Re: explain analyze output for review (was: optimizing a geo_distance()...) - Mailing list pgsql-performance

From Bruno Wolff III
Subject Re: explain analyze output for review (was: optimizing a geo_distance()...)
Date
Msg-id 20070206154508.GA13065@wolff.to
Whole thread Raw
In response to Re: explain analyze output for review (was: optimizing a geo_distance()...)  (Mark Stosberg <mark@summersault.com>)
List pgsql-performance
On Tue, Feb 06, 2007 at 09:39:54 -0500,
  Mark Stosberg <mark@summersault.com> wrote:
>
> I've been investigating partial indexes for the pets table. It has about
> 300,000 rows, but only about 10 are "active", and those are the ones we
> are care about. Queries are also frequently made on males vs females, dogs vs cats

It probably won't pay to make partial indexes on sex or species (at least
for the popular ones), as you aren't likely to save enough by eliminating only
half the cases to make up for maintaining another index. A partial index for
active rows probably does make sense.

> or specific ages, and those specific cases seem like possible candidates for partial indexes
> as well. I played with that approach some, but had trouble coming up with any thing that
> benchmarked faster.

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