Approximate rewriting of queries using views

Foto Afrati, Manik Chandrachud, Rada Chirkova, Prasenjit Mitra

Research output: Chapter in Book/Report/Conference proceedingConference contribution

4 Scopus citations


We study approximate, that is contained and containing, rewritings of queries using views. We consider conjunctive queries with arithmetic comparisons (CQACs), which capture the full expressive power of SQL select-project-join queries. For contained rewritings, we present a sound and complete algorithm for constructing, for CQAC queries and views, a maximally-contained rewriting (MCR) whose all CQAC disjuncts have up to a predetermined number of view literals. For containing rewritings, we present a sound and efficient algorithm pruned-MiCR, which computes a CQAC containing rewriting that does not contain any other CQAC containing rewriting (i.e., computes a minimally containing rewriting, MiCR) and that has the minimum possible number of relational subgoals. As a result, the MiCR rewriting produced by our algorithm may be very efficient to execute. Both algorithms have good scalability and perform well in many practical cases, due to their extensive pruning of the search space, see [1].

Original languageEnglish (US)
Title of host publicationAdvances in Databases and Information Systems - 13th East European Conference, ADBIS 2009, Proceedings
Number of pages15
StatePublished - 2009
Event13th East European Conference on Advances in Databases and Information Systems, ADBIS 2009 - Riga, Latvia
Duration: Sep 7 2009Sep 10 2009

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume5739 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Other13th East European Conference on Advances in Databases and Information Systems, ADBIS 2009

All Science Journal Classification (ASJC) codes

  • Theoretical Computer Science
  • General Computer Science


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