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Merge in MWL#68: Subquery optimization: Efficient NOT IN execution with NULLs

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2010-03-15 21:52:58 +02:00
parent 816a579f6f 3d2a74609a
commit f59d1dcf0a
26 changed files with 2426 additions and 253 deletions
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3
mysql-test/include/mix1.inc
View File

@ -1177,8 +1177,11 @@ DROP TABLE t1;
create table t1 (a bit(1) not null,b int) engine=myisam;
create table t2 (c int) engine=innodb;
set @save_optimizer_switch=@@optimizer_switch;
set @@optimizer_switch='partial_match_rowid_merge=off,partial_match_table_scan=off';
explain
select b from t1 where a not in (select b from t1,t2 group by a) group by a;
set optimizer_switch=@save_optimizer_switch;
DROP TABLE t1,t2;
--echo End of 5.0 tests

18
mysql-test/r/index_merge_myisam.result
View File

@ -1419,19 +1419,19 @@ drop table t1;
#
select @@optimizer_switch;
@@optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on
set optimizer_switch='index_merge=off,index_merge_union=off';
select @@optimizer_switch;
@@optimizer_switch
index_merge=off,index_merge_union=off,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on
index_merge=off,index_merge_union=off,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on
set optimizer_switch='index_merge_union=on';
select @@optimizer_switch;
@@optimizer_switch
index_merge=off,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on
index_merge=off,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on
set optimizer_switch='default,index_merge_sort_union=off';
select @@optimizer_switch;
@@optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=off,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on
index_merge=on,index_merge_union=on,index_merge_sort_union=off,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on
set optimizer_switch=4;
ERROR 42000: Variable 'optimizer_switch' can't be set to the value of '4'
set optimizer_switch=NULL;
@ -1458,21 +1458,21 @@ set optimizer_switch=default;
set optimizer_switch='index_merge=off,index_merge_union=off,default';
select @@optimizer_switch;
@@optimizer_switch
index_merge=off,index_merge_union=off,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on
index_merge=off,index_merge_union=off,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on
set optimizer_switch=default;
select @@global.optimizer_switch;
@@global.optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on
set @@global.optimizer_switch=default;
select @@global.optimizer_switch;
@@global.optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on
#
# Check index_merge's @@optimizer_switch flags
#
select @@optimizer_switch;
@@optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on
create table t0 (a int);
insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
create table t1 (a int, b int, c int, filler char(100),
@ -1582,5 +1582,5 @@ id select_type table type possible_keys key key_len ref rows Extra
set optimizer_switch=default;
show variables like 'optimizer_switch';
Variable_name Value
optimizer_switch index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on
optimizer_switch index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on
drop table t0, t1;

3
mysql-test/r/innodb_mysql.result
View File

@ -1425,12 +1425,15 @@ DROP TABLE t1;
#
create table t1 (a bit(1) not null,b int) engine=myisam;
create table t2 (c int) engine=innodb;
set @save_optimizer_switch=@@optimizer_switch;
set @@optimizer_switch='partial_match_rowid_merge=off,partial_match_table_scan=off';
explain
select b from t1 where a not in (select b from t1,t2 group by a) group by a;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables
2 DEPENDENT SUBQUERY t1 system NULL NULL NULL NULL 0 const row not found
2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 1
set optimizer_switch=@save_optimizer_switch;
DROP TABLE t1,t2;
End of 5.0 tests
CREATE TABLE `t2` (

2
mysql-test/r/myisam_mrr.result
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@ -394,7 +394,7 @@ drop table t0, t1;
# - engine_condition_pushdown does not affect ICP
select @@optimizer_switch;
@@optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on
create table t0 (a int);
insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
create table t1 (a int, b int, key(a));

3
mysql-test/r/ps.result
View File

@ -149,6 +149,8 @@ c29 longblob, c30 longtext, c31 enum('one', 'two', 'three'),
c32 set('monday', 'tuesday', 'wednesday')
) engine = MYISAM ;
create table t2 like t1;
set @save_optimizer_switch=@@optimizer_switch;
set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=off";
set @stmt= ' explain SELECT (SELECT SUM(c1 + c12 + 0.0) FROM t2 where (t1.c2 - 0e-3) = t2.c2 GROUP BY t1.c15 LIMIT 1) as scalar_s, exists (select 1.0e+0 from t2 where t2.c3 * 9.0000000000 = t1.c4) as exists_s, c5 * 4 in (select c6 + 0.3e+1 from t2) as in_s, (c7 - 4, c8 - 4) in (select c9 + 4.0, c10 + 40e-1 from t2) as in_row_s FROM t1, (select c25 x, c32 y from t2) tt WHERE x * 1 = c25 ' ;
prepare stmt1 from @stmt ;
execute stmt1 ;
@ -177,6 +179,7 @@ id select_type table type possible_keys key key_len ref rows Extra
2 DEPENDENT SUBQUERY NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables
deallocate prepare stmt1;
drop tables t1,t2;
set @@optimizer_switch=@save_optimizer_switch;
set @arg00=1;
prepare stmt1 from ' create table t1 (m int) as select 1 as m ' ;
execute stmt1 ;

3
mysql-test/r/subselect.result
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@ -1,4 +1,6 @@
drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t11,t12;
set @save_optimizer_switch=@@optimizer_switch;
set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=off";
select (select 2);
(select 2)
2
@ -4803,4 +4805,5 @@ SELECT 1 FROM t1 GROUP BY
1
1
DROP TABLE t1;
set @@optimizer_switch=@save_optimizer_switch;
End of 5.1 tests.

10
mysql-test/r/subselect3.result
View File

@ -63,12 +63,15 @@ Handler_read_rnd_next 11
select ' ^ This must show 11' Z;
Z
^ This must show 11
set @save_optimizer_switch=@@optimizer_switch;
set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=off";
explain extended select a in (select max(ie) from t1 where oref=4 group by grp) from t3;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t3 ALL NULL NULL NULL NULL 2 100.00
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 6 100.00 Using where; Using temporary; Using filesort
Warnings:
Note 1003 select <in_optimizer>(`test`.`t3`.`a`,<exists>(select max(`test`.`t1`.`ie`) AS `max(ie)` from `test`.`t1` where (`test`.`t1`.`oref` = 4) group by `test`.`t1`.`grp` having trigcond((<cache>(`test`.`t3`.`a`) = <ref_null_helper>(max(`test`.`t1`.`ie`)))))) AS `a in (select max(ie) from t1 where oref=4 group by grp)` from `test`.`t3`
set @@optimizer_switch=@save_optimizer_switch;
drop table t1, t2, t3;
create table t1 (a int, oref int, key(a));
insert into t1 values
@ -692,6 +695,8 @@ a MAX(b) test
2 3 h
3 4 i
DROP TABLE t1, t2;
set @save_optimizer_switch=@@optimizer_switch;
set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=off";
CREATE TABLE t1 (a int);
CREATE TABLE t2 (b int, PRIMARY KEY(b));
INSERT INTO t1 VALUES (1), (NULL), (4);
@ -759,6 +764,7 @@ id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t1 ALL NULL NULL NULL NULL 4 Using where
2 DEPENDENT SUBQUERY t2 unique_subquery PRIMARY PRIMARY 4 func 1 Using index; Using where
DROP TABLE t1, t2;
set @@optimizer_switch=@save_optimizer_switch;
CREATE TABLE t1 (a INT);
INSERT INTO t1 VALUES(1);
CREATE TABLE t2 (placeholder CHAR(11));
@ -960,7 +966,7 @@ i1 i2
# Baseline:
SHOW STATUS LIKE '%Handler_read_rnd_next';
Variable_name Value
Handler_read_rnd_next 17
Handler_read_rnd_next 18
INSERT INTO t1 VALUES (NULL, NULL);
FLUSH STATUS;
@ -977,7 +983,7 @@ i1 i2
# (read record from t1, but do not read from t2)
SHOW STATUS LIKE '%Handler_read_rnd_next';
Variable_name Value
Handler_read_rnd_next 18
Handler_read_rnd_next 19
DROP TABLE t1,t2;
End of 5.1 tests
CREATE TABLE t1 (

10
mysql-test/r/subselect3_jcl6.result
View File

@ -67,12 +67,15 @@ Handler_read_rnd_next 11
select ' ^ This must show 11' Z;
Z
^ This must show 11
set @save_optimizer_switch=@@optimizer_switch;
set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=off";
explain extended select a in (select max(ie) from t1 where oref=4 group by grp) from t3;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t3 ALL NULL NULL NULL NULL 2 100.00
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 6 100.00 Using where; Using temporary; Using filesort
Warnings:
Note 1003 select <in_optimizer>(`test`.`t3`.`a`,<exists>(select max(`test`.`t1`.`ie`) AS `max(ie)` from `test`.`t1` where (`test`.`t1`.`oref` = 4) group by `test`.`t1`.`grp` having trigcond((<cache>(`test`.`t3`.`a`) = <ref_null_helper>(max(`test`.`t1`.`ie`)))))) AS `a in (select max(ie) from t1 where oref=4 group by grp)` from `test`.`t3`
set @@optimizer_switch=@save_optimizer_switch;
drop table t1, t2, t3;
create table t1 (a int, oref int, key(a));
insert into t1 values
@ -696,6 +699,8 @@ a MAX(b) test
2 3 h
3 4 i
DROP TABLE t1, t2;
set @save_optimizer_switch=@@optimizer_switch;
set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=off";
CREATE TABLE t1 (a int);
CREATE TABLE t2 (b int, PRIMARY KEY(b));
INSERT INTO t1 VALUES (1), (NULL), (4);
@ -763,6 +768,7 @@ id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t1 ALL NULL NULL NULL NULL 4 Using where
2 DEPENDENT SUBQUERY t2 unique_subquery PRIMARY PRIMARY 4 func 1 Using index; Using where
DROP TABLE t1, t2;
set @@optimizer_switch=@save_optimizer_switch;
CREATE TABLE t1 (a INT);
INSERT INTO t1 VALUES(1);
CREATE TABLE t2 (placeholder CHAR(11));
@ -964,7 +970,7 @@ i1 i2
# Baseline:
SHOW STATUS LIKE '%Handler_read_rnd_next';
Variable_name Value
Handler_read_rnd_next 17
Handler_read_rnd_next 18
INSERT INTO t1 VALUES (NULL, NULL);
FLUSH STATUS;
@ -981,7 +987,7 @@ i1 i2
# (read record from t1, but do not read from t2)
SHOW STATUS LIKE '%Handler_read_rnd_next';
Variable_name Value
Handler_read_rnd_next 18
Handler_read_rnd_next 19
DROP TABLE t1,t2;
End of 5.1 tests
CREATE TABLE t1 (

7
mysql-test/r/subselect_no_mat.result
View File

@ -1,8 +1,10 @@
show variables like 'optimizer_switch';
Variable_name Value
optimizer_switch index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on
optimizer_switch index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on
set optimizer_switch='materialization=off';
drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t11,t12;
set @save_optimizer_switch=@@optimizer_switch;
set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=off";
select (select 2);
(select 2)
2
@ -4807,8 +4809,9 @@ SELECT 1 FROM t1 GROUP BY
1
1
DROP TABLE t1;
set @@optimizer_switch=@save_optimizer_switch;
End of 5.1 tests.
set optimizer_switch=default;
show variables like 'optimizer_switch';
Variable_name Value
optimizer_switch index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on
optimizer_switch index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on

7
mysql-test/r/subselect_no_opts.result
View File

@ -1,8 +1,10 @@
show variables like 'optimizer_switch';
Variable_name Value
optimizer_switch index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on
optimizer_switch index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on
set optimizer_switch='materialization=off,semijoin=off';
drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t11,t12;
set @save_optimizer_switch=@@optimizer_switch;
set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=off";
select (select 2);
(select 2)
2
@ -4807,8 +4809,9 @@ SELECT 1 FROM t1 GROUP BY
1
1
DROP TABLE t1;
set @@optimizer_switch=@save_optimizer_switch;
End of 5.1 tests.
set optimizer_switch=default;
show variables like 'optimizer_switch';
Variable_name Value
optimizer_switch index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on
optimizer_switch index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on

7
mysql-test/r/subselect_no_semijoin.result
View File

@ -1,8 +1,10 @@
show variables like 'optimizer_switch';
Variable_name Value
optimizer_switch index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on
optimizer_switch index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on
set optimizer_switch='semijoin=off';
drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t11,t12;
set @save_optimizer_switch=@@optimizer_switch;
set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=off";
select (select 2);
(select 2)
2
@ -4807,8 +4809,9 @@ SELECT 1 FROM t1 GROUP BY
1
1
DROP TABLE t1;
set @@optimizer_switch=@save_optimizer_switch;
End of 5.1 tests.
set optimizer_switch=default;
show variables like 'optimizer_switch';
Variable_name Value
optimizer_switch index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on
optimizer_switch index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on

18
mysql-test/r/subselect_sj.result
View File

@ -202,39 +202,39 @@ BUG#37120 optimizer_switch allowable values not according to specification
select @@optimizer_switch;
@@optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on
set optimizer_switch='default,materialization=off';
select @@optimizer_switch;
@@optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=off,semijoin=on
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=off,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on
set optimizer_switch='default,semijoin=off';
select @@optimizer_switch;
@@optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=off
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on
set optimizer_switch='default,loosescan=off';
select @@optimizer_switch;
@@optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=off,materialization=on,semijoin=on
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=off,materialization=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on
set optimizer_switch='default,semijoin=off,materialization=off';
select @@optimizer_switch;
@@optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=off,semijoin=off
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=off,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on
set optimizer_switch='default,materialization=off,semijoin=off';
select @@optimizer_switch;
@@optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=off,semijoin=off
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=off,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on
set optimizer_switch='default,semijoin=off,materialization=off,loosescan=off';
select @@optimizer_switch;
@@optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=off,materialization=off,semijoin=off
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=off,materialization=off,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on
set optimizer_switch='default,semijoin=off,loosescan=off';
select @@optimizer_switch;
@@optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=off,materialization=on,semijoin=off
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=off,materialization=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on
set optimizer_switch='default,materialization=off,loosescan=off';
select @@optimizer_switch;
@@optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=off,materialization=off,semijoin=on
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=off,materialization=off,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on
set optimizer_switch=default;
drop table t0, t1, t2;
drop table t10, t11, t12;

18
mysql-test/r/subselect_sj_jcl6.result
View File

@ -206,39 +206,39 @@ BUG#37120 optimizer_switch allowable values not according to specification
select @@optimizer_switch;
@@optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on
set optimizer_switch='default,materialization=off';
select @@optimizer_switch;
@@optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=off,semijoin=on
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=off,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on
set optimizer_switch='default,semijoin=off';
select @@optimizer_switch;
@@optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=off
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on
set optimizer_switch='default,loosescan=off';
select @@optimizer_switch;
@@optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=off,materialization=on,semijoin=on
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=off,materialization=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on
set optimizer_switch='default,semijoin=off,materialization=off';
select @@optimizer_switch;
@@optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=off,semijoin=off
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=off,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on
set optimizer_switch='default,materialization=off,semijoin=off';
select @@optimizer_switch;
@@optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=off,semijoin=off
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=on,materialization=off,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on
set optimizer_switch='default,semijoin=off,materialization=off,loosescan=off';
select @@optimizer_switch;
@@optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=off,materialization=off,semijoin=off
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=off,materialization=off,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on
set optimizer_switch='default,semijoin=off,loosescan=off';
select @@optimizer_switch;
@@optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=off,materialization=on,semijoin=off
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=off,materialization=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on
set optimizer_switch='default,materialization=off,loosescan=off';
select @@optimizer_switch;
@@optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=off,materialization=off,semijoin=on
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_condition_pushdown=on,firstmatch=on,loosescan=off,materialization=off,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on
set optimizer_switch=default;
drop table t0, t1, t2;
drop table t10, t11, t12;

5
mysql-test/t/ps.test
View File

@ -163,6 +163,9 @@ create table t1
) engine = MYISAM ;
create table t2 like t1;
set @save_optimizer_switch=@@optimizer_switch;
set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=off";
set @stmt= ' explain SELECT (SELECT SUM(c1 + c12 + 0.0) FROM t2 where (t1.c2 - 0e-3) = t2.c2 GROUP BY t1.c15 LIMIT 1) as scalar_s, exists (select 1.0e+0 from t2 where t2.c3 * 9.0000000000 = t1.c4) as exists_s, c5 * 4 in (select c6 + 0.3e+1 from t2) as in_s, (c7 - 4, c8 - 4) in (select c9 + 4.0, c10 + 40e-1 from t2) as in_row_s FROM t1, (select c25 x, c32 y from t2) tt WHERE x * 1 = c25 ' ;
prepare stmt1 from @stmt ;
execute stmt1 ;
@ -171,6 +174,8 @@ explain SELECT (SELECT SUM(c1 + c12 + 0.0) FROM t2 where (t1.c2 - 0e-3) = t2.c2
deallocate prepare stmt1;
drop tables t1,t2;
set @@optimizer_switch=@save_optimizer_switch;
#
# parameters from variables (for field creation)
#

5
mysql-test/t/subselect.test
View File

@ -11,6 +11,9 @@
drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t11,t12;
--enable_warnings
set @save_optimizer_switch=@@optimizer_switch;
set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=off";
select (select 2);
explain extended select (select 2);
SELECT (SELECT 1) UNION SELECT (SELECT 2);
@ -4061,4 +4064,6 @@ SELECT 1 FROM t1 GROUP BY
(SELECT LAST_INSERT_ID() FROM t1 ORDER BY MIN(a) ASC LIMIT 1);
DROP TABLE t1;
set @@optimizer_switch=@save_optimizer_switch;
--echo End of 5.1 tests.

9
mysql-test/t/subselect3.test
View File

@ -59,9 +59,13 @@ select a in (select max(ie) from t1 where oref=4 group by grp) from t3;
show status like 'Handler_read_rnd_next';
select ' ^ This must show 11' Z;
set @save_optimizer_switch=@@optimizer_switch;
set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=off";
# This must show trigcond:
explain extended select a in (select max(ie) from t1 where oref=4 group by grp) from t3;
set @@optimizer_switch=@save_optimizer_switch;
drop table t1, t2, t3;
#
@ -529,6 +533,9 @@ SELECT a, MAX(b),
DROP TABLE t1, t2;
# The next three test cases must be executed with the IN=>EXISTS strategy
set @save_optimizer_switch=@@optimizer_switch;
set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=off";
#
# Bug #27870: crash of an equijoin query with WHERE condition containing
@ -588,6 +595,8 @@ EXPLAIN SELECT a FROM t1 WHERE a NOT IN (SELECT a FROM t2);
DROP TABLE t1, t2;
set @@optimizer_switch=@save_optimizer_switch;
#
# Bug #34763: item_subselect.cc:1235:Item_in_subselect::row_value_transformer:
# Assertion failed, unexpected error message:

1
sql/item_cmpfunc.h
View File

@ -350,6 +350,7 @@ public:
CHARSET_INFO *compare_collation() { return cmp.cmp_collation.collation; }
uint decimal_precision() const { return 1; }
void top_level_item() { abort_on_null= TRUE; }
Arg_comparator *get_comparator() { return &cmp; }
friend class Arg_comparator;
};

1902
sql/item_subselect.cc
View File

File diff suppressed because it is too large Load Diff

437
sql/item_subselect.h
View File

@ -297,7 +297,7 @@ public:
Representation of IN subquery predicates of the form
"left_expr IN (SELECT ...)".
@detail
@details
This class has:
- A "subquery execution engine" (as a subclass of Item_subselect) that allows
it to evaluate subqueries. (and this class participates in execution by
@ -319,6 +319,12 @@ protected:
*/
List<Cached_item> *left_expr_cache;
bool first_execution;
/*
Set to TRUE if at query execution time we determine that this item's
value is a constant during this execution. We need this member because
it is not possible to substitute 'this' with a constant item.
*/
bool is_constant;
/*
expr & optimizer used in subselect rewriting to store Item for
@ -387,8 +393,8 @@ public:
Item_in_subselect(Item * left_expr, st_select_lex *select_lex);
Item_in_subselect()
:Item_exists_subselect(), left_expr_cache(0), first_execution(TRUE),
optimizer(0), abort_on_null(0), pushed_cond_guards(NULL),
exec_method(NOT_TRANSFORMED), upper_item(0)
is_constant(FALSE), optimizer(0), abort_on_null(0),
pushed_cond_guards(NULL), exec_method(NOT_TRANSFORMED), upper_item(0)
{}
void cleanup();
subs_type substype() { return IN_SUBS; }
@ -421,6 +427,8 @@ public:
void update_used_tables();
bool setup_engine();
bool init_left_expr_cache();
/* Inform 'this' that it was computed, and contains a valid result. */
void set_first_execution() { if (first_execution) first_execution= FALSE; }
bool is_expensive_processor(uchar *arg);
friend class Item_ref_null_helper;
@ -428,6 +436,7 @@ public:
friend class Item_in_optimizer;
friend class subselect_indexsubquery_engine;
friend class subselect_hash_sj_engine;
friend class subselect_partial_match_engine;
};
@ -462,7 +471,8 @@ public:
enum enum_engine_type {ABSTRACT_ENGINE, SINGLE_SELECT_ENGINE,
UNION_ENGINE, UNIQUESUBQUERY_ENGINE,
INDEXSUBQUERY_ENGINE, HASH_SJ_ENGINE};
INDEXSUBQUERY_ENGINE, HASH_SJ_ENGINE,
ROWID_MERGE_ENGINE, TABLE_SCAN_ENGINE};
subselect_engine(Item_subselect *si, select_result_interceptor *res)
:thd(0)
@ -635,8 +645,10 @@ public:
virtual void print (String *str, enum_query_type query_type);
bool change_result(Item_subselect *si, select_result_interceptor *result);
bool no_tables();
int index_lookup(); /* TIMOUR: this method needs refactoring. */
int scan_table();
bool copy_ref_key();
int copy_ref_key_simple(); /* TIMOUR: this method needs refactoring. */
bool no_rows() { return empty_result_set; }
virtual enum_engine_type engine_type() { return UNIQUESUBQUERY_ENGINE; }
};
@ -705,50 +717,439 @@ inline bool Item_subselect::is_uncacheable() const
/**
Compute an IN predicate via a hash semi-join. The subquery is materialized
during the first evaluation of the IN predicate. The IN predicate is executed
via the functionality inherited from subselect_uniquesubquery_engine.
Compute an IN predicate via a hash semi-join. This class is responsible for
the materialization of the subquery, and the selection of the correct and
optimal execution method (e.g. direct index lookup, or partial matching) for
the IN predicate.
*/
class subselect_hash_sj_engine: public subselect_uniquesubquery_engine
class subselect_hash_sj_engine : public subselect_engine
{
protected:
/* The table into which the subquery is materialized. */
TABLE *tmp_table;
/* TRUE if the subquery was materialized into a temp table. */
bool is_materialized;
/*
The old engine already chosen at parse time and stored in permanent memory.
Through this member we can re-create and re-prepare materialize_join for
each execution of a prepared statement. We akso resuse the functionality
each execution of a prepared statement. We also reuse the functionality
of subselect_single_select_engine::[prepare | cols].
*/
subselect_single_select_engine *materialize_engine;
/* The engine used to compute the IN predicate. */
subselect_engine *lookup_engine;
/*
QEP to execute the subquery and materialize its result into a
temporary table. Created during the first call to exec().
*/
JOIN *materialize_join;
/* Temp table context of the outer select's JOIN. */
TMP_TABLE_PARAM *tmp_param;
/* Keyparts of the only non-NULL composite index in a rowid merge. */
MY_BITMAP non_null_key_parts;
/* Keyparts of the single column indexes with NULL, one keypart per index. */
MY_BITMAP partial_match_key_parts;
uint count_partial_match_columns;
uint count_null_only_columns;
/*
A conjunction of all the equality condtions between all pairs of expressions
that are arguments of an IN predicate. We need these to post-filter some
IN results because index lookups sometimes match values that are actually
not equal to the search key in SQL terms.
*/
Item_cond_and *semi_join_conds;
/* Possible execution strategies that can be used to compute hash semi-join.*/
enum exec_strategy {
UNDEFINED,
COMPLETE_MATCH, /* Use regular index lookups. */
PARTIAL_MATCH, /* Use some partial matching strategy. */
PARTIAL_MATCH_MERGE, /* Use partial matching through index merging. */
PARTIAL_MATCH_SCAN, /* Use partial matching through table scan. */
IMPOSSIBLE /* Subquery materialization is not applicable. */
};
/* The chosen execution strategy. Computed after materialization. */
exec_strategy strategy;
protected:
exec_strategy get_strategy_using_schema();
exec_strategy get_strategy_using_data();
size_t rowid_merge_buff_size(bool has_non_null_key,
bool has_covering_null_row,
MY_BITMAP *partial_match_key_parts);
void choose_partial_match_strategy(bool has_non_null_key,
bool has_covering_null_row,
MY_BITMAP *partial_match_key_parts);
bool make_semi_join_conds();
subselect_uniquesubquery_engine* make_unique_engine();
public:
subselect_hash_sj_engine(THD *thd, Item_subselect *in_predicate,
subselect_single_select_engine *old_engine)
:subselect_uniquesubquery_engine(thd, NULL, in_predicate, NULL),
is_materialized(FALSE), materialize_engine(old_engine),
materialize_join(NULL), tmp_param(NULL)
{}
subselect_single_select_engine *old_engine)
:subselect_engine(in_predicate, NULL), tmp_table(NULL),
is_materialized(FALSE), materialize_engine(old_engine), lookup_engine(NULL),
materialize_join(NULL), count_partial_match_columns(0),
count_null_only_columns(0), semi_join_conds(NULL), strategy(UNDEFINED)
{
set_thd(thd);
}
~subselect_hash_sj_engine();
bool init_permanent(List<Item> *tmp_columns);
bool init_runtime();
void cleanup();
int prepare() { return 0; }
int prepare() { return 0; } /* Override virtual function in base class. */
int exec();
virtual void print (String *str, enum_query_type query_type);
virtual void print(String *str, enum_query_type query_type);
uint cols()
{
return materialize_engine->cols();
}
uint8 uncacheable() { return UNCACHEABLE_DEPENDENT; }
table_map upper_select_const_tables() { return 0; }
bool no_rows() { return !tmp_table->file->stats.records; }
virtual enum_engine_type engine_type() { return HASH_SJ_ENGINE; }
/*
TODO: factor out all these methods in a base subselect_index_engine class
because all of them have dummy implementations and should never be called.
*/
void fix_length_and_dec(Item_cache** row);//=>base class
void exclude(); //=>base class
//=>base class
bool change_result(Item_subselect *si, select_result_interceptor *result);
bool no_tables();//=>base class
};
/*
Distinguish the type od (0-based) row numbers from the type of the index into
an array of row numbers.
*/
typedef ha_rows rownum_t;
/*
An Ordered_key is an in-memory table index that allows O(log(N)) time
lookups of a multi-part key.
If the index is over a single column, then this column may contain NULLs, and
the NULLs are stored and tested separately for NULL in O(1) via is_null().
Multi-part indexes assume that the indexed columns do not contain NULLs.
TODO:
= Due to the unnatural assymetry between single and multi-part indexes, it
makes sense to somehow refactor or extend the class.
= This class can be refactored into a base abstract interface, and two
subclasses:
- one to represent single-column indexes, and
- another to represent multi-column indexes.
Such separation would allow slightly more efficient implementation of
the single-column indexes.
= The current design requires such indexes to be fully recreated for each
PS (re)execution, however most of the comprising objects can be reused.
*/
class Ordered_key : public Sql_alloc
{
protected:
/*
Index of the key in an array of keys. This index allows to
construct (sub)sets of keys represented by bitmaps.
*/
uint keyid;
/* The table being indexed. */
TABLE *tbl;
/* The columns being indexed. */
Item_field **key_columns;
/* Number of elements in 'key_columns' (number of key parts). */
uint key_column_count;
/*
An expression, or sequence of expressions that forms the search key.
The search key is a sequence when it is Item_row. Each element of the
sequence is accessible via Item::element_index(int i).
*/
Item *search_key;
/* Value index related members. */
/*
The actual value index, consists of a sorted sequence of row numbers.
*/
rownum_t *key_buff;
/* Number of elements in key_buff. */
ha_rows key_buff_elements;
/* Current element in 'key_buff'. */
ha_rows cur_key_idx;
/*
Mapping from row numbers to row ids. The element row_num_to_rowid[i]
contains a buffer with the rowid for the row numbered 'i'.
The memory for this member is not maintanined by this class because
all Ordered_key indexes of the same table share the same mapping.
*/
uchar *row_num_to_rowid;
/*
A sequence of predicates to compare the search key with the corresponding
columns of a table row from the index.
*/
Item_func_lt **compare_pred;
/* Null index related members. */
MY_BITMAP null_key;
/* Count of NULLs per column. */
ha_rows null_count;
/* The row number that contains the first NULL in a column. */
ha_rows min_null_row;
/* The row number that contains the last NULL in a column. */
ha_rows max_null_row;
protected:
bool alloc_keys_buffers();
/*
Quick sort comparison function that compares two rows of the same table
indentfied with their row numbers.
*/
int cmp_keys_by_row_data(rownum_t a, rownum_t b);
static int cmp_keys_by_row_data_and_rownum(Ordered_key *key,
rownum_t* a, rownum_t* b);
int cmp_key_with_search_key(rownum_t row_num);
public:
Ordered_key(uint keyid_arg, TABLE *tbl_arg,
Item *search_key_arg, ha_rows null_count_arg,
ha_rows min_null_row_arg, ha_rows max_null_row_arg,
uchar *row_num_to_rowid_arg);
~Ordered_key();
void cleanup();
/* Initialize a multi-column index. */
bool init(MY_BITMAP *columns_to_index);
/* Initialize a single-column index. */
bool init(int col_idx);
uint get_column_count() { return key_column_count; }
uint get_keyid() { return keyid; }
uint get_field_idx(uint i)
{
DBUG_ASSERT(i < key_column_count);
return key_columns[i]->field->field_index;
}
/*
Get the search key element that corresponds to the i-th key part of this
index.
*/
Item *get_search_key(uint i)
{
return search_key->element_index(key_columns[i]->field->field_index);
}
void add_key(rownum_t row_num)
{
/* The caller must know how many elements to add. */
DBUG_ASSERT(key_buff_elements && cur_key_idx < key_buff_elements);
key_buff[cur_key_idx]= row_num;
++cur_key_idx;
}
void sort_keys();
double null_selectivity();
/*
Position the current element at the first row that matches the key.
The key itself is propagated by evaluating the current value(s) of
this->search_key.
*/
bool lookup();
/* Move the current index cursor to the first key. */
void first()
{
DBUG_ASSERT(key_buff_elements);
cur_key_idx= 0;
}
/* TODO */
bool next_same();
/* Move the current index cursor to the next key. */
bool next()
{
DBUG_ASSERT(key_buff_elements);
if (cur_key_idx < key_buff_elements - 1)
{
++cur_key_idx;
return TRUE;
}
return FALSE;
};
/* Return the current index element. */
rownum_t current()
{
DBUG_ASSERT(key_buff_elements && cur_key_idx < key_buff_elements);
return key_buff[cur_key_idx];
}
void set_null(rownum_t row_num)
{
bitmap_set_bit(&null_key, row_num);
}
bool is_null(rownum_t row_num)
{
/*
Indexes consisting of only NULLs do not have a bitmap buffer at all.
Their only initialized member is 'n_bits', which is equal to the number
of temp table rows.
*/
if (null_count == tbl->file->stats.records)
{
DBUG_ASSERT(tbl->file->stats.records == null_key.n_bits);
return TRUE;
}
if (row_num > max_null_row || row_num < min_null_row)
return FALSE;
return bitmap_is_set(&null_key, row_num);
}
void print(String *str);
};
class subselect_partial_match_engine : public subselect_engine
{
protected:
/* The temporary table that contains a materialized subquery. */
TABLE *tmp_table;
/*
The engine used to check whether an IN predicate is TRUE or not. If not
TRUE, then subselect_rowid_merge_engine further distinguishes between
FALSE and UNKNOWN.
*/
subselect_uniquesubquery_engine *lookup_engine;
/* A list of equalities between each pair of IN operands. */
List<Item> *equi_join_conds;
/*
If there is a row, such that all its NULL-able components are NULL, this
member is set to the number of covered columns. If there is no covering
row, then this is 0.
*/
uint covering_null_row_width;
protected:
virtual bool partial_match()= 0;
public:
subselect_partial_match_engine(subselect_uniquesubquery_engine *engine_arg,
TABLE *tmp_table_arg, Item_subselect *item_arg,
select_result_interceptor *result_arg,
List<Item> *equi_join_conds_arg,
uint covering_null_row_width_arg);
int prepare() { return 0; }
int exec();
void fix_length_and_dec(Item_cache**) {}
uint cols() { /* TODO: what is the correct value? */ return 1; }
uint8 uncacheable() { return UNCACHEABLE_DEPENDENT; }
void exclude() {}
table_map upper_select_const_tables() { return 0; }
bool change_result(Item_subselect*, select_result_interceptor*)
{ DBUG_ASSERT(FALSE); return false; }
bool no_tables() { return false; }
bool no_rows()
{
/*
TODO: It is completely unclear what is the semantics of this
method. The current result is computed so that the call to no_rows()
from Item_in_optimizer::val_int() sets Item_in_optimizer::null_value
correctly.
*/
return !(((Item_in_subselect *) item)->null_value);
}
void print(String*, enum_query_type);
friend void subselect_hash_sj_engine::cleanup();
};
class subselect_rowid_merge_engine: public subselect_partial_match_engine
{
protected:
/*
Mapping from row numbers to row ids. The rowids are stored sequentially
in the array - rowid[i] is located in row_num_to_rowid + i * rowid_length.
*/
uchar *row_num_to_rowid;
/*
A subset of all the keys for which there is a match for the same row.
Used during execution. Computed for each outer reference
*/
MY_BITMAP matching_keys;
/*
The columns of the outer reference that are NULL. Computed for each
outer reference.
*/
MY_BITMAP matching_outer_cols;
/*
Columns that consist of only NULLs. Such columns match any value.
Computed once per query execution.
*/
MY_BITMAP null_only_columns;
/*
Indexes of row numbers, sorted by <column_value, row_number>. If an
index may contain NULLs, the NULLs are stored efficiently in a bitmap.
The indexes are sorted by the selectivity of their NULL sub-indexes, the
one with the fewer NULLs is first. Thus, if there is any index on
non-NULL columns, it is contained in keys[0].
*/
Ordered_key **merge_keys;
/* The number of elements in keys. */
uint keys_count;
/*
An index on all non-NULL columns of 'tmp_table'. The index has the
logical form: <[v_i1 | ... | v_ik], rownum>. It allows to find the row
number where the columns c_i1,...,c1_k contain the values v_i1,...,v_ik.
If such an index exists, it is always the first element of 'keys'.
*/
Ordered_key *non_null_key;
/*
Priority queue of Ordered_key indexes, one per NULLable column.
This queue is used by the partial match algorithm in method exec().
*/
QUEUE pq;
protected:
/*
Comparison function to compare keys in order of decreasing bitmap
selectivity.
*/
static int cmp_keys_by_null_selectivity(Ordered_key **k1, Ordered_key **k2);
/*
Comparison function used by the priority queue pq, the 'smaller' key
is the one with the smaller current row number.
*/
static int cmp_keys_by_cur_rownum(void *arg, uchar *k1, uchar *k2);
bool test_null_row(rownum_t row_num);
bool partial_match();
public:
subselect_rowid_merge_engine(subselect_uniquesubquery_engine *engine_arg,
TABLE *tmp_table_arg, uint keys_count_arg,
uint covering_null_row_width_arg,
Item_subselect *item_arg,
select_result_interceptor *result_arg,
List<Item> *equi_join_conds_arg)
:subselect_partial_match_engine(engine_arg, tmp_table_arg, item_arg,
result_arg, equi_join_conds_arg,
covering_null_row_width_arg),
keys_count(keys_count_arg), non_null_key(NULL)
{
thd= lookup_engine->get_thd();
}
~subselect_rowid_merge_engine();
bool init(MY_BITMAP *non_null_key_parts, MY_BITMAP *partial_match_key_parts);
void cleanup();
virtual enum_engine_type engine_type() { return ROWID_MERGE_ENGINE; }
};
class subselect_table_scan_engine: public subselect_partial_match_engine
{
protected:
bool partial_match();
public:
subselect_table_scan_engine(subselect_uniquesubquery_engine *engine_arg,
TABLE *tmp_table_arg, Item_subselect *item_arg,
select_result_interceptor *result_arg,
List<Item> *equi_join_conds_arg,
uint covering_null_row_width_arg);
void cleanup();
virtual enum_engine_type engine_type() { return TABLE_SCAN_ENGINE; }
};

18
sql/mysql_priv.h
View File

@ -552,12 +552,14 @@ protected:
#define OPTIMIZER_SWITCH_LOOSE_SCAN 64
#define OPTIMIZER_SWITCH_MATERIALIZATION 128
#define OPTIMIZER_SWITCH_SEMIJOIN 256
#define OPTIMIZER_SWITCH_PARTIAL_MATCH_ROWID_MERGE 512
#define OPTIMIZER_SWITCH_PARTIAL_MATCH_TABLE_SCAN 1024
#ifdef DBUG_OFF
# define OPTIMIZER_SWITCH_LAST 512
# define OPTIMIZER_SWITCH_LAST 2048
#else
# define OPTIMIZER_SWITCH_TABLE_ELIMINATION 512
# define OPTIMIZER_SWITCH_LAST 1024
# define OPTIMIZER_SWITCH_TABLE_ELIMINATION 2048
# define OPTIMIZER_SWITCH_LAST 4096
#endif
#ifdef DBUG_OFF
@ -570,8 +572,10 @@ protected:
OPTIMIZER_SWITCH_FIRSTMATCH | \
OPTIMIZER_SWITCH_LOOSE_SCAN | \
OPTIMIZER_SWITCH_MATERIALIZATION | \
OPTIMIZER_SWITCH_SEMIJOIN)
#else
OPTIMIZER_SWITCH_SEMIJOIN | \
OPTIMIZER_SWITCH_PARTIAL_MATCH_ROWID_MERGE|\
OPTIMIZER_SWITCH_PARTIAL_MATCH_TABLE_SCAN)
#else
# define OPTIMIZER_SWITCH_DEFAULT (OPTIMIZER_SWITCH_INDEX_MERGE | \
OPTIMIZER_SWITCH_INDEX_MERGE_UNION | \
OPTIMIZER_SWITCH_INDEX_MERGE_SORT_UNION | \
@ -581,7 +585,9 @@ protected:
OPTIMIZER_SWITCH_FIRSTMATCH | \
OPTIMIZER_SWITCH_LOOSE_SCAN | \
OPTIMIZER_SWITCH_MATERIALIZATION | \
OPTIMIZER_SWITCH_SEMIJOIN)
OPTIMIZER_SWITCH_SEMIJOIN | \
OPTIMIZER_SWITCH_PARTIAL_MATCH_ROWID_MERGE|\
OPTIMIZER_SWITCH_PARTIAL_MATCH_TABLE_SCAN)
#endif
/*

14
sql/mysqld.cc
View File

@ -301,7 +301,9 @@ static const char *optimizer_switch_names[]=
"index_merge","index_merge_union","index_merge_sort_union",
"index_merge_intersection",
"index_condition_pushdown",
"firstmatch","loosescan","materialization", "semijoin",
"firstmatch","loosescan","materialization", "semijoin",
"partial_match_rowid_merge",
"partial_match_table_scan",
#ifndef DBUG_OFF
"table_elimination",
#endif
@ -320,6 +322,8 @@ static const unsigned int optimizer_switch_names_len[]=
sizeof("loosescan") - 1,
sizeof("materialization") - 1,
sizeof("semijoin") - 1,
sizeof("partial_match_rowid_merge") - 1,
sizeof("partial_match_table_scan") - 1,
#ifndef DBUG_OFF
sizeof("table_elimination") - 1,
#endif
@ -5794,7 +5798,8 @@ enum options_mysqld
OPT_RECORD_RND_BUFFER, OPT_DIV_PRECINCREMENT, OPT_RELAY_LOG_SPACE_LIMIT,
OPT_RELAY_LOG_PURGE,
OPT_SLAVE_NET_TIMEOUT, OPT_SLAVE_COMPRESSED_PROTOCOL, OPT_SLOW_LAUNCH_TIME,
OPT_SLAVE_TRANS_RETRIES, OPT_READONLY, OPT_DEBUGGING, OPT_DEBUG_FLUSH,
OPT_SLAVE_TRANS_RETRIES, OPT_READONLY, OPT_ROWID_MERGE_BUFF_SIZE,
OPT_DEBUGGING, OPT_DEBUG_FLUSH,
OPT_SORT_BUFFER, OPT_TABLE_OPEN_CACHE, OPT_TABLE_DEF_CACHE,
OPT_THREAD_CONCURRENCY, OPT_THREAD_CACHE_SIZE,
OPT_TMP_TABLE_SIZE, OPT_THREAD_STACK,
@ -7130,6 +7135,11 @@ The minimum value for this variable is 4096.",
(uchar**) &max_system_variables.range_alloc_block_size, 0, GET_ULONG,
REQUIRED_ARG, RANGE_ALLOC_BLOCK_SIZE, RANGE_ALLOC_BLOCK_SIZE,
(longlong) ULONG_MAX, 0, 1024, 0},
{"rowid_merge_buff_size", OPT_ROWID_MERGE_BUFF_SIZE,
"The size of the buffers used [NOT] IN evaluation via partial matching.",
(uchar**) &global_system_variables.rowid_merge_buff_size,
(uchar**) &max_system_variables.rowid_merge_buff_size, 0, GET_ULONG,
REQUIRED_ARG, 8*1024*1024L, 0, MAX_MEM_TABLE_SIZE/2, 0, 1, 0},
{"read_buffer_size", OPT_RECORD_BUFFER,
"Each thread that does a sequential scan allocates a buffer of this size for each table it scans. If you do many sequential scans, you may want to increase this value.",
(uchar**) &global_system_variables.read_buff_size,

24
sql/opt_subselect.cc
View File

@ -187,10 +187,10 @@ int check_and_do_in_subquery_rewrites(JOIN *join)
does not call setup_subquery_materialization(). We could make
SELECT ... FROM DUAL call that function but that doesn't seem
to be the case that is worth handling.
4. Subquery predicate is a top-level predicate
(this implies it is not negated)
TODO: this is a limitation that should be lifted once we
implement correct NULL semantics (WL#3830)
4. Either the subquery predicate is a top-level predicate, or at
least one partial match strategy is enabled. If no partial match
strategy is enabled, then materialization cannot be used for
non-top-level queries because it cannot handle NULLs correctly.
5. Subquery is non-correlated
TODO:
This is an overly restrictive condition. It can be extended to:
@ -204,8 +204,8 @@ int check_and_do_in_subquery_rewrites(JOIN *join)
(*) The subquery must be part of a SELECT statement. The current
condition also excludes multi-table update statements.
We have to determine whether we will perform subquery materialization
before calling the IN=>EXISTS transformation, so that we know whether to
Determine whether we will perform subquery materialization before
calling the IN=>EXISTS transformation, so that we know whether to
perform the whole transformation or only that part of it which wraps
Item_in_subselect in an Item_in_optimizer.
*/
@ -215,12 +215,14 @@ int check_and_do_in_subquery_rewrites(JOIN *join)
select_lex->master_unit()->first_select()->leaf_tables && // 3
thd->lex->sql_command == SQLCOM_SELECT && // *
select_lex->outer_select()->leaf_tables && // 3A
subquery_types_allow_materialization(in_subs))
subquery_types_allow_materialization(in_subs) &&
// psergey-todo: duplicated_subselect_card_check: where it's done?
(in_subs->is_top_level_item() ||
optimizer_flag(thd, OPTIMIZER_SWITCH_PARTIAL_MATCH_ROWID_MERGE) ||
optimizer_flag(thd, OPTIMIZER_SWITCH_PARTIAL_MATCH_TABLE_SCAN)) &&//4
!in_subs->is_correlated && // 5
in_subs->exec_method == Item_in_subselect::NOT_TRANSFORMED) // 6
{
// psergey-todo: duplicated_subselect_card_check: where it's done?
if (in_subs->is_top_level_item() && // 4
!in_subs->is_correlated && // 5
in_subs->exec_method == Item_in_subselect::NOT_TRANSFORMED) // 6
in_subs->exec_method= Item_in_subselect::MATERIALIZATION;
}

3
sql/set_var.cc
View File

@ -540,6 +540,9 @@ static sys_var_long_ptr sys_query_cache_size(&vars, "query_cache_size",
static sys_var_thd_ulong sys_range_alloc_block_size(&vars, "range_alloc_block_size",
&SV::range_alloc_block_size);
static sys_var_thd_ulong sys_rowid_merge_buff_size(&vars, "rowid_merge_buff_size",
&SV::rowid_merge_buff_size);
static sys_var_thd_ulong sys_query_alloc_block_size(&vars, "query_alloc_block_size",
&SV::query_alloc_block_size,
0, fix_thd_mem_root);

66
sql/sql_class.cc
View File

@ -42,6 +42,7 @@
#include "sp_rcontext.h"
#include "sp_cache.h"
#include "sql_select.h" /* declares create_tmp_table() */
/*
The following is used to initialise Table_ident with a internal
@ -2877,6 +2878,71 @@ bool select_dumpvar::send_eof()
return 0;
}
bool
select_materialize_with_stats::
create_result_table(THD *thd_arg, List<Item> *column_types,
bool is_union_distinct, ulonglong options,
const char *table_alias, bool bit_fields_as_long)
{
DBUG_ASSERT(table == 0);
tmp_table_param.field_count= column_types->elements;
tmp_table_param.bit_fields_as_long= bit_fields_as_long;
if (! (table= create_tmp_table(thd_arg, &tmp_table_param, *column_types,
(ORDER*) 0, is_union_distinct, 1,
options, HA_POS_ERROR, (char*) table_alias)))
return TRUE;
col_stat= (Column_statistics*) table->in_use->alloc(table->s->fields *
sizeof(Column_statistics));
if (!stat)
return TRUE;
cleanup();
table->file->extra(HA_EXTRA_WRITE_CACHE);
table->file->extra(HA_EXTRA_IGNORE_DUP_KEY);
return FALSE;
}
/**
Override select_union::send_data to analyze each row for NULLs and to
update null_statistics before sending data to the client.
@return TRUE if fatal error when sending data to the client
@return FALSE on success
*/
bool select_materialize_with_stats::send_data(List<Item> &items)
{
List_iterator_fast<Item> item_it(items);
Item *cur_item;
Column_statistics *cur_col_stat= col_stat;
uint nulls_in_row= 0;
++count_rows;
while ((cur_item= item_it++))
{
if (cur_item->is_null())
{
++cur_col_stat->null_count;
cur_col_stat->max_null_row= count_rows;
if (!cur_col_stat->min_null_row)
cur_col_stat->min_null_row= count_rows;
++nulls_in_row;
}
++cur_col_stat;
}
if (nulls_in_row > max_nulls_in_row)
max_nulls_in_row= nulls_in_row;
return select_union::send_data(items);
}
/****************************************************************************
TMP_TABLE_PARAM
****************************************************************************/

79
sql/sql_class.h
View File

@ -343,6 +343,8 @@ struct system_variables
ulong mrr_buff_size;
ulong div_precincrement;
ulong sortbuff_size;
/* Total size of all buffers used by the subselect_rowid_merge_engine. */
ulong rowid_merge_buff_size;
ulong thread_handling;
ulong tx_isolation;
ulong completion_type;
@ -2740,19 +2742,20 @@ public:
class select_union :public select_result_interceptor
{
protected:
TMP_TABLE_PARAM tmp_table_param;
public:
TABLE *table;
select_union() :table(0) {}
select_union() :table(0) { tmp_table_param.init(); }
int prepare(List<Item> &list, SELECT_LEX_UNIT *u);
bool send_data(List<Item> &items);
bool send_eof();
bool flush();
bool create_result_table(THD *thd, List<Item> *column_types,
bool is_distinct, ulonglong options,
const char *alias, bool bit_fields_as_long);
virtual bool create_result_table(THD *thd, List<Item> *column_types,
bool is_distinct, ulonglong options,
const char *alias, bool bit_fields_as_long);
};
/* Base subselect interface class */
@ -2776,6 +2779,74 @@ public:
bool send_data(List<Item> &items);
};
/*
This class specializes select_union to collect statistics about the
data stored in the temp table. Currently the class collects statistcs
about NULLs.
*/
class select_materialize_with_stats : public select_union
{
protected:
class Column_statistics
{
public:
/* Count of NULLs per column. */
ha_rows null_count;
/* The row number that contains the first NULL in a column. */
ha_rows min_null_row;
/* The row number that contains the last NULL in a column. */
ha_rows max_null_row;
};
/* Array of statistics data per column. */
Column_statistics* col_stat;
/*
The number of columns in the biggest sub-row that consists of only
NULL values.
*/
ha_rows max_nulls_in_row;
/*
Count of rows writtent to the temp table. This is redundant as it is
already stored in handler::stats.records, however that one is relatively
expensive to compute (given we need that for evry row).
*/
ha_rows count_rows;
public:
select_materialize_with_stats() {}
virtual bool create_result_table(THD *thd, List<Item> *column_types,
bool is_distinct, ulonglong options,
const char *alias, bool bit_fields_as_long);
bool init_result_table(ulonglong select_options);
bool send_data(List<Item> &items);
void cleanup()
{
memset(col_stat, 0, table->s->fields * sizeof(Column_statistics));
max_nulls_in_row= 0;
count_rows= 0;
}
ha_rows get_null_count_of_col(uint idx)
{
DBUG_ASSERT(idx < table->s->fields);
return col_stat[idx].null_count;
}
ha_rows get_max_null_of_col(uint idx)
{
DBUG_ASSERT(idx < table->s->fields);
return col_stat[idx].max_null_row;
}
ha_rows get_min_null_of_col(uint idx)
{
DBUG_ASSERT(idx < table->s->fields);
return col_stat[idx].min_null_row;
}
ha_rows get_max_nulls_in_row() { return max_nulls_in_row; }
};
/* used in independent ALL/ANY optimisation */
class select_max_min_finder_subselect :public select_subselect
{

7
sql/sql_select.cc
View File

@ -874,6 +874,9 @@ JOIN::optimize()
{
DBUG_PRINT("info",("No tables"));
error= 0;
/* Create all structures needed for materialized subquery execution. */
if (setup_subquery_materialization())
DBUG_RETURN(1);
DBUG_RETURN(0);
}
error= -1; // Error is sent to client
@ -11258,7 +11261,7 @@ create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields,
param->group_buff=group_buff;
share->keys=1;
share->uniques= test(using_unique_constraint);
table->key_info=keyinfo;
table->key_info= table->s->key_info= keyinfo;
keyinfo->key_part=key_part_info;
keyinfo->flags=HA_NOSAME;
keyinfo->usable_key_parts=keyinfo->key_parts= param->group_parts;
@ -11344,7 +11347,7 @@ create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields,
keyinfo->key_parts * sizeof(KEY_PART_INFO))))
goto err;
bzero((void*) key_part_info, keyinfo->key_parts * sizeof(KEY_PART_INFO));
table->key_info=keyinfo;
table->key_info= table->s->key_info= keyinfo;
keyinfo->key_part=key_part_info;
keyinfo->flags=HA_NOSAME | HA_NULL_ARE_EQUAL;
keyinfo->key_length= 0; // Will compute the sum of the parts below.