Re: extremly low memory usage

On Aug 17, 2005, at 10:11 PM, Jeremiah Jahn wrote:

> I just put together a system with 6GB of ram on a 14 disk raid 10
> array.
> When I run my usual big painful queries, I get very little to know
> memory usage. My production box (raid 5 4GB ram) hovers at 3.9GB used
> most of the time. the new devel box sits at around 250MB.
>

Is the system performing fine?  Are you touching as much data as the
production box?

If the system is performing fine don't worry about it.

> work_mem = 2097151              # min 64, size in KB

This is EXTREMELY high.  You realize this is the amount of memory
that can be used per-sort and per-hash build in a query? You can end
up with multiples of this on a single query.   If you have some big
queries that are run infrequently have them set it manually.

> effective_cache_size = 3600000   <-----this is a little out of
> control, but would it have any real effect?

This doesn't allocate anything - it is a hint to the planner about
how much data it can assume is cached.

--
Jeff Trout <jeff@jefftrout.com>
http://www.jefftrout.com/
http://www.stuarthamm.net/