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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 (view raw or flat)
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>

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Subject: ANALYZE and indexes (was Re: Sort time)
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