MWL#128: Added into EXPLAIN output info about types of the used join buffers and

about the employed join algorithms.
Refactored constructors of the JOIN_CACHE* classes.
This commit is contained in:
Igor Babaev 2010-10-18 13:33:05 -07:00
commit 25f5debdc7
65 changed files with 1072 additions and 995 deletions

View file

@ -423,7 +423,7 @@ where (c1, c2) in (select b1, b2 from t2i where b2 > '0')) and
a1 = c1;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t1 ALL NULL NULL NULL NULL 3 100.00 Using where
1 PRIMARY t3 ALL NULL NULL NULL NULL 4 100.00 Using where; Using join buffer
1 PRIMARY t3 ALL NULL NULL NULL NULL 4 100.00 Using where; Using join buffer (flat, BNL join)
4 SUBQUERY t3 ALL NULL NULL NULL NULL 4 100.00 Using where
5 SUBQUERY t2i index it2i2 it2i3 18 NULL 5 100.00 Using where; Using index
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 3 100.00 Using where
@ -659,7 +659,7 @@ id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t1 ALL NULL NULL NULL NULL 3 100.00 Using where
2 DEPENDENT SUBQUERY t1_16 ALL NULL NULL NULL NULL 3 100.00 Using where
3 DEPENDENT SUBQUERY t2_16 ALL NULL NULL NULL NULL 3 100.00 Using where
3 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 5 100.00 Using where; Using join buffer
3 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 5 100.00 Using where; Using join buffer (flat, BNL join)
4 SUBQUERY t3 ALL NULL NULL NULL NULL 4 100.00 Using where
Warnings:
Note 1003 select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where <in_optimizer>(concat(`test`.`t1`.`a1`,'x'),<exists>(select 1 from `test`.`t1_16` where (<in_optimizer>((`test`.`t1_16`.`a1`,`test`.`t1_16`.`a2`),<exists>(select `test`.`t2_16`.`b1`,`test`.`t2_16`.`b2` from `test`.`t2_16` join `test`.`t2` where ((`test`.`t2`.`b2` = substr(`test`.`t2_16`.`b2`,1,6)) and <in_optimizer>(`test`.`t2`.`b1`,`test`.`t2`.`b1` in ( <materialize> (select `test`.`t3`.`c1` from `test`.`t3` where (`test`.`t3`.`c2` > '0') ), <primary_index_lookup>(`test`.`t2`.`b1` in <temporary table> on distinct_key where ((`test`.`t2`.`b1` = `materialized subselect`.`c1`))))) and (<cache>(`test`.`t1_16`.`a1`) = `test`.`t2_16`.`b1`) and (<cache>(`test`.`t1_16`.`a2`) = `test`.`t2_16`.`b2`)))) and (<cache>(concat(`test`.`t1`.`a1`,'x')) = left(`test`.`t1_16`.`a1`,8)))))
@ -1191,7 +1191,7 @@ SET @@optimizer_switch='default,semijoin=on,materialization=on';
EXPLAIN SELECT COUNT(*) FROM t1 WHERE (f1,f2) IN (SELECT f1,f2 FROM t2);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY subselect2 ALL unique_key NULL NULL NULL 2
1 PRIMARY t1 ALL NULL NULL NULL NULL 3 Using where; Using join buffer
1 PRIMARY t1 ALL NULL NULL NULL NULL 3 Using where; Using join buffer (flat, BNL join)
2 SUBQUERY t2 ALL NULL NULL NULL NULL 2
SELECT COUNT(*) FROM t1 WHERE (f1,f2) IN (SELECT f1,f2 FROM t2);
COUNT(*)