Re: BUG #13437: Seq Scan increases heap_blks_read instead of heap_blks_hit when no disk is read

Поиск
Список
Период
Сортировка
От Andres Freund
Тема Re: BUG #13437: Seq Scan increases heap_blks_read instead of heap_blks_hit when no disk is read
Дата
Msg-id 20150612132411.GD28424@awork2.anarazel.de
обсуждение исходный текст
Ответ на BUG #13437: Seq Scan increases heap_blks_read instead of heap_blks_hit when no disk is read  (polpot78@gmail.com)
Список pgsql-bugs
Дерево обсуждения 
On 2015-06-12 13:21:33 +0000, polpot78@gmail.com wrote:
> When a seq scan is performed, but no real disk reads is performed, then
> postgreSQL still reports that disk-reads are performed. iostat reports that
> no Blocks are read.

Note that postgres' reports everything as a disk read that goes to the
OS. Which then does it's own level of caching.

Greetings,

Andres Freund

В списке pgsql-bugs по дате отправления:

Предыдущее
От: polpot78@gmail.com
Дата:
Сообщение: BUG #13437: Seq Scan increases heap_blks_read instead of heap_blks_hit when no disk is read
Следующее
От: Alvaro Herrera
Дата:
Сообщение: Re: Lack of Sanity Checking in file 'pctcl.c' for PostgreSQL 9.4.x