> I have a dynamically built query that will periodically(2 times a day and becoming more frequent) make my server totally unresponsive.
does this query involve more than geqo_threshold (default 12) tables?
If so, this most probably is geqo (genetic query optimizer) kicking
in. Try to fiddle with some geqo parameters (raising geqo_effort is
the first choice).
Greetings
Marcin