Re: [Fwd: how to determine storage size of a numeric column]

On Tue, 25 Jan 2005 22:06:49 -0500, Chris Hoover
<revoohc(at)sermonaudio(dot)com> wrote:
> From: Chris Hoover <revoohc(at)sermonaudio(dot)com>
> To: psql-admin(at)postgresql(dot)org
> Date: Tue, 25 Jan 2005 16:27:45 -0500
> Subject: how to determine storage size of a numeric column
> I'm running 7.3.4, and am trying to calculate the space requirements for
> my tables. However, I have several tables that have numeric columns,
> and am not sure how much space postgres is using for them. Does anyone
> know how to determine this?
>
> I have tried looking at pg_attribute.attlen, but it is -l, I have tried
> looking at pg_attribute.atttypmod, but it is returning what would be
> huge space requirements (some of them are 786,4400, 786442, 1,179,645, .
> . .). Is that number really how many bytes it is taking up? I am
> thinking (and hoping) not.
>
> So, where else can I look for the size?

Be sure to use ANALYZE first.

You may want to use following select to find these values:
select attname,avg_width from pg_stats where tablename = 'foo';
...it certainly works well for me, v8 though. :)

Regards,
Dawid