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|
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;
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 MySQL 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
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));
show status like 'key_blocks_used';
Variable_name Value
Key_blocks_used 0
show status like 'key_blocks_unused';
Variable_name Value
Key_blocks_unused KEY_BLOCKS_UNUSED
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;
show status like 'key_blocks_used';
Variable_name Value
Key_blocks_used 4
show status like 'key_blocks_unused';
Variable_name Value
Key_blocks_unused KEY_BLOCKS_UNUSED
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 where; 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;
show status like 'key_blocks_used';
Variable_name Value
Key_blocks_used 4
show status like 'key_blocks_unused';
Variable_name Value
Key_blocks_unused KEY_BLOCKS_UNUSED
set global keycache2.key_buffer_size=0;
set global keycache3.key_buffer_size=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;
Warnings:
Warning 1438 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;
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;
show status like 'key_%';
Variable_name Value
Key_blocks_not_flushed 0
Key_blocks_unused KEY_BLOCKS_UNUSED
Key_blocks_used 4
Key_blocks_warm 0
Key_read_requests 22
Key_reads 0
Key_write_requests 26
Key_writes 6
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;
show status like 'key_%';
Variable_name Value
Key_blocks_not_flushed 0
Key_blocks_unused KEY_BLOCKS_UNUSED
Key_blocks_used 4
Key_blocks_warm 0
Key_read_requests 22
Key_reads 0
Key_write_requests 26
Key_writes 6
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;
show status like 'key_%';
Variable_name Value
Key_blocks_not_flushed 0
Key_blocks_unused KEY_BLOCKS_UNUSED
Key_blocks_used 4
Key_blocks_warm 0
Key_read_requests 22
Key_reads 0
Key_write_requests 26
Key_writes 6
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;
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 where
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 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;
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