On Wed, Nov 24, 2004 at 09:57:52AM -0500, Christian Fowler wrote:
> As for performance, lots of others will probably volunteer tips and 
> techniques. In my experience, properly written and tuned applications will 
> show only minor speed differences. I have seen several open-source apps 
> that "support postgres" but are not well tested on it. Query optimization 
> can cause orders of magnitude performance differences.

Definitely. My favourite is Request Tracker (we use 2.x, although 3.x is the
latest version), which used something like 5-600 queries (all seqscans since
the database schema only had an ordinary index on the varchar fields in
question, and the queries were automatically searching on LOWER(field) to
emulate MySQL's case-insensitivity on varchar fields) for _every_ page shown.
Needless to say, the web interface was dog slow -- some index manipulation
and a few bugfixes (they had some kind of cache layer which would eliminate
98% of the queries, but for some reason was broken for non-MySQL databases)
later, and we were down to 3-4 index scans, a few orders of magnitude faster.

/* Steinar */
Homepage: http://www.sesse.net/

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