Adding Valid Time to XPath
نویسندگان
چکیده
In this paper we extend the XPath data model and query language to include valid time. XPath is a language for specifying locations within an XML document. We extend XPath’s data model by adding to each node a list of disjoint intervals or instants that represents the valid time. The valid time for a node is constrained to be a subset of the valid time for a node’s parent. We extend the XPath query language with an axis to access nodes in a valid-time view of the valid time for a node. The view is a calendar-specific formatting of the valid time in XML. By rendering the time in XML, we can reuse nontemporal XPath to extract the desired information within a valid-time axis. The extension is fully backwards-compatible with XPath.
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