Re: Relational Algebra and Aggregate Functions

From: Sam Mason <sam(at)samason(dot)me(dot)uk>
To: pgsql-general(at)postgresql(dot)org
Subject: Re: Relational Algebra and Aggregate Functions
Date: 2009-07-26 23:02:14
Message-ID: 20090726230214.GV5407@samason.me.uk
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On Sun, Jul 26, 2009 at 03:36:26PM -0400, Robert James wrote:
> Can anyone
> recommend any papers or web pages which provide some good theoretical
> background for aggregate functions?

My knowledge of relational algebra is somewhat non-existent as well;
I tend to just think of them as a "fold" from normal functional
programming. The Wikipedia page is a reasonable description:

http://en.wikipedia.org/wiki/Fold_(higher-order_function)

Not sure how helpful that is though!

--
Sam http://samason.me.uk/

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