报告题目：Congressional Samples for Approximate Answering of Group-by Queries

报 告 人：周彧

报告时间：2017年3月29日（周三） 下午 2:30

报告地点：贵州大学北校区博学楼603室

报告内容摘要：

In this paper, we propose a general class of techniques for obtaining fast, highly:accurate answers for group-by queries. These techniques rely on precomputed non-uniform (biased) samples of the data. In particular, we propose congressional samples, a hybrid union of uniform and biased samples. Given a fixed amount of space, congressional samples seek to maximize the accuracy for all possible group-by queries on a set of columns.