Re: slow queries, possibly disk io
Josh Close <narshe@gmail.com>
From: Josh Close <narshe@gmail.com>
To: POSTGRES-PERFORMANCE <pgsql-performance@postgresql.org>
Date: 2005-05-27T12:52:16Z
Lists: pgsql-performance
> Setting shared buffers above something like 10-30% of memory is counter > productive. What is the reason behind it being counter productive? If shared buffers are at 30%, should effective cache size be at 70%? How do those two relate? > > Increasing sort_mem can help with various activities, but increasing it > too much can cause you to swap, which kills performance. The caution is > that you will likely use at least 1 sort_mem per connection, and can > likely use more than one if the query is complicated. I have a max of 100 connections and 2 gigs of mem. Right now the sort mem is a 4 megs. How much higher could I put that? -Josh