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Equivalences among Relational Expressions
1979
SIAM journal on computing (Print)
Many database queries can be formulated in terms of expressions whose operands represent tables of information (relations) and whose operators are the relational operations select, project, and join. This paper studies the equivalence problem for these relational expressions, with expression optimization in mind. A matrix, called a tableau, is proposed as a natural representative for the value of an expression. It is shown how tableaux can be made to reflect functional dependencies among
doi:10.1137/0208017
fatcat:emu2qnlc7vazfjyrserdevjcxm