mirror of
https://github.com/percona/percona-toolkit.git
synced 2025-09-18 01:33:14 +00:00
Add forked Maatkit tools in bin/ and their tests in t/.
This commit is contained in:
25
t/pt-visual-explain/samples/union_of_derived_unions.sql
Normal file
25
t/pt-visual-explain/samples/union_of_derived_unions.sql
Normal file
@@ -0,0 +1,25 @@
|
||||
explain
|
||||
select * from (
|
||||
select 1 as foo from sakila.actor as actor_1
|
||||
union
|
||||
select 1 from sakila.actor as actor_2
|
||||
) as der_1
|
||||
union
|
||||
select * from (
|
||||
select 1 as foo from sakila.actor as actor_3
|
||||
union all
|
||||
select 1 from sakila.actor as actor_4
|
||||
) as der_2;
|
||||
+----+--------------+------------+--------+---------------+---------+---------+------+------+-------------+
|
||||
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
|
||||
+----+--------------+------------+--------+---------------+---------+---------+------+------+-------------+
|
||||
| 1 | PRIMARY | <derived2> | system | NULL | NULL | NULL | NULL | 1 | |
|
||||
| 2 | DERIVED | actor_1 | index | NULL | PRIMARY | 2 | NULL | 200 | Using index |
|
||||
| 3 | UNION | actor_2 | index | NULL | PRIMARY | 2 | NULL | 200 | Using index |
|
||||
| NULL | UNION RESULT | <union2,3> | ALL | NULL | NULL | NULL | NULL | NULL | |
|
||||
| 4 | UNION | <derived5> | ALL | NULL | NULL | NULL | NULL | 400 | |
|
||||
| 5 | DERIVED | actor_3 | index | NULL | PRIMARY | 2 | NULL | 200 | Using index |
|
||||
| 6 | UNION | actor_4 | index | NULL | PRIMARY | 2 | NULL | 200 | Using index |
|
||||
| NULL | UNION RESULT | <union5,6> | ALL | NULL | NULL | NULL | NULL | NULL | |
|
||||
| NULL | UNION RESULT | <union1,4> | ALL | NULL | NULL | NULL | NULL | NULL | |
|
||||
+----+--------------+------------+--------+---------------+---------+---------+------+------+-------------+
|
Reference in New Issue
Block a user