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drop table if exists t1,t2,t3,t4;
set @save_storage_engine= @@storage_engine;
set storage_engine=InnoDB;
create table t1(a int);
show create table t1;
Table Create Table
t1 CREATE TABLE "t1" (
"a" int(11)
) ENGINE=InnoDB DEFAULT CHARSET=latin1
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 + 10*(B.a + 10*C.a) from t1 A, t1 B, t1 C;
create table t3 (
a char(8) not null, b char(8) not null, filler char(200),
key(a)
);
insert into t3 select @a:=concat('c-', 1000+ A.a, '=w'), @a, 'filler' from t2 A;
insert into t3 select concat('c-', 1000+A.a, '=w'), concat('c-', 2000+A.a, '=w'),
'filler-1' from t2 A;
insert into t3 select concat('c-', 1000+A.a, '=w'), concat('c-', 3000+A.a, '=w'),
'filler-2' from t2 A;
select a,filler from t3 where a >= 'c-9011=w';
a filler
select a,filler from t3 where a >= 'c-1011=w' and a <= 'c-1015=w';
a filler
c-1011=w filler
c-1012=w filler
c-1013=w filler
c-1014=w filler
c-1015=w filler
c-1011=w filler-1
c-1012=w filler-1
c-1013=w filler-1
c-1014=w filler-1
c-1015=w filler-1
c-1011=w filler-2
c-1012=w filler-2
c-1013=w filler-2
c-1014=w filler-2
c-1015=w filler-2
select a,filler from t3 where (a>='c-1011=w' and a <= 'c-1013=w') or
(a>='c-1014=w' and a <= 'c-1015=w');
a filler
c-1011=w filler
c-1012=w filler
c-1013=w filler
c-1014=w filler
c-1015=w filler
c-1011=w filler-1
c-1012=w filler-1
c-1013=w filler-1
c-1014=w filler-1
c-1015=w filler-1
c-1011=w filler-2
c-1012=w filler-2
c-1013=w filler-2
c-1014=w filler-2
c-1015=w filler-2
insert into t3 values ('c-1013=z', 'c-1013=z', 'err');
insert into t3 values ('a-1014=w', 'a-1014=w', 'err');
select a,filler from t3 where (a>='c-1011=w' and a <= 'c-1013=w') or
(a>='c-1014=w' and a <= 'c-1015=w');
a filler
c-1011=w filler
c-1012=w filler
c-1013=w filler
c-1014=w filler
c-1015=w filler
c-1011=w filler-1
c-1012=w filler-1
c-1013=w filler-1
c-1014=w filler-1
c-1015=w filler-1
c-1011=w filler-2
c-1012=w filler-2
c-1013=w filler-2
c-1014=w filler-2
c-1015=w filler-2
delete from t3 where b in ('c-1013=z', 'a-1014=w');
select a,filler from t3 where a='c-1011=w' or a='c-1012=w' or a='c-1013=w' or
a='c-1014=w' or a='c-1015=w';
a filler
c-1011=w filler
c-1012=w filler
c-1013=w filler
c-1014=w filler
c-1015=w filler
c-1011=w filler-1
c-1012=w filler-1
c-1013=w filler-1
c-1014=w filler-1
c-1015=w filler-1
c-1011=w filler-2
c-1012=w filler-2
c-1013=w filler-2
c-1014=w filler-2
c-1015=w filler-2
insert into t3 values ('c-1013=w', 'del-me', 'inserted');
select a,filler from t3 where a='c-1011=w' or a='c-1012=w' or a='c-1013=w' or
a='c-1014=w' or a='c-1015=w';
a filler
c-1011=w filler
c-1012=w filler
c-1013=w filler
c-1014=w filler
c-1015=w filler
c-1011=w filler-1
c-1012=w filler-1
c-1013=w filler-1
c-1014=w filler-1
c-1015=w filler-1
c-1011=w filler-2
c-1012=w filler-2
c-1013=w filler-2
c-1014=w filler-2
c-1015=w filler-2
c-1013=w inserted
delete from t3 where b='del-me';
alter table t3 add primary key(b);
select b,filler from t3 where (b>='c-1011=w' and b<= 'c-1018=w') or
b IN ('c-1019=w', 'c-1020=w', 'c-1021=w',
'c-1022=w', 'c-1023=w', 'c-1024=w');
b filler
c-1011=w filler
c-1012=w filler
c-1013=w filler
c-1014=w filler
c-1015=w filler
c-1016=w filler
c-1017=w filler
c-1018=w filler
c-1019=w filler
c-1020=w filler
c-1021=w filler
c-1022=w filler
c-1023=w filler
c-1024=w filler
select b,filler from t3 where (b>='c-1011=w' and b<= 'c-1020=w') or
b IN ('c-1021=w', 'c-1022=w', 'c-1023=w');
b filler
c-1011=w filler
c-1012=w filler
c-1013=w filler
c-1014=w filler
c-1015=w filler
c-1016=w filler
c-1017=w filler
c-1018=w filler
c-1019=w filler
c-1020=w filler
c-1021=w filler
c-1022=w filler
c-1023=w filler
select b,filler from t3 where (b>='c-1011=w' and b<= 'c-1018=w') or
b IN ('c-1019=w', 'c-1020=w') or
(b>='c-1021=w' and b<= 'c-1023=w');
b filler
c-1011=w filler
c-1012=w filler
c-1013=w filler
c-1014=w filler
c-1015=w filler
c-1016=w filler
c-1017=w filler
c-1018=w filler
c-1019=w filler
c-1020=w filler
c-1021=w filler
c-1022=w filler
c-1023=w filler
create table t4 (a varchar(10), b int, c char(10), filler char(200),
key idx1 (a, b, c));
insert into t4 (filler) select concat('NULL-', 15-a) from t2 order by a limit 15;
insert into t4 (a,b,c,filler)
select 'b-1',NULL,'c-1', concat('NULL-', 15-a) from t2 order by a limit 15;
insert into t4 (a,b,c,filler)
select 'b-1',NULL,'c-222', concat('NULL-', 15-a) from t2 order by a limit 15;
insert into t4 (a,b,c,filler)
select 'bb-1',NULL,'cc-2', concat('NULL-', 15-a) from t2 order by a limit 15;
insert into t4 (a,b,c,filler)
select 'zz-1',NULL,'cc-2', 'filler-data' from t2 order by a limit 500;
explain
select * from t4 where a IS NULL and b IS NULL and (c IS NULL or c='no-such-row1'
or c='no-such-row2');
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t4 range idx1 idx1 29 NULL 16 Using index condition; Using MRR
select * from t4 where a IS NULL and b IS NULL and (c IS NULL or c='no-such-row1'
or c='no-such-row2');
a b c filler
NULL NULL NULL NULL-15
NULL NULL NULL NULL-14
NULL NULL NULL NULL-13
NULL NULL NULL NULL-12
NULL NULL NULL NULL-11
NULL NULL NULL NULL-10
NULL NULL NULL NULL-9
NULL NULL NULL NULL-8
NULL NULL NULL NULL-7
NULL NULL NULL NULL-6
NULL NULL NULL NULL-5
NULL NULL NULL NULL-4
NULL NULL NULL NULL-3
NULL NULL NULL NULL-2
NULL NULL NULL NULL-1
explain
select * from t4 where (a ='b-1' or a='bb-1') and b IS NULL and (c='c-1' or c='cc-2');
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t4 range idx1 idx1 29 NULL 32 Using index condition; Using MRR
select * from t4 where (a ='b-1' or a='bb-1') and b IS NULL and (c='c-1' or c='cc-2');
a b c filler
b-1 NULL c-1 NULL-15
b-1 NULL c-1 NULL-14
b-1 NULL c-1 NULL-13
b-1 NULL c-1 NULL-12
b-1 NULL c-1 NULL-11
b-1 NULL c-1 NULL-10
b-1 NULL c-1 NULL-9
b-1 NULL c-1 NULL-8
b-1 NULL c-1 NULL-7
b-1 NULL c-1 NULL-6
b-1 NULL c-1 NULL-5
b-1 NULL c-1 NULL-4
b-1 NULL c-1 NULL-3
b-1 NULL c-1 NULL-2
b-1 NULL c-1 NULL-1
bb-1 NULL cc-2 NULL-15
bb-1 NULL cc-2 NULL-14
bb-1 NULL cc-2 NULL-13
bb-1 NULL cc-2 NULL-12
bb-1 NULL cc-2 NULL-11
bb-1 NULL cc-2 NULL-10
bb-1 NULL cc-2 NULL-9
bb-1 NULL cc-2 NULL-8
bb-1 NULL cc-2 NULL-7
bb-1 NULL cc-2 NULL-6
bb-1 NULL cc-2 NULL-5
bb-1 NULL cc-2 NULL-4
bb-1 NULL cc-2 NULL-3
bb-1 NULL cc-2 NULL-2
bb-1 NULL cc-2 NULL-1
select * from t4 ignore index(idx1) where (a ='b-1' or a='bb-1') and b IS NULL and (c='c-1' or c='cc-2');
a b c filler
b-1 NULL c-1 NULL-15
b-1 NULL c-1 NULL-14
b-1 NULL c-1 NULL-13
b-1 NULL c-1 NULL-12
b-1 NULL c-1 NULL-11
b-1 NULL c-1 NULL-10
b-1 NULL c-1 NULL-9
b-1 NULL c-1 NULL-8
b-1 NULL c-1 NULL-7
b-1 NULL c-1 NULL-6
b-1 NULL c-1 NULL-5
b-1 NULL c-1 NULL-4
b-1 NULL c-1 NULL-3
b-1 NULL c-1 NULL-2
b-1 NULL c-1 NULL-1
bb-1 NULL cc-2 NULL-15
bb-1 NULL cc-2 NULL-14
bb-1 NULL cc-2 NULL-13
bb-1 NULL cc-2 NULL-12
bb-1 NULL cc-2 NULL-11
bb-1 NULL cc-2 NULL-10
bb-1 NULL cc-2 NULL-9
bb-1 NULL cc-2 NULL-8
bb-1 NULL cc-2 NULL-7
bb-1 NULL cc-2 NULL-6
bb-1 NULL cc-2 NULL-5
bb-1 NULL cc-2 NULL-4
bb-1 NULL cc-2 NULL-3
bb-1 NULL cc-2 NULL-2
bb-1 NULL cc-2 NULL-1
set storage_engine= @save_storage_engine;
drop table t1, t2, t3, t4;
set @read_rnd_buffer_size_save= @@read_rnd_buffer_size;
set read_rnd_buffer_size=64;
create table t1(a int);
insert into t1 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
create table t2(a char(8), b char(8), c char(8), filler char(100), key(a,b,c) ) engine=InnoDB;
insert into t2 select
concat('a-', 1000 + A.a, '-a'),
concat('b-', 1000 + B.a, '-b'),
concat('c-', 1000 + C.a, '-c'),
'filler'
from t1 A, t1 B, t1 C;
explain
select count(length(a) + length(filler)) from t2 where a>='a-1000-a' and a <'a-1001-a';
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range a a 9 NULL 99 Using index condition; Using MRR
select count(length(a) + length(filler)) from t2 where a>='a-1000-a' and a <'a-1001-a';
count(length(a) + length(filler))
100
drop table t2;
create table t2 (a char(100), b char(100), c char(100), d int,
filler char(10), key(d), primary key (a,b,c)) engine= innodb;
insert into t2 select A.a, B.a, B.a, A.a, 'filler' from t1 A, t1 B;
explain select * from t2 force index (d) where d < 10;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range d d 5 NULL 47 Using index condition; Using MRR
drop table t2;
drop table t1;
set @@read_rnd_buffer_size= @read_rnd_buffer_size_save;
create table t1 (f1 int not null, f2 int not null,f3 int not null, f4 char(1), primary key (f1,f2), key ix(f3))Engine=InnoDB;
select * from t1 where (f3>=5 and f3<=10) or (f3>=1 and f3<=4);
f1 f2 f3 f4
1 1 1 A
2 2 2 A
3 3 3 A
4 4 4 A
5 5 5 A
6 6 6 A
7 7 7 A
8 8 8 A
9 9 9 A
10 10 10 A
drop table t1;
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