Query Size Estimation by Adaptive Sampling
暂无分享,去创建一个
Abstract We present an adaptive, random sampling algorithm for estimating the size of general queries. The algorithm can be used for any query D over a database D such that (1) for some n, the answer to L can be partitioned into n disjoint subsets L 1, L 2, ..., L n, and (2) for 1 ≤ i ≤ n, the size of L i, is bounded by some function b(D, L ), and (3) there is some algorithm by which we can compute the size of L i, where i is chosen randomly. We consider the performance of the algorithm on three special cases of the algorithm: join queries, transitive closure queries, and general recursive Datalog queries.
[1] Carlo Zaniolo,et al. LDL: A Logic-Based Data Language , 1986, VLDB.
[2] Jeffrey D. Ullman,et al. Design Overview of the NAIL! System , 1986, ICLP.