Using Association Rules to Add or Eliminate Query Constraints Automatically Agathoniki Trigoni and Ken Moody   View Paper (PDF)   Return to Query Processing, Optimization and Constraints Abstract : i) if a selection on attribute A is implied by another selection condition on attribute B and A is not an index attribute, then the selection on A can be removed from the query; ii) if a relation R in the query has a restricted attribute A and an unrestricted cluster index attribute B, then look for a rule where the restriction on A implies a restriction on B. The contribution of our work is twofold. First, we present detailed algorithms that apply these heuristics. Hence, our ideas are easy to implement. Second, we discuss conditions under which it is worth applying these optimization techniques, and we show the extent to which they speed up query execution. DiSC'02 © 2003 Association for Computing Machinery