Regular path query languages for data graphs are essentially \emph{untyped}. The lack of type information greatly limits the optimization opportunities for query engines and makes application development more complex. In this paper we discuss a simple, yet expressive, schema language for edge-labelled data graphs. This schema language is, then, used to define a query type inference approach with good precision properties.
@article{arxiv.1507.01708,
title = {Typing Regular Path Query Languages for Data Graphs},
author = {Dario Colazzo and Carlo Sartiani},
journal= {arXiv preprint arXiv:1507.01708},
year = {2015}
}