Re: Massive performance issues - Mailing list pgsql-performance

From Alvaro Herrera
Subject Re: Massive performance issues
Date
Msg-id 20050901193331.GA31313@surnet.cl
Whole thread Raw
In response to Re: Massive performance issues  ("Merlin Moncure" <merlin.moncure@rcsonline.com>)
List pgsql-performance
On Thu, Sep 01, 2005 at 02:04:54PM -0400, Merlin Moncure wrote:
> >                   Table "public.address"
> >         Column        |          Type          | Modifiers
> > ----------------------+------------------------+-----------
> >  postcode_top         | character varying(2)   | not null
> >  postcode_middle      | character varying(4)   | not null
> >  postcode_bottom      | character varying(7)   | not null
>
> consider making above fields char(x) not varchar(x) for small but
> important savings.

Huh, hang on -- AFAIK there's no saving at all by doing that.  Quite the
opposite really, because with char(x) you store the padding blanks,
which are omitted with varchar(x), so less I/O (not necessarily a
measurable amount, mind you, maybe even zero because of padding issues.)

--
Alvaro Herrera -- Valdivia, Chile         Architect, www.EnterpriseDB.com
You liked Linux a lot when he was just the gawky kid from down the block
mowing your lawn or shoveling the snow. But now that he wants to date
your daughter, you're not so sure he measures up. (Larry Greenemeier)

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