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