From: | "Zeugswetter Andreas DCP SD" <ZeugswetterA(at)spardat(dot)at> |
---|---|
To: | "Peter Eisentraut" <peter_e(at)gmx(dot)net>, "Theo Schlossnagle" <jesus(at)omniti(dot)com> |
Cc: | <pgsql-hackers(at)postgresql(dot)org>, "Merlin Moncure" <mmoncure(at)gmail(dot)com> |
Subject: | Re: Prepared statements considered harmful |
Date: | 2006-09-01 10:44:18 |
Message-ID: | E1539E0ED7043848906A8FF995BDA579014DBEBF@m0143.s-mxs.net |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
> > I don't chime in very often, but I do think the refusal to
incorporate
> > hints into the planner system is fantastically stubborn and
> > nonsensical.
>
> What is actually fantastically nonsensical about this is that
> the issues I outlined about prepared statements would merely
> become worse if planner hints were used. Then, you wouldn't
> only have to worry about plans that were created earlier
> during the session, you would be faced with plans that were
> created earlier during the application's development. In
> general, the solutions to the prepared statement issues need
> to effect that the plans are created more often, not less often.
I have yet to see one of our partial Informix hints (where the planner
does it's
usual job only with one path with lowered/elevated costs) fall foul on
not anticipated change of underlying data.
Thus I don't buy the argument that hints are always bad.
Of course their use should be extremely rare and well thought out.
Most of the time sql tuning involves a concerted effort between the
programmer and a db performance expert, usually resulting in
rewritten sql or program logic without adding hints.
I can see arguments for hints the dba can set himself centrally on the
server,
but in my experience chances for substantial improvement are very
limited in that case.
Andreas
From | Date | Subject | |
---|---|---|---|
Next Message | Michael Glaesemann | 2006-09-01 10:54:57 | Re: [HACKERS] Interval aggregate regression failure |
Previous Message | Stefan Kaltenbrunner | 2006-09-01 10:40:53 | Re: [pgsql-advocacy] Thought provoking piece on |