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BUG#16166, "Can't use index_merge with FORCE INDEX": adjust the heurstics check to take into

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account that "FORCE INDEX" disables full table scans, and not range/index_merge scans.
(with post-review fixes)
This commit is contained in:
sergefp@mysql.com
2006-01-12 10:48:27 +03:00
parent 86e8958a4e
commit e40759e370
3 changed files with 76 additions and 7 deletions
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18
mysql-test/r/index_merge.result
View File

@ -384,3 +384,21 @@ max(A.key1 + B.key1 + A.key2 + B.key2 + A.key3 + B.key3 + A.key4 + B.key4 + A.ke
8186
set join_buffer_size= @save_join_buffer_size;
drop table t0, t1, t2, t3, t4;
CREATE TABLE t1 (
cola char(3) not null, colb char(3) not null, filler char(200),
key(cola), key(colb)
);
INSERT INTO t1 VALUES ('foo','bar', 'ZZ'),('fuz','baz', 'ZZ');
OPTIMIZE TABLE t1;
Table Op Msg_type Msg_text
test.t1 optimize status OK
select count(*) from t1;
count(*)
8704
explain select * from t1 WHERE cola = 'foo' AND colb = 'bar';
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge cola,colb cola,colb 3,3 NULL 24 Using intersect(cola,colb); Using where
explain select * from t1 force index(cola,colb) WHERE cola = 'foo' AND colb = 'bar';
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge cola,colb cola,colb 3,3 NULL 24 Using intersect(cola,colb); Using where
drop table t1;

30
mysql-test/t/index_merge.test
View File

@ -327,3 +327,33 @@ set join_buffer_size= @save_join_buffer_size;
drop table t0, t1, t2, t3, t4;
# BUG#16166
CREATE TABLE t1 (
cola char(3) not null, colb char(3) not null, filler char(200),
key(cola), key(colb)
);
INSERT INTO t1 VALUES ('foo','bar', 'ZZ'),('fuz','baz', 'ZZ');
--disable_query_log
let $1=9;
while ($1)
{
eval INSERT INTO t1 SELECT * from t1 WHERE cola = 'foo';
dec $1;
}
let $1=13;
while ($1)
{
eval INSERT INTO t1 SELECT * from t1 WHERE cola <> 'foo';
dec $1;
}
--enable_query_log
OPTIMIZE TABLE t1;
select count(*) from t1;
explain select * from t1 WHERE cola = 'foo' AND colb = 'bar';
explain select * from t1 force index(cola,colb) WHERE cola = 'foo' AND colb = 'bar';
drop table t1;