Re: Trivial query, large query, but very sad results.

=?iso-8859-1?Q?Alexander_Hav=E4ng?= <eel@musiknet.se> writes:
> I'm using postgresql 7.1.3 (linux 2.4.17, 2*1.13 Mhz SMP), and I've created a table with 10 million rows.

> When I do a query, say,
> SELECT count(id) FROM bigtable WHERE somestring='something';

What's the query plan (see EXPLAIN)?  What fraction of the rows are
actually selected by that WHERE clause?  Is there anything else
going on in Postgres?

7.1.* is known to have performance problems on SMP machines, but I do
not think the problems affect a single-query situation.  On the other
hand, if you are running multiple queries in parallel, that could
explain your poor results.  Try 7.2...

            regards, tom lane