Re: Sort time

From: Rod Taylor <rbt(at)rbt(dot)ca>
To: josh(at)agliodbs(dot)com
Cc: pginfo <pginfo(at)t1(dot)unisoftbg(dot)com>, "scott(dot)marlowe" <scott(dot)marlowe(at)ihs(dot)com>, "pgsql-performance(at)postgresql(dot)org" <pgsql-performance(at)postgresql(dot)org>
Subject: Re: Sort time
Date: 2002-11-15 22:40:19
Message-ID: 1037400019.62804.0.camel@jester
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-performance

On Fri, 2002-11-15 at 16:18, Josh Berkus wrote:
> Rod,
>
> > > Hmmm ... how big *is* that varchar field? 8 characters gives us about 6mb
> for
> > > the column. Of course, if it's a 128-char global unque id, that;s a bit
> > > larger.
> >
> > 20 characters long in the Unicode locale -- which is 40 bytes?
>
> Well, 40+, probably about 43. Should be about 29mb, yes?
> Here's a question: is the total size of the column a good indicator of the
> sort_mem required? Or does the rowsize affect it somehow?

I'd suspect the total row is sorted, especially in this case where he's
sorting more than one attribute.

--
Rod Taylor <rbt(at)rbt(dot)ca>

In response to

Responses

Browse pgsql-performance by date

  From Date Subject
Next Message Tom Lane 2002-11-15 23:02:15 ANALYZE and indexes (was Re: Sort time)
Previous Message Josh Berkus 2002-11-15 21:18:33 Re: Sort time