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 …

We study fundamental aspects related to the efficient processing of the SPARQL query
language for RDF, proposed by the W3C to encode machine-readable information in the …

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 …

Despite the fact that JSON is currently one of the most popular formats for exchanging data
on the Web, there are very few studies on this topic and there is no agreement upon a …

The problem of exchanging data between different databases with different schemas is an
area of immense importance. Consequently data exchange has been one of the most active …

We study the complexity and expressive power of conjunctive queries over unranked
labeled trees represented using a variety of structure relations such as “child”,“descendant” …

The goal of the work presented in this paper is to obtain large amounts of semistructured
data from the web. Harvesting semistructured data is a prerequisite to enabling large-scale …

WS-BPEL applications are a kind of service-oriented application. They use XPath
extensively to integrate loosely-coupled workflow steps. However, XPath may extract wrong …

Automata for unranked trees form a foundation for XML Schemas, querying and pattern
languages. We study the problem of efficiently minimizing such automata. First, we study …

An algorithmic meta theorem for a logic and a class C of structures states that all problems
expressible in this logic can be solved efficiently for inputs from $ C $. The prime example is …