Satisfiability of Simple XPath Fragments under Fixed DTDs
نویسنده
چکیده
The XPath satisfiability problem is to decide, for an XPath expression q and a DTD D, if there exists an XML document t valid against D such that the answer of q on t is nonempty. It is shown that the satisfiability problem is intractable for many XPath fragments. In this paper, we focus on fixed DTDs and consider the problem under fixed DTDs. We first show that, for a very restricted XPath fragment, the satisfiability problem is NP-complete under fixed DTDs. Then we show several XPath fragments for which satisfiability is in PTIME under fixed DTDs.
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تاریخ انتشار 2011