On 4/8/09 9:44 AM, Tom Lane wrote:
> Josh Berkus<josh@agliodbs.com> writes:
>> What about seq scans?
>
> If the kernel can't read-ahead a seqscan by itself, it's unlikely to
> be smart enough to be helped by posix_fadvise ... or at least so I
> would think. Do you have reason to think differently?
Well, Solaris 10 + UFS should be helped by fadvise -- in theory at
least, it would eliminate the need to modify your mount points for
better readahead when setting up a PG-Solaris server. Solaris-UFS quite
lazy about readahead. Zdenek, Jignesh?
You're probably correct about Linux and FreeBSD. I don't know if OSX +
HFS supports fadvise. If so, it could only help; readahead on HFS right
now is nonexistant.
Presumably fadvise is useless on Windows. Anyone know?
--
Josh Berkus
PostgreSQL Experts Inc.
www.pgexperts.com
