drop table if exists t1, t2, t3;
SET @save_key_buffer_size=@@key_buffer_size;
SET @save_key_cache_block_size=@@key_cache_block_size;
SET @save_key_cache_segments=@@key_cache_segments;
SET @save_key_cache_file_hash_size=@@key_cache_file_hash_size;
SELECT @@key_buffer_size, @@small.key_buffer_size;
@@key_buffer_size	@@small.key_buffer_size
2097152	131072
SET @@global.key_buffer_size=16*1024*1024;
SET @@global.default.key_buffer_size=16*1024*1024;
SET @@global.default.key_buffer_size=16*1024*1024;
SET @@global.small.key_buffer_size=1*1024*1024;
SET @@global.medium.key_buffer_size=4*1024*1024;
SET @@global.medium.key_buffer_size=0;
SET @@global.medium.key_buffer_size=0;
SHOW VARIABLES like "key_buffer_size";
Variable_name	Value
key_buffer_size	16777216
SELECT @@key_buffer_size;
@@key_buffer_size
16777216
SELECT @@global.key_buffer_size;
@@global.key_buffer_size
16777216
SELECT @@global.default.key_buffer_size;
@@global.default.key_buffer_size
16777216
SELECT @@global.default.`key_buffer_size`;
@@global.default.`key_buffer_size`
16777216
SELECT @@global.`default`.`key_buffer_size`;
@@global.`default`.`key_buffer_size`
16777216
SELECT @@`default`.key_buffer_size;
@@`default`.key_buffer_size
16777216
SELECT @@small.key_buffer_size;
@@small.key_buffer_size
1048576
SELECT @@medium.key_buffer_size;
@@medium.key_buffer_size
0
SET @@global.key_buffer_size=@save_key_buffer_size;
SELECT @@default.key_buffer_size;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'default.key_buffer_size' at line 1
SELECT @@skr.storage_engine="test";
ERROR HY000: Variable 'storage_engine' is not a variable component (can't be used as XXXX.variable_name)
select @@keycache1.key_cache_block_size;
@@keycache1.key_cache_block_size
0
select @@keycache1.key_buffer_size;
@@keycache1.key_buffer_size
0
set global keycache1.key_cache_block_size=2048;
select @@keycache1.key_buffer_size;
@@keycache1.key_buffer_size
0
select @@keycache1.key_cache_block_size;
@@keycache1.key_cache_block_size
2048
set global keycache1.key_buffer_size=1*1024*1024;
select @@keycache1.key_buffer_size;
@@keycache1.key_buffer_size
1048576
select @@keycache1.key_cache_block_size;
@@keycache1.key_cache_block_size
2048
set global keycache2.key_buffer_size=4*1024*1024;
select @@keycache2.key_buffer_size;
@@keycache2.key_buffer_size
4194304
select @@keycache2.key_cache_block_size;
@@keycache2.key_cache_block_size
1024
set global keycache1.key_buffer_size=0;
select @@keycache1.key_buffer_size;
@@keycache1.key_buffer_size
0
select @@keycache1.key_cache_block_size;
@@keycache1.key_cache_block_size
2048
select @@key_buffer_size;
@@key_buffer_size
2097152
select @@key_cache_block_size;
@@key_cache_block_size
1024
select @@key_cache_file_hash_size;
@@key_cache_file_hash_size
512
set global keycache1.key_buffer_size=1024*1024;
create table t1 (p int primary key, a char(10)) delay_key_write=1;
create table t2 (p int primary key, i int, a char(10), key k1(i), key k2(a));
select @org_key_blocks_unused-unused_blocks as key_blocks_unused, used_blocks as key_blocks_used from information_schema.key_caches where key_cache_name="default";
key_blocks_unused	key_blocks_used
0	0
insert into t1 values (1, 'qqqq'), (11, 'yyyy');
insert into t2 values (1, 1, 'qqqq'), (2, 1, 'pppp'),
(3, 1, 'yyyy'), (4, 3, 'zzzz');
select * from t1;
p	a
1	qqqq
11	yyyy
select * from t2;
p	i	a
1	1	qqqq
2	1	pppp
3	1	yyyy
4	3	zzzz
update t1 set p=2 where p=1;
update t2 set i=2 where i=1;
select @org_key_blocks_unused-unused_blocks as key_blocks_unused, used_blocks as key_blocks_used from information_schema.key_caches where key_cache_name="default";
key_blocks_unused	key_blocks_used
4	4
cache index t1 key (`primary`) in keycache1;
Table	Op	Msg_type	Msg_text
test.t1	assign_to_keycache	status	OK
explain select p from t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	NULL	PRIMARY	4	NULL	2	Using index
select p from t1;
p
2
11
explain select i from t2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	k1	5	NULL	4	Using index
select i from t2;
i
2
2
2
3
explain select count(*) from t1, t2 where t1.p = t2.i;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	PRIMARY	PRIMARY	4	NULL	2	Using index
1	SIMPLE	t2	ref	k1	k1	5	test.t1.p	2	Using index
select count(*) from t1, t2 where t1.p = t2.i;
count(*)
3
cache index t2 in keycache1;
Table	Op	Msg_type	Msg_text
test.t2	assign_to_keycache	status	OK
update t2 set p=p+1000, i=2 where a='qqqq';
cache index t2 in keycache2;
Table	Op	Msg_type	Msg_text
test.t2	assign_to_keycache	status	OK
insert into t2 values (2000, 3, 'yyyy');
cache index t2 in keycache1;
Table	Op	Msg_type	Msg_text
test.t2	assign_to_keycache	status	OK
update t2 set p=3000 where a='zzzz';
select * from t2;
p	i	a
1001	2	qqqq
2	2	pppp
3	2	yyyy
3000	3	zzzz
2000	3	yyyy
explain select p from t2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	PRIMARY	4	NULL	5	Using index
select p from t2;
p
2
3
1001
2000
3000
explain select i from t2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	k1	5	NULL	5	Using index
select i from t2;
i
2
2
2
3
3
explain select a from t2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	k2	11	NULL	5	Using index
select a from t2;
a
pppp
qqqq
yyyy
yyyy
zzzz
cache index t1 in unknown_key_cache;
ERROR HY000: Unknown key cache 'unknown_key_cache'
cache index t1 key (unknown_key) in keycache1;
Table	Op	Msg_type	Msg_text
test.t1	assign_to_keycache	Error	Key 'unknown_key' doesn't exist in table 't1'
test.t1	assign_to_keycache	status	Operation failed
select @@keycache2.key_buffer_size;
@@keycache2.key_buffer_size
4194304
select @@keycache2.key_cache_block_size;
@@keycache2.key_cache_block_size
1024
set global keycache2.key_buffer_size=0;
select @@keycache2.key_buffer_size;
@@keycache2.key_buffer_size
0
select @@keycache2.key_cache_block_size;
@@keycache2.key_cache_block_size
1024
set global keycache2.key_buffer_size=1024*1024;
select @@keycache2.key_buffer_size;
@@keycache2.key_buffer_size
1048576
update t2 set p=4000 where a='zzzz';
update t1 set p=p+1;
set global keycache1.key_buffer_size=0;
select * from t2;
p	i	a
1001	2	qqqq
2	2	pppp
3	2	yyyy
4000	3	zzzz
2000	3	yyyy
select p from t2;
p
2
3
1001
2000
4000
explain select i from t2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	k1	5	NULL	5	Using index
select i from t2;
i
2
2
2
3
3
explain select a from t2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	k2	11	NULL	5	Using index
select a from t2;
a
pppp
qqqq
yyyy
yyyy
zzzz
select * from t1;
p	a
3	qqqq
12	yyyy
select p from t1;
p
3
12
create table t3 (like t1);
cache index t3 in small;
Table	Op	Msg_type	Msg_text
test.t3	assign_to_keycache	status	OK
insert into t3 select * from t1;
cache index t3 in keycache2;
Table	Op	Msg_type	Msg_text
test.t3	assign_to_keycache	status	OK
cache index t1,t2 in default;
Table	Op	Msg_type	Msg_text
test.t1	assign_to_keycache	status	OK
test.t2	assign_to_keycache	status	OK
drop table t1,t2,t3;
select @org_key_blocks_unused-unused_blocks as key_blocks_unused, used_blocks as key_blocks_used from information_schema.key_caches where key_cache_name="default";
key_blocks_unused	key_blocks_used
0	4
create table t1 (a int primary key);
cache index t1 in keycache2;
Table	Op	Msg_type	Msg_text
test.t1	assign_to_keycache	status	OK
insert t1 values (1),(2),(3),(4),(5),(6),(7),(8);
set global keycache2.key_buffer_size=0;
select * from t1;
a
1
2
3
4
5
6
7
8
drop table t1;
set global keycache3.key_buffer_size=100;
Warnings:
Warning	1292	Truncated incorrect key_buffer_size value: '100'
set global keycache3.key_buffer_size=0;
create table t1 (mytext text, FULLTEXT (mytext));
insert t1 values ('aaabbb');
check table t1;
Table	Op	Msg_type	Msg_text
test.t1	check	status	OK
set @my_key_cache_block_size= @@global.key_cache_block_size;
set GLOBAL key_cache_block_size=2048;
check table t1;
Table	Op	Msg_type	Msg_text
test.t1	check	status	OK
drop table t1;
set global key_cache_block_size= @my_key_cache_block_size;
CREATE TABLE t1(a int NOT NULL AUTO_INCREMENT PRIMARY KEY);
SET @my_key_cache_block_size= @@global.key_cache_block_size;
SET GLOBAL key_cache_block_size=1536;
INSERT INTO t1 VALUES (1);
SELECT @@key_cache_block_size;
@@key_cache_block_size
1536
CHECK TABLE t1;
Table	Op	Msg_type	Msg_text
test.t1	check	status	OK
DROP TABLE t1;
CREATE TABLE t1(a int NOT NULL AUTO_INCREMENT PRIMARY KEY, b int);
CREATE TABLE t2(a int NOT NULL AUTO_INCREMENT PRIMARY KEY, b int);
SET GLOBAL key_cache_block_size=1536;
INSERT INTO t1 VALUES (1,0);
INSERT INTO t2(b) SELECT b FROM t1;
INSERT INTO t1(b) SELECT b FROM t2;
INSERT INTO t2(b) SELECT b FROM t1;
INSERT INTO t1(b) SELECT b FROM t2;
INSERT INTO t2(b) SELECT b FROM t1;
INSERT INTO t1(b) SELECT b FROM t2;
INSERT INTO t2(b) SELECT b FROM t1;
INSERT INTO t1(b) SELECT b FROM t2;
INSERT INTO t2(b) SELECT b FROM t1;
INSERT INTO t1(b) SELECT b FROM t2;
INSERT INTO t2(b) SELECT b FROM t1;
INSERT INTO t1(b) SELECT b FROM t2;
INSERT INTO t2(b) SELECT b FROM t1;
INSERT INTO t1(b) SELECT b FROM t2;
INSERT INTO t2(b) SELECT b FROM t1;
INSERT INTO t1(b) SELECT b FROM t2;
INSERT INTO t2(b) SELECT b FROM t1;
INSERT INTO t1(b) SELECT b FROM t2;
SELECT COUNT(*) FROM t1;
COUNT(*)
4181
SELECT @@key_cache_block_size;
@@key_cache_block_size
1536
CHECK TABLE t1;
Table	Op	Msg_type	Msg_text
test.t1	check	status	OK
DROP TABLE t1,t2;
set global key_cache_block_size= @my_key_cache_block_size;
set @@global.key_buffer_size=0;
ERROR HY000: Cannot drop default keycache
select @@global.key_buffer_size;
@@global.key_buffer_size
2097152
SET @bug28478_key_cache_block_size= @@global.key_cache_block_size;
SET GLOBAL key_cache_block_size= 1536;
CREATE TABLE t1 (
id BIGINT NOT NULL AUTO_INCREMENT PRIMARY KEY,
c1 CHAR(150),
c2 CHAR(150),
c3 CHAR(150),
KEY(c1, c2, c3)
) ENGINE= MyISAM;
INSERT INTO t1 (c1, c2, c3) VALUES
('a', 'b', 'c'), ('b', 'c', 'd'), ('c', 'd', 'e'), ('d', 'e', 'f'),
('e', 'f', 'g'), ('f', 'g', 'h'), ('g', 'h', 'i'), ('h', 'i', 'j'),
('i', 'j', 'k'), ('j', 'k', 'l'), ('k', 'l', 'm'), ('l', 'm', 'n'),
('m', 'n', 'o'), ('n', 'o', 'p'), ('o', 'p', 'q'), ('p', 'q', 'r'),
('q', 'r', 's'), ('r', 's', 't'), ('s', 't', 'u'), ('t', 'u', 'v'),
('u', 'v', 'w'), ('v', 'w', 'x'), ('w', 'x', 'y'), ('x', 'y', 'z');
INSERT INTO t1 (c1, c2, c3) SELECT c1, c2, c3 from t1;
INSERT INTO t1 (c1, c2, c3) SELECT c1, c2, c3 from t1;
INSERT INTO t1 (c1, c2, c3) SELECT c1, c2, c3 from t1;
CHECK TABLE t1;
Table	Op	Msg_type	Msg_text
test.t1	check	status	OK
SHOW VARIABLES LIKE 'key_cache_block_size';
Variable_name	Value
key_cache_block_size	1536
SET GLOBAL key_cache_block_size= @bug28478_key_cache_block_size;
DROP TABLE t1;
#
# Bug#12361113: crash when load index into cache
#
# Note that this creates an empty disabled key cache!
SET GLOBAL key_cache_none.key_cache_block_size = 1024;
CREATE TABLE t1 (a INT, b INTEGER NOT NULL, KEY (b) ) ENGINE = MYISAM;
INSERT INTO t1 VALUES (1, 1);
CACHE INDEX t1 in key_cache_none;
ERROR HY000: Unknown key cache 'key_cache_none'
# The bug crashed the server at LOAD INDEX below. Now it will succeed 
# since the default cache is used due to CACHE INDEX failed for
# key_cache_none.
LOAD INDEX INTO CACHE t1;
Table	Op	Msg_type	Msg_text
test.t1	preload_keys	status	OK
DROP TABLE t1;
set global key_buffer_size=@save_key_buffer_size;
set global key_cache_block_size=@save_key_cache_block_size;
select @@key_buffer_size;
@@key_buffer_size
2097152
select @@key_cache_block_size;
@@key_cache_block_size
1024
select @@key_cache_segments;
@@key_cache_segments
0
create table t1 (
p int not null auto_increment primary key,
a char(10));
create table t2 (
p int  not null auto_increment primary key,
i int, a char(10), key k1(i), key k2(a));
select @@key_cache_segments;
@@key_cache_segments
0
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	NULL	NULL	2097152	1024	0	#	0	0	0	0	0
small	NULL	NULL	1048576	1024	1	#	0	1	0	2	1
insert into t1 values (1, 'qqqq'), (2, 'yyyy');
insert into t2 values (1, 1, 'qqqq'), (2, 1, 'pppp'),
(3, 1, 'yyyy'), (4, 3, 'zzzz');
select * from t1;
p	a
1	qqqq
2	yyyy
select * from t2;
p	i	a
1	1	qqqq
2	1	pppp
3	1	yyyy
4	3	zzzz
update t1 set p=3 where p=1;
update t2 set i=2 where i=1;
select * from information_schema.session_status where variable_name like 'key_%' and variable_name != 'Key_blocks_unused';
VARIABLE_NAME	VARIABLE_VALUE
KEY_BLOCKS_NOT_FLUSHED	0
KEY_BLOCKS_USED	4
KEY_BLOCKS_WARM	0
KEY_READ_REQUESTS	22
KEY_READS	0
KEY_WRITE_REQUESTS	26
KEY_WRITES	6
select variable_value into @key_blocks_unused from information_schema.session_status where variable_name = 'Key_blocks_unused';
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	NULL	NULL	2097152	1024	4	#	0	22	0	26	6
small	NULL	NULL	1048576	1024	1	#	0	1	0	2	1
delete from t2 where a='zzzz';
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	NULL	NULL	2097152	1024	4	#	0	29	0	32	9
small	NULL	NULL	1048576	1024	1	#	0	1	0	2	1
delete from t1;
delete from t2;
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	NULL	NULL	2097152	1024	4	#	0	29	0	32	9
small	NULL	NULL	1048576	1024	1	#	0	1	0	2	1
set global key_cache_segments=2;
select @@key_cache_segments;
@@key_cache_segments
2
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	2	NULL	2097152	1024	0	#	0	0	0	0	0
small	NULL	NULL	1048576	1024	1	#	0	1	0	2	1
insert into t1 values (1, 'qqqq'), (2, 'yyyy');
insert into t2 values (1, 1, 'qqqq'), (2, 1, 'pppp'),
(3, 1, 'yyyy'), (4, 3, 'zzzz');
select * from t1;
p	a
1	qqqq
2	yyyy
select * from t2;
p	i	a
1	1	qqqq
2	1	pppp
3	1	yyyy
4	3	zzzz
update t1 set p=3 where p=1;
update t2 set i=2 where i=1;
select * from information_schema.session_status where variable_name like 'key_%' and variable_name != 'Key_blocks_unused';
VARIABLE_NAME	VARIABLE_VALUE
KEY_BLOCKS_NOT_FLUSHED	0
KEY_BLOCKS_USED	4
KEY_BLOCKS_WARM	0
KEY_READ_REQUESTS	22
KEY_READS	0
KEY_WRITE_REQUESTS	26
KEY_WRITES	6
select variable_value < @key_blocks_unused from information_schema.session_status where variable_name = 'Key_blocks_unused';
variable_value < @key_blocks_unused
1
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	2	NULL	2097152	1024	4	#	0	22	0	26	6
small	NULL	NULL	1048576	1024	1	#	0	1	0	2	1
delete from t1;
delete from t2;
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	2	NULL	2097152	1024	4	#	0	22	0	26	6
small	NULL	NULL	1048576	1024	1	#	0	1	0	2	1
set global key_cache_segments=1;
select @@key_cache_segments;
@@key_cache_segments
1
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	1	NULL	2097152	1024	0	#	0	0	0	0	0
small	NULL	NULL	1048576	1024	1	#	0	1	0	2	1
insert into t1 values (1, 'qqqq'), (2, 'yyyy');
insert into t2 values (1, 1, 'qqqq'), (2, 1, 'pppp'),
(3, 1, 'yyyy'), (4, 3, 'zzzz');
select * from t1;
p	a
1	qqqq
2	yyyy
select * from t2;
p	i	a
1	1	qqqq
2	1	pppp
3	1	yyyy
4	3	zzzz
update t1 set p=3 where p=1;
update t2 set i=2 where i=1;
select * from information_schema.session_status where variable_name like 'key_%' and variable_name != 'Key_blocks_unused';
VARIABLE_NAME	VARIABLE_VALUE
KEY_BLOCKS_NOT_FLUSHED	0
KEY_BLOCKS_USED	4
KEY_BLOCKS_WARM	0
KEY_READ_REQUESTS	22
KEY_READS	0
KEY_WRITE_REQUESTS	26
KEY_WRITES	6
select variable_value = @key_blocks_unused from information_schema.session_status where variable_name = 'Key_blocks_unused';
variable_value = @key_blocks_unused
1
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	1	NULL	2097152	1024	4	#	0	22	0	26	6
small	NULL	NULL	1048576	1024	1	#	0	1	0	2	1
delete from t1;
delete from t2;
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	1	NULL	2097152	1024	4	#	0	22	0	26	6
small	NULL	NULL	1048576	1024	1	#	0	1	0	2	1
flush tables;
flush status;
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	1	NULL	2097152	1024	4	#	0	0	0	0	0
small	NULL	NULL	1048576	1024	1	#	0	0	0	0	0
set global key_buffer_size=32*1024;
set global key_cache_file_hash_size=128;
select @@key_buffer_size;
@@key_buffer_size
32768
set global key_cache_segments=2;
select @@key_cache_segments;
@@key_cache_segments
2
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	2	NULL	32768	1024	0	#	0	0	0	0	0
small	NULL	NULL	1048576	1024	1	#	0	0	0	0	0
insert into t1 values (1, 'qqqq'), (2, 'yyyy');
insert into t2 values (1, 1, 'qqqq'), (2, 1, 'pppp'),
(3, 1, 'yyyy'), (4, 3, 'zzzz');
select * from t1;
p	a
1	qqqq
2	yyyy
select * from t2;
p	i	a
1	1	qqqq
2	1	pppp
3	1	yyyy
4	3	zzzz
update t1 set p=3 where p=1;
update t2 set i=2 where i=1;
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	2	NULL	32768	1024	4	#	0	22	0	26	6
small	NULL	NULL	1048576	1024	1	#	0	0	0	0	0
insert into t1(a) select a from t1;
insert into t1(a) select a from t1;
insert into t1(a) select a from t1;
insert into t1(a) select a from t1;
insert into t1(a) select a from t1;
insert into t1(a) select a from t1;
insert into t1(a) select a from t1;
insert into t1(a) select a from t1;
insert into t2(i,a) select i,a from t2;
insert into t2(i,a) select i,a from t2;
insert into t2(i,a) select i,a from t2;
insert into t2(i,a) select i,a from t2;
insert into t2(i,a) select i,a from t2;
insert into t2(i,a) select i,a from t2;
insert into t2(i,a) select i,a from t2;
insert into t2(i,a) select i,a from t2;
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	2	NULL	32768	1024	#	#	0	6733	#	3684	103
small	NULL	NULL	1048576	1024	#	#	0	0	#	0	0
select * from t1 where p between 1010 and 1020 ;
p	a
select * from t2 where p between 1010 and 1020 ;
p	i	a
1010	2	pppp
1011	2	yyyy
1012	3	zzzz
1013	2	qqqq
1014	2	pppp
1015	2	yyyy
1016	3	zzzz
1017	2	qqqq
1018	2	pppp
1019	2	yyyy
1020	3	zzzz
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	2	NULL	32768	1024	#	#	0	6750	#	3684	103
small	NULL	NULL	1048576	1024	#	#	0	0	#	0	0
flush tables;
flush status;
update t1 set a='zzzz' where a='qqqq';
update t2 set i=1 where i=2;
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	2	NULL	32768	1024	#	#	0	3076	18	1552	18
small	NULL	NULL	1048576	1024	#	#	0	0	0	0	0
set global keycache1.key_buffer_size=256*1024;
select @@keycache1.key_buffer_size;
@@keycache1.key_buffer_size
262144
set global keycache1.key_cache_segments=7;
select @@keycache1.key_cache_segments;
@@keycache1.key_cache_segments
7
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	2	NULL	32768	1024	#	#	0	3076	18	1552	18
small	NULL	NULL	1048576	1024	#	#	0	0	0	0	0
keycache1	7	NULL	262143	2048	#	#	0	0	0	0	0
select * from information_schema.key_caches where key_cache_name like "key%"
                                                  and segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
keycache1	7	NULL	262143	2048	0	#	0	0	0	0	0
cache index t1 key (`primary`) in keycache1;
Table	Op	Msg_type	Msg_text
test.t1	assign_to_keycache	status	OK
explain select p from t1 where p between 1010 and 1020;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	PRIMARY	PRIMARY	4	NULL	1	Using where; Using index
select p from t1 where p between 1010 and 1020;
p
explain select i from t2 where p between 1010 and 1020;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	PRIMARY	PRIMARY	4	NULL	28	Using index condition
select i from t2 where p between 1010 and 1020;
i
1
1
3
1
1
1
3
1
1
1
3
explain select count(*) from t1, t2 where t1.p = t2.i;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	k1	k1	5	NULL	1024	Using where; Using index
1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.i	1	Using index
select count(*) from t1, t2 where t1.p = t2.i;
count(*)
256
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	2	NULL	32768	1024	#	#	0	3172	24	1552	18
small	NULL	NULL	1048576	1024	#	#	0	0	0	0	0
keycache1	7	NULL	262143	2048	#	#	0	14	3	0	0
select * from information_schema.key_caches where key_cache_name like "key%"
                                                  and segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
keycache1	7	NULL	262143	2048	3	#	0	14	3	0	0
cache index t2 in keycache1;
Table	Op	Msg_type	Msg_text
test.t2	assign_to_keycache	status	OK
update t2 set p=p+3000, i=2 where a='qqqq';
select * from information_schema.key_caches where key_cache_name like "key%"
                                                  and segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
keycache1	7	NULL	262143	2048	25	#	0	2082	25	1071	19
set global keycache2.key_buffer_size=1024*1024;
cache index t2 in keycache2;
Table	Op	Msg_type	Msg_text
test.t2	assign_to_keycache	status	OK
insert into t2 values (2000, 3, 'yyyy');
select * from information_schema.key_caches where key_cache_name like "keycache2"
                                                  and segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
keycache2	NULL	NULL	1048576	1024	6	#	0	6	6	3	3
select * from information_schema.key_caches where key_cache_name like "key%" 
and segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
keycache1	7	NULL	262143	2048	25	#	0	2082	25	1071	19
keycache2	NULL	NULL	1048576	1024	6	#	0	6	6	3	3
cache index t2 in keycache1;
Table	Op	Msg_type	Msg_text
test.t2	assign_to_keycache	status	OK
update t2 set p=p+5000 where a='zzzz';
select * from t2 where p between 1010 and 1020;
p	i	a
1010	1	pppp
1011	1	yyyy
1014	1	pppp
1015	1	yyyy
1018	1	pppp
1019	1	yyyy
explain select p from t2  where p between 1010 and 1020;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	PRIMARY	PRIMARY	4	NULL	7	Using where; Using index
select p from t2 where p between 1010 and 1020;
p
1010
1011
1014
1015
1018
1019
explain select i from t2 where a='yyyy' and i=3;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	ref	k1,k2	k1	5	const	188	Using where
select i from t2 where a='yyyy' and i=3;
i
3
explain select a from t2 where a='yyyy' and i=3;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	ref	k1,k2	k1	5	const	188	Using where
select a from t2 where a='yyyy' and i=3 ;
a
yyyy
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	2	NULL	32768	1024	#	#	0	3172	24	1552	18
small	NULL	NULL	1048576	1024	#	#	0	0	0	0	0
keycache1	7	NULL	262143	2048	#	#	0	3201	43	1594	30
keycache2	NULL	NULL	1048576	1024	#	#	0	6	6	3	3
set global keycache1.key_cache_block_size=2*1024;
insert into t2 values (7000, 3, 'yyyy');
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	2	NULL	32768	1024	#	#	0	3172	24	1552	18
small	NULL	NULL	1048576	1024	#	#	0	0	0	0	0
keycache1	7	NULL	262143	2048	#	#	0	6	6	3	3
keycache2	NULL	NULL	1048576	1024	#	#	0	6	6	3	3
set global keycache1.key_cache_block_size=8*1024;
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	2	NULL	32768	1024	#	#	0	3172	24	1552	18
small	NULL	NULL	1048576	1024	#	#	0	0	0	0	0
keycache1	3	NULL	262143	8192	#	#	0	0	0	0	0
keycache2	NULL	NULL	1048576	1024	#	#	0	6	6	3	3
insert into t2 values (8000, 3, 'yyyy');
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	2	NULL	32768	1024	#	#	0	3172	24	1552	18
small	NULL	NULL	1048576	1024	#	#	0	0	0	0	0
keycache1	3	NULL	262143	8192	#	#	0	6	5	3	3
keycache2	NULL	NULL	1048576	1024	#	#	0	6	6	3	3
set global keycache1.key_buffer_size=64*1024;
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	2	NULL	32768	1024	#	#	0	3172	24	1552	18
small	NULL	NULL	1048576	1024	#	#	0	0	0	0	0
keycache2	NULL	NULL	1048576	1024	#	#	0	6	6	3	3
set global keycache1.key_cache_block_size=2*1024;
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	2	NULL	32768	1024	#	#	0	3172	24	1552	18
small	NULL	NULL	1048576	1024	#	#	0	0	0	0	0
keycache1	3	NULL	65535	2048	#	#	0	0	0	0	0
keycache2	NULL	NULL	1048576	1024	#	#	0	6	6	3	3
set global keycache1.key_cache_block_size=8*1024;
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	2	NULL	32768	1024	#	#	0	3172	24	1552	18
small	NULL	NULL	1048576	1024	#	#	0	0	0	0	0
keycache2	NULL	NULL	1048576	1024	#	#	0	6	6	3	3
set global keycache1.key_buffer_size=0;
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	2	NULL	32768	1024	#	#	0	3172	24	1552	18
small	NULL	NULL	1048576	1024	#	#	0	0	0	0	0
keycache2	NULL	NULL	1048576	1024	#	#	0	6	6	3	3
set global keycache1.key_cache_block_size=8*1024;
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	2	NULL	32768	1024	#	#	0	3172	24	1552	18
small	NULL	NULL	1048576	1024	#	#	0	0	0	0	0
keycache2	NULL	NULL	1048576	1024	#	#	0	6	6	3	3
set global keycache1.key_buffer_size=0;
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	2	NULL	32768	1024	#	#	0	3172	24	1552	18
small	NULL	NULL	1048576	1024	#	#	0	0	0	0	0
keycache2	NULL	NULL	1048576	1024	#	#	0	6	6	3	3
set global keycache1.key_buffer_size=128*1024;
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	2	NULL	32768	1024	#	#	0	3172	24	1552	18
small	NULL	NULL	1048576	1024	#	#	0	0	0	0	0
keycache1	1	NULL	131072	8192	#	#	0	0	0	0	0
keycache2	NULL	NULL	1048576	1024	#	#	0	6	6	3	3
set global keycache1.key_cache_block_size=1024;
select * from information_schema.key_caches where segment_number is null;
KEY_CACHE_NAME	SEGMENTS	SEGMENT_NUMBER	FULL_SIZE	BLOCK_SIZE	USED_BLOCKS	UNUSED_BLOCKS	DIRTY_BLOCKS	READ_REQUESTS	READS	WRITE_REQUESTS	WRITES
default	2	NULL	32768	1024	#	#	0	3172	24	1552	18
small	NULL	NULL	1048576	1024	#	#	0	0	0	0	0
keycache1	7	NULL	131068	1024	#	#	0	0	0	0	0
keycache2	NULL	NULL	1048576	1024	#	#	0	6	6	3	3
drop table t1,t2;
set global keycache1.key_buffer_size=0;
set global keycache2.key_buffer_size=0;
set global key_buffer_size=@save_key_buffer_size;
set global key_cache_segments=@save_key_cache_segments;
set global key_cache_file_hash_size=@save_key_cache_file_hash_size;