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BUG#35850 "Performance regression in 5.1.23/5.1.24"

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- Disable the "prefer full scan on clustered primary key over full scan
  of any secondary key" rule introduced by BUG#35850.
- Update test results accordingly 
(bk trigger: file this for BUG#35850)


mysql-test/r/innodb.result:
  BUG#35850 "Performance regression in 5.1.23/5.1.24"
  - Update test results
mysql-test/r/innodb_mysql.result:
  BUG#35850 "Performance regression in 5.1.23/5.1.24"
  - Testcase
  - Update test results
mysql-test/r/join_outer_innodb.result:
  BUG#35850 "Performance regression in 5.1.23/5.1.24"
  - Update test results
mysql-test/t/innodb_mysql.test:
  BUG#35850 "Performance regression in 5.1.23/5.1.24"
  - Testcase
sql/sql_select.cc:
  BUG#35850 "Performance regression in 5.1.23/5.1.24"
  - Disable the "prefer full scan on clustered primary key over full scan
    of any secondary key" rule introduced by BUG#35850.
This commit is contained in:
unknown 2008-05-07 09:58:21 +04:00
parent d1361c86e7
commit 87e5098249
5 changed files with 57 additions and 28 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

30
mysql-test/r/innodb.result
View file

@ -925,7 +925,7 @@ id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL b 4 NULL # Using index
explain select a,b from t1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL PRIMARY 4 NULL #
1 SIMPLE t1 index NULL b 4 NULL # Using index
explain select a,b,c from t1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL #
@ -1166,14 +1166,14 @@ UPDATE t1 set a=a+100 where b between 2 and 3 and a < 1000;
SELECT * from t1;
a b
1 1
102 2
103 3
4 4
5 5
6 6
7 7
8 8
9 9
102 2
103 3
drop table t1;
CREATE TABLE t1 (a int not null primary key, b int not null, key (b)) engine=innodb;
CREATE TABLE t2 (a int not null primary key, b int not null, key (b)) engine=innodb;
@ -1197,6 +1197,7 @@ a b
update t1,t2 set t1.a=t1.a+100 where t1.a=101;
select * from t1;
a b
201 1
102 2
103 3
104 4
@ -1208,11 +1209,10 @@ a b
110 10
111 11
112 12
201 1
update t1,t2 set t1.b=t1.b+10 where t1.b=2;
select * from t1;
a b
102 12
201 1
103 3
104 4
105 5
@ -1222,34 +1222,34 @@ a b
109 9
110 10
111 11
102 12
112 12
201 1
update t1,t2 set t1.b=t1.b+2,t2.b=t1.b+10 where t1.b between 3 and 5 and t1.a=t2.a+100;
select * from t1;
a b
102 12
201 1
103 5
104 6
105 7
106 6
105 7
107 7
108 8
109 9
110 10
111 11
102 12
112 12
201 1
select * from t2;
a b
1 1
2 2
3 13
4 14
5 15
6 6
7 7
8 8
9 9
3 13
4 14
5 15
drop table t1,t2;
CREATE TABLE t2 ( NEXT_T BIGINT NOT NULL PRIMARY KEY) ENGINE=MyISAM;
CREATE TABLE t1 ( B_ID INTEGER NOT NULL PRIMARY KEY) ENGINE=InnoDB;
@ -1300,11 +1300,11 @@ insert into t1 (id) values (null),(null),(null),(null),(null);
update t1 set fk=69 where fk is null order by id limit 1;
SELECT * from t1;
id fk
1 69
2 NULL
3 NULL
4 NULL
5 NULL
1 69
drop table t1;
create table t1 (a int not null, b int not null, key (a));
insert into t1 values (1,1),(1,2),(1,3),(3,1),(3,2),(3,3),(3,1),(3,2),(3,3),(2,1),(2,2),(2,3);
@ -2438,8 +2438,8 @@ insert into t1 (b) values (1);
replace into t1 (b) values (2), (1), (3);
select * from t1;
a b
2 2
3 1
2 2
4 3
truncate table t1;
insert into t1 (b) values (1);
@ -2448,8 +2448,8 @@ replace into t1 (b) values (1);
replace into t1 (b) values (3);
select * from t1;
a b
2 2
3 1
2 2
4 3
drop table t1;
create table t1 (rowid int not null auto_increment, val int not null,primary

26
mysql-test/r/innodb_mysql.result
View file

@ -355,13 +355,13 @@ EXPLAIN
SELECT COUNT(*) FROM t2 LEFT JOIN t1 ON t2.fkey = t1.id
WHERE t1.name LIKE 'A%';
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index PRIMARY,name PRIMARY 4 NULL 3 Using where
1 SIMPLE t1 index PRIMARY,name name 23 NULL 3 Using where; Using index
1 SIMPLE t2 ref fkey fkey 5 test.t1.id 1 Using where; Using index
EXPLAIN
SELECT COUNT(*) FROM t2 LEFT JOIN t1 ON t2.fkey = t1.id
WHERE t1.name LIKE 'A%' OR FALSE;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 index NULL PRIMARY 4 NULL 5
1 SIMPLE t2 index NULL fkey 5 NULL 5 Using index
1 SIMPLE t1 eq_ref PRIMARY PRIMARY 4 test.t2.fkey 1 Using where
DROP TABLE t1,t2;
CREATE TABLE t1 (
@ -1268,11 +1268,11 @@ select_type SIMPLE
table t1
type index
possible_keys NULL
key PRIMARY
key_len 4
key b
key_len 5
ref NULL
rows 3
Extra Using filesort
Extra Using index; Using filesort
SELECT * FROM t1 ORDER BY b ASC, a DESC;
a b
1 1
@ -1284,11 +1284,11 @@ select_type SIMPLE
table t1
type index
possible_keys NULL
key PRIMARY
key_len 4
key b
key_len 5
ref NULL
rows 3
Extra Using filesort
Extra Using index; Using filesort
SELECT * FROM t1 ORDER BY b DESC, a ASC;
a b
2 2
@ -1654,3 +1654,13 @@ ALTER TABLE t1 CHANGE id id2 INT;
DROP TABLE t2;
DROP TABLE t1;
End of 5.1 tests
drop table if exists t1, t2, t3;
create table t1(a int);
insert into t1 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
create table t2 (a int, b int, pk int, key(a,b), primary key(pk)) engine=innodb;
insert into t2 select @a:=A.a+10*(B.a + 10*C.a),@a, @a from t1 A, t1 B, t1 C;
this must use key 'a', not PRIMARY:
explain select a from t2 where a=b;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 index NULL a 10 NULL # Using where; Using index
drop table t1, t2;

4
mysql-test/r/join_outer_innodb.result
View file

@ -8,12 +8,12 @@ EXPLAIN
SELECT COUNT(*) FROM t2 LEFT JOIN t1 ON t2.fkey = t1.id
WHERE t1.name LIKE 'A%';
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index PRIMARY,name PRIMARY 4 NULL 3 Using where
1 SIMPLE t1 index PRIMARY,name name 23 NULL 3 Using where; Using index
1 SIMPLE t2 ref fkey fkey 5 test.t1.id 1 Using where; Using index
EXPLAIN
SELECT COUNT(*) FROM t2 LEFT JOIN t1 ON t2.fkey = t1.id
WHERE t1.name LIKE 'A%' OR FALSE;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 index NULL PRIMARY 4 NULL 5
1 SIMPLE t2 index NULL fkey 5 NULL 5 Using index
1 SIMPLE t1 eq_ref PRIMARY PRIMARY 4 test.t2.fkey 1 Using where
DROP TABLE t1,t2;

16
mysql-test/t/innodb_mysql.test
View file

@ -13,3 +13,19 @@ let $test_foreign_keys= 1;
set global innodb_support_xa=default;
set session innodb_support_xa=default;
--source include/mix1.inc
--disable_warnings
drop table if exists t1, t2, t3;
--enable_warnings
#
# BUG#35850: Performance regression in 5.1.23/5.1.24
#
create table t1(a int);
insert into t1 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
create table t2 (a int, b int, pk int, key(a,b), primary key(pk)) engine=innodb;
insert into t2 select @a:=A.a+10*(B.a + 10*C.a),@a, @a from t1 A, t1 B, t1 C;
--echo this must use key 'a', not PRIMARY:
--replace_column 9 #
explain select a from t2 where a=b;
drop table t1, t2;

9
sql/sql_select.cc
View file

@ -6506,13 +6506,16 @@ make_join_readinfo(JOIN *join, ulonglong options)
!(tab->select && tab->select->quick))
{ // Only read index tree
/*
See bug #26447: "Using the clustered index for a table scan
is always faster than using a secondary index".
*/
It has turned out that the below change, while speeding things
up for disk-bound loads, slows them down for cases when the data
is in disk cache (see BUG#35850):
// See bug #26447: "Using the clustered index for a table scan
// is always faster than using a secondary index".
if (table->s->primary_key != MAX_KEY &&
table->file->primary_key_is_clustered())
tab->index= table->s->primary_key;
else
*/
tab->index=find_shortest_key(table, & table->covering_keys);
tab->read_first_record= join_read_first;
tab->type=JT_NEXT; // Read with index_first / index_next