In big data query processing, there is a trade-off between accuracy and efficiency, for example, sampling approaches completeness efficiency. this article, we argue that performance can be significantly improved by slightly losing the possibility of completeness, is, chance complete. To quantify possibility, define new concept, Probability Completeness (hereinafter referred to as PC). For If ex...

Programming distributed-memory machines requires careful placement of data to balance the computationalload among the nodes and minimize excess data movement between the nodes. Most current approaches to data placement require the programmer or compiler to place data initially and then possibly to move it explicitly during a computation. This paper describes a new, adaptive approach. It is impl...