| From: | "Merlin Moncure" <mmoncure(at)gmail(dot)com> |
|---|---|
| To: | "Luke Lonergan" <llonergan(at)greenplum(dot)com> |
| Cc: | "Martijn van Oosterhout" <kleptog(at)svana(dot)org>, "Raja Agrawal" <raja(dot)agrawal(at)gmail(dot)com>, pgsql-hackers(at)postgresql(dot)org |
| Subject: | Re: Asynchronous I/O Support |
| Date: | 2006-10-17 17:18:19 |
| Message-ID: | b42b73150610171018y3a80a088w9b221fad66c11190@mail.gmail.com |
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| Lists: | pgsql-hackers |
On 10/15/06, Luke Lonergan <llonergan(at)greenplum(dot)com> wrote:
> Martijn,
> The killer use-case we've identified is for the scattered I/O associated
> with index + heap scans in Postgres. If we can issue ~5-15 I/Os in advance
> when the TIDs are widely separated it has the potential to increase the I/O
> speed by the number of disks in the tablespace being scanned. At this
> point, that pattern will only use one disk.
did you have a chance to look at posix_fadvise?
merlin
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