pg.ddx.io  pgsql-performance@postgresql.org mailing list archive  

help / color / mirror / Atom feed
From: Guillaume Smet <guillaume_ml@smet.org>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: josh@agliodbs.com
Cc: pgsql-performance@postgresql.org
Subject: Re: Bad plan after vacuum analyze
Date: Wed, 11 May 2005 22:59:40 +0200
Message-ID: <4282723C.5080903@smet.org> (raw)
In-Reply-To: <17017.1115843555@sss.pgh.pa.us>
References: <42823F94.8050009@smet.org>
	<200505111110.15983.josh@agliodbs.com>
	<13964.1115837926@sss.pgh.pa.us>
	<42825DBB.7000703@smet.org>
	<14301.1115840296@sss.pgh.pa.us>
	<4282638E.2020307@smet.org>
	<17017.1115843555@sss.pgh.pa.us>

Josh, Tom,

Thanks for your explanations.

> In the meantime it seems like the quickest answer for Guillaume might
> be to try to avoid keeping any NULLs in parent_application_id.

I can't do that as the majority of the applications don't have any 
parent one. Moreover, we use a third party application and we cannot 
modify all its internals.

Anyway, I tried to work on the statistics as you told me and here are 
the results:
ccm_perf=# ALTER TABLE acs_objects ALTER COLUMN object_id SET STATISTICS 30;
ALTER TABLE
ccm_perf=# ANALYZE acs_objects;
ANALYZE

ccm_perf=# \i query_section.sql
... correct plan ...
  Total runtime: 0.555 ms

So I think I will use this solution for the moment.

Thanks a lot for your help.

Regards

--
Guillaume



view thread (10+ messages)  latest in thread

Message-ID: <4282723C.5080903@smet.org>
Permalink:  ../4282723C.5080903@smet.org/
Also on:    postgresql.org/message-id/4282723C.5080903@smet.org

 · 

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: guillaume_ml@smet.org, tgl@sss.pgh.pa.us, josh@agliodbs.com
  Subject: Re: Bad plan after vacuum analyze
  In-Reply-To: <4282723C.5080903@smet.org>

* 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