XML is a widely accepted standard for exchanging business data. To optimize the management of XML and help companies build up their business partner networks over the Internet, database servers have introduced new XML storage and query features. However, each enterprise defines its own data elements in XML and modifies the XML documents to handle the evolving business needs. This makes XML data conform to heterogeneous schemas or schemas that evolve over time, which is not suitable for XML database storage. We provide an overview of the current XML database strategies and presents a streaming metadata-processing approach, enabling databases to handle multiple XML formats seamlessly.

The authors discuss the implementation and performance assessment of a multilevel data structure system prototype. They compare the multilevel data structure approach with corresponding fault-intolerant implementations to assess the overhead imposed for incorporating fault tolerance. The simulation shows promising results in using multilevel data structures.