Andrew,
> I would be very suspicious of that much memory for sort. Please see
> the docs for what that does. That is the amount that _each sort_ can
> allocate before spilling to disk.
> If some set of your users are
> causing complicated queries with, say, four sorts apiece, then each
> user is potentially allocating 4x that much memory. That's going to
> wreak havoc on your disk buffers (which are tricky to monitor on most
> systems, and impossible on some).
Yes, we have effectively complicated queries. That's why we put the
sort_mem so high. I'll see if we can put it lower for the next few days
to see if it improves our performances.
Thanks for your help.
--
Guillaume
