Containment of Aggregate Queries Sara Cohen, Werner Nutt, and Yehoshua Sagiv   View Paper (PDF)   Return to Research Papers Abstract 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 distinct), count, sum, avg, mdn and stdv (standard deviation) are shown to be expandable. It is shown that even in the presence of integrity constraints, containment can be reduced to equivalence. For conjunctive count and sum-queries, simpler characterizations for containment are given, that do not require checking equivalence. These results are built upon in order to solve the problem of finding maximally-contained sets of rewritings for conjunctive count-queries. BIBTEX  Lecture Notes in Computer Science  Publisher: Springer-Verlag Heidelberg  ISSN: 0302-9743  Subject:  Computer Science  Volume 2572 / 2003  Title:  : Database Theory - ICDT 2003: 9th International Conference Siena, Italy, January 8-10, 2003. Proceedings  Editors:  D. Calvanese, M. Lenzerini, R. Motwani (Eds.) :  Chapter: pp. 111 - 125 }, ©2005 Association for Computing Machinery