values ('aa', 'aaaa');
explain select a,b from t1 where b in (select a from t1);
explain select a,b from t1 where b in (select a from t1);
id select_type table type possible_keys key key_len ref rows Extra
id select_type table type possible_keys key key_len ref rows Extra