On the semantics and evaluation of top-k queries in probabilistic databases

We formulate three intuitive semantic properties for topk queries in probabilistic databases, and propose GlobalTopk query semantics which satisfies all of them. We provide a dynamic programming algorithm to evaluate top-k queries under Global-Topk semantics in simple probabilistic relations. For general probabilistic relations, we show a polynomial reduction to the simple case. Our analysis shows that the complexity of query evaluation is linear in k and at most quadratic in database size.

• Type: Conference
• Year: 2008
• Where: ICDE
• Authors: Xi Zhang, Jan Chomicki
• Keywords: Database, GlobalTopk Query Semantics, ICDE 2008, Probabilistic Relations, Simple Probabilistic Relations