Checking Multivalued Dependencies in XML

Recently, the issues of how to define functional dependencies (XFDs) and multivalued dependencies (XMVDs) in XML have been investigated. In this paper we consider the problem of checking the satisfaction of a set of XMVDs in an XML document. We present an algorithm using extensible hashing to check whether an XML document satisfies a given set of XMVDs. The performance of the algorithm is shown to be linear in relation to the ”tuple size” of the XML document, a measure which is related to, but not the same as, the size of the XML document. We then propose a method to estimate the ”tuple size” of an XML document. We also conduct a comparison between the hashed based approach and a sorting based approach to checking XMVDs and show that the hash based approach provides superior performance.