This survey gives an overview of formal results on the XML query language XPath. We
identify several important fragments of XPath, focusing on subsets of XPath 1.0. We then …

Labeled unranked trees are used as a model of XML documents, and logical languages for
them have been studied actively over the past several years. Such logics have different …

We study the satisfiability problem associated with XPath in the presence of DTDs. This is
the problem of determining, given a query p in an XPath fragment and a DTD D, whether or …

Data exchange is the problem of finding an instance of a target schema, given an instance of
a source schema and a specification of the relationship between the source and the target …

XML repositories are now a widespread means for storing and exchanging information on
the Web. As these repositories become increasingly used in dynamic applications such as e …

Abstract In the Database-As-a-Service (DAS) model, clients store their database contents at
servers belonging to potentially untrusted service providers. To maintain data confidentiality …

XPath is a simple language for navigating an XML tree and returning a set of answer nodes.
The focus in this paper is on the complexity of the containment problem for various …

A number of techniques have been developed to facilitate powerful data retrieval on the
Web and Semantic Web. Three categories of Web query languages can be distinguished …

Consider an XML publish-subscribe scenario with hundreds of subscribers and tens of
thousands of XML documents to be delivered per day. Subscribers specify the documents in …

We study absolute and relative keys for XML, and investigate their associated decision
problems. We argue that these keys are important to many forms of hierarchically structured …