Scalar Aggregation in Inconsistent Databases
Author(s):- Marcelo Arenas
- Leo Bertossi
- Jan Chomicki
- Xin He
- Vijay Raghavan
- Jeremy Spinrad
Theoretical Computer Science, volume 296, number 3, pages 405-434, 2003.
Abstract
We consider here scalar aggregation queries in databases that may violate a given set of functional dependencies. We define consistent answers to such queries to be greatest-lowest/least-upper bounds on the value of the scalar function across all (minimal) repairs of the database. We show how to compute such answers. We provide a complete characterization of the computational complexity of this problem. We also show how tractability can be improved in several special cases (one involves a novel application of Boyce–Codd Normal Form) and present a practical hybrid query evaluation method.
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BibTeX
@article{ABCHRS03, author = {Marcelo Arenas and Leopoldo E. Bertossi and Jan Chomicki and Xin He and Vijay Raghavan and Jeremy Spinrad}, title = {Scalar aggregation in inconsistent databases}, journal = {Theoretical Computer Science}, volume = {3}, number = {296}, year = {2003}, pages = {405-434} }