On Fri, 2007-09-21 at 11:34 +0100, Heikki Linnakangas wrote:
> Which version of Postgres is this? In 8.3, a scan like that really won't
> suck it all into the shared buffer cache. For seq scans on tables larger
> than shared_buffers/4, it switches to the bulk read strategy, using only
> a few buffers, and choosing the starting point with the scan
> synchronization facility.
>
This was on 8.1.9 installed via apt-get on Debian 4.1.1-21. In any case
I'm pretty sure linux swaps shared buffers, as I always got worse
performance for shared buffers more than about 1/3 of the memory. But in
that case the output of top is misleading.
Cheers,
Csaba.