database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-12-24 11:21:21 +03:00
Code Activity

BUG#14940 "MySQL choose wrong index", v.2

Browse Source 
- Make the range-et-al optimizer produce E(#table records after table 
                                           condition is applied),
- Make the join optimizer use this value,
- Add "filtered" column to EXPLAIN EXTENDED to show 
  fraction of records left after table condition is applied
- Adjust test results, add comments
This commit is contained in:
sergefp@mysql.com
2006-07-28 21:27:01 +04:00
parent 1459784aba
commit 699291a8e6
75 changed files with 942 additions and 683 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
mysql-test/r/func_gconcat.result
View File

@@ -15,8 +15,8 @@ grp group_concat(c)
2 b,c
3 E,C,D,d,d,D
explain extended select grp,group_concat(c) from t1 group by grp;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 9 Using filesort
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 9 100.00 Using filesort
Warnings:
Note 1003 select `test`.`t1`.`grp` AS `grp`,group_concat(`test`.`t1`.`c` separator ',') AS `group_concat(c)` from `test`.`t1` group by `test`.`t1`.`grp`
select grp,group_concat(a,c) from t1 group by grp;
@@ -90,8 +90,8 @@ grp group_concat(distinct c order by c desc)
2 c,b
3 E,D,C
explain extended select grp,group_concat(distinct c order by c desc) from t1 group by grp;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 9 Using filesort
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 9 100.00 Using filesort
Warnings:
Note 1003 select `test`.`t1`.`grp` AS `grp`,group_concat(distinct `test`.`t1`.`c` order by `test`.`t1`.`c` DESC separator ',') AS `group_concat(distinct c order by c desc)` from `test`.`t1` group by `test`.`t1`.`grp`
select grp,group_concat(c order by c separator ",") from t1 group by grp;
@@ -110,8 +110,8 @@ grp group_concat(distinct c order by c separator ",")
2 b,c
3 C,D,E
explain extended select grp,group_concat(distinct c order by c separator ",") from t1 group by grp;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 9 Using filesort
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 9 100.00 Using filesort
Warnings:
Note 1003 select `test`.`t1`.`grp` AS `grp`,group_concat(distinct `test`.`t1`.`c` order by `test`.`t1`.`c` ASC separator ',') AS `group_concat(distinct c order by c separator ",")` from `test`.`t1` group by `test`.`t1`.`grp`
select grp,group_concat(distinct c order by c desc separator ",") from t1 group by grp;