Probabilistic XML functional dependencies based on possible world model
Ping Yan1, Teng Lv2, Weimin He3
1School of Science, Anhui Agricultural University, Hefei 230036, China
2Teaching and Research Section of Computer, Army Officer Academy, Hefei 230031, China
3Department of Computing and New Media Technologies, University of Wisconsin-Stevens Point, 2100 Main Street, Stevens Point, WI 54481
With the increase of uncertain data in many new applications, such as sensor network, data integration, web extraction, etc., uncertainty both in relational databases and XML datasets has attracted more and more research interests in recent years. As functional dependencies (FDs) are critical and necessary to schema design and data rectification in relational databases and XML datasets, it is also significant to study FDs in uncertain XML datasets. This paper first proposed XML functional dependencies (XFDs) of deterministic XML dataset based on tree tuple models. Then two new kinds of functional dependencies based on possible worlds model for probabilistic XML dataset are introduced: probabilistic XML functional dependencies (pXFDs) and probabilistic approximate XML functional dependencies (pAXFDs). pXFDs extend the concept of XFDs of deterministic XML dataset by considering the probability of each possible world of probabilistic XML dataset, and pAXFDs extend the concept of probabilistic XML functional dependencies of probabilistic XML dataset by considering the degree of truth of tree tuples in each possible world of probabilistic XML dataset.