Optimizing probabilistic query processing on continuous uncertain data

Abstract

Uncertain data management is becoming increasingly important in many applications, in particular, in scientific databases and data stream systems. Uncertain data in these new environments is naturally modeled by continuous random variables. An important class of queries uses complex selection and join predicates and requires query answers to be returned if their existence probabilities pass a threshold. In this work, we optimize threshold query processing for continuous uncertain data by ( i ) expediting joins using new indexes on uncertain data, ( ii ) expediting selections by reducing dimensionality of integration and using faster filters, and ( iii ) optimizing a query plan using a dynamic, per-tuple based approach. Evaluation results using real-world data and benchmark queries show the accuracy and efficiency of our techniques and significant performance gains over a state-of-the-art threshold query optimizer.