On Mon, 2009-05-11 at 11:23 -0400, Tom Lane wrote:
> Dimitri <dimitrik.fr@gmail.com> writes:
> > Anyone may explain me why analyze target may have so huge negative
> > secondary effect?..
>
> If these are simple queries, maybe what you're looking at is the
> increase in planning time caused by having to process 10x as much
> statistical data. Cranking statistics_target to the max just because
> you can is not necessarily a good strategy.
statistics_target effects tables, so we have problems if you have a mix
of simple and complex queries. IMHO we need an explicit planner_effort
control, rather than the more arcane *_limit knobs which are effectively
the same thing, just harder to use in practice.
--
Simon Riggs www.2ndQuadrant.com
PostgreSQL Training, Services and Support
