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Can I read Equivalences Among Aggregate Queries with Negation on EtoBox?
Equivalences Among Aggregate Queries with Negation by Sara Cohen; Yehoshua Sagiv; Werner Nutt is a Computer Science article available to read on EtoBox.
What is Equivalences Among Aggregate Queries with Negation about?
Query equivalence is investigated for disjunctive aggregate queries with negated subgoals, constants and comparisons. A full characterization of equivalence is given for the aggregation functions __count, max, sum, prod, top2__ and __parity__ . A related problem is that of determining, for a given natural number __N__ , whether two given queries are equivalent over all databases with at most __N__ constants. This problem is called __bounded equivalence__ . A complete characterization of decidability of bounded equivalence is given. In particular, it is shown that this problem is decidable for all the above aggregation functions as well as for __cntd__ (count distinct) and __avg__ . For quasilinear queries (i.e., queries in which predicates that occur positively are not repeated), it is shown that equivalence can be decided in polynomial time for the aggregation functions __count, max, sum, prty, prod, top2__ and __avg__ . A similar result holds for __cntd__ provided that a few additional conditions hold. The results are couched in terms of abstract characteristics of aggregation functions, and new proof techniques are used. Finally, the results above also imply that equivalence, un
Who reads Equivalences Among Aggregate Queries with Negation?
It is typically read by researchers, students, and practitioners in Computer Science.
- Author
- Sara Cohen; Yehoshua Sagiv; Werner Nutt
- Publisher
- ACM
- Published
- 2005
- Language
- EN
- Field
- Computer Science (Physical Sciences)