Why does splitting $PGDATA and xlog yield a performance benefit?
От | David Kerr |
---|---|
Тема | Why does splitting $PGDATA and xlog yield a performance benefit? |
Дата | |
Msg-id | 20150825170848.GA2656@mr-paradox.net обсуждение исходный текст |
Ответы |
Re: Why does splitting $PGDATA and xlog yield a performance
benefit?
Re: Why does splitting $PGDATA and xlog yield a performance benefit? |
Список | pgsql-general |
Howdy All, For a very long time I've held the belief that splitting PGDATA and xlog on linux systems fairly universally gives a decentperformance benefit for many common workloads. (i've seen up to 20% personally). I was under the impression that this had to do with regular fsync()'s from the WAL interfearing with and over-reaching writing out the filesystem buffers. Basically, I think i was conflating fsync() with sync(). So if it's not that, then that just leaves bandwith (ignoring all of the other best practice reasons for reliablity, etc.).So, in theory if you're not swamping your disk I/O then you won't really benefit from relocating your XLOGs. However, I know from experience that's not entirely true, (although it's not always easy to measure all aspects of your I/Obandwith). Am I missing something? Thanks
В списке pgsql-general по дате отправления: