Re: Relational Algebra and Aggregate Functions

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От Sam Mason
Тема Re: Relational Algebra and Aggregate Functions
Дата
Msg-id 20090726230214.GV5407@samason.me.uk
обсуждение исходный текст
Ответ на Relational Algebra and Aggregate Functions  (Robert James <srobertjames@gmail.com>)
Ответы Re: Relational Algebra and Aggregate Functions
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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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