Re: sort mem: size in RAM vs size on Disk

On Thu, Mar 10, 2011 at 8:03 AM, Peter Geoghegan <peter(at)2ndquadrant(dot)com> wrote:
> What version of PostgreSQL are you using? sort_mem is now called
> work_mem (to better reflect the reality that it isn't just used in
> sorting, I think), and has been for some time.
>
> --
> Peter Geoghegan       http://www.2ndQuadrant.com/
> PostgreSQL Development, 24x7 Support, Training and Services
>

I hang my head somewhat down in shame as I type this...- 8.3.7

I just used the term "sort mem" as it's the sorting operations that I
am typically seeing spilling over to disk when I check the query with
an explain analyze.

I understand that work_mem is a more accurate description.

in summary it seems that if I see a temp file logged of say 20MB I
need about 40MB of work_mem before it doesn't spill to disk. just
wondering if I am at all accurate with this or if I am way off base.

thanks

-Mark