set @mrr_icp_extra_tmp=@@optimizer_switch; set optimizer_switch='mrr=on,mrr_sort_keys=on,index_condition_pushdown=on'; set optimizer_switch='rowid_filter=off'; SET optimizer_use_condition_selectivity=4; set @innodb_stats_persistent_save= @@innodb_stats_persistent; set @innodb_stats_persistent_sample_pages_save= @@innodb_stats_persistent_sample_pages; set global innodb_stats_persistent= 1; set global innodb_stats_persistent_sample_pages=100; CREATE TABLE t1 ( event_date date DEFAULT '0000-00-00' NOT NULL, type int(11) DEFAULT '0' NOT NULL, event_id int(11) DEFAULT '0' NOT NULL, PRIMARY KEY (event_date,type,event_id) ); INSERT INTO t1 VALUES ('1999-07-10',100100,24), ('1999-07-11',100100,25), ('1999-07-13',100600,0), ('1999-07-13',100600,4), ('1999-07-13',100600,26), ('1999-07-14',100600,10), ('1999-07-15',100600,16), ('1999-07-15',100800,45), ('1999-07-15',101000,47), ('1999-07-16',100800,46), ('1999-07-20',100600,5), ('1999-07-20',100600,27), ('1999-07-21',100600,11), ('1999-07-22',100600,17), ('1999-07-23',100100,39), ('1999-07-24',100100,39), ('1999-07-24',100500,40), ('1999-07-25',100100,39), ('1999-07-27',100600,1), ('1999-07-27',100600,6), ('1999-07-27',100600,28), ('1999-07-28',100600,12), ('1999-07-29',100500,41), ('1999-07-29',100600,18), ('1999-07-30',100500,41), ('1999-07-31',100500,41), ('1999-08-01',100700,34), ('1999-08-03',100600,7), ('1999-08-03',100600,29), ('1999-08-04',100600,13), ('1999-08-05',100500,42), ('1999-08-05',100600,19), ('1999-08-06',100500,42), ('1999-08-07',100500,42), ('1999-08-08',100500,42), ('1999-08-10',100600,2), ('1999-08-10',100600,9), ('1999-08-10',100600,30), ('1999-08-11',100600,14), ('1999-08-12',100600,20), ('1999-08-17',100500,8), ('1999-08-17',100600,31), ('1999-08-18',100600,15), ('1999-08-19',100600,22), ('1999-08-24',100600,3), ('1999-08-24',100600,32), ('1999-08-27',100500,43), ('1999-08-31',100600,33), ('1999-09-17',100100,37), ('1999-09-18',100100,37), ('1999-09-19',100100,37), ('2000-12-18',100700,38); select event_date,type,event_id from t1 WHERE event_date >= "1999-07-01" AND event_date < "1999-07-15" AND (type=100600 OR type=100100) ORDER BY event_date; event_date type event_id 1999-07-10 100100 24 1999-07-11 100100 25 1999-07-13 100600 0 1999-07-13 100600 4 1999-07-13 100600 26 1999-07-14 100600 10 explain select event_date,type,event_id from t1 WHERE type = 100601 and event_date >= "1999-07-01" AND event_date < "1999-07-15" AND (type=100600 OR type=100100) ORDER BY event_date; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible WHERE select event_date,type,event_id from t1 WHERE event_date >= "1999-07-01" AND event_date <= "1999-07-15" AND (type=100600 OR type=100100) or event_date >= "1999-07-01" AND event_date <= "1999-07-15" AND type=100099; event_date type event_id 1999-07-10 100100 24 1999-07-11 100100 25 1999-07-13 100600 0 1999-07-13 100600 4 1999-07-13 100600 26 1999-07-14 100600 10 1999-07-15 100600 16 drop table t1; CREATE TABLE t1 ( PAPER_ID smallint(6) DEFAULT '0' NOT NULL, YEAR smallint(6) DEFAULT '0' NOT NULL, ISSUE smallint(6) DEFAULT '0' NOT NULL, CLOSED tinyint(4) DEFAULT '0' NOT NULL, ISS_DATE date DEFAULT '0000-00-00' NOT NULL, PRIMARY KEY (PAPER_ID,YEAR,ISSUE) ); INSERT INTO t1 VALUES (3,1999,34,0,'1999-07-12'), (1,1999,111,0,'1999-03-23'), (1,1999,222,0,'1999-03-23'), (3,1999,33,0,'1999-07-12'), (3,1999,32,0,'1999-07-12'), (3,1999,31,0,'1999-07-12'), (3,1999,30,0,'1999-07-12'), (3,1999,29,0,'1999-07-12'), (3,1999,28,0,'1999-07-12'), (1,1999,40,1,'1999-05-01'), (1,1999,41,1,'1999-05-01'), (1,1999,42,1,'1999-05-01'), (1,1999,46,1,'1999-05-01'), (1,1999,47,1,'1999-05-01'), (1,1999,48,1,'1999-05-01'), (1,1999,49,1,'1999-05-01'), (1,1999,50,0,'1999-05-01'), (1,1999,51,0,'1999-05-01'), (1,1999,200,0,'1999-06-28'), (1,1999,52,0,'1999-06-28'), (1,1999,53,0,'1999-06-28'), (1,1999,54,0,'1999-06-28'), (1,1999,55,0,'1999-06-28'), (1,1999,56,0,'1999-07-01'), (1,1999,57,0,'1999-07-01'), (1,1999,58,0,'1999-07-01'), (1,1999,59,0,'1999-07-01'), (1,1999,60,0,'1999-07-01'), (3,1999,35,0,'1999-07-12'); select YEAR,ISSUE from t1 where PAPER_ID=3 and (YEAR>1999 or (YEAR=1999 and ISSUE>28)) order by YEAR,ISSUE; YEAR ISSUE 1999 29 1999 30 1999 31 1999 32 1999 33 1999 34 1999 35 check table t1; Table Op Msg_type Msg_text test.t1 check status OK repair table t1; Table Op Msg_type Msg_text test.t1 repair status OK drop table t1; CREATE TABLE t1 ( id int(11) NOT NULL auto_increment, parent_id int(11) DEFAULT '0' NOT NULL, level tinyint(4) DEFAULT '0' NOT NULL, PRIMARY KEY (id), KEY parent_id (parent_id), KEY level (level) ); INSERT INTO t1 VALUES (1,0,0), (3,1,1), (4,1,1), (8,2,2), (9,2,2), (17,3,2), (22,4,2), (24,4,2), (28,5,2), (29,5,2), (30,5,2), (31,6,2), (32,6,2), (33,6,2), (203,7,2), (202,7,2), (20,3,2), (157,0,0), (193,5,2), (40,7,2), (2,1,1), (15,2,2), (6,1,1), (34,6,2), (35,6,2), (16,3,2), (7,1,1), (36,7,2), (18,3,2), (26,5,2), (27,5,2), (183,4,2), (38,7,2), (25,5,2), (37,7,2), (21,4,2), (19,3,2), (5,1,1), (179,5,2); SELECT * FROM t1 WHERE level = 1 AND parent_id = 1; id parent_id level 3 1 1 4 1 1 2 1 1 6 1 1 7 1 1 5 1 1 SELECT * FROM t1 WHERE level = 1 AND parent_id = 1 order by id; id parent_id level 2 1 1 3 1 1 4 1 1 5 1 1 6 1 1 7 1 1 drop table t1; create table t1( Satellite varchar(25) not null, SensorMode varchar(25) not null, FullImageCornersUpperLeftLongitude double not null, FullImageCornersUpperRightLongitude double not null, FullImageCornersUpperRightLatitude double not null, FullImageCornersLowerRightLatitude double not null, index two (Satellite, SensorMode, FullImageCornersUpperLeftLongitude, FullImageCornersUpperRightLongitude, FullImageCornersUpperRightLatitude, FullImageCornersLowerRightLatitude)); insert into t1 values("OV-3","PAN1",91,-92,40,50); insert into t1 values("OV-4","PAN1",91,-92,40,50); select * from t1 where t1.Satellite = "OV-3" and t1.SensorMode = "PAN1" and t1.FullImageCornersUpperLeftLongitude > -90.000000 and t1.FullImageCornersUpperRightLongitude < -82.000000; Satellite SensorMode FullImageCornersUpperLeftLongitude FullImageCornersUpperRightLongitude FullImageCornersUpperRightLatitude FullImageCornersLowerRightLatitude OV-3 PAN1 91 -92 40 50 drop table t1; create table t1 ( aString char(100) not null default "", key aString (aString(10)) ); insert t1 (aString) values ( "believe in myself" ), ( "believe" ), ("baaa" ), ( "believe in love"); select * from t1 where aString < "believe in myself" order by aString; aString baaa believe believe in love select * from t1 where aString > "believe in love" order by aString; aString believe in myself alter table t1 drop key aString; select * from t1 where aString < "believe in myself" order by aString; aString baaa believe believe in love select * from t1 where aString > "believe in love" order by aString; aString believe in myself drop table t1; CREATE TABLE t1 ( t1ID int(10) unsigned NOT NULL auto_increment, art binary(1) NOT NULL default '', KNR char(5) NOT NULL default '', RECHNR char(6) NOT NULL default '', POSNR char(2) NOT NULL default '', ARTNR char(10) NOT NULL default '', TEX char(70) NOT NULL default '', PRIMARY KEY (t1ID), KEY IdxArt (art), KEY IdxKnr (KNR), KEY IdxArtnr (ARTNR) ) ENGINE=MyISAM; INSERT INTO t1 (art) VALUES ('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'), ('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'), ('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'), ('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'), ('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'), ('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'), ('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'), ('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'), ('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'), ('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'), ('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'), ('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'), ('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'), ('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'), ('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'), ('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'), ('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'), ('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'), ('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'), ('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'), ('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'), ('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'), ('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'), ('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'), ('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'), ('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'), ('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'), ('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'), ('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'), ('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'), ('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'), ('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'), ('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'), ('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'), ('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'), ('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'), ('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'), ('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'); select count(*) from t1 where upper(art) = 'J'; count(*) 213 select count(*) from t1 where art = 'J' or art = 'j'; count(*) 602 select count(*) from t1 where art = 'j' or art = 'J'; count(*) 602 select count(*) from t1 where art = 'j'; count(*) 389 select count(*) from t1 where art = 'J'; count(*) 213 drop table t1; create table t1 (x int, y int, index(x), index(y)); insert into t1 (x) values (1),(2),(3),(4),(5),(6),(7),(8),(9); update t1 set y=x; explain select * from t1, t1 t2 where t1.y = 8 and t2.x between 7 and t1.y+0; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ref y y 5 const 1 1 SIMPLE t2 range x x 5 NULL 2 Using index condition; Using where; Rowid-ordered scan; Using join buffer (flat, BNL join) explain select * from t1, t1 t2 where t1.y = 8 and t2.x >= 7 and t2.x <= t1.y+0; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ref y y 5 const 1 1 SIMPLE t2 range x x 5 NULL 2 Using index condition; Using where; Rowid-ordered scan; Using join buffer (flat, BNL join) explain select * from t1, t1 t2 where t1.y = 2 and t2.x between t1.y-1 and t1.y+1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ref y y 5 const 1 1 SIMPLE t2 range x x 5 NULL 3 Using index condition; Using where; Rowid-ordered scan; Using join buffer (flat, BNL join) explain select * from t1, t1 t2 where t1.y = 2 and t2.x >= t1.y-1 and t2.x <= t1.y+1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ref y y 5 const 1 1 SIMPLE t2 range x x 5 NULL 3 Using index condition; Using where; Rowid-ordered scan; Using join buffer (flat, BNL join) explain select * from t1, t1 t2 where t1.y = 2 and t2.x between 0 and t1.y; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ref y y 5 const 1 1 SIMPLE t2 range x x 5 NULL 2 Using index condition; Using where; Rowid-ordered scan; Using join buffer (flat, BNL join) explain select * from t1, t1 t2 where t1.y = 2 and t2.x >= 0 and t2.x <= t1.y; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ref y y 5 const 1 1 SIMPLE t2 range x x 5 NULL 2 Using index condition; Using where; Rowid-ordered scan; Using join buffer (flat, BNL join) explain select count(*) from t1 where x in (1); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ref x x 5 const 1 Using index explain select count(*) from t1 where x in (1,2,3,4); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index x x 5 NULL 9 Using where; Using index drop table t1; CREATE TABLE t1 (key1 int(11) NOT NULL default '0', KEY i1 (key1)); INSERT INTO t1 VALUES (0),(0),(0),(0),(0),(1),(1); CREATE TABLE t2 (keya int(11) NOT NULL default '0', KEY j1 (keya)); INSERT INTO t2 VALUES (0),(0),(1),(1),(2),(2); explain select * from t1, t2 where (t1.key1 0; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range uid_index uid_index 4 NULL 111 Using index condition; Rowid-ordered scan 1 SIMPLE t2 ref uid_index uid_index 4 test.t1.uid 38 explain select * from t1, t2 where t1.uid=t2.uid AND t2.uid > 0; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range uid_index uid_index 4 NULL 111 Using index condition; Rowid-ordered scan 1 SIMPLE t2 ref uid_index uid_index 4 test.t1.uid 38 explain select * from t1, t2 where t1.uid=t2.uid AND t1.uid != 0; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range uid_index uid_index 4 NULL 112 Using index condition; Rowid-ordered scan 1 SIMPLE t2 ref uid_index uid_index 4 test.t1.uid 38 explain select * from t1, t2 where t1.uid=t2.uid AND t2.uid != 0; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range uid_index uid_index 4 NULL 112 Using index condition; Rowid-ordered scan 1 SIMPLE t2 ref uid_index uid_index 4 test.t1.uid 38 select * from t1, t2 where t1.uid=t2.uid AND t1.uid > 0; id name uid id name uid 1001 A 1 1001 A 1 1002 B 2 1002 B 2 1003 C 3 1003 C 3 1004 D 4 1004 D 4 1005 E 5 1005 E 5 1006 F 6 1006 F 6 1007 G 7 1007 G 7 1008 H 8 1008 H 8 1009 I 9 1009 I 9 1010 J 10 1010 J 10 1011 K 11 1011 K 11 1012 L 12 1012 L 12 1013 M 13 1013 M 13 1014 N 14 1014 N 14 1015 O 15 1015 O 15 1016 P 16 1016 P 16 1017 Q 17 1017 Q 17 1018 R 18 1018 R 18 1019 S 19 1019 S 19 1020 T 20 1020 T 20 1021 U 21 1021 U 21 1022 V 22 1022 V 22 1023 W 23 1023 W 23 1024 X 24 1024 X 24 1025 Y 25 1025 Y 25 1026 Z 26 1026 Z 26 select * from t1, t2 where t1.uid=t2.uid AND t1.uid != 0; id name uid id name uid 1001 A 1 1001 A 1 1002 B 2 1002 B 2 1003 C 3 1003 C 3 1004 D 4 1004 D 4 1005 E 5 1005 E 5 1006 F 6 1006 F 6 1007 G 7 1007 G 7 1008 H 8 1008 H 8 1009 I 9 1009 I 9 1010 J 10 1010 J 10 1011 K 11 1011 K 11 1012 L 12 1012 L 12 1013 M 13 1013 M 13 1014 N 14 1014 N 14 1015 O 15 1015 O 15 1016 P 16 1016 P 16 1017 Q 17 1017 Q 17 1018 R 18 1018 R 18 1019 S 19 1019 S 19 1020 T 20 1020 T 20 1021 U 21 1021 U 21 1022 V 22 1022 V 22 1023 W 23 1023 W 23 1024 X 24 1024 X 24 1025 Y 25 1025 Y 25 1026 Z 26 1026 Z 26 drop table t1,t2; create table t1 (x bigint unsigned not null); insert into t1(x) values (0xfffffffffffffff0); insert into t1(x) values (0xfffffffffffffff1); select * from t1; x 18446744073709551600 18446744073709551601 select count(*) from t1 where x>0; count(*) 2 select count(*) from t1 where x=0; count(*) 0 select count(*) from t1 where x<0; count(*) 0 select count(*) from t1 where x < -16; count(*) 0 select count(*) from t1 where x = -16; count(*) 0 select count(*) from t1 where x > -16; count(*) 2 select count(*) from t1 where x = 18446744073709551601; count(*) 1 create table t2 (x bigint not null); insert into t2(x) values (-16); insert into t2(x) values (-15); select * from t2; x -16 -15 select count(*) from t2 where x>0; count(*) 0 select count(*) from t2 where x=0; count(*) 0 select count(*) from t2 where x<0; count(*) 2 select count(*) from t2 where x < -16; count(*) 0 select count(*) from t2 where x = -16; count(*) 1 select count(*) from t2 where x > -16; count(*) 1 select count(*) from t2 where x = 18446744073709551601; count(*) 0 drop table t1,t2; create table t1 (x bigint unsigned not null primary key) engine=innodb; insert into t1(x) values (0xfffffffffffffff0); insert into t1(x) values (0xfffffffffffffff1); select * from t1; x 18446744073709551600 18446744073709551601 select count(*) from t1 where x>0; count(*) 2 select count(*) from t1 where x=0; count(*) 0 select count(*) from t1 where x<0; count(*) 0 select count(*) from t1 where x < -16; count(*) 0 select count(*) from t1 where x = -16; count(*) 0 select count(*) from t1 where x > -16; count(*) 2 select count(*) from t1 where x = 18446744073709551601; count(*) 1 drop table t1; create table t1 (a bigint unsigned); create index t1i on t1(a); insert into t1 select 18446744073709551615; insert into t1 select 18446744073709551614; explain select * from t1 where a <> -1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index t1i t1i 9 NULL 2 Using where; Using index select * from t1 where a <> -1; a 18446744073709551614 18446744073709551615 explain select * from t1 where a > -1 or a < -1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index t1i t1i 9 NULL 2 Using where; Using index select * from t1 where a > -1 or a < -1; a 18446744073709551614 18446744073709551615 explain select * from t1 where a > -1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index t1i t1i 9 NULL 2 Using where; Using index select * from t1 where a > -1; a 18446744073709551614 18446744073709551615 explain select * from t1 where a < -1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables select * from t1 where a < -1; a drop table t1; set names latin1; create table t1 (a char(10), b text, key (a)) character set latin1; INSERT INTO t1 (a) VALUES ('111'),('222'),('222'),('222'),('222'),('444'),('aaa'),('AAA'),('bbb'); explain select * from t1 where a='aaa'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ref a a 11 const 2 Using index condition explain select * from t1 where a=binary 'aaa'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ref a a 11 const 2 Using index condition explain select * from t1 where a='aaa' collate latin1_bin; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ref a a 11 const 2 Using index condition explain select * from t1 where a='aaa' collate latin1_german1_ci; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL a NULL NULL NULL 9 Using where drop table t1; CREATE TABLE t1 ( `CLIENT` char(3) character set latin1 collate latin1_bin NOT NULL default '000', `ARG1` char(3) character set latin1 collate latin1_bin NOT NULL default '', `ARG2` char(3) character set latin1 collate latin1_bin NOT NULL default '', `FUNCTION` varchar(10) character set latin1 collate latin1_bin NOT NULL default '', `FUNCTINT` int(11) NOT NULL default '0', KEY `VERI_CLNT~2` (`ARG1`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1; INSERT INTO t1 VALUES ('000',' 0',' 0','Text 001',0), ('000',' 0',' 1','Text 002',0), ('000',' 1',' 2','Text 003',0), ('000',' 2',' 3','Text 004',0), ('001',' 3',' 0','Text 017',0); SELECT count(*) FROM t1 WHERE CLIENT='000' AND (ARG1 != ' 1' OR ARG1 != ' 2'); count(*) 4 SELECT count(*) FROM t1 WHERE CLIENT='000' AND (ARG1 != ' 2' OR ARG1 != ' 1'); count(*) 4 drop table t1; create table t1 (a int); insert into t1 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9); CREATE TABLE t2 ( pk1 int(11) NOT NULL, pk2 int(11) NOT NULL, pk3 int(11) NOT NULL, pk4 int(11) NOT NULL, filler char(82), PRIMARY KEY (pk1,pk2,pk3,pk4) ) DEFAULT CHARSET=latin1; insert into t2 select 1, A.a+10*B.a, 432, 44, 'fillerZ' from t1 A, t1 B; INSERT INTO t2 VALUES (2621, 2635, 0, 0,'filler'), (2621, 2635, 1, 0,'filler'), (2621, 2635, 10, 0,'filler'), (2621, 2635, 11, 0,'filler'), (2621, 2635, 14, 0,'filler'), (2621, 2635, 1000015, 0,'filler'); SELECT * FROM t2 WHERE ((((pk4 =0) AND (pk1 =2621) AND (pk2 =2635))) OR ((pk4 =1) AND (((pk1 IN ( 7, 2, 1 ))) OR (pk1 =522)) AND ((pk2 IN ( 0, 2635)))) ) AND (pk3 >=1000000); pk1 pk2 pk3 pk4 filler 2621 2635 1000015 0 filler drop table t1, t2; create table t1(a char(2), key(a(1))); insert into t1 values ('x'), ('xx'); explain select a from t1 where a > 'x'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range a a 2 NULL 2 Using where select a from t1 where a > 'x'; a xx drop table t1; CREATE TABLE t1 ( OXID varchar(32) COLLATE latin1_german2_ci NOT NULL DEFAULT '', OXPARENTID varchar(32) COLLATE latin1_german2_ci NOT NULL DEFAULT 'oxrootid', OXLEFT int NOT NULL DEFAULT '0', OXRIGHT int NOT NULL DEFAULT '0', OXROOTID varchar(32) COLLATE latin1_german2_ci NOT NULL DEFAULT '', PRIMARY KEY (OXID), KEY OXNID (OXID), KEY OXLEFT (OXLEFT), KEY OXRIGHT (OXRIGHT), KEY OXROOTID (OXROOTID) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 COLLATE=latin1_german2_ci; INSERT INTO t1 VALUES ('d8c4177d09f8b11f5.52725521','oxrootid',1,40,'d8c4177d09f8b11f5.52725521'), ('d8c4177d151affab2.81582770','d8c4177d09f8b11f5.52725521',2,3, 'd8c4177d09f8b11f5.52725521'), ('d8c4177d206a333d2.74422679','d8c4177d09f8b11f5.52725521',4,5, 'd8c4177d09f8b11f5.52725521'), ('d8c4177d225791924.30714720','d8c4177d09f8b11f5.52725521',6,7, 'd8c4177d09f8b11f5.52725521'), ('d8c4177d2380fc201.39666693','d8c4177d09f8b11f5.52725521',8,9, 'd8c4177d09f8b11f5.52725521'), ('d8c4177d24ccef970.14957924','d8c4177d09f8b11f5.52725521',10,11, 'd8c4177d09f8b11f5.52725521'); INSERT INTO t1 VALUES ('d8c4177d09f8b11f5.52725522','oxrootid',1,40,'d8c4177d09f8b11f5.52725522'), ('d8c4177d151affab2.81582771','d8c4177d09f8b11f5.52725521',2,3, 'd8c4177d09f8b11f5.52725522'), ('d8c4177d206a333d2.74422678','d8c4177d09f8b11f5.52725521',4,5, 'd8c4177d09f8b11f5.52725522'), ('d8c4177d225791924.30714721','d8c4177d09f8b11f5.52725521',6,7, 'd8c4177d09f8b11f5.52725522'), ('d8c4177d2380fc201.39666694','d8c4177d09f8b11f5.52725521',8,9, 'd8c4177d09f8b11f5.52725522'), ('d8c4177d24ccef970.14957925','d8c4177d09f8b11f5.52725521',10,11, 'd8c4177d09f8b11f5.52725522'); EXPLAIN SELECT s.oxid FROM t1 v, t1 s WHERE v.oxrootid ='d8c4177d09f8b11f5.52725521' AND s.oxleft > v.oxleft AND s.oxleft < v.oxright; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE v ref OXLEFT,OXRIGHT,OXROOTID OXROOTID 34 const 6 Using index condition 1 SIMPLE s ALL OXLEFT NULL NULL NULL 12 Range checked for each record (index map: 0x4) SELECT s.oxid FROM t1 v, t1 s WHERE v.oxrootid ='d8c4177d09f8b11f5.52725521' AND s.oxleft > v.oxleft AND s.oxleft < v.oxright; oxid d8c4177d151affab2.81582770 d8c4177d206a333d2.74422679 d8c4177d225791924.30714720 d8c4177d2380fc201.39666693 d8c4177d24ccef970.14957924 d8c4177d151affab2.81582771 d8c4177d206a333d2.74422678 d8c4177d225791924.30714721 d8c4177d2380fc201.39666694 d8c4177d24ccef970.14957925 DROP TABLE t1; create table t1 ( c1 char(10), c2 char(10), c3 char(10), c4 char(10), c5 char(10), c6 char(10), c7 char(10), c8 char(10), c9 char(10), c10 char(10), c11 char(10), c12 char(10), c13 char(10), c14 char(10), c15 char(10), c16 char(10), index(c1, c2, c3, c4, c5, c6, c7, c8, c9, c10, c11, c12,c13,c14,c15,c16) ); insert into t1 (c1) values ('1'),('1'),('1'),('1'); select * from t1 where c1 in ("abcdefgh", "123456789", "qwertyuio", "asddfgh", "abcdefg1", "123456781", "qwertyui1", "asddfg1", "abcdefg2", "123456782", "qwertyui2", "asddfg2", "abcdefg3", "123456783", "qwertyui3", "asddfg3", "abcdefg4", "123456784", "qwertyui4", "asddfg4", "abcdefg5", "123456785", "qwertyui5", "asddfg5", "abcdefg6", "123456786", "qwertyui6", "asddfg6", "abcdefg7", "123456787", "qwertyui7", "asddfg7", "abcdefg8", "123456788", "qwertyui8", "asddfg8", "abcdefg9", "123456789", "qwertyui9", "asddfg9", "abcdefgA", "12345678A", "qwertyuiA", "asddfgA", "abcdefgB", "12345678B", "qwertyuiB", "asddfgB", "abcdefgC", "12345678C", "qwertyuiC", "asddfgC") and c2 in ("abcdefgh", "123456789", "qwertyuio", "asddfgh", "abcdefg1", "123456781", "qwertyui1", "asddfg1", "abcdefg2", "123456782", "qwertyui2", "asddfg2", "abcdefg3", "123456783", "qwertyui3", "asddfg3", "abcdefg4", "123456784", "qwertyui4", "asddfg4", "abcdefg5", "123456785", "qwertyui5", "asddfg5", "abcdefg6", "123456786", "qwertyui6", "asddfg6", "abcdefg7", "123456787", "qwertyui7", "asddfg7", "abcdefg8", "123456788", "qwertyui8", "asddfg8", "abcdefg9", "123456789", "qwertyui9", "asddfg9", "abcdefgA", "12345678A", "qwertyuiA", "asddfgA", "abcdefgB", "12345678B", "qwertyuiB", "asddfgB", "abcdefgC", "12345678C", "qwertyuiC", "asddfgC") and c3 in ("abcdefgh", "123456789", "qwertyuio", "asddfgh", "abcdefg1", "123456781", "qwertyui1", "asddfg1", "abcdefg2", "123456782", "qwertyui2", "asddfg2", "abcdefg3", "123456783", "qwertyui3", "asddfg3", "abcdefg4", "123456784", "qwertyui4", "asddfg4", "abcdefg5", "123456785", "qwertyui5", "asddfg5", "abcdefg6", "123456786", "qwertyui6", "asddfg6", "abcdefg7", "123456787", "qwertyui7", "asddfg7", "abcdefg8", "123456788", "qwertyui8", "asddfg8", "abcdefg9", "123456789", "qwertyui9", "asddfg9", "abcdefgA", "12345678A", "qwertyuiA", "asddfgA", "abcdefgB", "12345678B", "qwertyuiB", "asddfgB", "abcdefgC", "12345678C", "qwertyuiC", "asddfgC") and c4 in ("abcdefgh", "123456789", "qwertyuio", "asddfgh", "abcdefg1", "123456781", "qwertyui1", "asddfg1", "abcdefg2", "123456782", "qwertyui2", "asddfg2", "abcdefg3", "123456783", "qwertyui3", "asddfg3", "abcdefg4", "123456784", "qwertyui4", "asddfg4", "abcdefg5", "123456785", "qwertyui5", "asddfg5", "abcdefg6", "123456786", "qwertyui6", "asddfg6", "abcdefg7", "123456787", "qwertyui7", "asddfg7", "abcdefg8", "123456788", "qwertyui8", "asddfg8", "abcdefg9", "123456789", "qwertyui9", "asddfg9", "abcdefgA", "12345678A", "qwertyuiA", "asddfgA", "abcdefgB", "12345678B", "qwertyuiB", "asddfgB", "abcdefgC", "12345678C", "qwertyuiC", "asddfgC") and c5 in ("abcdefgh", "123456789", "qwertyuio", "asddfgh", "abcdefg1", "123456781", "qwertyui1", "asddfg1", "abcdefg2", "123456782", "qwertyui2", "asddfg2", "abcdefg3", "123456783", "qwertyui3", "asddfg3", "abcdefg4", "123456784", "qwertyui4", "asddfg4", "abcdefg5", "123456785", "qwertyui5", "asddfg5", "abcdefg6", "123456786", "qwertyui6", "asddfg6", "abcdefg7", "123456787", "qwertyui7", "asddfg7", "abcdefg8", "123456788", "qwertyui8", "asddfg8", "abcdefg9", "123456789", "qwertyui9", "asddfg9", "abcdefgA", "12345678A", "qwertyuiA", "asddfgA", "abcdefgB", "12345678B", "qwertyuiB", "asddfgB", "abcdefgC", "12345678C", "qwertyuiC", "asddfgC") and c6 in ("abcdefgh", "123456789", "qwertyuio", "asddfgh", "abcdefg1", "123456781", "qwertyui1", "asddfg1", "abcdefg2", "123456782", "qwertyui2", "asddfg2", "abcdefg3", "123456783", "qwertyui3", "asddfg3", "abcdefg4", "123456784", "qwertyui4", "asddfg4", "abcdefg5", "123456785", "qwertyui5", "asddfg5", "abcdefg6", "123456786", "qwertyui6", "asddfg6", "abcdefg7", "123456787", "qwertyui7", "asddfg7", "abcdefg8", "123456788", "qwertyui8", "asddfg8", "abcdefg9", "123456789", "qwertyui9", "asddfg9", "abcdefgA", "12345678A", "qwertyuiA", "asddfgA", "abcdefgB", "12345678B", "qwertyuiB", "asddfgB", "abcdefgC", "12345678C", "qwertyuiC", "asddfgC") and c7 in ("abcdefgh", "123456789", "qwertyuio", "asddfgh", "abcdefg1", "123456781", "qwertyui1", "asddfg1", "abcdefg2", "123456782", "qwertyui2", "asddfg2", "abcdefg3", "123456783", "qwertyui3", "asddfg3", "abcdefg4", "123456784", "qwertyui4", "asddfg4", "abcdefg5", "123456785", "qwertyui5", "asddfg5", "abcdefg6", "123456786", "qwertyui6", "asddfg6", "abcdefg7", "123456787", "qwertyui7", "asddfg7", "abcdefg8", "123456788", "qwertyui8", "asddfg8", "abcdefg9", "123456789", "qwertyui9", "asddfg9", "abcdefgA", "12345678A", "qwertyuiA", "asddfgA", "abcdefgB", "12345678B", "qwertyuiB", "asddfgB", "abcdefgC", "12345678C", "qwertyuiC", "asddfgC") and c8 in ("abcdefgh", "123456789", "qwertyuio", "asddfgh", "abcdefg1", "123456781", "qwertyui1", "asddfg1", "abcdefg2", "123456782", "qwertyui2", "asddfg2", "abcdefg3", "123456783", "qwertyui3", "asddfg3", "abcdefg4", "123456784", "qwertyui4", "asddfg4", "abcdefg5", "123456785", "qwertyui5", "asddfg5", "abcdefg6", "123456786", "qwertyui6", "asddfg6", "abcdefg7", "123456787", "qwertyui7", "asddfg7", "abcdefg8", "123456788", "qwertyui8", "asddfg8", "abcdefg9", "123456789", "qwertyui9", "asddfg9", "abcdefgA", "12345678A", "qwertyuiA", "asddfgA", "abcdefgB", "12345678B", "qwertyuiB", "asddfgB", "abcdefgC", "12345678C", "qwertyuiC", "asddfgC") and c9 in ("abcdefgh", "123456789", "qwertyuio", "asddfgh", "abcdefg1", "123456781", "qwertyui1", "asddfg1", "abcdefg2", "123456782", "qwertyui2", "asddfg2", "abcdefg3", "123456783", "qwertyui3", "asddfg3", "abcdefg4", "123456784", "qwertyui4", "asddfg4", "abcdefg5", "123456785", "qwertyui5", "asddfg5", "abcdefg6", "123456786", "qwertyui6", "asddfg6", "abcdefg7", "123456787", "qwertyui7", "asddfg7", "abcdefg8", "123456788", "qwertyui8", "asddfg8", "abcdefg9", "123456789", "qwertyui9", "asddfg9", "abcdefgA", "12345678A", "qwertyuiA", "asddfgA", "abcdefgB", "12345678B", "qwertyuiB", "asddfgB", "abcdefgC", "12345678C", "qwertyuiC", "asddfgC") and c10 in ("abcdefgh", "123456789", "qwertyuio", "asddfgh", "abcdefg1", "123456781", "qwertyui1", "asddfg1", "abcdefg2", "123456782", "qwertyui2", "asddfg2", "abcdefg3", "123456783", "qwertyui3", "asddfg3", "abcdefg4", "123456784", "qwertyui4", "asddfg4", "abcdefg5", "123456785", "qwertyui5", "asddfg5", "abcdefg6", "123456786", "qwertyui6", "asddfg6", "abcdefg7", "123456787", "qwertyui7", "asddfg7", "abcdefg8", "123456788", "qwertyui8", "asddfg8", "abcdefg9", "123456789", "qwertyui9", "asddfg9", "abcdefgA", "12345678A", "qwertyuiA", "asddfgA", "abcdefgB", "12345678B", "qwertyuiB", "asddfgB", "abcdefgC", "12345678C", "qwertyuiC", "asddfgC"); c1 c2 c3 c4 c5 c6 c7 c8 c9 c10 c11 c12 c13 c14 c15 c16 drop table t1; End of 4.1 tests CREATE TABLE t1 ( id int(11) NOT NULL auto_increment, status varchar(20), PRIMARY KEY (id), KEY (status) ); INSERT INTO t1 VALUES (1,'B'), (2,'B'), (3,'B'), (4,'B'), (5,'B'), (6,'B'), (7,'B'), (8,'B'), (9,'B'), (10,'B'), (11,'B'), (12,'B'), (13,'B'), (14,'B'), (15,'B'), (16,'B'), (17,'B'), (18,'B'), (19,'B'), (20,'B'), (21,'B'), (22,'B'), (23,'B'), (24,'B'), (25,'A'), (26,'A'), (27,'A'), (28,'A'), (29,'A'), (30,'A'), (31,'A'), (32,'A'), (33,'A'), (34,'A'), (35,'A'), (36,'A'), (37,'A'), (38,'A'), (39,'A'), (40,'A'), (41,'A'), (42,'A'), (43,'A'), (44,'A'), (45,'A'), (46,'A'), (47,'A'), (48,'A'), (49,'A'), (50,'A'), (51,'A'), (52,'A'), (53,'C'), (54,'C'), (55,'C'), (56,'C'), (57,'C'), (58,'C'), (59,'C'), (60,'C'); INSERT INTO t1(status) SELECT status FROM t1; EXPLAIN SELECT * FROM t1 WHERE status <> 'A' AND status <> 'B'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range status status 23 NULL 18 Using index condition; Rowid-ordered scan EXPLAIN SELECT * FROM t1 WHERE status NOT IN ('A','B'); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range status status 23 NULL 18 Using index condition; Rowid-ordered scan SELECT * FROM t1 WHERE status <> 'A' AND status <> 'B'; id status 53 C 54 C 55 C 56 C 57 C 58 C 59 C 60 C 113 C 114 C 115 C 116 C 117 C 118 C 119 C 120 C SELECT * FROM t1 WHERE status NOT IN ('A','B'); id status 53 C 54 C 55 C 56 C 57 C 58 C 59 C 60 C 113 C 114 C 115 C 116 C 117 C 118 C 119 C 120 C EXPLAIN SELECT status FROM t1 WHERE status <> 'A' AND status <> 'B'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range status status 23 NULL 18 Using where; Using index EXPLAIN SELECT status FROM t1 WHERE status NOT IN ('A','B'); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range status status 23 NULL 18 Using where; Using index EXPLAIN SELECT * FROM t1 WHERE status NOT BETWEEN 'A' AND 'B'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range status status 23 NULL 17 Using index condition; Rowid-ordered scan EXPLAIN SELECT * FROM t1 WHERE status < 'A' OR status > 'B'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range status status 23 NULL 17 Using index condition; Rowid-ordered scan SELECT * FROM t1 WHERE status NOT BETWEEN 'A' AND 'B'; id status 53 C 54 C 55 C 56 C 57 C 58 C 59 C 60 C 113 C 114 C 115 C 116 C 117 C 118 C 119 C 120 C SELECT * FROM t1 WHERE status < 'A' OR status > 'B'; id status 53 C 54 C 55 C 56 C 57 C 58 C 59 C 60 C 113 C 114 C 115 C 116 C 117 C 118 C 119 C 120 C DROP TABLE t1; CREATE TABLE t1 (a int, b int, primary key(a,b)); INSERT INTO t1 VALUES (1,1),(1,2),(1,3),(2,1),(2,2),(2,3),(3,1),(3,2),(3,3),(4,1),(4,2),(4,3); CREATE VIEW v1 as SELECT a,b FROM t1 WHERE b=3; EXPLAIN SELECT a,b FROM t1 WHERE a < 2 and b=3; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range PRIMARY PRIMARY 4 NULL 3 Using where; Using index EXPLAIN SELECT a,b FROM v1 WHERE a < 2 and b=3; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range PRIMARY PRIMARY 4 NULL 3 Using where; Using index EXPLAIN SELECT a,b FROM t1 WHERE a < 2; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range PRIMARY PRIMARY 4 NULL 3 Using where; Using index EXPLAIN SELECT a,b FROM v1 WHERE a < 2; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range PRIMARY PRIMARY 4 NULL 3 Using where; Using index SELECT a,b FROM t1 WHERE a < 2 and b=3; a b 1 3 SELECT a,b FROM v1 WHERE a < 2 and b=3; a b 1 3 DROP VIEW v1; DROP TABLE t1; CREATE TABLE t1 (name varchar(15) NOT NULL, KEY idx(name)); INSERT INTO t1 VALUES ('Betty'), ('Anna'); SELECT * FROM t1; name Anna Betty DELETE FROM t1 WHERE name NOT LIKE 'A%a'; SELECT * FROM t1; name Anna DROP TABLE t1; CREATE TABLE t1 (a int, KEY idx(a)); INSERT INTO t1 VALUES (NULL), (1), (2), (3); SELECT * FROM t1; a NULL 1 2 3 DELETE FROM t1 WHERE NOT(a <=> 2); SELECT * FROM t1; a 2 DROP TABLE t1; create table t1 (a int, b int, primary key(a,b)); create view v1 as select a, b from t1; INSERT INTO `t1` VALUES (0,0),(1,0),(2,0),(3,0),(4,0),(5,1),(6,1),(7,1),(8,1),(9,1),(10,2),(11,2),(12,2) ,(13,2),(14,2),(15,3),(16,3),(17,3),(18,3),(19,3); explain select * from t1 where a in (3,4) and b in (1,2,3); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index PRIMARY PRIMARY 8 NULL # Using where; Using index explain select * from v1 where a in (3,4) and b in (1,2,3); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index PRIMARY PRIMARY 8 NULL # Using where; Using index explain select * from t1 where a between 3 and 4 and b between 1 and 2; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range PRIMARY PRIMARY 8 NULL # Using where; Using index explain select * from v1 where a between 3 and 4 and b between 1 and 2; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range PRIMARY PRIMARY 8 NULL # Using where; Using index drop view v1; drop table t1; create table t3 (a int); insert into t3 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9); create table t1 (a varchar(10), filler char(200), key(a)) charset=binary; insert into t1 values ('a',''); insert into t1 values ('a ',''); insert into t1 values ('a ', ''); insert into t1 select concat('a', 1000 + A.a + 10 * (B.a + 10 * C.a)), '' from t3 A, t3 B, t3 C; create table t2 (a varchar(10), filler char(200), key(a)); insert into t2 select * from t1; explain select * from t1 where a between 'a' and 'a '; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range a a 13 NULL # Using index condition; Rowid-ordered scan explain select * from t1 where a = 'a' or a='a '; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range a a 13 NULL # Using index condition; Rowid-ordered scan explain select * from t2 where a between 'a' and 'a '; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t2 ref a a 13 const # Using index condition explain select * from t2 where a = 'a' or a='a '; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t2 ref a a 13 const # Using index condition update t1 set a='b' where a<>'a'; explain select * from t1 where a not between 'b' and 'b'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range a a 13 NULL # Using index condition; Rowid-ordered scan select a, hex(filler) from t1 where a not between 'b' and 'b'; a hex(filler) a 0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 drop table t1,t2,t3; CREATE TABLE t1 ( id int NOT NULL DEFAULT '0', b int NOT NULL DEFAULT '0', c int NOT NULL DEFAULT '0', INDEX idx1(b,c), INDEX idx2(c)); INSERT INTO t1(id) VALUES (1), (2), (3), (4), (5), (6), (7), (8); INSERT INTO t1(b,c) VALUES (3,4), (3,4); SELECT * FROM t1 WHERE b<=3 AND 3<=c; id b c 0 3 4 0 3 4 SELECT * FROM t1 WHERE 3 BETWEEN b AND c; id b c 0 3 4 0 3 4 EXPLAIN SELECT * FROM t1 WHERE b<=3 AND 3<=c; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range idx1,idx2 idx2 4 NULL 2 Using index condition; Using where; Rowid-ordered scan EXPLAIN SELECT * FROM t1 WHERE 3 BETWEEN b AND c; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range idx1,idx2 idx2 4 NULL 2 Using where; Rowid-ordered scan SELECT * FROM t1 WHERE 0 < b OR 0 > c; id b c 0 3 4 0 3 4 SELECT * FROM t1 WHERE 0 NOT BETWEEN b AND c; id b c 0 3 4 0 3 4 EXPLAIN SELECT * FROM t1 WHERE 0 < b OR 0 > c; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index_merge idx1,idx2 idx1,idx2 4,4 NULL 3 Using sort_union(idx1,idx2); Using where EXPLAIN SELECT * FROM t1 WHERE 0 NOT BETWEEN b AND c; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index_merge idx1,idx2 idx1,idx2 4,4 NULL 3 Using sort_union(idx1,idx2); Using where DROP TABLE t1; CREATE TABLE t1 ( item char(20) NOT NULL default '', started datetime NOT NULL default '0000-00-00 00:00:00', price decimal(16,3) NOT NULL default '0.000', PRIMARY KEY (item,started) ) ENGINE=MyISAM; INSERT INTO t1 VALUES ('A1','2005-11-01 08:00:00',1000), ('A1','2005-11-15 00:00:00',2000), ('A1','2005-12-12 08:00:00',3000), ('A2','2005-12-01 08:00:00',1000); EXPLAIN SELECT * FROM t1 WHERE item='A1' AND started<='2005-12-01 24:00:00'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ref PRIMARY PRIMARY 20 const 3 Using index condition SELECT * FROM t1 WHERE item='A1' AND started<='2005-12-01 24:00:00'; item started price Warnings: Warning 1292 Truncated incorrect datetime value: '2005-12-01 24:00:00' SELECT * FROM t1 WHERE item='A1' AND started<='2005-12-02 00:00:00'; item started price A1 2005-11-01 08:00:00 1000.000 A1 2005-11-15 00:00:00 2000.000 DROP INDEX `PRIMARY` ON t1; EXPLAIN SELECT * FROM t1 WHERE item='A1' AND started<='2005-12-01 24:00:00'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 4 Using where SELECT * FROM t1 WHERE item='A1' AND started<='2005-12-01 24:00:00'; item started price Warnings: Warning 1292 Truncated incorrect datetime value: '2005-12-01 24:00:00' SELECT * FROM t1 WHERE item='A1' AND started<='2005-12-02 00:00:00'; item started price A1 2005-11-01 08:00:00 1000.000 A1 2005-11-15 00:00:00 2000.000 DROP TABLE t1; BUG#32198 "Comparison of DATE with DATETIME still not using indexes correctly" CREATE TABLE t1 ( id int(11) NOT NULL auto_increment, dateval date default NULL, PRIMARY KEY (id), KEY dateval (dateval) ) AUTO_INCREMENT=173; INSERT INTO t1 VALUES (1,'2007-01-01'),(2,'2007-01-02'),(3,'2007-01-03'),(4,'2007-01-04'), (5,'2007-01-05'),(6,'2007-01-06'),(7,'2007-01-07'),(8,'2007-01-08'), (9,'2007-01-09'),(10,'2007-01-10'),(11,'2007-01-11'); This must use range access: explain select * from t1 where dateval >= '2007-01-01 00:00:00' and dateval <= '2007-01-02 23:59:59'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range dateval dateval 4 NULL 2 Using index condition; Rowid-ordered scan drop table t1; CREATE TABLE t1 ( a varchar(32), index (a) ) DEFAULT CHARSET=latin1 COLLATE=latin1_bin; INSERT INTO t1 VALUES ('B'), ('A'), ('A'), ('C'), ('B'), ('A'), ('A'), ('C'), ('A'); SELECT a FROM t1 WHERE a='b' OR a='B'; a B B EXPLAIN SELECT a FROM t1 WHERE a='b' OR a='B'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range a a 35 NULL 3 Using where; Using index DROP TABLE t1; CREATE TABLE t1 (f1 TINYINT(11) UNSIGNED NOT NULL, PRIMARY KEY (f1)); INSERT INTO t1 VALUES (127),(254),(0),(1),(255); SELECT SQL_NO_CACHE COUNT(*) FROM t1 WHERE f1 < 256; COUNT(*) 5 SELECT SQL_NO_CACHE COUNT(*) FROM t1 WHERE f1 < 256.0; COUNT(*) 5 SELECT SQL_NO_CACHE COUNT(*) FROM t1 WHERE f1 < 255; COUNT(*) 4 SELECT SQL_NO_CACHE COUNT(*) FROM t1 WHERE f1 < -1; COUNT(*) 0 SELECT SQL_NO_CACHE COUNT(*) FROM t1 WHERE f1 > -1; COUNT(*) 5 DROP TABLE t1; CREATE TABLE t1 ( f1 TINYINT(11) NOT NULL, PRIMARY KEY (f1)); INSERT INTO t1 VALUES (127),(126),(0),(-128),(-127); SELECT SQL_NO_CACHE COUNT(*) FROM t1 WHERE f1 < 128; COUNT(*) 5 SELECT SQL_NO_CACHE COUNT(*) FROM t1 WHERE f1 < 128.0; COUNT(*) 5 SELECT SQL_NO_CACHE COUNT(*) FROM t1 WHERE f1 < 127; COUNT(*) 4 SELECT SQL_NO_CACHE COUNT(*) FROM t1 WHERE f1 > -129; COUNT(*) 5 SELECT SQL_NO_CACHE COUNT(*) FROM t1 WHERE f1 > -129.0; COUNT(*) 5 SELECT SQL_NO_CACHE COUNT(*) FROM t1 WHERE f1 > -128; COUNT(*) 4 DROP TABLE t1; 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, filler char(100)); insert into t2 select A.a + 10 * (B.a + 10 * C.a), 10, 'filler' from t1 A, t1 B, t1 C where A.a < 5; insert into t2 select 1000, b, 'filler' from t2; alter table t2 add index (a,b); select 'In following EXPLAIN the access method should be ref, #rows~=500 (and not 2)' Z; Z In following EXPLAIN the access method should be ref, #rows~=500 (and not 2) explain select * from t2 where a=1000 and b<11; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t2 ref a a 5 const 503 Using index condition drop table t1, t2; CREATE TABLE t1( a INT, b INT, KEY( a, b ) ); CREATE TABLE t2( a INT, b INT, KEY( a, b ) ); CREATE TABLE t3( a INT, b INT, KEY( a, b ) ); INSERT INTO t1( a, b ) VALUES (0, 1), (1, 2), (1, 4), (2, 3), (5, 0), (9, 7), (10, 11), (11,12), (11, 14), (12, 13), (15, 10), (19, 17), (20, 21), (21,22), (21, 24), (22, 23), (25, 20), (29, 27); INSERT INTO t2( a, b ) VALUES ( 1, 1), ( 2, 1), ( 3, 1), ( 4, 1), ( 5, 1), ( 6, 1), ( 7, 1), ( 8, 1), ( 9, 1), (10, 1), (11, 1), (12, 1), (13, 1), (14, 1), (15, 1), (16, 1), (17, 1), (18, 1), (19, 1), (20, 1); INSERT INTO t2 SELECT a, 2 FROM t2 WHERE b = 1; INSERT INTO t2 SELECT a, 3 FROM t2 WHERE b = 1; INSERT INTO t2 SELECT -1, -1 FROM t2; INSERT INTO t2 SELECT -1, -1 FROM t2; INSERT INTO t2 SELECT -1, -1 FROM t2; INSERT INTO t3 VALUES (1, 0), (2, 0), (3, 0), (4, 0), (5, 0), (6, 0), (7, 0), (8, 0), (9, 0), (10, 0), (11, 0), (12, 0), (13, 0), (14, 0), (15, 0), (16, 0), (17, 0), (18, 0), (19, 0), (20, 0); INSERT INTO t3 SELECT * FROM t3 WHERE a = 10; INSERT INTO t3 SELECT * FROM t3 WHERE a = 10; SELECT * FROM t1 WHERE 23 <= a AND a < 25 OR 25 < a AND b = 23 OR 23 <= a; a b 25 20 29 27 EXPLAIN SELECT * FROM t1 WHERE 23 <= a AND a < 25 OR 25 < a AND b = 23 OR 23 <= a; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range a a 5 NULL 2 Using where; Using index SELECT * FROM t1 WHERE 23 <= a AND a < 25 OR 25 <= a AND b = 23 OR 23 <= a; a b 25 20 29 27 EXPLAIN SELECT * FROM t1 WHERE 23 <= a AND a < 25 OR 25 <= a AND b = 23 OR 23 <= a; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range a a 5 NULL 3 Using where; Using index SELECT * FROM t1 WHERE 23 <= a AND a <= 25 OR 25 <= a AND b = 23 OR 23 <= a; a b 25 20 29 27 EXPLAIN SELECT * FROM t1 WHERE 23 <= a AND a <= 25 OR 25 <= a AND b = 23 OR 23 <= a; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range a a 5 NULL 2 Using where; Using index SELECT * FROM t1 WHERE 23 <= a AND a <= 25 OR 23 <= a; a b 25 20 29 27 EXPLAIN SELECT * FROM t1 WHERE 23 <= a AND a <= 25 OR 23 <= a; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range a a 5 NULL 2 Using where; Using index SELECT * FROM t2 WHERE 5 <= a AND a < 10 AND b = 1 OR 15 <= a AND a < 20 AND b = 3 OR 1 <= a AND b = 1; a b 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 1 10 1 11 1 12 1 13 1 14 1 15 1 15 3 16 1 16 3 17 1 17 3 18 1 18 3 19 1 19 3 20 1 EXPLAIN SELECT * FROM t2 WHERE 5 <= a AND a < 10 AND b = 1 OR 15 <= a AND a < 20 AND b = 3 OR 1 <= a AND b = 1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t2 range a a 10 NULL 49 Using where; Using index SELECT * FROM t2 WHERE 5 <= a AND a < 10 AND b = 2 OR 15 <= a AND a < 20 AND b = 3 OR 1 <= a AND b = 1; a b 1 1 2 1 3 1 4 1 5 1 5 2 6 1 6 2 7 1 7 2 8 1 8 2 9 1 9 2 10 1 11 1 12 1 13 1 14 1 15 1 15 3 16 1 16 3 17 1 17 3 18 1 18 3 19 1 19 3 20 1 EXPLAIN SELECT * FROM t2 WHERE 5 <= a AND a < 10 AND b = 2 OR 15 <= a AND a < 20 AND b = 3 OR 1 <= a AND b = 1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t2 range a a 10 NULL 49 Using where; Using index SELECT * FROM t3 WHERE 5 <= a AND a < 10 AND b = 3 OR a < 5 OR a < 10; a b 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 EXPLAIN SELECT * FROM t3 WHERE 5 <= a AND a < 10 AND b = 3 OR a < 5 OR a < 10; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t3 range a a 5 NULL 9 Using where; Using index DROP TABLE t1, t2, t3; # # Bug #47123: Endless 100% CPU loop with STRAIGHT_JOIN # CREATE TABLE t1(a INT, KEY(a)); INSERT INTO t1 VALUES (1), (NULL); SELECT * FROM t1 WHERE a <> NULL and (a <> NULL or a <= NULL); a DROP TABLE t1; # # Bug#47925: regression of range optimizer and date comparison in 5.1.39! # CREATE TABLE t1 ( a DATE, KEY ( a ) ); CREATE TABLE t2 ( a DATETIME, KEY ( a ) ); # Make optimizer choose range scan INSERT INTO t1 VALUES ('2009-09-22'), ('2009-09-22'), ('2009-09-22'); INSERT INTO t1 VALUES ('2009-09-23'), ('2009-09-23'), ('2009-09-23'); INSERT INTO t1 VALUES ('2009-09-20'), ('2009-09-20'), ('2009-09-20'); INSERT INTO t1 VALUES ('2009-09-21'), ('2009-09-21'), ('2009-09-21'); INSERT INTO t2 VALUES ('2009-09-22 12:00:00'), ('2009-09-22 12:00:00'), ('2009-09-22 12:00:00'); INSERT INTO t2 VALUES ('2009-09-23 12:00:00'), ('2009-09-23 12:00:00'), ('2009-09-23 12:00:00'); INSERT INTO t2 VALUES ('2009-09-20 12:00:00'), ('2009-09-20 12:00:00'), ('2009-09-20 12:00:00'); INSERT INTO t2 VALUES ('2009-09-21 12:00:00'), ('2009-09-21 12:00:00'), ('2009-09-21 12:00:00'); # DATE vs DATE EXPLAIN SELECT * FROM t1 WHERE a >= '2009/09/23'; id select_type table type possible_keys key key_len ref rows Extra X X X range a a X X X X SELECT * FROM t1 WHERE a >= '2009/09/23'; a 2009-09-23 2009-09-23 2009-09-23 SELECT * FROM t1 WHERE a >= '20090923'; a 2009-09-23 2009-09-23 2009-09-23 SELECT * FROM t1 WHERE a >= 20090923; a 2009-09-23 2009-09-23 2009-09-23 SELECT * FROM t1 WHERE a >= '2009-9-23'; a 2009-09-23 2009-09-23 2009-09-23 SELECT * FROM t1 WHERE a >= '2009.09.23'; a 2009-09-23 2009-09-23 2009-09-23 SELECT * FROM t1 WHERE a >= '2009:09:23'; a 2009-09-23 2009-09-23 2009-09-23 # DATE vs DATETIME EXPLAIN SELECT * FROM t2 WHERE a >= '2009/09/23'; id select_type table type possible_keys key key_len ref rows Extra X X X range a a X X X X SELECT * FROM t2 WHERE a >= '2009/09/23'; a 2009-09-23 12:00:00 2009-09-23 12:00:00 2009-09-23 12:00:00 SELECT * FROM t2 WHERE a >= '2009/09/23'; a 2009-09-23 12:00:00 2009-09-23 12:00:00 2009-09-23 12:00:00 SELECT * FROM t2 WHERE a >= '20090923'; a 2009-09-23 12:00:00 2009-09-23 12:00:00 2009-09-23 12:00:00 SELECT * FROM t2 WHERE a >= 20090923; a 2009-09-23 12:00:00 2009-09-23 12:00:00 2009-09-23 12:00:00 SELECT * FROM t2 WHERE a >= '2009-9-23'; a 2009-09-23 12:00:00 2009-09-23 12:00:00 2009-09-23 12:00:00 SELECT * FROM t2 WHERE a >= '2009.09.23'; a 2009-09-23 12:00:00 2009-09-23 12:00:00 2009-09-23 12:00:00 SELECT * FROM t2 WHERE a >= '2009:09:23'; a 2009-09-23 12:00:00 2009-09-23 12:00:00 2009-09-23 12:00:00 # DATETIME vs DATETIME EXPLAIN SELECT * FROM t2 WHERE a >= '2009/09/23 12:00:00'; id select_type table type possible_keys key key_len ref rows Extra X X X range a a X X X X SELECT * FROM t2 WHERE a >= '2009/09/23 12:00:00'; a 2009-09-23 12:00:00 2009-09-23 12:00:00 2009-09-23 12:00:00 SELECT * FROM t2 WHERE a >= '20090923120000'; a 2009-09-23 12:00:00 2009-09-23 12:00:00 2009-09-23 12:00:00 SELECT * FROM t2 WHERE a >= 20090923120000; a 2009-09-23 12:00:00 2009-09-23 12:00:00 2009-09-23 12:00:00 SELECT * FROM t2 WHERE a >= '2009-9-23 12:00:00'; a 2009-09-23 12:00:00 2009-09-23 12:00:00 2009-09-23 12:00:00 SELECT * FROM t2 WHERE a >= '2009.09.23 12:00:00'; a 2009-09-23 12:00:00 2009-09-23 12:00:00 2009-09-23 12:00:00 SELECT * FROM t2 WHERE a >= '2009:09:23 12:00:00'; a 2009-09-23 12:00:00 2009-09-23 12:00:00 2009-09-23 12:00:00 # DATETIME vs DATE EXPLAIN SELECT * FROM t1 WHERE a >= '2009/09/23 00:00:00'; id select_type table type possible_keys key key_len ref rows Extra X X X range a a X X X X SELECT * FROM t1 WHERE a >= '2009/09/23 00:00:00'; a 2009-09-23 2009-09-23 2009-09-23 SELECT * FROM t1 WHERE a >= '2009/09/23 00:00:00'; a 2009-09-23 2009-09-23 2009-09-23 SELECT * FROM t1 WHERE a >= '20090923000000'; a 2009-09-23 2009-09-23 2009-09-23 SELECT * FROM t1 WHERE a >= 20090923000000; a 2009-09-23 2009-09-23 2009-09-23 SELECT * FROM t1 WHERE a >= '2009-9-23 00:00:00'; a 2009-09-23 2009-09-23 2009-09-23 SELECT * FROM t1 WHERE a >= '2009.09.23 00:00:00'; a 2009-09-23 2009-09-23 2009-09-23 SELECT * FROM t1 WHERE a >= '2009:09:23 00:00:00'; a 2009-09-23 2009-09-23 2009-09-23 # Test of the new get_date_from_str implementation # Behavior differs slightly between the trunk and mysql-pe. # The former may give errors for the truncated values, while the latter # gives warnings. The purpose of this test is not to interfere, and only # preserve existing behavior. SELECT str_to_date('2007-10-00', '%Y-%m-%d') >= '' AND str_to_date('2007-10-00', '%Y-%m-%d') <= '2007/10/20'; str_to_date('2007-10-00', '%Y-%m-%d') >= '' AND str_to_date('2007-10-00', '%Y-%m-%d') <= '2007/10/20' 1 Warnings: Warning 1292 Truncated incorrect datetime value: '' SELECT str_to_date('2007-20-00', '%Y-%m-%d') >= '2007/10/20' AND str_to_date('2007-20-00', '%Y-%m-%d') <= ''; str_to_date('2007-20-00', '%Y-%m-%d') >= '2007/10/20' AND str_to_date('2007-20-00', '%Y-%m-%d') <= '' NULL Warnings: Warning 1411 Incorrect datetime value: '2007-20-00' for function str_to_date Warning 1411 Incorrect datetime value: '2007-20-00' for function str_to_date Warning 1411 Incorrect datetime value: '2007-20-00' for function str_to_date Warning 1411 Incorrect datetime value: '2007-20-00' for function str_to_date SELECT str_to_date('2007-10-00', '%Y-%m-%d') BETWEEN '' AND '2007/10/20'; str_to_date('2007-10-00', '%Y-%m-%d') BETWEEN '' AND '2007/10/20' 1 Warnings: Warning 1292 Truncated incorrect datetime value: '' SELECT str_to_date('2007-20-00', '%Y-%m-%d') BETWEEN '2007/10/20' AND ''; str_to_date('2007-20-00', '%Y-%m-%d') BETWEEN '2007/10/20' AND '' NULL Warnings: Warning 1411 Incorrect datetime value: '2007-20-00' for function str_to_date SELECT str_to_date('', '%Y-%m-%d'); str_to_date('', '%Y-%m-%d') 0000-00-00 DROP TABLE t1, t2; # # Bug#48459: valgrind errors with query using 'Range checked for each # record' # CREATE TABLE t1 ( a INT, b CHAR(2), c INT, d INT, KEY ( c ), KEY ( d, a, b ( 2 ) ), KEY ( b ( 1 ) ) ); INSERT INTO t1 VALUES ( NULL, 'a', 1, 2 ), ( NULL, 'a', 1, 2 ), ( 1, 'a', 1, 2 ), ( 1, 'a', 1, 2 ); CREATE TABLE t2 ( a INT, c INT, e INT, KEY ( e ) ); INSERT INTO t2 VALUES ( 1, 1, NULL ), ( 1, 1, NULL ); # Should not give Valgrind warnings SELECT 1 FROM t1, t2 WHERE t1.d <> '1' AND t1.b > '1' AND t1.a = t2.a AND t1.c = t2.c; 1 1 1 1 1 DROP TABLE t1, t2; # # Bug #48665: sql-bench's insert test fails due to wrong result # CREATE TABLE t1 (a INT, b INT, PRIMARY KEY (a)); INSERT INTO t1 VALUES (0,0), (1,1); EXPLAIN SELECT * FROM t1 FORCE INDEX (PRIMARY) WHERE (a>=1 AND a<=2) OR (a>=4 AND a<=5) OR (a>=0 AND a <=10); id select_type table type possible_keys key key_len ref rows Extra @ @ @ range @ @ @ @ @ @ # Should return 2 rows SELECT * FROM t1 FORCE INDEX (PRIMARY) WHERE (a>=1 AND a<=2) OR (a>=4 AND a<=5) OR (a>=0 AND a <=10); a b 0 0 1 1 DROP TABLE t1; # # Bug #54802: 'NOT BETWEEN' evaluation is incorrect # CREATE TABLE t1 (c_key INT, c_notkey INT, KEY(c_key)); INSERT INTO t1 VALUES (1, 1), (2, 2), (3, 3); EXPLAIN SELECT * FROM t1 WHERE 2 NOT BETWEEN c_notkey AND c_key; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL c_key NULL NULL NULL 3 Using where SELECT * FROM t1 WHERE 2 NOT BETWEEN c_notkey AND c_key; c_key c_notkey 1 1 3 3 DROP TABLE t1; # # Bug #57030: 'BETWEEN' evaluation is incorrect # CREATE TABLE t1(pk INT PRIMARY KEY, i4 INT); CREATE UNIQUE INDEX i4_uq ON t1(i4); INSERT INTO t1 VALUES (1,10), (2,20), (3,30), (4,40), (5,50), (6,60), (7,70), (8,80); EXPLAIN SELECT * FROM t1 WHERE i4 BETWEEN 10 AND 10; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 const i4_uq i4_uq 5 const 1 SELECT * FROM t1 WHERE i4 BETWEEN 10 AND 10; pk i4 1 10 EXPLAIN SELECT * FROM t1 WHERE 10 BETWEEN i4 AND i4; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 const i4_uq i4_uq 5 const 1 SELECT * FROM t1 WHERE 10 BETWEEN i4 AND i4; pk i4 1 10 EXPLAIN SELECT * FROM t1 WHERE 70 BETWEEN 70 AND i4; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range i4_uq i4_uq 5 NULL 2 Using index condition; Rowid-ordered scan SELECT * FROM t1 WHERE 70 BETWEEN 70 AND i4; pk i4 7 70 8 80 EXPLAIN SELECT * FROM t1 WHERE 10 BETWEEN i4 AND 10; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range i4_uq i4_uq 5 NULL 1 Using index condition; Rowid-ordered scan SELECT * FROM t1 WHERE 10 BETWEEN i4 AND 10; pk i4 1 10 EXPLAIN SELECT * FROM t1 WHERE 10 BETWEEN 10 AND 10; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 8 SELECT * FROM t1 WHERE 10 BETWEEN 10 AND 10; pk i4 1 10 2 20 3 30 4 40 5 50 6 60 7 70 8 80 EXPLAIN SELECT * FROM t1 WHERE 10 BETWEEN 11 AND 11; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible WHERE SELECT * FROM t1 WHERE 10 BETWEEN 11 AND 11; pk i4 EXPLAIN SELECT * FROM t1 WHERE 10 BETWEEN 100 AND 0; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible WHERE SELECT * FROM t1 WHERE 10 BETWEEN 100 AND 0; pk i4 EXPLAIN SELECT * FROM t1 WHERE i4 BETWEEN 100 AND 0; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables SELECT * FROM t1 WHERE i4 BETWEEN 100 AND 0; pk i4 EXPLAIN SELECT * FROM t1 WHERE i4 BETWEEN 70 AND 99999999999999999; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range i4_uq i4_uq 5 NULL 2 Using index condition; Rowid-ordered scan SELECT * FROM t1 WHERE i4 BETWEEN 70 AND 99999999999999999; pk i4 7 70 8 80 EXPLAIN SELECT * FROM t1 WHERE i4 BETWEEN 999999999999999 AND 30; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables SELECT * FROM t1 WHERE i4 BETWEEN 999999999999999 AND 30; pk i4 EXPLAIN SELECT * FROM t1 WHERE i4 BETWEEN 10 AND '20'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range i4_uq i4_uq 5 NULL 2 Using index condition; Rowid-ordered scan SELECT * FROM t1 WHERE i4 BETWEEN 10 AND '20'; pk i4 1 10 2 20 EXPLAIN SELECT * FROM t1, t1 as t2 WHERE t2.pk BETWEEN t1.i4 AND t1.i4; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL i4_uq NULL NULL NULL 8 1 SIMPLE t2 eq_ref PRIMARY PRIMARY 4 test.t1.i4 1 Using index condition SELECT * FROM t1, t1 as t2 WHERE t2.pk BETWEEN t1.i4 AND t1.i4; pk i4 pk i4 EXPLAIN SELECT * FROM t1, t1 as t2 WHERE t1.i4 BETWEEN t2.pk AND t2.pk; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL i4_uq NULL NULL NULL 8 1 SIMPLE t2 eq_ref PRIMARY PRIMARY 4 test.t1.i4 1 Using index condition SELECT * FROM t1, t1 as t2 WHERE t1.i4 BETWEEN t2.pk AND t2.pk; pk i4 pk i4 DROP TABLE t1; # # BUG#13519696 - 62940: SELECT RESULTS VARY WITH VERSION AND # WITH/WITHOUT INDEX RANGE SCAN # create table t1 (id int unsigned not null auto_increment primary key); insert into t1 values (null); insert into t1 select null from t1; insert into t1 select null from t1; insert into t1 select null from t1; insert into t1 select null from t1; insert into t1 select null from t1; insert into t1 select null from t1; insert into t1 select null from t1; insert into t1 select null from t1; create table t2 ( id int unsigned not null auto_increment, val decimal(5,3) not null, primary key (id,val), unique key (val,id), unique key (id)); insert into t2 select null,id*0.0009 from t1; select count(val) from t2 ignore index (val) where val > 0.1155; count(val) 128 select count(val) from t2 force index (val) where val > 0.1155; count(val) 128 drop table t2, t1; # # BUG#13453382 - REGRESSION SINCE 5.1.39, RANGE OPTIMIZER WRONG # RESULTS WITH DECIMAL CONVERSION # create table t1 (a int,b int,c int,primary key (a,c)); insert into t1 values (1,1,2),(1,1,3),(1,1,4); select convert(3, signed integer) > 2.9; convert(3, signed integer) > 2.9 1 select * from t1 force index (primary) where a=1 and c>= 2.9; a b c 1 1 3 1 1 4 select * from t1 ignore index (primary) where a=1 and c>= 2.9; a b c 1 1 3 1 1 4 select * from t1 force index (primary) where a=1 and c> 2.9; a b c 1 1 3 1 1 4 select * from t1 ignore index (primary) where a=1 and c> 2.9; a b c 1 1 3 1 1 4 drop table t1; # # BUG#13463488 - 63437: CHAR & BETWEEN WITH INDEX RETURNS WRONG # RESULT AFTER MYSQL 5.1. # CREATE TABLE t1( F1 CHAR(5) NOT NULL, F2 CHAR(5) NOT NULL, F3 CHAR(5) NOT NULL, PRIMARY KEY(F1), INDEX IDX_F2(F2) ); INSERT INTO t1 VALUES ('A','A','A'),('AA','AA','AA'),('AAA','AAA','AAA'), ('AAAA','AAAA','AAAA'),('AAAAA','AAAAA','AAAAA'); SELECT * FROM t1 WHERE F1 = 'A '; F1 F2 F3 A A A SELECT * FROM t1 IGNORE INDEX(PRIMARY) WHERE F1 = 'A '; F1 F2 F3 A A A SELECT * FROM t1 WHERE F1 >= 'A '; F1 F2 F3 A A A AA AA AA AAA AAA AAA AAAA AAAA AAAA AAAAA AAAAA AAAAA SELECT * FROM t1 WHERE F1 > 'A '; F1 F2 F3 AA AA AA AAA AAA AAA AAAA AAAA AAAA AAAAA AAAAA AAAAA SELECT * FROM t1 WHERE F1 BETWEEN 'A ' AND 'AAAAA'; F1 F2 F3 A A A AA AA AA AAA AAA AAA AAAA AAAA AAAA AAAAA AAAAA AAAAA SELECT * FROM t1 WHERE F2 BETWEEN 'A ' AND 'AAAAA'; F1 F2 F3 A A A AA AA AA AAA AAA AAA AAAA AAAA AAAA AAAAA AAAAA AAAAA SELECT * FROM t1 WHERE F3 BETWEEN 'A ' AND 'AAAAA'; F1 F2 F3 A A A AA AA AA AAA AAA AAA AAAA AAAA AAAA AAAAA AAAAA AAAAA SELECT * FROM t1 IGNORE INDEX(PRIMARY) WHERE F1 BETWEEN 'A ' AND 'AAAAA'; F1 F2 F3 A A A AA AA AA AAA AAA AAA AAAA AAAA AAAA AAAAA AAAAA AAAAA DROP TABLE t1; # # mdev-4894: Poor performance with unnecessary # (bug#70021) 'Range checked for each record' # create table t1( key1 int not null, INDEX i1(key1) ); insert into t1 values (1),(2),(3),(4),(5),(6),(7),(8); insert into t1 select key1+8 from t1; insert into t1 select key1+16 from t1; insert into t1 select key1+32 from t1; insert into t1 select key1+64 from t1; insert into t1 select key1+128 from t1; insert into t1 select key1+256 from t1; insert into t1 select key1+512 from t1; alter table t1 add key2 int not null, add index i2(key2); update t1 set key2=key1; analyze table t1; Table Op Msg_type Msg_text test.t1 analyze status Engine-independent statistics collected test.t1 analyze status OK create table t2 (a int); insert into t2 values (1),(2),(3),(4),(5),(6),(7),(8); insert into t2 select a+16 from t2; insert into t2 select a+32 from t2; insert into t2 select a+64 from t2; explain select count(*) from t2 left join t1 on (t1.key1 < 3 or t1.key1 between 920 and 930) and t1.key2 < 1000; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t2 ALL NULL NULL NULL NULL 64 1 SIMPLE t1 range i1,i2 i1 4 NULL 12 Using where; Rowid-ordered scan; Using join buffer (flat, BNL join) select count(*) from t2 left join t1 on (t1.key1 < 3 or t1.key1 between 920 and 930) and t1.key2 < 1000; count(*) 832 explain select count(*) from t2 left join t1 on (t1.key1 < 3 or t1.key1 between 920 and 930) and t1.key2 < t2.a; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t2 ALL NULL NULL NULL NULL 64 1 SIMPLE t1 range i1,i2 i1 4 NULL 12 Using where; Rowid-ordered scan; Using join buffer (flat, BNL join) select count(*) from t2 left join t1 on (t1.key1 < 3 or t1.key1 between 920 and 930) and t1.key2 < t2.a; count(*) 126 drop table t1,t2; End of 5.1 tests # # LP Bug #533117: Wrong use_count in SEL_ARG trees # (Bug #58731) # create table t1 (a int, b int, c int, key idx (a,b,c)); insert into t1 values (0,0,0), (2,2,0), (1,1,1), (2,2,1); explain select * from t1 force index (idx) where a >=1 and c <= 1 and a=b and b > 1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index idx idx 15 NULL 4 Using where; Using index select * from t1 force index (idx) where a >=1 and c <= 1 and a=b and b > 1; a b c 2 2 0 2 2 1 drop table t1; create table t1 (f1 datetime, key (f1)); insert into t1 values ('2000-03-09 15:56:59'),('2000-05-05 23:24:28'),('2000-06-13 13:12:06'); select min(f1) from t1 where f1 >= '2006-05-25 07:00:20' and f1 between '2003-11-23 10:00:09' and '2010-01-01 01:01:01' and f1 > '2001-01-01 01:01:01'; min(f1) NULL drop table t1; # # BUG#11765831: 'RANGE ACCESS' MAY INCORRECTLY FILTER # AWAY QUALIFYING ROWS # CREATE TABLE t10( K INT NOT NULL AUTO_INCREMENT, I INT, J INT, PRIMARY KEY(K), KEY(I,J) ); INSERT INTO t10(I,J) VALUES (6,1),(6,2),(6,3),(6,4),(6,5), (6,6),(6,7),(6,8),(6,9),(6,0); CREATE TABLE t100 LIKE t10; INSERT INTO t100(I,J) SELECT X.I, X.K+(10*Y.K) FROM t10 AS X,t10 AS Y; INSERT INTO t100(I,J) VALUES(8,26); EXPLAIN SELECT * FROM t100 WHERE I <> 6 OR (I <> 8 AND J = 5); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t100 range I I 10 NULL 3 Using index condition; Rowid-ordered scan SELECT * FROM t100 WHERE I <> 6 OR (I <> 8 AND J = 5); K I J 101 8 26 DROP TABLE t10,t100; # # lp:817363: Wrong result with sort_union and multipart key in maria-5.3 # CREATE TABLE t1 (a int NOT NULL , b int, c int, d varchar(32), KEY (d,b), PRIMARY KEY (a)) ; INSERT INTO t1 VALUES (7,7,NULL,'e'),(8,1,0,'p'),(9,7,1,'s'),(10,1,1,'j'),(12,2,0,'c'),(13,0,0,'a'),(14,1,1,'q'); SELECT c FROM t1 WHERE d='q' OR d>='q' OR a > 97 OR (d IN ('j','s','i') AND b = 102); c 1 1 SELECT c FROM t1 ignore index (d) WHERE d='q' OR d>='q' OR a > 97 OR (d IN ('j','s','i') AND b = 102); c 1 1 SELECT * FROM t1 ignore index(d) WHERE d = 'q' OR d >= 'q' OR (d IN ( 'j' , 's' , 'i' ) AND ( b = 102 )); a b c d 9 7 1 s 14 1 1 q SELECT * FROM t1 force index(d) WHERE d = 'q' OR d >= 'q' OR (d IN ( 'j' , 's' , 'i' ) AND ( b = 102 )); a b c d 9 7 1 s 14 1 1 q DROP TABLE t1; # # BUG#13256446 - ASSERTION QUICK->HEAD->READ_SET == # SAVE_READ_SET' FAILED IN OPT_RANGE.CC:1606 # CREATE TABLE t1 ( f1 INT AUTO_INCREMENT, f2 INT, f3 INT, f4 INT, PRIMARY KEY (f1),KEY(f2) ) ENGINE=INNODB; CREATE ALGORITHM=MERGE VIEW v2 AS SELECT f1,f2,f3,f4 FROM t1 WHERE f2=103; INSERT INTO t1 VALUES (154,0,NULL,0),(0,NULL,9,0), (NULL,102,NULL,3),(0,3,NULL,0), (9,0,NULL,0),(0,9,NULL,157); SELECT * FROM v2; f1 f2 f3 f4 UPDATE v2 SET f4=0, f2=NULL, f1=NULL WHERE f1 > 16 ORDER BY f1; SELECT * FROM v2; f1 f2 f3 f4 DROP TABLE t1; DROP VIEW v2; CREATE TABLE t1 ( f1 INT AUTO_INCREMENT, f2 INT, f3 INT, f4 INT, PRIMARY KEY (f1),KEY(f2) ) ENGINE=INNODB; INSERT INTO t1 VALUES(1,NULL,NULL,0), (2,2,0,3), (9,0,107,18), (10,0,0,0), (231,0,0,0), (232,0,8,0), (234,0,0,NULL), (235,8,0,3); CREATE ALGORITHM=MERGE VIEW v3 AS SELECT f1,f2,f3,f4 FROM t1 WHERE f1<=85 ; SELECT * FROM v3; f1 f2 f3 f4 1 NULL NULL 0 2 2 0 3 9 0 107 18 10 0 0 0 UPDATE v3 SET f3=0, f4=4 WHERE f2=68 ORDER BY f1; SELECT * FROM v3; f1 f2 f3 f4 1 NULL NULL 0 2 2 0 3 9 0 107 18 10 0 0 0 DROP TABLE t1; DROP VIEW v3; # # MDEV-6105: Emoji unicode character string search query makes mariadb performance down # SET NAMES utf8; DROP TABLE IF EXISTS t1; Warnings: Note 1051 Unknown table 'test.t1' CREATE TABLE t1( id int AUTO_INCREMENT, fd varchar(20), primary key(id), index ix_fd(fd) )engine=innodb default charset=UTF8; INSERT INTO t1(id, fd) VALUES (null, ''),(null, 'matt'),(null, 'pitt'),(null, 'lee'),(null, 'kim'); INSERT INTO t1 (fd) SELECT fd FROM t1; INSERT INTO t1 (fd) SELECT fd FROM t1; INSERT INTO t1 (fd) SELECT fd FROM t1; INSERT INTO t1 (fd) SELECT fd FROM t1; INSERT INTO t1 (fd) SELECT fd FROM t1; INSERT INTO t1 (fd) SELECT fd FROM t1; INSERT INTO t1 (fd) SELECT fd FROM t1; INSERT INTO t1 (fd) SELECT fd FROM t1; INSERT INTO t1 (fd) SELECT fd FROM t1; INSERT INTO t1 (fd) SELECT fd FROM t1; INSERT INTO t1 (fd) SELECT fd FROM t1; INSERT INTO t1 (fd) SELECT fd FROM t1; INSERT INTO t1 (fd) SELECT fd FROM t1; # The following should show "Impossible WHERE" : explain SELECT * FROM t1 WHERE fd='😁'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables Warnings: Warning 1366 Incorrect string value: '\xF0\x9F\x98\x81' for column `test`.`t1`.`fd` at row 1 SELECT * FROM t1 WHERE fd='😁'; id fd Warnings: Warning 1366 Incorrect string value: '\xF0\x9F\x98\x81' for column `test`.`t1`.`fd` at row 1 # The following must not use range access: explain select count(*) from t1 where fd <'😁'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index ix_fd ix_fd 63 NULL # Using where; Using index Warnings: Warning 1366 Incorrect string value: '\xF0\x9F\x98\x81' for column `test`.`t1`.`fd` at row 1 select count(*) from t1 where fd <'😁'; count(*) 40960 Warnings: Warning 1366 Incorrect string value: '\xF0\x9F\x98\x81' for column `test`.`t1`.`fd` at row 1 select count(*) from t1 ignore index (ix_fd) where fd <'😁'; count(*) 40960 drop table t1; set names default; create table t2 (a int, b int, c int, d int, key x(a, b)); insert into t2 values (2, 2, 2, 2), (3, 3, 3, 3), (4, 4, 4, 4), (5, 5, 5, 5), (6, 6, 6, 6), (7, 7, 7, 7), (8, 8, 8, 8), (9, 9, 9, 9); insert into t2 select * from t2; insert into t2 values (0, 0, 0, 0), (1, 1, 1, 1); analyze table t2; Table Op Msg_type Msg_text test.t2 analyze status Engine-independent statistics collected test.t2 analyze status OK select a, b from t2 where (a, b) in ((0, 0), (1, 1)); a b 0 0 1 1 drop table t2; # # MDEV-10228: Delete missing rows with OR conditions # (The example uses UPDATE, because UPDATE allows to use index hints # and so it's possible to make an example that works with any storage # engine) # CREATE TABLE t1 ( key1varchar varchar(14) NOT NULL, key2int int(11) NOT NULL DEFAULT '0', col1 int, PRIMARY KEY (key1varchar,key2int), KEY key1varchar (key1varchar), KEY key2int (key2int) ) DEFAULT CHARSET=utf8; insert into t1 values ('value1',0, 0), ('value1',1, 0), ('value1',1000685, 0), ('value1',1003560, 0), ('value1',1004807, 0); update t1 force index (PRIMARY) set col1=12345 where (key1varchar='value1' AND (key2int <=1 OR key2int > 1)); # The following must show col1=12345 for all rows: select * from t1; key1varchar key2int col1 value1 0 12345 value1 1 12345 value1 1000685 12345 value1 1003560 12345 value1 1004807 12345 drop table t1; # # BUG#13731380: RANGE OPTIMIZER CALLS RECORDS_IN_RANGE() FOR OPEN RANGE # CREATE TABLE t1 (pk INT PRIMARY KEY); INSERT INTO t1 VALUES (1),(3),(5); SELECT * FROM t1 WHERE pk <> 3 OR pk < 4; pk 1 3 5 DROP TABLE t1; # # BUG#13803810: TOO FEW ROWS RETURNED FOR RANGE ACCESS IN # VARCHAR INDEX USING DATETIME VALUE CREATE TABLE t1 (a DATETIME); INSERT INTO t1 VALUES ('2001-01-01 00:00:00'); INSERT INTO t1 VALUES ('2001-01-01 11:22:33'); CREATE TABLE t2 (b VARCHAR(64), KEY (b)); INSERT INTO t2 VALUES ('2001-01-01'); INSERT INTO t2 VALUES ('2001.01.01'); INSERT INTO t2 VALUES ('2001#01#01'); INSERT INTO t2 VALUES ('2001-01-01 00:00:00'); INSERT INTO t2 VALUES ('2001-01-01 11:22:33'); # range/ref access cannot be used for this query EXPLAIN SELECT * FROM t2 WHERE b=CAST('2001-01-01' AS DATE); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t2 index b b 67 NULL 5 Using where; Using index SELECT * FROM t2 WHERE b=CAST('2001-01-01' AS DATE); b 2001#01#01 2001-01-01 2001-01-01 00:00:00 2001.01.01 # range/ref access cannot be used for any of the queries below. # See BUG#13814468 about 'Range checked for each record' EXPLAIN SELECT * FROM t1, t2 WHERE a=b ORDER BY BINARY a, BINARY b; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 2 Using temporary; Using filesort 1 SIMPLE t2 ALL b NULL NULL NULL 5 Range checked for each record (index map: 0x1) SELECT * FROM t1, t2 WHERE a=b ORDER BY BINARY a, BINARY b; a b 2001-01-01 00:00:00 2001#01#01 2001-01-01 00:00:00 2001-01-01 2001-01-01 00:00:00 2001-01-01 00:00:00 2001-01-01 00:00:00 2001.01.01 2001-01-01 11:22:33 2001-01-01 11:22:33 EXPLAIN SELECT * FROM t1, t2 WHERE b=a ORDER BY BINARY a, BINARY b; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 2 Using temporary; Using filesort 1 SIMPLE t2 ALL b NULL NULL NULL 5 Range checked for each record (index map: 0x1) SELECT * FROM t1, t2 WHERE b=a ORDER BY BINARY a, BINARY b; a b 2001-01-01 00:00:00 2001#01#01 2001-01-01 00:00:00 2001-01-01 2001-01-01 00:00:00 2001-01-01 00:00:00 2001-01-01 00:00:00 2001.01.01 2001-01-01 11:22:33 2001-01-01 11:22:33 DROP TABLE t1,t2; # # MDEV-5606: range optimizer: "x < y" is sargable, while "y > x" is not # create table t1(a int); insert into t1 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9); create table t2(a int); insert into t2 select A.a + B.a* 10 + C.a * 100 from t1 A, t1 B, t1 C; alter table t2 add key(a); # Should have "range checked for each table" for second table: explain select * from t1, t2 where t2.a < t1.a; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 10 1 SIMPLE t2 ALL a NULL NULL NULL 1000 Range checked for each record (index map: 0x1) # Should have "range checked for each table" for second table: explain select * from t1, t2 where t1.a > t2.a; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 10 1 SIMPLE t2 ALL a NULL NULL NULL 1000 Range checked for each record (index map: 0x1) create table t3 (a int primary key, b int); insert into t3 select a,a from t1; # The second table should use 'range': explain select * from t3, t2 where t2.a < t3.b and t3.a=1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t3 const PRIMARY PRIMARY 4 const 1 1 SIMPLE t2 range a a 5 NULL 1 Using where; Using index # The second table should use 'range': explain select * from t3, t2 where t3.b > t2.a and t3.a=1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t3 const PRIMARY PRIMARY 4 const 1 1 SIMPLE t2 range a a 5 NULL 1 Using where; Using index drop table t1,t2,t3; # # MDEV-6480: Remove conditions for which range optimizer returned SEL_ARG::IMPOSSIBLE. # 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, c int, key(a), key(b)); insert into t2 select A.a + B.a* 10 + C.a * 100, A.a + B.a* 10 + C.a * 100, 12345 from t1 A, t1 B, t1 C; # EXPLAIN EXTENDED should show that 'b > 25 and b < 15' is removed from the WHERE: explain extended select * from t2 where (b > 25 and b < 15) or a<44; id select_type table type possible_keys key key_len ref rows filtered Extra 1 SIMPLE t2 range a,b a 5 NULL 43 100.00 Using index condition; Rowid-ordered scan Warnings: Note 1003 select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t2`.`c` AS `c` from `test`.`t2` where `test`.`t2`.`a` < 44 # EXPLAIN EXTENDED should show that 'b > 25 and b < 15' is removed from the WHERE: explain extended select * from t2 where a < 44 or (b > 25 and b < 15); id select_type table type possible_keys key key_len ref rows filtered Extra 1 SIMPLE t2 range a,b a 5 NULL 43 100.00 Using index condition; Rowid-ordered scan Warnings: Note 1003 select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t2`.`c` AS `c` from `test`.`t2` where `test`.`t2`.`a` < 44 # Here, conditions b will not be removed, because "c<44" is not sargable # and hence (b.. and .. b) part is not analyzed at all: explain extended select * from t2 where c < 44 or (b > 25 and b < 15); id select_type table type possible_keys key key_len ref rows filtered Extra 1 SIMPLE t2 ALL b NULL NULL NULL 1000 100.00 Using where Warnings: Note 1003 select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t2`.`c` AS `c` from `test`.`t2` where `test`.`t2`.`c` < 44 or `test`.`t2`.`b` > 25 and `test`.`t2`.`b` < 15 # EXPLAIN EXTENDED should show that 'b > 25 and b < 15' is removed from the WHERE: explain extended select * from t2 where (b > 25 and b < 15) or c < 44; id select_type table type possible_keys key key_len ref rows filtered Extra 1 SIMPLE t2 ALL b NULL NULL NULL 1000 100.00 Using where Warnings: Note 1003 select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t2`.`c` AS `c` from `test`.`t2` where `test`.`t2`.`c` < 44 # Try a case where both OR parts produce SEL_ARG::IMPOSSIBLE: explain extended select * from t2 where (b > 25 and b < 15) or (a>55 and a<44); id select_type table type possible_keys key key_len ref rows filtered Extra 1 SIMPLE NULL NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables Warnings: Note 1003 select 44 AS `a`,15 AS `b`,NULL AS `c` from `test`.`t2` where 0 drop table t1,t2; # # Start of 10.1 tests # # # MDEV-8189 field<>const and const<>field are not symmetric # CREATE TABLE t1 (a INT, b INT, KEY(a)); INSERT INTO t1 (a) VALUES (10),(10),(10),(10),(10),(10),(10),(10),(10),(10),(70); EXPLAIN SELECT * FROM t1 WHERE a<>10; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range a a 5 NULL 2 Using index condition; Rowid-ordered scan EXPLAIN SELECT * FROM t1 WHERE 10<>a; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range a a 5 NULL 2 Using index condition; Rowid-ordered scan SELECT * FROM t1 WHERE a<>10; a b 70 NULL SELECT * FROM t1 WHERE 10<>a; a b 70 NULL DROP TABLE t1; # # MDEV-8613 Full table scan for WHERE indexed_varchar_column <=> 'bad-character' # SET NAMES utf8; CREATE TABLE t1 (a VARCHAR(10) CHARACTER SET utf8, KEY(a)) ENGINE=MyISAM; INSERT INTO t1 VALUES ('a'),('b'),('c'),('d'),('e'); EXPLAIN SELECT * FROM t1 WHERE a<=>'😎'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables Warnings: Warning 1366 Incorrect string value: '\xF0\x9F\x98\x8E' for column `test`.`t1`.`a` at row 1 DROP TABLE t1; # # MDEV-10185: Assertion `tree1->keys[key_no] && tree2->keys[key_no]' failed in # sel_trees_can_be_ored(RANGE_OPT_PARAM*, SEL_TREE*, SEL_TREE*, key_map*) # CREATE TABLE t1 (pk INT PRIMARY KEY); INSERT INTO t1 VALUES (1),(2); SELECT * FROM t1 WHERE pk != 1000 OR pk IN ( 1000, 0, 1, 100, 2 ) OR pk >= 5; pk 1 2 DROP TABLE t1; # # End of 10.1 tests # # # MDEV-10454: range access keys extracted # from IN () # create table t1(a int, b int, c varchar(16), key idx(a,b)) engine=myisam; insert into t1 values (1,1,'xx'), (2,2,'yyy'), (3,3,'zzzz'), (1,2,'zz'), (1,3,'x'), (2,3,'yy'), (4,5,'ww'), (7,8,'xxxxx'), (4,3,'zyx'), (1,2,'uuu'), (2,1,'w'), (5,5,'wx'), (2,3,'ww'), (7,7,'xxxyy'), (3,3,'zyxw'), (3,2,'uuuw'), (2,2,'wxz'), (5,5,'xw'), (12,12,'xx'), (12,12,'y'), (13,13,'z'), (11,12,'zz'), (11,13,'x'), (12,13,'y'), (14,15,'w'), (17,18,'xx'), (14,13,'zx'), (11,12,'u'), (12,11,'w'), (5,5,'wx'), (12,13,'ww'), (17,17,'xxxyy'), (13,13,'zyxw'), (13,12,'uuuw'), (12,12,'wxz'), (15,15,'xw'), (1,1,'xa'), (2,2,'yya'), (3,3,'zzza'), (1,2,'za'), (1,3,'xb'), (2,3,'ya'), (4,5,'wa'), (7,8,'xxxxa'), (4,3,'zya'), (1,2,'uua'), (2,1,'wb'), (5,5,'wc'), (2,3,'wa'), (7,7,'xxxya'), (3,3,'zyxa'), (3,2,'uuua'), (2,2,'wxa'), (5,5,'xa'), (12,12,'xa'), (22,12,'yb'), (23,13,'zb'), (21,12,'za'), (24,13,'c'), (32,13,'d'), (34,15,'wd'), (47,18,'xa'), (54,13,'za'), (51,12,'ub'), (52,11,'wc'), (5,5,'wd'), (62,13,'wa'), (67,17,'xxxya'), (63,13,'zyxa'), (73,12,'uuua'), (82,12,'wxa'), (85,15,'xd'); # range access to t1 by 2-component keys for index idx explain select * from t1 where (a,b) IN ((2, 3),(3,3),(8,8),(7,7)); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range idx idx 10 NULL 6 Using where; Rowid-ordered scan explain format=json select * from t1 where (a,b) IN ((2, 3),(3,3),(8,8),(7,7)); EXPLAIN { "query_block": { "select_id": 1, "table": { "table_name": "t1", "access_type": "range", "possible_keys": ["idx"], "key": "idx", "key_length": "10", "used_key_parts": ["a", "b"], "rows": 6, "filtered": 100, "attached_condition": "(t1.a,t1.b) in (((2,3)),((3,3)),((8,8)),((7,7)))", "mrr_type": "Rowid-ordered scan" } } } select * from t1 where (a,b) IN ((2, 3),(3,3),(8,8),(7,7)); a b c 3 3 zzzz 2 3 yy 2 3 ww 7 7 xxxyy 3 3 zyxw 3 3 zzza 2 3 ya 2 3 wa 7 7 xxxya 3 3 zyxa prepare stmt from "select * from t1 where (a,b) IN ((2, 3),(3,3),(8,8),(7,7))"; execute stmt; a b c 3 3 zzzz 2 3 yy 2 3 ww 7 7 xxxyy 3 3 zyxw 3 3 zzza 2 3 ya 2 3 wa 7 7 xxxya 3 3 zyxa execute stmt; a b c 3 3 zzzz 2 3 yy 2 3 ww 7 7 xxxyy 3 3 zyxw 3 3 zzza 2 3 ya 2 3 wa 7 7 xxxya 3 3 zyxa deallocate prepare stmt; # range access to t1 by 1-component keys for index idx explain select * from t1 where (a,b+a) IN ((4,9),(8,8),(7,7)); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range idx idx 5 NULL 5 Using where; Rowid-ordered scan explain format=json select * from t1 where (a,b+a) IN ((4,9),(8,8),(7,7)); EXPLAIN { "query_block": { "select_id": 1, "table": { "table_name": "t1", "access_type": "range", "possible_keys": ["idx"], "key": "idx", "key_length": "5", "used_key_parts": ["a"], "rows": 5, "filtered": 100, "attached_condition": "(t1.a,t1.b + t1.a) in (((4,9)),((8,8)),((7,7)))", "mrr_type": "Rowid-ordered scan" } } } select * from t1 where (a,b+a) IN ((4,9),(8,8),(7,7)); a b c 4 5 ww 4 5 wa # range access to t1 by 1-component keys for index idx explain select * from t1 where (a,b) IN ((4,a-1),(8,a+8),(7,a+7)); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range idx idx 5 NULL 5 Using where; Rowid-ordered scan explain format=json select * from t1 where (a,b) IN ((4,a-1),(8,a+8),(7,a+7)); EXPLAIN { "query_block": { "select_id": 1, "table": { "table_name": "t1", "access_type": "range", "possible_keys": ["idx"], "key": "idx", "key_length": "5", "used_key_parts": ["a"], "rows": 5, "filtered": 100, "attached_condition": "(t1.a,t1.b) in ((4,t1.a - 1),(8,t1.a + 8),(7,t1.a + 7))", "mrr_type": "Rowid-ordered scan" } } } select * from t1 where (a,b) IN ((4,a-1),(8,a+8),(7,a+7)); a b c 4 3 zyx 4 3 zya set @save_optimizer_switch=@@optimizer_switch; set optimizer_switch='index_merge=off'; create table t2( d int, e int, key idx1(d), key idx2(e), f varchar(32) ) engine=myisam; insert into t2 values (9,5,'a'), (9,8,'b'), (9,3,'c'), (9,2,'d'), (9,1,'e'), (6,5,'f'), (6,3,'g'), (6,7,'h'), (3,3,'i'), (6,2,'j'), (9,5,'aa'), (9,8,'ba'), (9,3,'ca'), (2,2,'da'), (9,1,'ea'), (6,5,'fa'), (6,3,'ga'), (6,7,'ha'), (9,3,'ia'), (6,2,'ja'); # join order: (t2,t1) with ref access of t1 # range access to t1 by keys for index idx1 explain select * from t1,t2 where a = d and (a,e) in ((3,3),(7,7),(2,2)); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t2 range idx1,idx2 idx1 5 NULL 3 Using index condition; Using where; Rowid-ordered scan 1 SIMPLE t1 ref idx idx 5 test.t2.d 8 explain format=json select * from t1,t2 where a = d and (a,e) in ((3,3),(7,7),(2,2)); EXPLAIN { "query_block": { "select_id": 1, "table": { "table_name": "t2", "access_type": "range", "possible_keys": ["idx1", "idx2"], "key": "idx1", "key_length": "5", "used_key_parts": ["d"], "rows": 3, "filtered": 60, "index_condition": "t2.d is not null", "attached_condition": "(t2.d,t2.e) in (((3,3)),((7,7)),((2,2)))", "mrr_type": "Rowid-ordered scan" }, "table": { "table_name": "t1", "access_type": "ref", "possible_keys": ["idx"], "key": "idx", "key_length": "5", "used_key_parts": ["a"], "ref": ["test.t2.d"], "rows": 8, "filtered": 100 } } } select * from t1,t2 where a = d and (a,e) in ((3,3),(7,7),(2,2)); a b c d e f 3 2 uuuw 3 3 i 3 2 uuua 3 3 i 3 3 zzzz 3 3 i 3 3 zyxw 3 3 i 3 3 zzza 3 3 i 3 3 zyxa 3 3 i 2 1 w 2 2 da 2 1 wb 2 2 da 2 2 yyy 2 2 da 2 2 wxz 2 2 da 2 2 yya 2 2 da 2 2 wxa 2 2 da 2 3 yy 2 2 da 2 3 ww 2 2 da 2 3 ya 2 2 da 2 3 wa 2 2 da insert into t2 values (4,5,'a'), (7,8,'b'), (4,3,'c'), (1,2,'d'), (2,1,'e'), (5,5,'f'), (2,3,'g'), (7,7,'h'), (3,3,'i'), (3,2,'j'), (2,2,'k'), (5,5,'l'), (4,5,'aa'), (7,8,'bb'), (4,3,'cc'), (1,2,'dd'), (2,1,'ee'), (9,5,'ff'), (2,3,'gg'), (7,7,'hh'), (3,3,'ii'), (3,2,'jj'), (2,2,'kk'), (9,5,'ll'), (4,5,'aaa'), (7,8,'bbb'), (4,3,'ccc'), (1,2,'ddd'), (2,1,'eee'), (5,5,'fff'), (2,3,'ggg'), (7,7,'hhh'), (3,3,'iii'), (3,2,'jjj'), (2,2,'kkk'), (5,5,'lll'), (14,15,'a'), (17,18,'b'), (14,13,'c'), (11,12,'d'), (12,11,'e'), (15,15,'f'), (12,13,'g'), (17,17,'h'), (13,13,'i'), (13,12,'j'), (12,12,'k'), (15,15,'l'), (24,25,'a'), (27,28,'b'), (24,23,'c'), (21,22,'d'), (22,21,'e'), (25,25,'f'), (22,23,'g'), (27,27,'h'), (23,23,'i'), (23,22,'j'), (22,22,'k'), (25,25,'l'), (34,35,'a'), (37,38,'b'), (34,33,'c'), (31,32,'d'), (32,31,'e'), (35,35,'f'), (32,33,'g'), (37,37,'h'), (33,33,'i'), (33,32,'j'), (32,32,'k'), (35,35,'l'), (44,45,'a'), (47,48,'b'), (44,43,'c'), (41,42,'d'), (42,41,'e'), (45,45,'f'), (42,43,'g'), (47,47,'h'), (43,43,'i'), (43,42,'j'), (42,42,'k'), (45,45,'l'); # join order: (t1,t2) with ref access of t2 # range access to t1 by 1-component keys for index idx explain select * from t1,t2 where a = d and (a,e) in ((3,3),(7,7),(8,8)) and length(f) = 1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t2 range idx1,idx2 idx1 5 NULL 8 Using index condition; Using where; Rowid-ordered scan 1 SIMPLE t1 ref idx idx 5 test.t2.d 8 explain format=json select * from t1,t2 where a = d and (a,e) in ((3,3),(7,7),(8,8)) and length(f) = 1; EXPLAIN { "query_block": { "select_id": 1, "table": { "table_name": "t2", "access_type": "range", "possible_keys": ["idx1", "idx2"], "key": "idx1", "key_length": "5", "used_key_parts": ["d"], "rows": 8, "filtered": 14.423, "index_condition": "t2.d is not null", "attached_condition": "(t2.d,t2.e) in (((3,3)),((7,7)),((8,8))) and octet_length(t2.f) = 1", "mrr_type": "Rowid-ordered scan" }, "table": { "table_name": "t1", "access_type": "ref", "possible_keys": ["idx"], "key": "idx", "key_length": "5", "used_key_parts": ["a"], "ref": ["test.t2.d"], "rows": 8, "filtered": 100 } } } select * from t1,t2 where a = d and (a,e) in ((3,3),(7,7),(8,8)) and length(f) = 1; a b c d e f 3 2 uuuw 3 3 i 3 2 uuua 3 3 i 3 3 zzzz 3 3 i 3 3 zyxw 3 3 i 3 3 zzza 3 3 i 3 3 zyxa 3 3 i 7 7 xxxyy 7 7 h 7 7 xxxya 7 7 h 7 8 xxxxx 7 7 h 7 8 xxxxa 7 7 h 3 2 uuuw 3 3 i 3 2 uuua 3 3 i 3 3 zzzz 3 3 i 3 3 zyxw 3 3 i 3 3 zzza 3 3 i 3 3 zyxa 3 3 i prepare stmt from "select * from t1,t2 where a = d and (a,e) in ((3,3),(7,7),(8,8)) and length(f) = 1"; execute stmt; a b c d e f 3 2 uuuw 3 3 i 3 2 uuua 3 3 i 3 3 zzzz 3 3 i 3 3 zyxw 3 3 i 3 3 zzza 3 3 i 3 3 zyxa 3 3 i 7 7 xxxyy 7 7 h 7 7 xxxya 7 7 h 7 8 xxxxx 7 7 h 7 8 xxxxa 7 7 h 3 2 uuuw 3 3 i 3 2 uuua 3 3 i 3 3 zzzz 3 3 i 3 3 zyxw 3 3 i 3 3 zzza 3 3 i 3 3 zyxa 3 3 i execute stmt; a b c d e f 3 2 uuuw 3 3 i 3 2 uuua 3 3 i 3 3 zzzz 3 3 i 3 3 zyxw 3 3 i 3 3 zzza 3 3 i 3 3 zyxa 3 3 i 7 7 xxxyy 7 7 h 7 7 xxxya 7 7 h 7 8 xxxxx 7 7 h 7 8 xxxxa 7 7 h 3 2 uuuw 3 3 i 3 2 uuua 3 3 i 3 3 zzzz 3 3 i 3 3 zyxw 3 3 i 3 3 zzza 3 3 i 3 3 zyxa 3 3 i deallocate prepare stmt; insert into t1 select * from t1; # join order: (t2,t1) with ref access of t1 # range access to t2 by keys for index idx2 explain select * from t1,t2 where a = d and (a,e) in ((4,4),(7,7),(8,8)) and length(f) = 1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t2 range idx1,idx2 idx1 5 NULL 7 Using index condition; Using where; Rowid-ordered scan 1 SIMPLE t1 ref idx idx 5 test.t2.d 11 explain format=json select * from t1,t2 where a = d and (a,e) in ((4,4),(7,7),(8,8)) and length(f) = 1; EXPLAIN { "query_block": { "select_id": 1, "table": { "table_name": "t2", "access_type": "range", "possible_keys": ["idx1", "idx2"], "key": "idx1", "key_length": "5", "used_key_parts": ["d"], "rows": 7, "filtered": 6.7308, "index_condition": "t2.d is not null", "attached_condition": "(t2.d,t2.e) in (((4,4)),((7,7)),((8,8))) and octet_length(t2.f) = 1", "mrr_type": "Rowid-ordered scan" }, "table": { "table_name": "t1", "access_type": "ref", "possible_keys": ["idx"], "key": "idx", "key_length": "5", "used_key_parts": ["a"], "ref": ["test.t2.d"], "rows": 11, "filtered": 100 } } } select * from t1,t2 where a = d and (a,e) in ((4,4),(7,7),(8,8)) and length(f) = 1; a b c d e f 7 7 xxxyy 7 7 h 7 7 xxxya 7 7 h 7 7 xxxyy 7 7 h 7 7 xxxya 7 7 h 7 8 xxxxx 7 7 h 7 8 xxxxa 7 7 h 7 8 xxxxx 7 7 h 7 8 xxxxa 7 7 h alter table t2 drop index idx1, drop index idx2, add index idx3(d,e); # join order: (t2,t1) with ref access of t1 # range access to t2 by 2-component keys for index idx3 explain select * from t1,t2 where a = d and (a,e) in ((4,4),(7,7),(8,8)) and length(f) = 1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t2 range idx3 idx3 10 NULL 5 Using index condition; Using where; Rowid-ordered scan 1 SIMPLE t1 ref idx idx 5 test.t2.d 11 explain format=json select * from t1,t2 where a = d and (a,e) in ((4,4),(7,7),(8,8)) and length(f) = 1; EXPLAIN { "query_block": { "select_id": 1, "table": { "table_name": "t2", "access_type": "range", "possible_keys": ["idx3"], "key": "idx3", "key_length": "10", "used_key_parts": ["d", "e"], "rows": 5, "filtered": 100, "index_condition": "t2.d is not null", "attached_condition": "(t2.d,t2.e) in (((4,4)),((7,7)),((8,8))) and octet_length(t2.f) = 1", "mrr_type": "Rowid-ordered scan" }, "table": { "table_name": "t1", "access_type": "ref", "possible_keys": ["idx"], "key": "idx", "key_length": "5", "used_key_parts": ["a"], "ref": ["test.t2.d"], "rows": 11, "filtered": 100 } } } select * from t1,t2 where a = d and (a,e) in ((4,4),(7,7),(8,8)) and length(f) = 1; a b c d e f 7 7 xxxyy 7 7 h 7 7 xxxya 7 7 h 7 7 xxxyy 7 7 h 7 7 xxxya 7 7 h 7 8 xxxxx 7 7 h 7 8 xxxxa 7 7 h 7 8 xxxxx 7 7 h 7 8 xxxxa 7 7 h # join order: (t1,t2) with ref access of t2 # range access to t1 by 1-component keys for index idx explain select * from t1,t2 where a = d and (a,e) in ((4,d+1),(7,d+1),(8,d+1)) and length(f) = 1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range idx idx 5 NULL 15 Using index condition; Rowid-ordered scan 1 SIMPLE t2 ref idx3 idx3 5 test.t1.a 3 Using where explain format=json select * from t1,t2 where a = d and (a,e) in ((4,d+1),(7,d+1),(8,d+1)) and length(f) = 1; EXPLAIN { "query_block": { "select_id": 1, "table": { "table_name": "t1", "access_type": "range", "possible_keys": ["idx"], "key": "idx", "key_length": "5", "used_key_parts": ["a"], "rows": 15, "filtered": 100, "index_condition": "t1.a is not null", "mrr_type": "Rowid-ordered scan" }, "table": { "table_name": "t2", "access_type": "ref", "possible_keys": ["idx3"], "key": "idx3", "key_length": "5", "used_key_parts": ["d"], "ref": ["test.t1.a"], "rows": 3, "filtered": 100, "attached_condition": "(t1.a,t2.e) in ((4,t1.a + 1),(7,t1.a + 1),(8,t1.a + 1)) and octet_length(t2.f) = 1" } } } select * from t1,t2 where a = d and (a,e) in ((4,d+1),(7,d+1),(8,d+1)) and length(f) = 1; a b c d e f 4 5 ww 4 5 a 7 8 xxxxx 7 8 b 4 3 zyx 4 5 a 7 7 xxxyy 7 8 b 4 5 wa 4 5 a 7 8 xxxxa 7 8 b 4 3 zya 4 5 a 7 7 xxxya 7 8 b 4 5 ww 4 5 a 7 8 xxxxx 7 8 b 4 3 zyx 4 5 a 7 7 xxxyy 7 8 b 4 5 wa 4 5 a 7 8 xxxxa 7 8 b 4 3 zya 4 5 a 7 7 xxxya 7 8 b # join order: (t1,t2) with ref access of t2 # no range access explain select * from t1,t2 where a = d and (a,e) in ((e,d+1),(7,7),(8,8)) and length(f) = 1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL idx NULL NULL NULL 144 Using where 1 SIMPLE t2 ref idx3 idx3 5 test.t1.a 3 Using where explain format=json select * from t1,t2 where a = d and (a,e) in ((e,d+1),(7,7),(8,8)) and length(f) = 1; EXPLAIN { "query_block": { "select_id": 1, "table": { "table_name": "t1", "access_type": "ALL", "possible_keys": ["idx"], "rows": 144, "filtered": 100, "attached_condition": "t1.a is not null" }, "table": { "table_name": "t2", "access_type": "ref", "possible_keys": ["idx3"], "key": "idx3", "key_length": "5", "used_key_parts": ["d"], "ref": ["test.t1.a"], "rows": 3, "filtered": 100, "attached_condition": "(t1.a,t2.e) in ((t2.e,t1.a + 1),((7,7)),((8,8))) and octet_length(t2.f) = 1" } } } select * from t1,t2 where a = d and (a,e) in ((e,d+1),(7,7),(8,8)) and length(f) = 1; a b c d e f 7 8 xxxxx 7 7 h 7 7 xxxyy 7 7 h 7 8 xxxxa 7 7 h 7 7 xxxya 7 7 h 7 8 xxxxx 7 7 h 7 7 xxxyy 7 7 h 7 8 xxxxa 7 7 h 7 7 xxxya 7 7 h # join order: (t1,t2) with ref access of t2 # range access to t1 by 1-component keys for index idx explain select * from t1,t2 where a = d and (a,2) in ((2,2),(7,7),(8,8)) and length(c) = 1 and length(f) = 1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range idx idx 5 NULL 12 Using index condition; Using where; Rowid-ordered scan 1 SIMPLE t2 ref idx3 idx3 5 test.t1.a 3 Using where explain format=json select * from t1,t2 where a = d and (a,2) in ((2,2),(7,7),(8,8)) and length(c) = 1 and length(f) = 1; EXPLAIN { "query_block": { "select_id": 1, "table": { "table_name": "t1", "access_type": "range", "possible_keys": ["idx"], "key": "idx", "key_length": "5", "used_key_parts": ["a"], "rows": 12, "filtered": 100, "index_condition": "t1.a is not null", "attached_condition": "(t1.a,2) in (((2,2)),((7,7)),((8,8))) and octet_length(t1.c) = 1", "mrr_type": "Rowid-ordered scan" }, "table": { "table_name": "t2", "access_type": "ref", "possible_keys": ["idx3"], "key": "idx3", "key_length": "5", "used_key_parts": ["d"], "ref": ["test.t1.a"], "rows": 3, "filtered": 100, "attached_condition": "octet_length(t2.f) = 1" } } } select * from t1,t2 where a = d and (a,2) in ((2,2),(7,7),(8,8)) and length(c) = 1 and length(f) = 1; a b c d e f 2 1 w 2 1 e 2 1 w 2 2 k 2 1 w 2 3 g 2 1 w 2 1 e 2 1 w 2 2 k 2 1 w 2 3 g prepare stmt from "select * from t1,t2 where a = d and (a,2) in ((2,2),(7,7),(8,8)) and length(c) = 1 and length(f) = 1"; execute stmt; a b c d e f 2 1 w 2 1 e 2 1 w 2 2 k 2 1 w 2 3 g 2 1 w 2 1 e 2 1 w 2 2 k 2 1 w 2 3 g execute stmt; a b c d e f 2 1 w 2 1 e 2 1 w 2 2 k 2 1 w 2 3 g 2 1 w 2 1 e 2 1 w 2 2 k 2 1 w 2 3 g deallocate prepare stmt; create table t3 (id int primary key, v int) engine=myisam; insert into t3 values (3,2), (1,1), (4,12), (2,15); # join order: (t3,t1,t2) with const t3 and ref access of t2 # range access to t1 by 1-component keys for index idx explain select * from t1,t2,t3 where id = 1 and a = d and (a,v+1) in ((2,2),(7,7),(8,8)) and length(c) = 1 and length(f) = 1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t3 const PRIMARY PRIMARY 4 const 1 1 SIMPLE t1 range idx idx 5 NULL 12 Using index condition; Using where; Rowid-ordered scan 1 SIMPLE t2 ref idx3 idx3 5 test.t1.a 3 Using where explain format=json select * from t1,t2,t3 where id = 1 and a = d and (a,v+1) in ((2,2),(7,7),(8,8)) and length(c) = 1 and length(f) = 1; EXPLAIN { "query_block": { "select_id": 1, "table": { "table_name": "t3", "access_type": "const", "possible_keys": ["PRIMARY"], "key": "PRIMARY", "key_length": "4", "used_key_parts": ["id"], "ref": ["const"], "rows": 1, "filtered": 100 }, "table": { "table_name": "t1", "access_type": "range", "possible_keys": ["idx"], "key": "idx", "key_length": "5", "used_key_parts": ["a"], "rows": 12, "filtered": 100, "index_condition": "t1.a is not null", "attached_condition": "(t1.a,1 + 1) in (((2,2)),((7,7)),((8,8))) and octet_length(t1.c) = 1", "mrr_type": "Rowid-ordered scan" }, "table": { "table_name": "t2", "access_type": "ref", "possible_keys": ["idx3"], "key": "idx3", "key_length": "5", "used_key_parts": ["d"], "ref": ["test.t1.a"], "rows": 3, "filtered": 100, "attached_condition": "octet_length(t2.f) = 1" } } } select * from t1,t2,t3 where id = 1 and a = d and (a,v+1) in ((2,2),(7,7),(8,8)) and length(c) = 1 and length(f) = 1; a b c d e f id v 2 1 w 2 1 e 1 1 2 1 w 2 2 k 1 1 2 1 w 2 3 g 1 1 2 1 w 2 1 e 1 1 2 1 w 2 2 k 1 1 2 1 w 2 3 g 1 1 # IN predicate is always FALSE explain select * from t1,t2,t3 where id = 1 and a = d and (a,v+1) in ((9,9),(7,7),(8,8)) and length(c) = 1 and length(f) = 1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables prepare stmt from "select * from t1,t2,t3 where id = 1 and a = d and (a,v+1) in ((9,9),(7,7),(8,8)) and length(c) = 1 and length(f) = 1"; execute stmt; a b c d e f id v execute stmt; a b c d e f id v deallocate prepare stmt; set optimizer_switch=@save_optimizer_switch; drop table t1,t2,t3; # # MDEV-16934: using system variable eq_range_index_dive_limit # to reduce the number of index dives # create table t1 (a int, b varchar(31), index idx(a)); insert into t1 values (7,'xxxx'), (1,'yy'), (3,'aaa'), (1,'bbb'), (2,'zz'), (4,'vvvvv'), (7,'ddd'), (9,'zzzzz'), (1,'cc'), (5,'ffff'); insert into t1 select a+10, concat(b,'zz') from t1; insert into t1 select a+15, concat(b,'yy') from t1; insert into t1 select a+100, concat(b,'xx') from t1; analyze table t1; Table Op Msg_type Msg_text test.t1 analyze status Engine-independent statistics collected test.t1 analyze status OK select cast(count(a)/count(distinct a) as unsigned) as rec_per_key from t1; rec_per_key 2 set eq_range_index_dive_limit=0; explain select * from t1 where a in (8, 15, 31, 1, 9); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range idx idx 5 NULL 7 Using index condition; Rowid-ordered scan select * from t1 where a in (8, 15, 31, 1, 9); a b 1 yy 1 bbb 9 zzzzz 1 cc 15 ffffzz set eq_range_index_dive_limit=2; explain select * from t1 where a in (8, 15, 31, 1, 9); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range idx idx 5 NULL 5 Using index condition; Rowid-ordered scan select * from t1 where a in (8, 15, 31, 1, 9); a b 1 yy 1 bbb 9 zzzzz 1 cc 15 ffffzz set eq_range_index_dive_limit=default; drop table t1; # # MDEV-18551: New defaults for eq_range_index_dive_limit # create table ten(a int); insert into ten values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9); create table t1(a int, key(a)); insert into t1 select A.a + B.a*10 + C.a*100 from ten A, ten B,ten C; insert into t1 select 1 from ten A, ten B,ten C; create table t2(a int, key(a)); insert into t2 select A.a + B.a*10 + C.a*100 from ten A, ten B,ten C where A.a + B.a*10 + C.a*100 < 199; # expected type=range, rows=1487 , reason=using index dives analyze SELECT * FROM t1 where a in (0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,160,161,162,163,164,165,166,167,168,169,170,171,172,173,174,175,176,177,178,179,180,181,182,183,184,185,186,187,188,189,190,191,192,193,194,195,196,197,198); id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra 1 SIMPLE t1 range a a 5 NULL 1487 1199.00 100.00 100.00 Using where; Using index insert into t2 values (200),(201); # expected type=range, rows=201 , reason=using index statistics analyze SELECT * FROM t1 where a in (0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,160,161,162,163,164,165,166,167,168,169,170,171,172,173,174,175,176,177,178,179,180,181,182,183,184,185,186,187,188,189,190,191,192,193,194,195,196,197,198,200,201); id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra 1 SIMPLE t1 range a a 5 NULL 201 1201.00 100.00 100.00 Using where; Using index drop table t1,ten,t2; # # End of 10.2 tests # set global innodb_stats_persistent= @innodb_stats_persistent_save; set global innodb_stats_persistent_sample_pages= @innodb_stats_persistent_sample_pages_save; set optimizer_switch=@mrr_icp_extra_tmp;