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make JOIN::prepare, JOIN::optimize only once for EXPLAIN of derived table

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(BUG#2120 sfter merge)
This commit is contained in:
bell@sanja.is.com.ua
2004-02-01 20:07:44 +02:00
parent bd259f54c9
commit f9af8578bc
6 changed files with 47 additions and 16 deletions
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21
mysql-test/r/derived.result
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@@ -141,7 +141,7 @@ a t
explain select count(*) from t1 as tt1, (select * from t1) as tt2;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
2 DERIVED t1 index NULL a 4 NULL 10000 Using index
2 DERIVED t1 ALL NULL NULL NULL NULL 10000
drop table t1;
SELECT * FROM (SELECT (SELECT * FROM (SELECT 1 as a) as a )) as b;
(SELECT * FROM (SELECT 1 as a) as a )
@@ -189,13 +189,13 @@ id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY m2 ALL NULL NULL NULL NULL 9
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 6 Using where
2 DERIVED mp ALL NULL NULL NULL NULL 9 Using temporary; Using filesort
2 DERIVED m1 index NULL PRIMARY 3 NULL 9 Using index
2 DERIVED m1 eq_ref PRIMARY PRIMARY 3 test.mp.mat_id 1
explain SELECT STRAIGHT_JOIN d.pla_id, m2.test FROM t1 m2 INNER JOIN (SELECT mp.pla_id, MIN(m1.matintnum) AS matintnum FROM t2 mp INNER JOIN t1 m1 ON mp.mat_id=m1.mat_id GROUP BY mp.pla_id) d ON d.matintnum=m2.matintnum;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY m2 ALL NULL NULL NULL NULL 9
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 6 Using where
2 DERIVED mp ALL NULL NULL NULL NULL 9 Using temporary; Using filesort
2 DERIVED m1 index NULL PRIMARY 3 NULL 9 Using index
2 DERIVED m1 eq_ref PRIMARY PRIMARY 3 test.mp.mat_id 1
drop table t1,t2;
SELECT a.x FROM (SELECT 1 AS x) AS a HAVING a.x = 1;
x
@@ -229,8 +229,8 @@ explain select count(*) from t1 INNER JOIN (SELECT A.E1, A.E2, A.E3 FROM t1 AS A
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 2
1 PRIMARY t1 eq_ref PRIMARY PRIMARY 4 THEMAX.E2 1 Using where
2 DERIVED A index NULL PRIMARY 4 NULL 2 Using where; Using index
3 DEPENDENT SUBQUERY B index NULL PRIMARY 4 NULL 2 Using where; Using index
2 DERIVED A ALL NULL NULL NULL NULL 2 Using where
3 DEPENDENT SUBQUERY B ALL NULL NULL NULL NULL 2 Using where
drop table t1;
create table t1 (a int);
insert into t1 values (1),(2);
@@ -309,3 +309,14 @@ id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 3 Using temporary; Using filesort
2 DERIVED x ALL NULL NULL NULL NULL 17 Using temporary; Using filesort
2 DERIVED y ALL NULL NULL NULL NULL 17 Using where
drop table t1;
create table t2 (a int, b int, primary key (a));
insert into t2 values (1,7),(2,7);
explain select a from t2 where a>1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range PRIMARY PRIMARY 4 NULL 2 Using where; Using index
explain select a from (select a from t2 where a>1) tt;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <derived2> system NULL NULL NULL NULL 1
2 DERIVED t2 range PRIMARY PRIMARY 4 NULL 2 Using where; Using index
drop table t2;