Finding Equivalent Rewritings in the Presence of Arithmetic Comparisons

The problem of rewriting queries using views has received significant attention because of its applications in a wide variety of datamanagement problems. For select-project-join SQL (a.k.a. conjunctive) queries and views, there are efficient algorithms in the literature, which find equivalent and maximally contained rewritings. In the presence of arithmetic comparisons (ACs) the problem becomes more complex. We do not know how to find maximally contained rewritings in the general case. There are algorithms which find maximally contained rewritings only for special cases such as when ACs are restricted to be semi-interval. However, we know that the problem of finding an equivalent rewriting (if there exists one) in the presence of ACs is decidable, yet still doubly exponential. This complexity calls for an efficient algorithm which will perform better on average than the complete enumeration algorithm. In this work we present such an algorithm which is sound and complete. Its efficiency...

• Type: Conference
• Year: 2006
• Where: EDBT
• Authors: Foto N. Afrati, Rada Chirkova, Manolis Gergatsoulis, Vassia Pavlaki
• Keywords: Complete Enumeration Algorithm, Database, EDBT 2006, Equivalent Rewriting, Fewer Candidate Rewritings