From: Kevin Grittner <kgrittn@mail.com>
To: "Böckler Andreas" <andy@boeckler.org>
To: pgsql-performance@postgresql.org
Subject: Re: Query-Planer from 6seconds TO DAYS
Date: Fri, 26 Oct 2012 11:41:12 -0400
Message-ID: <20121026154112.306890@gmx.com> (raw)
Böckler Andreas wrote:
> b) they high seq costs might be true for that table (partition at
> 40gb), but not for the rest of the database Seqscan-Costs per
> table would be great.
You can set those per tablespace. Again, with about 40 spindles in
our RAID, we got about ten times the speed with a sequential scan as
random access, and an index scan has to hit more pages (index and
heap rather than just the heap), so you can easily shoot yourself in
the foot by assuming that accessing a large portion of the table by
index is faster.
Really, if you stop focusing on what you think the solution is, and
provide a more clear statement of your problem, with sufficient
datail, you are likely to get a real solution.
http://wiki.postgresql.org/wiki/SlowQueryQuestions
-Kevin
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: kgrittn@mail.com, andy@boeckler.org
Subject: Re: Query-Planer from 6seconds TO DAYS
In-Reply-To: <20121026154112.306890@gmx.com>
* 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