From: Josh Berkus <josh@agliodbs.com>
To: Konrad Garus <konrad.garus@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Paritioning vs. caching
Date: Mon, 08 Mar 2010 12:30:03 -0800
Message-ID: <4B955E4B.9060805@agliodbs.com> (raw)
In-Reply-To: <6645f6441003081028v6dbca8f4s2a480114b86cb2a6@mail.gmail.com>
References: <6645f6441003081028v6dbca8f4s2a480114b86cb2a6@mail.gmail.com>
> 1. When I query the table by ID, it performs index scan on each
> partition. The result is only found in one partition, but I understand
> why it needs to look in all of them. How much disk reading does it
> involve? Is only the "head" of indexes for partitions that do not
> include the row scanned, or are always whole indexes read? I would
> like to know the general rule for index scans.
If you're not including the partition criterion in most of your queries,
you're probably partitioning on the wrong value.
--Josh Berkus
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: josh@agliodbs.com, konrad.garus@gmail.com
Subject: Re: Paritioning vs. caching
In-Reply-To: <4B955E4B.9060805@agliodbs.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