@@ -75,7 +75,7 @@ id select_type tABle type possiBle_keys key key_len ref rows filtered ExtrA
1 PRIMARY B ALL NULL NULL NULL NULL 3 100.00 Using where
2 DEPENDENT SUBQUERY t10 unique_suBquery PRIMARY PRIMARY 4 func 1 100.00 Using index
Warnings:
Note 1003 select `test`.`t1`.`A` AS `A`,`test`.`t1`.`B` AS `B`,`test`.`A`.`A` AS `A`,`test`.`A`.`B` AS `B`,`test`.`B`.`A` AS `A`,`test`.`B`.`B` AS `B` from `test`.`t1` left join (`test`.`t2` `A` join `test`.`t2` `B`) on(((`test`.`A`.`A` = `test`.`t1`.`A`) And <in_optimizer>(`test`.`B`.`A`,<exists>(<primAry_index_lookup>(<cAche>(`test`.`B`.`A`) in t10 on PRIMARY))))) where 1
Note 1003 select `test`.`t1`.`A` AS `A`,`test`.`t1`.`B` AS `B`,`test`.`A`.`A` AS `A`,`test`.`A`.`B` AS `B`,`test`.`B`.`A` AS `A`,`test`.`B`.`B` AS `B` from `test`.`t1` left join (`test`.`t2` `A` join `test`.`t2` `B`) on((<in_optimizer>(`test`.`B`.`A`,<exists>(<primAry_index_lookup>(<cAche>(`test`.`B`.`A`) in t10 on PRIMARY))) And (`test`.`A`.`A` = `test`.`t1`.`A`))) where 1
t2 should be wrapped into OJ-nest, so we have "t1 LJ (t2 J t10)"
explAin extended
select * from t1 left join t2 on (t2.A= t1.A And t2.A in (select pk from t10));
...
...
@@ -84,7 +84,7 @@ id select_type tABle type possiBle_keys key key_len ref rows filtered ExtrA
1 PRIMARY t2 ALL NULL NULL NULL NULL 3 100.00 Using where
2 DEPENDENT SUBQUERY t10 unique_suBquery PRIMARY PRIMARY 4 func 1 100.00 Using index
Warnings:
Note 1003 select `test`.`t1`.`A` AS `A`,`test`.`t1`.`B` AS `B`,`test`.`t2`.`A` AS `A`,`test`.`t2`.`B` AS `B` from `test`.`t1` left join `test`.`t2` on(((`test`.`t2`.`A` = `test`.`t1`.`A`) And <in_optimizer>(`test`.`t2`.`A`,<exists>(<primAry_index_lookup>(<cAche>(`test`.`t2`.`A`) in t10 on PRIMARY))))) where 1
Note 1003 select `test`.`t1`.`A` AS `A`,`test`.`t1`.`B` AS `B`,`test`.`t2`.`A` AS `A`,`test`.`t2`.`B` AS `B` from `test`.`t1` left join `test`.`t2` on((<in_optimizer>(`test`.`t2`.`A`,<exists>(<primAry_index_lookup>(<cAche>(`test`.`t2`.`A`) in t10 on PRIMARY))) And (`test`.`t2`.`A` = `test`.`t1`.`A`))) where 1
we shouldn't flatten if we're going to get a join of > MAX_TABLES.
@@ -79,7 +79,7 @@ id select_type tABle type possiBle_keys key key_len ref rows filtered ExtrA
1 PRIMARY B ALL NULL NULL NULL NULL 3 100.00 Using where; Using join Buffer
2 DEPENDENT SUBQUERY t10 unique_suBquery PRIMARY PRIMARY 4 func 1 100.00 Using index
Warnings:
Note 1003 select `test`.`t1`.`A` AS `A`,`test`.`t1`.`B` AS `B`,`test`.`A`.`A` AS `A`,`test`.`A`.`B` AS `B`,`test`.`B`.`A` AS `A`,`test`.`B`.`B` AS `B` from `test`.`t1` left join (`test`.`t2` `A` join `test`.`t2` `B`) on(((`test`.`A`.`A` = `test`.`t1`.`A`) And <in_optimizer>(`test`.`B`.`A`,<exists>(<primAry_index_lookup>(<cAche>(`test`.`B`.`A`) in t10 on PRIMARY))))) where 1
Note 1003 select `test`.`t1`.`A` AS `A`,`test`.`t1`.`B` AS `B`,`test`.`A`.`A` AS `A`,`test`.`A`.`B` AS `B`,`test`.`B`.`A` AS `A`,`test`.`B`.`B` AS `B` from `test`.`t1` left join (`test`.`t2` `A` join `test`.`t2` `B`) on((<in_optimizer>(`test`.`B`.`A`,<exists>(<primAry_index_lookup>(<cAche>(`test`.`B`.`A`) in t10 on PRIMARY))) And (`test`.`A`.`A` = `test`.`t1`.`A`))) where 1
t2 should be wrapped into OJ-nest, so we have "t1 LJ (t2 J t10)"
explAin extended
select * from t1 left join t2 on (t2.A= t1.A And t2.A in (select pk from t10));
...
...
@@ -88,7 +88,7 @@ id select_type tABle type possiBle_keys key key_len ref rows filtered ExtrA
1 PRIMARY t2 ALL NULL NULL NULL NULL 3 100.00 Using where; Using join Buffer
2 DEPENDENT SUBQUERY t10 unique_suBquery PRIMARY PRIMARY 4 func 1 100.00 Using index
Warnings:
Note 1003 select `test`.`t1`.`A` AS `A`,`test`.`t1`.`B` AS `B`,`test`.`t2`.`A` AS `A`,`test`.`t2`.`B` AS `B` from `test`.`t1` left join `test`.`t2` on(((`test`.`t2`.`A` = `test`.`t1`.`A`) And <in_optimizer>(`test`.`t2`.`A`,<exists>(<primAry_index_lookup>(<cAche>(`test`.`t2`.`A`) in t10 on PRIMARY))))) where 1
Note 1003 select `test`.`t1`.`A` AS `A`,`test`.`t1`.`B` AS `B`,`test`.`t2`.`A` AS `A`,`test`.`t2`.`B` AS `B` from `test`.`t1` left join `test`.`t2` on((<in_optimizer>(`test`.`t2`.`A`,<exists>(<primAry_index_lookup>(<cAche>(`test`.`t2`.`A`) in t10 on PRIMARY))) And (`test`.`t2`.`A` = `test`.`t1`.`A`))) where 1
we shouldn't flatten if we're going to get a join of > MAX_TABLES.