Towards a Unified Declarative and Imperative XQuery Processor

Since the birth of XML, the processing of XML query languages like XQuery/XQueryP has been widely researched in the academic and industrial communities. Most of the approaches consider XQuery as a declarative query language similar to SQL, for which the iterator-based (stream-based), lazy evaluation processing strategy can be applied. The processing is combined with XML indexing, materialized view, XML view query rewrite over source data. An alternative approach views XQuery as a procedural programming language associated with eager, step-based evaluation, where each expression is fully evaluated by the end of the corresponding expression execution step. Usually, this approach uses a virtual machine running byte-code for compiled programs. In this paper, we share our experience of building a unified XQuery engine for the Oracle XML DB integrating both approaches. The key contribution of our approach is that the unified XQuery processor integrates both declarative and imperati ve XQuer...

• Type: Journal
• Year: 2008
• Where: DEBU
• Authors: Zhen Hua Liu, Anguel Novoselsky, Vikas Arora
• Keywords: Approach Views Xquery, DEBU 2008, Unified Xquery, XQuery