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drop table if exists t1, t2;
set global aria_checkpoint_interval=0;
create temporary table initial
select variable_name,variable_value from
information_schema.global_status where variable_name like "Aria_pagecache_reads";
create table t1 (
a int not null auto_increment,
b char(16) not null,
primary key (a),
key (b)
) engine=aria row_format=dynamic;
create table t2(
a int not null auto_increment,
b char(16) not null,
primary key (a),
key (b)
) engine=aria row_format=dynamic;
insert into t1(b) values
('test0'),
('test1'),
('test2'),
('test3'),
('test4'),
('test5'),
('test6'),
('test7');
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(*)
33448
select count(*) from t2;
count(*)
20672
flush tables;
flush status;
select g.variable_name,g.variable_value-i.variable_value from information_schema.global_status as g,initial as i where g.variable_name like "Aria_pagecache_read%" and g.variable_name=i.variable_name order by g.variable_name desc;
variable_name g.variable_value-i.variable_value
ARIA_PAGECACHE_READS 2
select count(*) from t1 where b = 'test1';
count(*)
4181
select g.variable_name,g.variable_value-i.variable_value from information_schema.global_status as g,initial as i where g.variable_name like "Aria_pagecache_read%" and g.variable_name=i.variable_name order by g.variable_name desc;
variable_name g.variable_value-i.variable_value
ARIA_PAGECACHE_READS 11
select count(*) from t1 where b = 'test1';
count(*)
4181
select g.variable_name,g.variable_value-i.variable_value from information_schema.global_status as g,initial as i where g.variable_name like "Aria_pagecache_read%" and g.variable_name=i.variable_name order by g.variable_name desc;
variable_name g.variable_value-i.variable_value
ARIA_PAGECACHE_READS 11
flush tables;
flush status;
select @@preload_buffer_size;
@@preload_buffer_size
32768
load index into cache t1;
Table Op Msg_type Msg_text
test.t1 preload_keys status OK
select g.variable_name,g.variable_value-i.variable_value from information_schema.global_status as g,initial as i where g.variable_name like "Aria_pagecache_read%" and g.variable_name=i.variable_name order by g.variable_name desc;
variable_name g.variable_value-i.variable_value
ARIA_PAGECACHE_READS 107
select count(*) from t1 where b = 'test1';
count(*)
4181
select g.variable_name,g.variable_value-i.variable_value from information_schema.global_status as g,initial as i where g.variable_name like "Aria_pagecache_read%" and g.variable_name=i.variable_name order by g.variable_name desc;
variable_name g.variable_value-i.variable_value
ARIA_PAGECACHE_READS 107
flush tables;
flush status;
select g.variable_name,g.variable_value-i.variable_value from information_schema.global_status as g,initial as i where g.variable_name like "Aria_pagecache_read%" and g.variable_name=i.variable_name order by g.variable_name desc;
variable_name g.variable_value-i.variable_value
ARIA_PAGECACHE_READS 107
set session preload_buffer_size=256*1024;
select @@preload_buffer_size;
@@preload_buffer_size
262144
load index into cache t1 ignore leaves;
Table Op Msg_type Msg_text
test.t1 preload_keys status OK
select g.variable_name,g.variable_value-i.variable_value from information_schema.global_status as g,initial as i where g.variable_name like "Aria_pagecache_read%" and g.variable_name=i.variable_name order by g.variable_name desc;
variable_name g.variable_value-i.variable_value
ARIA_PAGECACHE_READS 203
select count(*) from t1 where b = 'test1';
count(*)
4181
select g.variable_name,g.variable_value-i.variable_value from information_schema.global_status as g,initial as i where g.variable_name like "Aria_pagecache_read%" and g.variable_name=i.variable_name order by g.variable_name desc;
variable_name g.variable_value-i.variable_value
ARIA_PAGECACHE_READS 211
flush tables;
flush status;
select g.variable_name,g.variable_value-i.variable_value from information_schema.global_status as g,initial as i where g.variable_name like "Aria_pagecache_read%" and g.variable_name=i.variable_name order by g.variable_name desc;
variable_name g.variable_value-i.variable_value
ARIA_PAGECACHE_READS 211
set session preload_buffer_size=1*1024;
select @@preload_buffer_size;
@@preload_buffer_size
1024
load index into cache t1, t2 key (primary,b) ignore leaves;
Table Op Msg_type Msg_text
test.t1 preload_keys status OK
test.t2 preload_keys status OK
select g.variable_name,g.variable_value-i.variable_value from information_schema.global_status as g,initial as i where g.variable_name like "Aria_pagecache_read%" and g.variable_name=i.variable_name order by g.variable_name desc;
variable_name g.variable_value-i.variable_value
ARIA_PAGECACHE_READS 364
select count(*) from t1 where b = 'test1';
count(*)
4181
select count(*) from t2 where b = 'test1';
count(*)
2584
select g.variable_name,g.variable_value-i.variable_value from information_schema.global_status as g,initial as i where g.variable_name like "Aria_pagecache_read%" and g.variable_name=i.variable_name order by g.variable_name desc;
variable_name g.variable_value-i.variable_value
ARIA_PAGECACHE_READS 369
flush tables;
flush status;
select g.variable_name,g.variable_value-i.variable_value from information_schema.global_status as g,initial as i where g.variable_name like "Aria_pagecache_read%" and g.variable_name=i.variable_name order by g.variable_name desc;
variable_name g.variable_value-i.variable_value
ARIA_PAGECACHE_READS 369
load index into cache t3, t2 key (primary,b) ;
Table Op Msg_type Msg_text
test.t3 preload_keys Error Table 'test.t3' doesn't exist
test.t3 preload_keys status Operation failed
test.t2 preload_keys status OK
select g.variable_name,g.variable_value-i.variable_value from information_schema.global_status as g,initial as i where g.variable_name like "Aria_pagecache_read%" and g.variable_name=i.variable_name order by g.variable_name desc;
variable_name g.variable_value-i.variable_value
ARIA_PAGECACHE_READS 426
flush tables;
flush status;
select g.variable_name,g.variable_value-i.variable_value from information_schema.global_status as g,initial as i where g.variable_name like "Aria_pagecache_read%" and g.variable_name=i.variable_name order by g.variable_name desc;
variable_name g.variable_value-i.variable_value
ARIA_PAGECACHE_READS 426
load index into cache t3 key (b), t2 key (c) ;
Table Op Msg_type Msg_text
test.t3 preload_keys Error Table 'test.t3' doesn't exist
test.t3 preload_keys status Operation failed
test.t2 preload_keys Error Key 'c' doesn't exist in table 't2'
test.t2 preload_keys status Operation failed
select g.variable_name,g.variable_value-i.variable_value from information_schema.global_status as g,initial as i where g.variable_name like "Aria_pagecache_read%" and g.variable_name=i.variable_name order by g.variable_name desc;
variable_name g.variable_value-i.variable_value
ARIA_PAGECACHE_READS 426
drop table t1, t2;
drop temporary table initial;
show status like "key_read%";
Variable_name Value
Key_read_requests 0
Key_reads 0
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