Labels:bulletin board | hakham | reckoner | sky OCR: set-difference Used produce relation with all tuples that are in one but not in the other of the two argument relations These five fundamental operations can then be combined te produce ad ditional opetions, such as set-intersection, theta-join, natural-join and division These operations simplify queries but op not add any power the algebra and are for this reason not explained here Relational calculus nonprocedural query language Relational calculus founded on branch of mathematical logic called predicate callus There are two types of relational calculus tuple cal culus using tuple variables (and proposed by Codd) and domain calculus using domain variables These two types are quite similar and only tuple cal Iculus C mentioned here A query in the tuple relational calculus is expressed as ...
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