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In-Reply-To: <27913694.post@talk.nabble.com>
References: <27913694.post@talk.nabble.com>
Date: Tue, 16 Mar 2010 10:58:08 -0600
Message-ID: <dcc563d11003160958kbf7194ma78cdda771ffc09f@mail.gmail.com>
Subject: Re: Postgres DB maintainenance - vacuum and reindex
From: Scott Marlowe <scott.marlowe@gmail.com>
To: Meena_Ramkumar <winmeena_ramkumar@yahoo.co.in>
Cc: pgsql-performance@postgresql.org
Content-Type: text/plain; charset=ISO-8859-1

On Mon, Mar 15, 2010 at 11:30 PM, Meena_Ramkumar
<winmeena_ramkumar@yahoo.co.in> wrote:
>
> How to run vacuumdb and reindex for Postgres DB in a non-stop server? Will it
> be made without shutting the server? If so, then what will be performance
> degradation percentage?

vacuum can be tuned by the various vacuum_* parameters in the
postgresql.conf file to have little or no impact on other processes
running.  Depending on your IO subsystem, you can tune it up or down
to fit your needs (speed versus impact on other processes).  reindex
however tends to be more intrusive to the system, and may cause some
performance degradation, which will be very dependent on your IO
subsystem (i.e. a single 7200RPM SATA drive system is more likely to
notice and be slowed down by reindexing than a 48 disk 15krpm SAS
RAID-10 array.

The more important question is what problem are you trying to solve,
and are there other, better approaches than the ones you're trying.
Without more info, no one can really say.