Gangqiang Xia

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We tackle the problem of maintaining materialized top-k views in this paper. Top-k queries, including MIN and MAX as important special cases, occur frequently in common database workloads. A top-k view can be materialized to improve query performance, but in general it is not self-maintainable unless it contains all tuples in the base table. Deletions and(More)
In a spatial data analysis problem, usually we build a hierarchical model with spatial structure described though random effects using a Gaussian process. If the sample size is very large, exact likelihood based inference becomes unstable and, eventually, infeasible since it involves computing quadratic forms and determinants associate with a large(More)
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