期刊名称：Bulletin of the Technical Committee on Data Engineering
出版年度：2015
卷号：38
期号：3
出版社：IEEE Computer Society
摘要：A significant portion of data on the web is available on private or hidden databases that lie behind form-like query interfaces that allow users to browse these databases in a controlled manner. In this paper, wedescribe System HYDRA that enables fast sampling and data analytics over a hidden web database witha form-like web search interface. Broadly, it consists of three major components: (1) SAMPLE-GENwhich produces samples according to a given sampling distribution (2) SAMPLE-EVAL that evaluatessamples produced by SAMPLE-GEN and also generates estimations for a given aggregate query and (3)TIMBR that enables fast and easy construction of a wrapper that models both input and output interfaceof the web database thereby translating supported search queries to HTTP requests and retrieving top-kquery answers from HTTP responses.
