Difference between revisions of "Edu talk:Relation"

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(Created page with "* Predicate is also used in relation to ''relation'', but that covers either sense as well, and it can be unary (which a relation cannot be). * ''Relation''...")
 
(Moved first three entries to main 'Relation' page.)
 
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* [[Edu:Predicate|Predicate]] is also used in relation to ''relation'', but that covers either sense as well, and it can be unary (which a relation cannot be).
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* ''Relation'' has a specific meaning in relational database theory, it being a set of tuples (d1, d2, ..., dn) where each dj (with 1 <= j <= n) is a member of data domain Dj. (reference: any database text book)
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* The definitions above are my own (M Keet), as the sources consulted either had a formal definition alike in the database context, or informal hand waiving descriptions on having to do with 'between', rather than a neat definition that could be copied.
* If one takes the mathematics definition of ''relation'', then also functions and attributes are relations.
 
* The definitions above are my own (M Keet), as the sources consulted either had a formal definition alike in the database context, or informal handwaiving descriptions on having to do with 'between', rather than a neat definition that could be copied.
 

Latest revision as of 18:40, 20 January 2020

  • The definitions above are my own (M Keet), as the sources consulted either had a formal definition alike in the database context, or informal hand waiving descriptions on having to do with 'between', rather than a neat definition that could be copied.