Selecting and using views to compute aggregate queries

  • Authors:
  • Foto Afrati;Rada Chirkova

  • Affiliations:
  • Electrical and Computing Eng., National Technical University of Athens, Athens, Greece;Computer Science Department, North Carolina State University, Raleigh, NC

  • Venue:
  • ICDT'05 Proceedings of the 10th international conference on Database Theory
  • Year:
  • 2005

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Abstract

We consider a workload of aggregate queries and investigate the problem of selecting views that (1) provide equivalent rewritings for all queries, and (2) are optimal, in that the cost of evaluating the query workload is minimized. We consider conjunctive views and rewritings, with or without aggregation; in each rewriting, only one view contributes to computing the aggregated query output. We look at query rewriting using existing views and at view selection. In the query-rewriting problem, we give su.cient and necessary conditions for a rewriting to exist. For view selection, we prove complexity results. Finally, we give algorithms for obtaining rewritings and selecting views.