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Update matching_candidates_in_table() to treat all conditions similar

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Fixed also that the 'with_found_constraint parameter' to
matching_candidates_in_table() is as documented: It is now true only
if there is a reference to a previous table in the WHERE condition for
the current examined table (as it was originally documented)

Changes in test results:
- Filtered was 25% smaller for some queries (expected).
- Some join order changed (probably because the tables had very few rows).
- Some more table scans, probably because there would be fewer returned
  rows.
- Some tests exposes a bug that if there is more filtered rows, then the
  cost for table scan will be higher. This will be fixed in a later commit.
This commit is contained in:
Monty
2021-10-07 20:15:34 +03:00
committed by Sergei Petrunia
parent dc2f0d138d
commit b67144893a
41 changed files with 286 additions and 269 deletions
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12
mysql-test/main/subselect_no_exists_to_in.result
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@ -1444,7 +1444,7 @@ a
explain extended select * from t2 where t2.a in (select a from t1);
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t2 index PRIMARY PRIMARY 4 NULL 4 100.00 Using index
1 PRIMARY t1 eq_ref PRIMARY PRIMARY 4 test.t2.a 1 100.00 Using index
1 PRIMARY t1 index PRIMARY PRIMARY 4 NULL 4 75.00 Using where; Using index; Using join buffer (flat, BNL join)
Warnings:
Note 1003 select `test`.`t2`.`a` AS `a` from `test`.`t1` join `test`.`t2` where `test`.`t1`.`a` = `test`.`t2`.`a`
select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
@ -1454,7 +1454,7 @@ a
explain extended select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t2 index PRIMARY PRIMARY 4 NULL 4 100.00 Using index
1 PRIMARY t1 eq_ref PRIMARY PRIMARY 4 test.t2.a 1 100.00 Using where
1 PRIMARY t1 ALL PRIMARY NULL NULL NULL 4 75.00 Using where; Using join buffer (flat, BNL join)
Warnings:
Note 1003 select `test`.`t2`.`a` AS `a` from `test`.`t1` join `test`.`t2` where `test`.`t1`.`a` = `test`.`t2`.`a` and `test`.`t1`.`b` <> 30
select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a);
@ -1463,11 +1463,11 @@ a
3
explain extended select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a);
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t2 index PRIMARY PRIMARY 4 NULL 4 100.00 Using index
1 PRIMARY t1 eq_ref PRIMARY PRIMARY 4 test.t2.a 1 100.00
1 PRIMARY t3 index PRIMARY PRIMARY 4 NULL 3 100.00 Using where; Using index; Using join buffer (flat, BNL join)
1 PRIMARY t1 ALL PRIMARY NULL NULL NULL 4 100.00
1 PRIMARY t3 index PRIMARY PRIMARY 4 NULL 3 75.00 Using where; Using index; Using join buffer (flat, BNL join)
1 PRIMARY t2 eq_ref PRIMARY PRIMARY 4 test.t1.a 1 100.00 Using index
Warnings:
Note 1003 select `test`.`t2`.`a` AS `a` from `test`.`t1` join `test`.`t3` join `test`.`t2` where `test`.`t3`.`a` = `test`.`t1`.`b` and `test`.`t1`.`a` = `test`.`t2`.`a`
Note 1003 select `test`.`t2`.`a` AS `a` from `test`.`t1` join `test`.`t3` join `test`.`t2` where `test`.`t3`.`a` = `test`.`t1`.`b` and `test`.`t2`.`a` = `test`.`t1`.`a`
drop table t1, t2, t3;
create table t1 (a int, b int, index a (a,b));
create table t2 (a int, index a (a));