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Notation for the grouping operator (γ)

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• Recall: grouping tuples by common (shared) attribute values
  • Previously, we discussed grouping tuples by their attribute values:

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  • The notation to express the grouping operation is F:

    This is the notation used by another text book that I used for CS377 (Undergraduate Database Systems)

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• The grouping operator used in CS554
  • The text book of this class uses the following notation for grouping:

    γattr1,attr2,... ( R )

    The set functions are not specified in the operator

    (Because: in CS554, we study algorithms to process the grouping operator

    The set functions are not important (= does not affect) in the implementation of the grouping algorithm)