Existing work for query processing over graph data models often relies on pre-computing the
transitive closure or path indexes. In this paper, we propose a family of stack-based …

Static analysis is a fundamental task in query optimization. In this article we study static
analysis and optimization techniques for SPARQL, which is the standard language for …

Graph data appears in a variety of application domains, and many uses of it, such as
querying, matching, and transforming data, naturally result in incompletely specified graph …

Graph data appears in a variety of application domains, and many uses of it, such as
querying, matching, and transforming data, naturally result in incompletely specified graph …

Evaluation of twig queries over probabilistic XML is investigated. Projection is allowed and,
in particular, a query may be Boolean. It is shown that for a well-known model of probabilistic …

Top-k dominating (TKD) query retrieves the top k items that dominate other objects in the
dataset. This is a key decision-making tool for any organization since it allows data analysts …

We study models of incomplete information for XML, their computational properties, and
query answering. While our approach is motivated by the study of relational incompleteness …

A considerable amount of twig pattern matching algorithms have been proposed to
holistically process a twig query. Those algorithms mainly focus on twig pattern query with …

In order to find all occurrences of a twig pattern in XML documents, a considerable amount
of twig pattern matching algorithms have been proposed. At the same time, previous work …

In this thesis, observations on structural properties of natural networks are taken as a starting
point for developing efficient algorithms for natural instances of different graph problems …