Datalog Rewritings of Regular Path Queries using Views [dataset]

Nadime Francis, Luc Segoufin, Cristina Sirangelo
2014 International Conference on Database Theory  
We consider query answering using views on graph databases, i.e. databases structured as edge-labeled graphs. We consider views and queries specified by Regular Path Queries. These are queries selecting pairs of nodes in a graph database that are connected via a path whose sequence of edge labels belongs to some regular language. A view V determines a query Q if for all graph databases D, the view image VpDq always contains enough information to answer Q on D. In other words, there is a well
more » ... there is a well defined function from VpDq to QpDq. Our main result shows that when this function is monotone, there exists a rewriting of Q as a Datalog query over the view instance VpDq. In particular the query can be evaluated in time polynomial in the size of VpDq. As a side result we also prove that it is decidable whether an RPQ query can be rewritten in Datalog using RPQ views.
doi:10.5441/002/icdt.2014.14 dblp:conf/icdt/FrancisSS14 fatcat:6pyiif6w2zfwxmdx3zqclnpc3y