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mirror of https://github.com/MariaDB/server.git synced 2025-08-01 03:47:19 +03:00

Merge bk-internal:/home/bk/mysql-4.1-opt

into  macbook.gmz:/Users/kgeorge/mysql/work/B21180-4.1-opt
This commit is contained in:
gkodinov/kgeorge@macbook.gmz
2006-09-15 18:56:05 +03:00
4 changed files with 70 additions and 3 deletions

View File

@ -2917,3 +2917,32 @@ retailerID statusID changed
0048 1 2006-01-06 12:37:50
0059 1 2006-01-06 12:37:50
drop table t1;
create table t1(a int, primary key (a));
insert into t1 values (10);
create table t2 (a int primary key, b varchar(32), c int, unique key b(c, b));
insert into t2(a, c, b) values (1,10,'359'), (2,10,'35988'), (3,10,'35989');
explain SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r
ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
ORDER BY t2.c DESC, t2.b DESC LIMIT 1) WHERE t1.a = 10;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t1 system PRIMARY NULL NULL NULL 1
1 PRIMARY r const PRIMARY PRIMARY 4 const 1
2 DEPENDENT SUBQUERY t2 range b b 38 NULL 2 Using where
SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r
ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
ORDER BY t2.c DESC, t2.b DESC LIMIT 1) WHERE t1.a = 10;
a a b
10 3 35989
explain SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r
ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
ORDER BY t2.c, t2.b LIMIT 1) WHERE t1.a = 10;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t1 system PRIMARY NULL NULL NULL 1
1 PRIMARY r const PRIMARY PRIMARY 4 const 1
2 DEPENDENT SUBQUERY t2 range b b 38 NULL 2 Using where
SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r
ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
ORDER BY t2.c, t2.b LIMIT 1) WHERE t1.a = 10;
a a b
10 1 359
drop table t1,t2;