blob: 55882ad337a8cc6ea1d29008b51bc70b71457af5 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
|
#
# Bug #725050: print keyuse info when hash join is used
#
create table t1 (a int, b int);
insert into t1 values (2,2), (1,1);
create table t2 (a int);
insert into t2 values (2), (3);
set session join_cache_level=3;
set @@debug_dbug= 'd,opt';
explain select t1.b from t1,t2 where t1.b=t2.a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 2 Using where
1 SIMPLE t2 hash_ALL NULL #hash#$hj 5 test.t1.b 2 Using where; Using join buffer (flat, BNLH join)
select t1.b from t1,t2 where t1.b=t2.a;
b
2
set session join_cache_level=default;
drop table t1,t2;
|
