Re: posix_fadvise v22

On Fri, 2 Jan 2009, Tom Lane wrote:

> ISTM that you *should* be able to see an improvement on even
> single-spindle systems, due to better overlapping of CPU and I/O effort.

The earlier synthetic tests I did:

http://archives.postgresql.org/pgsql-hackers/2008-09/msg01401.php

Showed a substantial speedup even in the single spindle case on a couple 
of systems, but one didn't really seem to benefit.  So we could theorize 
that Robert's test system is more like that one.  If someone can help out 
with making a more formal test case showing this in action, I'll dig into 
the details of what's different between that system and the others.

--
* Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD