On Mon, Sep 15, 2003 at 17:34:12 -0400, Joseph Bove <[EMAIL PROTECTED]> wrote: > > I do a rather simple query: select count (*) from large-table where column > = some value; > > About 80% of the time, the response time is sub-second. However, at 10% of > the time, the response time is 5 - 10 seconds. > > This is nothing readily apparent at the system level that comes close to > explaining the performance hits. CPU and memory usage (as measured by top) > appear to be fine. > > Although there are certain tuning issues within the database itself, no > documentation I have seen seems to indicate that tuning issues would lead > to such inconsistent response time.
Looking at the output from explain analyze for the query would be useful. It may be that there are a lot of rows that have the value in the problem queries. ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html