A practical query language for graph DBs

Abstract

Query languages for current graph DB systems lack clear syntax and semantics, which difficults the understanding of its expressiveness and complexity. In particular, many of them suffer from poor performance due to the inherently high complexity of the queries they can express. We propose propositional dynamic logic (PDL) as a yardstick query language for graph database engines, based on the fact that it can express many relevant properties with very low computational cost. We present an implementation of the language that shows its potential applicability for querying massive graph databases by building on existing graph database support.