Valid updates for persistent XML objects

Abstract: XML has emerged as the industry standard for representing and exchanging data and is already predominant in several applications today. Business, analytic and structered data will be exchanged as XML between applications and web services. XQuery is a language designed and developed for querying, filtering and generating XML structured data and is currently being standardized by the World Wide Web Consortium(W3C). XQuery seems to become the query language in context of (native) XML databases. Moreover in the context of document management XQuery seems suitable for querying large collections of documents with more irregular and deeply nested data structures. Despite these promising features XQuery or more precisely its FLWOR expression lacks of any update capability. In this paper we present important results concerning the development of XOBEDBPL (XML OBjEcts DataBase Programming Language). XOBEDBPL is the successor of the XOBE project. XOBE integrates XML and XPath into the Java programming language. In XOBEDBPL XML objects can become persistent. Moreover, a new feature in XOBEDBPL is the integration of xFLWOR(extended FLWOR) expressions for updating and querying XML objects. XML updates and queries in XOBEDBPL are statically typechecked. Finally we perform experiments with the XOBEDBPL prototype showing that the performance of low level API-based interfaces can be improved, as well as the performance of related approaches.