pg.ddx.io  pgsql-performance@postgresql.org mailing list archive  
help / color / mirror / Atom feed
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Pallav Kalva <pkalva@livedatagroup.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Optimizer Not using the Right plan
Date: Tue, 04 Dec 2007 11:32:58 -0500
Message-ID: <29382.1196785978@sss.pgh.pa.us> (raw)
In-Reply-To: <47557AED.8050005@livedatagroup.com>
References: <47557AED.8050005@livedatagroup.com>

Pallav Kalva <pkalva@livedatagroup.com> writes:
>    why does it have different plans for different values

Because the values occur different numbers of times (or so it thinks
anyway).  If the rowcount estimates are far from reality, perhaps
increasing the statistics target would help.  However, since you
only showed EXPLAIN and not EXPLAIN ANALYZE output, no one can
really tell whether the optimizer did anything wrong here.

			regards, tom lane



view thread (4+ messages)  latest in thread

Message-ID: <29382.1196785978@sss.pgh.pa.us>
Permalink:  ../29382.1196785978@sss.pgh.pa.us/
Also on:    postgresql.org/message-id/29382.1196785978@sss.pgh.pa.us

 · 

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: pgsql-performance@postgresql.org
  Cc: tgl@sss.pgh.pa.us, pkalva@livedatagroup.com
  Subject: Re: Optimizer Not using the Right plan
  In-Reply-To: <29382.1196785978@sss.pgh.pa.us>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox