Now showing items 1-4 of 4

    • Containment of aggregate queries 

      Cohen, S; Nutt, W; Sagiv, Y (Springer, 2003)
      The problem of deciding containment of aggregate queries is investigated. Containment is reduced to equivalence for queries with expandable aggregation functions. Many common aggregation functions, such as max, cntd (count ...
    • Deciding equivalences among conjunctive aggregate queries 

      Cohen, S; Nutt, W; Sagiv, Y (Association for Computing Machinery, 2007)
      Equivalence of aggregate queries is investigated for the class of conjunctive queries with comparisons and the aggregate operators count, count-distinct, min, max, and sum. Essentially, this class contains unnested SQL ...
    • Equivalences among Aggregate Queries with Negation 

      Cohen, S; Nutt, W; Sagiv, Y (Association for Computing Machinery (ACM), 2005)
      Query equivalence is investigated for disjunctive aggregate queries with negated subgoals, constants and comparisons. A full characterization of equivalence is given for the aggregation functions count, max, sum, prod, ...
    • Rewriting queries with arbitrary aggregation functions using views 

      Cohen, S; Nutt, W; Sagiv, Y (Association for Computing Machinery (ACM), 2006)
      The problem of rewriting aggregate queries using views is studied for conjunctive queries with arbitrary aggregation functions and built-in predicates. Two types of queries over views are introduced for rewriting aggregate ...