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Re: Searching for algorithm

From: Jan Hidders <hidders_at_REMOVE.THIS.win.tue.nl>
Date: 2000/09/21
Message-ID: <8qcgoe$jk1$1@news.tue.nl>#1/1

moon wrote:
> I looking for a algorithm to calculate the closure of a Set of FDs

Algorithm 1:

Apply Armstrong's rules until no more new dependencies are added.

Algorithm 2:

Let S be an empty set of functional dependencies. For every set X of attributes (in the relation) do: - determine X+ (the closure of X)
- For every Y that is a subset of X+ do:

For details (Armstrong's rules and computing the closure of a set of attributes) see:

  http://www.cis.ohio-state.edu/~gurari/course/cis670/cis670Ch10.html

-- 
Kind regards,

    Jan Hidders
Received on Thu Sep 21 2000 - 00:00:00 CDT

Original text of this message

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