Re: O_DIRECT for WAL writes - Mailing list pgsql-patches

From Neil Conway
Subject Re: O_DIRECT for WAL writes
Date
Msg-id 4295D9EB.4000703@samurai.com
Whole thread Raw
In response to O_DIRECT for WAL writes  (ITAGAKI Takahiro <itagaki.takahiro@lab.ntt.co.jp>)
Responses Re: O_DIRECT for WAL writes  (ITAGAKI Takahiro <itagaki.takahiro@lab.ntt.co.jp>)
List pgsql-patches
ITAGAKI Takahiro wrote:
> The patch adds a new choice "open_direct" to wal_sync_method.
> It uses O_DIRECT flags for WAL writes, like O_SYNC.

Have you looked at what the performance difference of this option is?
For example, these benchmark results seem to indicate that an older
version of the patch is not a performance win, at least for OSDL's workload:

http://www.mail-archive.com/pgsql-patches@postgresql.org/msg07186.html

Is this data still applicable to the revised patch?

-Neil

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