| From: | Bruce Momjian <bruce(at)momjian(dot)us> |
|---|---|
| To: | Merlin Moncure <mmoncure(at)gmail(dot)com> |
| Cc: | david(at)lang(dot)hm, Greg Smith <gsmith(at)gregsmith(dot)com>, Guillaume Cottenceau <gc(at)mnc(dot)ch>, pgsql-performance(at)postgresql(dot)org |
| Subject: | Re: Choosing a filesystem |
| Date: | 2008-09-23 17:02:01 |
| Message-ID: | 200809231702.m8NH21118074@momjian.us |
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| Lists: | pgsql-performance |
Merlin Moncure wrote:
> > although for postgres the thing that you are doing the fsync on is the WAL
> > log file. that is a single (usually) contiguous file. As such it is very
> > efficiant to write large chunks of it. so while you will degrade from the
> > battery-only mode, the fact that the controller can flush many requests
> > worth of writes out to the WAL log at once while you fill the cache with
> > them one at a time is still a significant win.
>
> The heap files have to be synced as well during checkpoints, etc.
True, but as of 8.3 those checkpoint fsyncs are spread over the interval
between checkpoints.
--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com
+ If your life is a hard drive, Christ can be your backup. +
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