drop table if exists t1, t2, t3;
set @read_rnd_buffer_size_save= @@read_rnd_buffer_size;
set read_rnd_buffer_size=79;
select @@read_rnd_buffer_size;
@@read_rnd_buffer_size
79
set @save_storage_engine= @@storage_engine;
set storage_engine=Maria;
create table t1(a int);
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `a` int(11) DEFAULT NULL
) ENGINE=MARIA DEFAULT CHARSET=latin1 PAGE_CHECKSUM=1
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-1013=w	inserted
c-1015=w	filler-2
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
drop table t1, t2, t3, t4;
create table t1 (a int, b int not null,unique key (a,b),index(b));
insert ignore into t1 values (1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(null,7),(9,9),(8,8),(7,7),(null,9),(null,9),(6,6);
create table t2 like t1;
insert into t2 select * from t1;
alter table t1 modify b blob not null, add c int not null, drop key a, add unique key (a,b(20),c), drop key b, add key (b(10));
select * from t1 where a is null;
a	b	c
NULL	7	0
NULL	9	0
NULL	9	0
select * from t1 where (a is null or a > 0 and a < 3) and b > 7 limit 3;
a	b	c
NULL	9	0
NULL	9	0
select * from t1 where a is null and b=9 or a is null and b=7 limit 3;
a	b	c
NULL	7	0
NULL	9	0
NULL	9	0
drop table t1, t2;
set storage_engine= @save_storage_engine;
set @@read_rnd_buffer_size= @read_rnd_buffer_size_save;
