From: Alvaro Herrera <alvherre@commandprompt.com>
To: Craig A. James <cjames@modgraph-usa.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: No vacuum for insert-only database?
Date: Mon, 13 Mar 2006 13:41:35 -0400
Message-ID: <20060313174135.GA16213@surnet.cl> (raw)
In-Reply-To: <4415A9A4.5020903@modgraph-usa.com>
References: <44158989.6020103@modgraph-usa.com>
<20060313150949.GK8274@surnet.cl>
<4415A9A4.5020903@modgraph-usa.com>
Craig A. James wrote:
> Alvaro Herrera wrote:
> >>If I only insert data into a table, never update or delete, then I should
> >>never have to vacuum it. Is that correct?
> >
> >You still need to vacuum eventually, to avoid transaction Id wraparound
> >issues. But not as often.
>
> Thanks. Any suggestions for what "not as often" means? For example, if my
> database will never contain more than 10 million rows, is that a problem?
> 100 million rows? When does transaction ID wraparound become a problem?
Transaction ID wraparound will be a problem at a bit less than 2 billion
transactions. So if you vacuum the table every 1 billion transactions
you are safe. I suggest you read the "routine maintenance" section in
the docs; the wraparound issue is explained there.
--
Alvaro Herrera http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support
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: alvherre@commandprompt.com, cjames@modgraph-usa.com
Subject: Re: No vacuum for insert-only database?
In-Reply-To: <20060313174135.GA16213@surnet.cl>
* 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