On Wed, Sep 14, 2022 at 05:02:07PM +0200, tiaswin@gmx.de wrote:
> <html><head></head><body><div style="font-family: Verdana;font-size: 12.0px;"><div>What could be the reason of a
query,which is sometimes fast and sometimes slow (factor >10x)?</div>
> <div>(running on a large table).</div>
> <div> </div>
> <div> </div></div></body></html>
Lots of possible issues. Is it using a different query plan ?
Collect a good plan and a bad one and compare, or send both.
Perhaps use autoexplain to do so.
Turn on logging and send as much information as you can as described
here.
https://wiki.postgresql.org/wiki/Slow_Query_Questions
Please try to configure your mail client to send text mail (instead of
or in addition to the html one).
--
Justin