We present algorithms for computing frequency counts exceeding a user-specified threshold over data streams. Our algorithms are simple and have provably small memory footprints. A...
We investigate the problem of how to extend constraint query languages with aggregate operators. We deal with standard relational aggregation, and also with aggregates speci c to ...
Many websites provide restrictive form-like interfaces which allow users to execute search queries on the underlying hidden databases. In this paper, we consider the problem of es...
Arjun Dasgupta, Xin Jin, Bradley Jewell, Nan Zhang...
Approximate predicates can be used to reduce the number of comparisons made by expensive, complex predicates. For example, to check if a point is within a region (expensive predic...
We present a formal analysis of the database layout problem, i.e., the problem of determining how database objects such as tables and indexes are assigned to disk drives. Optimizin...