Re: Closing some 8.4 open items

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