Edu talk:Relation

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  • 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 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)
  • 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.
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