Proc. of the 12th Int. Symposium on Database Programming Languages (DBPL 2009). Volume 5708 of Lecture Notes in Computer Science. 2009.
In this paper we present Regular XPath (RXPath), which is a natural extension of XPath with regular expressions over paths that has the same computational properties as XPath: linear-time query evaluation and exponential-time reasoning. To establish these results, we devise a unifying automata-theoretic framework based on two-way weak alternating tree automata. Specifically, we consider automata that have infinite runs on finite trees. This enables us to leverage and simplify existing automata-theoretic machinery and develop algorithms both for query evaluation and for reasoning over queries. With respect to the latter problem, we consider RXPath as a constraint language, and study constraint satisfiability, and query satisfiability and containment under constraints in the setting of RXPath.
@inproceedings{DBPL-2009, title = "An Automata-Theoretic Approach to Regular XPath", year = "2009", author = "Diego Calvanese and De Giacomo, Giuseppe and Maurizio Lenzerini and Moshe Y. Vardi", booktitle = "Proc. of the 12th Int. Symposium on Database Programming Languages (DBPL 2009)", pages = "18--35", volume = "5708", publisher = "Springer", series = "Lecture Notes in Computer Science", doi = "10.1007/978-3-642-03793-1_2", }pdf url