A Generic Framework for Querying and Updating Secondary XML Index Structures

To cope with the increasing number and size of XML documents, XML databases provide index structures to accelerate queries on the content and structure of documents. To adapt indices to the query workload, XML databases require various secondary index structures. This paper presents a generic index framework called SCIENS (Structure and Content Indexing with Extensible, Nestable Structures). In contrast to existing work on XML indexing, this framework can integrate arbitrary index structures and adapt them to different query requirements. It supports defining, accessing and maintaining indices without affecting query and update processing. By offering a great flexibility of what to index, the framework allows for processing queries more efficiently.