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subqueries made printable

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new EXPLAIN parameter to show real query as it was interpreted
(SCRUM) (WL#1274)
This commit is contained in:
bell@sanja.is.com.ua
2003-10-16 15:54:47 +03:00
parent ddf4d1e529
commit a7bdd19707
18 changed files with 735 additions and 181 deletions
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8
mysql-test/r/union.result
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@ -86,10 +86,12 @@ a b
1 a
(select a,b from t1 limit 2) union all (select a,b from t2 order by a limit 1) order by t1.b;
ERROR 42000: Table 't1' from one of SELECT's can not be used in global ORDER clause
explain (select a,b from t1 limit 2) union all (select a,b from t2 order by a limit 1) order by b desc;
explain extended (select a,b from t1 limit 2) union all (select a,b from t2 order by a limit 1) order by b desc;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t1 ALL NULL NULL NULL NULL 4
2 UNION t2 ALL NULL NULL NULL NULL 4 Using filesort
Warnings:
Note 1003 (select high_priority test.t1.a AS `a`,test.t1.b AS `b` from test.t1 limit 2) union all (select test.t2.a AS `a`,test.t2.b AS `b` from test.t2 order by test.t2.a limit 1) order by b desc
(select sql_calc_found_rows a,b from t1 limit 2) union all (select a,b from t2 order by a) limit 2;
a b
1 a
@ -463,10 +465,12 @@ create table t1 (a int not null primary key auto_increment, b int, key(b));
create table t2 (a int not null primary key auto_increment, b int);
insert into t1 (b) values (1),(2),(2),(3);
insert into t2 (b) values (10),(11),(12),(13);
explain (select * from t1 where a=1) union (select * from t2 where a=1);
explain extended (select * from t1 where a=1) union (select * from t2 where a=1);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t1 const PRIMARY PRIMARY 4 const 1
2 UNION t2 const PRIMARY PRIMARY 4 const 1
Warnings:
Note 1003 (select high_priority test.t1.a AS `a`,test.t1.b AS `b` from test.t1 where (test.t1.a = 1)) union (select test.t2.a AS `a`,test.t2.b AS `b` from test.t2 where (test.t2.a = 1))
(select * from t1 where a=5) union (select * from t2 where a=1);
a b
1 10