Access control mechanisms are commonly used to provide control over who may access sensitive information. However, malicious users can exploit the correlation among the data and in...
We study the problem of answering queries posed on virtual views of XML documents, a problem commonly encountered when enforcing XML access control and integrating data. We approa...
DarGridâ…ˇ is an implemented database gird system whose goal is to provide a semantic solution for integrating database resources on the web. Although many algorithms have been pro...
Xiaoqing Zheng, Huajun Chen, Zhaohui Wu, Yuxin Mao
The class of unions of conjunctive queries (UCQ) has been shown to be particularly well-behaved for data exchange; its certain answers can be computed in polynomial time (in terms...
The role of database knowledge 1susually limited to the evaluation of data queries In this paper we argue that when this knowledge 1sof substantial volume and complexity, there 1s...