A Dynamic Approach to Deductive Query Evaluation

In this paper, a dynamic approach to deductive query evaluation is presented which combines the e ects of di erent SIP strategies used for the magic set rewriting technique. Given a query execution plan obtained by a single magic set transformation, this plan is normally not reoptimized, and the actual number of facts generated during query processing cannot be considered. But applying the magic set transformation again during a query evaluation process allows the use of a di erent SIP strategy which takes into account dynamic criteria as well, e.g. the number of generated answer facts or the number of accesses to relations. It will be shown that adapting query plans at runtime can reduce the overall number of generated facts and hence reach optimization e ects which cannot be achieved by magic sets based on a single choice of SIP strategy.

• Type: Conference
• Year: 2000
• Where: WLP
• Authors: Andreas Behrend
• Keywords: Artificial Intelligence, Di Erent Sip, Magic Set Transformation, Magic Sets, WLP 2000