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MDEV-5123 Remove duplicated conditions pushed both to join_tab->select_cond and join_tab->cache_select->cond for blocked joins.

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BNL and BNLH joins pre-filter the records from a joined table via JOIN_TAB::cache_select->cond.
There is no need to re-evaluate the same conditions via JOIN_TAB::select_cond. This patch removes
the duplicated conditions from the top-level conjuncts of each pushed condition.

The added "Using where" in few EXPLAINs is due to taking into account tab->cache_select->cond
in addition to tab->select_cond in JOIN::save_explain_data_intern.
This commit is contained in:
timour@askmonty.org
2013-10-18 11:45:25 +03:00
parent adbb439358
commit afed809297
12 changed files with 210 additions and 27 deletions
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12
mysql-test/r/range.result
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@ -221,27 +221,27 @@ update t1 set y=x;
explain select * from t1, t1 t2 where t1.y = 8 and t2.x between 7 and t1.y+0;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref y y 5 const 1
1 SIMPLE t2 range x x 5 NULL 2 Using index condition; Using join buffer (flat, BNL join)
1 SIMPLE t2 range x x 5 NULL 2 Using index condition; Using where; Using join buffer (flat, BNL join)
explain select * from t1, t1 t2 where t1.y = 8 and t2.x >= 7 and t2.x <= t1.y+0;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref y y 5 const 1
1 SIMPLE t2 range x x 5 NULL 2 Using index condition; Using join buffer (flat, BNL join)
1 SIMPLE t2 range x x 5 NULL 2 Using index condition; Using where; Using join buffer (flat, BNL join)
explain select * from t1, t1 t2 where t1.y = 2 and t2.x between t1.y-1 and t1.y+1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref y y 5 const 1
1 SIMPLE t2 range x x 5 NULL 3 Using index condition; Using join buffer (flat, BNL join)
1 SIMPLE t2 range x x 5 NULL 3 Using index condition; Using where; Using join buffer (flat, BNL join)
explain select * from t1, t1 t2 where t1.y = 2 and t2.x >= t1.y-1 and t2.x <= t1.y+1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref y y 5 const 1
1 SIMPLE t2 range x x 5 NULL 3 Using index condition; Using join buffer (flat, BNL join)
1 SIMPLE t2 range x x 5 NULL 3 Using index condition; Using where; Using join buffer (flat, BNL join)
explain select * from t1, t1 t2 where t1.y = 2 and t2.x between 0 and t1.y;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref y y 5 const 1
1 SIMPLE t2 range x x 5 NULL 2 Using index condition; Using join buffer (flat, BNL join)
1 SIMPLE t2 range x x 5 NULL 2 Using index condition; Using where; Using join buffer (flat, BNL join)
explain select * from t1, t1 t2 where t1.y = 2 and t2.x >= 0 and t2.x <= t1.y;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref y y 5 const 1
1 SIMPLE t2 range x x 5 NULL 2 Using index condition; Using join buffer (flat, BNL join)
1 SIMPLE t2 range x x 5 NULL 2 Using index condition; Using where; Using join buffer (flat, BNL join)
explain select count(*) from t1 where x in (1);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref x x 5 const 1 Using index