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drop table if exists t1, t2, t3;
SET @save_key_buffer=@@key_buffer_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;
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 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;
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;
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;
|