From: Heikki Linnakangas <heikki@enterprisedb.com>
To: Gábor Farkas <gabor@nekomancer.net>
Cc: pgsql-performance@postgresql.org
Subject: Re: select count(*) performance (vacuum did not help)
Date: Mon, 24 Sep 2007 16:07:51 +0100
Message-ID: <46F7D2C7.70105@enterprisedb.com> (raw)
In-Reply-To: <46F7D207.3000901@nekomancer.net>
References: <46F7C494.1050604@nekomancer.net>
<46F7C9F1.1080805@enterprisedb.com>
<46F7D207.3000901@nekomancer.net>
Gábor Farkas wrote:
> hmm... can a full-vacuum be performed while the database is still "live"
> (i mean serving requests)?
>
> will the db still be able to respond to queries?
VACUUM FULL will exclusive lock the table, which means that other
queries accessing it will block and wait until it's finished.
> or in a different way:
>
> if i do a full vacuum to that table only, will the database still serve
> data from the other tables at a normal speed?
Yes. The extra I/O load vacuum full generates while it's running might
disrupt other activity, though.
--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com
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: heikki@enterprisedb.com, gabor@nekomancer.net
Subject: Re: select count(*) performance (vacuum did not help)
In-Reply-To: <46F7D2C7.70105@enterprisedb.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