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Diffstat (limited to 'mysql-test/main/selectivity.result')
| -rw-r--r-- | mysql-test/main/selectivity.result | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/mysql-test/main/selectivity.result b/mysql-test/main/selectivity.result index 33c7c9be47a..7db951ccafe 100644 --- a/mysql-test/main/selectivity.result +++ b/mysql-test/main/selectivity.result @@ -1637,3 +1637,37 @@ set @@use_stat_tables= @save_use_stat_tables; set @@optimizer_use_condition_selectivity=@save_optimizer_use_condition_selectivity; drop table t1; drop function f1; +# +# MDEV-19834 Selectivity of an equality condition discounted twice +# +set @@optimizer_use_condition_selectivity=4; +set @@use_stat_tables='preferably'; +create table t1 (a int, b int, key (b), key (a)); +insert into t1 +select (rand(1)*1000)/10, (rand(1001)*1000)/50 from seq_1_to_1000; +analyze table t1 ; +Table Op Msg_type Msg_text +test.t1 analyze status Engine-independent statistics collected +test.t1 analyze status Table is already up to date +# Check what info the optimizer has about selectivities +explain extended select * from t1 use index () where a in (17,51,5); +id select_type table type possible_keys key key_len ref rows filtered Extra +1 SIMPLE t1 ALL NULL NULL NULL NULL 1000 3.90 Using where +Warnings: +Note 1003 select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` USE INDEX () where `test`.`t1`.`a` in (17,51,5) +explain extended select * from t1 use index () where b=2; +id select_type table type possible_keys key key_len ref rows filtered Extra +1 SIMPLE t1 ALL NULL NULL NULL NULL 1000 5.47 Using where +Warnings: +Note 1003 select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` USE INDEX () where `test`.`t1`.`b` = 2 +# Now, the equality is used for ref access, while the range condition +# gives selectivity data +explain extended select * from t1 where a in (17,51,5) and b=2; +id select_type table type possible_keys key key_len ref rows filtered Extra +1 SIMPLE t1 ref|filter b,a b|a 5|5 const 58 (3%) 2.90 Using where; Using rowid filter +Warnings: +Note 1003 select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` where `test`.`t1`.`b` = 2 and `test`.`t1`.`a` in (17,51,5) +drop table t1; +set use_stat_tables= @save_use_stat_tables; +set optimizer_use_condition_selectivity=@save_optimizer_use_condition_selectivity; +# End of 10.1 tests |