Regular expressions for querying data graphs

Abstract

The standard regular expressions over finite alphabets have been widely accepted as the most basic formalism to query graph databases. However, the major drawback of this approach is that it ignores the presence of data. In this paper we study the so called {\em regular expressions with binding} (REWB), that is, regular expressions equipped with variables to store data within a well defined scope. In particular, we study the complexity of the query evaluation of REWB queries over graph databases.