Re: Query performance over a large proportion of data

>
>
>
> *"Kevin Grittner" <Kevin(dot)Grittner(at)wicourts(dot)gov>*
> 03/10/2009 05:06 PM EST
>
> > enable_seqscan = off
>
> Not a good idea; some queries will optimize better with seqscans.
> You can probably get the behavior you want using other adjustments.
>
The bullet to cure the headache, as Scott said.

>
> You probably need to reduce random_page_cost. If your caching is
> complete enough, you might want to set it equal to seq_page_cost
> (never set it lower that seq_page_cost!) and possibly reduce both of
> these to 0.1.
>
> Reducing seq_page_cost relative to random_page_cost seems to make an
enormous difference for this query. Removing the nested loop seems to be
what makes a difference. We'll continue to play with these and check there
are no adverse effects on other queries.

Thanks again, Steve