drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
create table t1 ( a int not null) partition by hash(a) partitions 2;
insert into t1 values (1),(2),(3);
explain select * from t1 where a=5 and a=6;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
drop table t1;
create table t1 (
a int(11) not null
) partition by hash (a) partitions 2;
insert into t1 values (1),(2),(3);
explain partitions select * from t1 where a=1;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	p1	ALL	NULL	NULL	NULL	NULL	2	Using where
explain partitions select * from t1 where a=2;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	p0	system	NULL	NULL	NULL	NULL	1	
explain partitions select * from t1 where a=1 or a=2;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	p0,p1	ALL	NULL	NULL	NULL	NULL	3	Using where
create table t2 (
a int not null,
b int not null
) partition by key(a,b) partitions 2;
insert into t2 values (1,1),(2,2),(3,3);
explain partitions select * from t2 where a=1;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	p0,p1	ALL	NULL	NULL	NULL	NULL	3	Using where
explain partitions select * from t2 where b=1;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	p0,p1	ALL	NULL	NULL	NULL	NULL	3	Using where
explain partitions select * from t2 where a=1 and b=1;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	p0	ALL	NULL	NULL	NULL	NULL	3	Using where
create table t3 (
a int
)
partition by range (a*1) ( 
partition p0 values less than (10),
partition p1 values less than (20)
);
insert into t3 values (5),(15);
explain partitions select * from t3 where a=11;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
explain partitions select * from t3 where a=10;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
explain partitions select * from t3 where a=20;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
explain partitions select * from t3 where a=30;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
create table t4 (a int not null, b int not null) partition by LIST (a+b) (
partition p0 values in (12),
partition p1 values in (14)
);
insert into t4 values (10,2), (10,4);
explain partitions select * from t4 where (a=10 and b=1) or (a=10 and b=2);
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t4	p0	system	NULL	NULL	NULL	NULL	1	
explain partitions select * from t4 
where (a=10 and b=1) or (a=10 and b=2) or (a=10 and b = 3);
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t4	p0	system	NULL	NULL	NULL	NULL	1	
explain partitions select * from t4 where (a=10 and b=2) or (a=10 and b=3)
or (a=10 and b = 4);
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t4	p0,p1	ALL	NULL	NULL	NULL	NULL	2	Using where
explain partitions select * from t4 where (a=10 and b=1) or a=11;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t4	p0,p1	ALL	NULL	NULL	NULL	NULL	2	Using where
explain partitions select * from t4 where (a=10 and b=2) or a=11;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t4	p0,p1	ALL	NULL	NULL	NULL	NULL	2	Using where
drop table t1, t2, t3, t4;
create table t5 (a int not null, b int not null, 
c int not null, d int not null) 
partition by LIST(a+b) subpartition by HASH (c+d) subpartitions 2
(
partition p0 values in (12),
partition p1 values in (14)
);
insert into t5 values (10,2,0,0), (10,4,0,0), (10,2,0,1), (10,4,0,1);
explain partitions select * from t5;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t5	p0_sp0,p0_sp1,p1_sp0,p1_sp1	ALL	NULL	NULL	NULL	NULL	4	
explain partitions select * from t5
where (a=10 and b=1) or (a=10 and b=2) or (a=10 and b = 3);
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t5	p0_sp0,p0_sp1	ALL	NULL	NULL	NULL	NULL	2	Using where
explain partitions select * from t5 where (a=10 and b=2) or (a=10 and b=3)
or (a=10 and b = 4);
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t5	p0_sp0,p0_sp1,p1_sp0,p1_sp1	ALL	NULL	NULL	NULL	NULL	4	Using where
explain partitions select * from t5 where (c=1 and d=1);
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t5	p0_sp0,p1_sp0	ALL	NULL	NULL	NULL	NULL	2	Using where
explain partitions select * from t5 where (c=2 and d=1);
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t5	p0_sp1,p1_sp1	ALL	NULL	NULL	NULL	NULL	2	Using where
explain partitions select * from t5 where (a=10 and b=2 and c=1 and d=1) or 
(c=2 and d=1);
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t5	p0_sp0,p0_sp1,p1_sp1	ALL	NULL	NULL	NULL	NULL	3	Using where
explain partitions select * from t5 where (a=10 and b=2 and c=1 and d=1) or 
(b=2 and c=2 and d=1);
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t5	p0_sp0,p0_sp1,p1_sp1	ALL	NULL	NULL	NULL	NULL	3	Using where
create table t6 (a int not null) partition by LIST(a) (
partition p1 values in (1),
partition p3 values in (3),
partition p5 values in (5),
partition p7 values in (7),
partition p9 values in (9)
);
insert into t6 values (1),(3),(5);
explain partitions select * from t6 where a <  1;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
explain partitions select * from t6 where a <= 1;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t6	p1	system	NULL	NULL	NULL	NULL	1	
explain partitions select * from t6 where a >  9;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
explain partitions select * from t6 where a >= 9;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
explain partitions select * from t6 where a > 0 and a < 5;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t6	p1,p3	ALL	NULL	NULL	NULL	NULL	2	Using where
explain partitions select * from t6 where a > 5 and a < 12;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
explain partitions select * from t6 where a > 3 and a < 8 ;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t6	p5,p7	system	NULL	NULL	NULL	NULL	1	
explain partitions select * from t6 where a >= 0 and a <= 5;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t6	p1,p3,p5	ALL	NULL	NULL	NULL	NULL	3	Using where
explain partitions select * from t6 where a >= 5 and a <= 12;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t6	p5,p7,p9	system	NULL	NULL	NULL	NULL	1	
explain partitions select * from t6 where a >= 3 and a <= 8;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t6	p3,p5,p7	ALL	NULL	NULL	NULL	NULL	2	Using where
explain partitions select * from t6 where a > 3 and a < 5;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
create table t7 (a int not null) partition by RANGE(a) (
partition p10 values less than (10),
partition p30 values less than (30),
partition p50 values less than (50),
partition p70 values less than (70),
partition p90 values less than (90)
);
insert into t7 values (10),(30),(50);
explain partitions select * from t7 where a < 5;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
explain partitions select * from t7 where a < 10;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
explain partitions select * from t7 where a <= 10;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t7	p10,p30	system	NULL	NULL	NULL	NULL	1	
explain partitions select * from t7 where a = 10;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t7	p30	system	NULL	NULL	NULL	NULL	1	
explain partitions select * from t7 where a < 90;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t7	p10,p30,p50,p70,p90	ALL	NULL	NULL	NULL	NULL	3	Using where
explain partitions select * from t7 where a = 90;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
explain partitions select * from t7 where a > 90;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
explain partitions select * from t7 where a >= 90;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
explain partitions select * from t7 where a > 11 and a < 29;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
create table t8 (a date not null) partition by RANGE(YEAR(a)) (
partition p0 values less than (1980),
partition p1 values less than (1990),
partition p2 values less than (2000)
);
insert into t8 values ('1985-05-05'),('1995-05-05');
explain partitions select * from t8 where a < '1980-02-02';
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
create table t9 (a date not null) partition by RANGE(TO_DAYS(a)) (
partition p0 values less than (732299), -- 2004-12-19
partition p1 values less than (732468), -- 2005-06-06
partition p2 values less than (732664)  -- 2005-12-19
);
insert into t9 values ('2005-05-05'), ('2005-04-04');
explain partitions select * from t9 where a <  '2004-12-19';
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
explain partitions select * from t9 where a <= '2004-12-19';
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t9	p0,p1	ALL	NULL	NULL	NULL	NULL	2	Using where
drop table t5,t6,t7,t8,t9;
create table t1 (a enum('a','b','c','d') default 'a') 
partition by hash (ascii(a)) partitions 2;
insert into t1 values ('a'),('b'),('c');
explain partitions select * from t1 where a='b';
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	p0,p1	ALL	NULL	NULL	NULL	NULL	3	Using where
drop table t1;
create table t1 (
a1 int not null
)
partition by range (a1) (
partition p0 values less than (3),
partition p1 values less than (6),
partition p2 values less than (9)
);
insert into t1 values (1),(2),(3);
explain partitions select * from t1 where a1 > 3;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
explain partitions select * from t1 where a1 >= 3;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	p1,p2	system	NULL	NULL	NULL	NULL	1	
explain partitions select * from t1 where a1 < 3 and a1 > 3;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
drop table t1;
create table t3 (a int, b int) 
partition by list(a) subpartition by hash(b) subpartitions 4 (
partition p0 values in (1),
partition p1 values in (2),
partition p2 values in (3),
partition p3 values in (4)
);
insert into t3 values (1,1),(2,2),(3,3);
explain partitions select * from t3 where a=2 or b=1;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t3	p0_sp1,p1_sp0,p1_sp1,p1_sp2,p1_sp3,p2_sp1,p3_sp1	ALL	NULL	NULL	NULL	NULL	2	Using where
explain partitions select * from t3 where a=4 or b=2;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t3	p0_sp2,p1_sp2,p2_sp2,p3_sp0,p3_sp1,p3_sp2,p3_sp3	system	NULL	NULL	NULL	NULL	1	
explain partitions select * from t3 where (a=2 or b=1) and (a=4 or b=2) ;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t3	p1_sp2,p3_sp1	system	NULL	NULL	NULL	NULL	1	
drop table t3;
create table t1 (a int) partition by hash(a) partitions 2;
insert into t1 values (1),(2);
explain partitions select * from t1 where a is null;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
explain partitions select * from t1 where a is not null;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	p0,p1	ALL	NULL	NULL	NULL	NULL	2	Using where
drop table t1;
create table t1 (a int not null, b int not null, key(a), key(b))
partition by hash(a) partitions 4;
insert into t1 values (1,1),(2,2),(3,3),(4,4);
explain partitions 
select * from t1 X, t1 Y 
where X.b = Y.b and (X.a=1 or X.a=2) and (Y.a=2 or Y.a=3);
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	X	p1,p2	ALL	a,b	NULL	NULL	NULL	2	Using where
1	SIMPLE	Y	p2,p3	ref	a,b	b	4	test.X.b	2	Using where
explain partitions
select * from t1 X, t1 Y where X.a = Y.a and (X.a=1 or X.a=2);
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	X	p1,p2	ALL	a	NULL	NULL	NULL	2	Using where
1	SIMPLE	Y	p1,p2	ref	a	a	4	test.X.a	2	
drop table t1;
create table t1 (a int) partition by hash(a) partitions 20;
insert into t1 values (1),(2),(3);
explain partitions select * from t1 where a >  1 and a < 3;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	p2	system	NULL	NULL	NULL	NULL	1	
explain partitions select * from t1 where a >= 1 and a < 3;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	p1,p2	ALL	NULL	NULL	NULL	NULL	2	Using where
explain partitions select * from t1 where a >  1 and a <= 3;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	p2,p3	ALL	NULL	NULL	NULL	NULL	2	Using where
explain partitions select * from t1 where a >= 1 and a <= 3;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	p1,p2,p3	ALL	NULL	NULL	NULL	NULL	3	Using where
drop table t1;
create table t1 (a int, b int) 
partition by list(a) subpartition by hash(b) subpartitions 20 
(
partition p0 values in (0),
partition p1 values in (1),
partition p2 values in (2),
partition p3 values in (3)
);
insert into t1 values (1,1),(2,2),(3,3);
explain partitions select * from t1 where b >  1 and b < 3;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	p0_sp2,p1_sp2,p2_sp2,p3_sp2	system	NULL	NULL	NULL	NULL	1	
explain partitions select * from t1 where b >  1 and b < 3 and (a =1 or a =2);
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	p1_sp2,p2_sp2	system	NULL	NULL	NULL	NULL	1	
drop table t1;
create table t1 (a int) partition by list(a) (
partition p0 values in (1,2),
partition p1 values in (3,4)
);
insert into t1 values (1),(1),(2),(2),(3),(4),(3),(4);
flush status;
update t1 set a=100 where a=5;
show status like 'Handler_read_rnd_next';
Variable_name	Value
Handler_read_rnd_next	0
flush status;
update t1 set a=100 where a+1=5+1;
show status like 'Handler_read_rnd_next';
Variable_name	Value
Handler_read_rnd_next	10
flush status;
delete from t1 where a=5;
show status like 'Handler_read_rnd_next';
Variable_name	Value
Handler_read_rnd_next	0
flush status;
delete from t1 where a+1=5+1;
show status like 'Handler_read_rnd_next';
Variable_name	Value
Handler_read_rnd_next	10
create table t2 like t1;
insert into t2 select * from t2;
flush status;
update t1,t2 set t1.a=1000, t2.a=1000 where t1.a=5 and t2.a=5;
show status like 'Handler_read_rnd_next';
Variable_name	Value
Handler_read_rnd_next	0
flush status;
delete t1,t2 from t1, t2 where t1.a=5 and t2.a=5;
show status like 'Handler_read_rnd_next';
Variable_name	Value
Handler_read_rnd_next	0
drop table t1,t2;
CREATE TABLE `t1` (
`a` int(11) default NULL
);
INSERT INTO t1 VALUES (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
CREATE TABLE `t2` (
`a` int(11) default NULL,
KEY `a` (`a`)
) ;
insert into t2 select A.a + 10*(B.a + 10* C.a) from t1 A, t1 B, t1 C ;
insert into t1 select a from t2;
drop table t2;
CREATE TABLE `t2` (
`a` int(11) default NULL,
`b` int(11) default NULL
) 
PARTITION BY RANGE (a) (
PARTITION p0 VALUES LESS THAN (200),
PARTITION p1 VALUES LESS THAN (400),
PARTITION p2 VALUES LESS THAN (600),
PARTITION p3 VALUES LESS THAN (800),
PARTITION p4 VALUES LESS THAN (1001));
insert into t2 select a,1 from t1 where a < 200;
insert into t2 select a,2 from t1 where a >= 200 and a < 400;
insert into t2 select a,3 from t1 where a >= 400 and a < 600;
insert into t2 select a,4 from t1 where a >= 600 and a < 800;
insert into t2 select a,5 from t1 where a >= 800 and a < 1001;
explain partitions select * from t2;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	p0,p1,p2,p3,p4	ALL	NULL	NULL	NULL	NULL	1010	
explain partitions select * from t2 where a < 801 and a > 200;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	p1,p2,p3,p4	ALL	NULL	NULL	NULL	NULL	800	Using where
explain partitions select * from t2 where a < 801 and a > 800;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	p4	ALL	NULL	NULL	NULL	NULL	200	Using where
explain partitions select * from t2 where a > 600;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	p3,p4	ALL	NULL	NULL	NULL	NULL	400	Using where
explain partitions select * from t2 where a > 600 and b = 1;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	p3,p4	ALL	NULL	NULL	NULL	NULL	400	Using where
explain partitions select * from t2 where a > 600 and b = 4;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	p3,p4	ALL	NULL	NULL	NULL	NULL	400	Using where
explain partitions select * from t2 where a > 600 and b = 5;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	p3,p4	ALL	NULL	NULL	NULL	NULL	400	Using where
explain partitions select * from t2 where b = 5;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	p0,p1,p2,p3,p4	ALL	NULL	NULL	NULL	NULL	1010	Using where
flush status;
update t2 set b = 100 where b = 6;
show status like 'Handler_read_rnd_next';
Variable_name	Value
Handler_read_rnd_next	1015
flush status;
update t2 set a = 1002 where a = 1001;
show status like 'Handler_read_rnd_next';
Variable_name	Value
Handler_read_rnd_next	0
flush status;
update t2 set b = 6 where a = 600;
show status like 'Handler_read_rnd_next';
Variable_name	Value
Handler_read_rnd_next	201
flush status;
update t2 set b = 6 where a > 600 and a < 800;
show status like 'Handler_read_rnd_next';
Variable_name	Value
Handler_read_rnd_next	201
flush status;
delete from t2 where a > 600;
show status like 'Handler_read_rnd_next';
Variable_name	Value
Handler_read_rnd_next	402
drop table t2;
CREATE TABLE `t2` (
`a` int(11) default NULL,
`b` int(11) default NULL,
index (b)
) 
PARTITION BY RANGE (a) (
PARTITION p0 VALUES LESS THAN (200),
PARTITION p1 VALUES LESS THAN (400),
PARTITION p2 VALUES LESS THAN (600),
PARTITION p3 VALUES LESS THAN (800),
PARTITION p4 VALUES LESS THAN (1001));
insert into t2 select a,1 from t1 where a < 100;
insert into t2 select a,2 from t1 where a >= 200 and a < 300;
insert into t2 select a,3 from t1 where a >= 300 and a < 400;
insert into t2 select a,4 from t1 where a >= 400 and a < 500;
insert into t2 select a,5 from t1 where a >= 500 and a < 600;
insert into t2 select a,6 from t1 where a >= 600 and a < 700;
insert into t2 select a,7 from t1 where a >= 700 and a < 800;
insert into t2 select a,8 from t1 where a >= 800 and a < 900;
insert into t2 select a,9 from t1 where a >= 900 and a < 1001;
explain partitions select * from t2;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	p0,p1,p2,p3,p4	ALL	NULL	NULL	NULL	NULL	910	
explain partitions select * from t2 where a = 101;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	p0	ALL	NULL	NULL	NULL	NULL	110	Using where
explain partitions select * from t2 where a = 550;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	p2	ALL	NULL	NULL	NULL	NULL	200	Using where
explain partitions select * from t2 where a = 833;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	p4	ALL	NULL	NULL	NULL	NULL	200	Using where
explain partitions select * from t2 where (a = 100 OR a = 900);
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	p0,p4	ALL	NULL	NULL	NULL	NULL	310	Using where
explain partitions select * from t2 where (a > 100 AND a < 600);
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	p0,p1,p2,p3	ALL	NULL	NULL	NULL	NULL	710	Using where
explain partitions select * from t2 where b = 4;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	p0,p1,p2,p3,p4	ref	b	b	5	const	76	Using where
explain partitions select * from t2 where b = 6;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	p0,p1,p2,p3,p4	ref	b	b	5	const	76	Using where
explain partitions select * from t2 where b in (1,3,5);
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	p0,p1,p2,p3,p4	ALL	b	NULL	NULL	NULL	910	Using where
explain partitions select * from t2 where b in (2,4,6);
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	p0,p1,p2,p3,p4	ALL	b	NULL	NULL	NULL	910	Using where
explain partitions select * from t2 where b in (7,8,9);
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	p0,p1,p2,p3,p4	ALL	b	NULL	NULL	NULL	910	Using where
explain partitions select * from t2 where b > 5;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	p0,p1,p2,p3,p4	ALL	b	NULL	NULL	NULL	910	Using where
explain partitions select * from t2 where b > 5 and b < 8;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	p0,p1,p2,p3,p4	ALL	b	NULL	NULL	NULL	910	Using where
explain partitions select * from t2 where b > 5 and b < 7;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	p0,p1,p2,p3,p4	range	b	b	5	NULL	76	Using where
explain partitions select * from t2 where b > 0 and b < 5;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	p0,p1,p2,p3,p4	ALL	b	NULL	NULL	NULL	910	Using where
flush status;
update t2 set a = 111 where b = 10;
show status like 'Handler_read_rnd_next';
Variable_name	Value
Handler_read_rnd_next	0
show status like 'Handler_read_key';
Variable_name	Value
Handler_read_key	5
flush status;
update t2 set a = 111 where b in (5,6);
show status like 'Handler_read_rnd_next';
Variable_name	Value
Handler_read_rnd_next	915
show status like 'Handler_read_key';
Variable_name	Value
Handler_read_key	0
flush status;
update t2 set a = 222 where b = 7;
show status like 'Handler_read_rnd_next';
Variable_name	Value
Handler_read_rnd_next	0
show status like 'Handler_read_key';
Variable_name	Value
Handler_read_key	5
flush status;
delete from t2 where b = 7;
show status like 'Handler_read_rnd_next';
Variable_name	Value
Handler_read_rnd_next	0
show status like 'Handler_read_key';
Variable_name	Value
Handler_read_key	5
flush status;
delete from t2 where b > 5;
show status like 'Handler_read_rnd_next';
Variable_name	Value
Handler_read_rnd_next	1215
show status like 'Handler_read_key';
Variable_name	Value
Handler_read_key	0
show status like 'Handler_read_prev';
Variable_name	Value
Handler_read_prev	0
show status like 'Handler_read_next';
Variable_name	Value
Handler_read_next	0
flush status;
delete from t2 where b < 5 or b > 3;
show status like 'Handler_read_rnd_next';
Variable_name	Value
Handler_read_rnd_next	1215
show status like 'Handler_read_key';
Variable_name	Value
Handler_read_key	0
show status like 'Handler_read_prev';
Variable_name	Value
Handler_read_prev	0
show status like 'Handler_read_next';
Variable_name	Value
Handler_read_next	0
drop table t1, t2;
