Deferred Incremental Refresh of XML Materialized Views : Algorithms and Performance Evaluation

The view mechanism can provide the user with an appropriate portion of database through data filtering and integration. Views are often materialized for query performance improvement, and in that case, their consistency needs to be maintained against the updates of the underlying data. They can be either recomputed or incrementally refreshed by reflecting only the relevant updates. With the emergence of XML as the standard for data exchange on the Web, active research is under way for efficient storing and querying XML documents with the DBMS. In this paper, we investigate XML views, their materialization and incremental refresh. The object-relational DBMS is employed for storing XML documents and their materialized views, and the update log is used for deferred view refresh. The algorithms for checking a update’s relevance to views and for generating the operations and data necessary for view refresh are proposed. The experimental results show that the proposed scheme outperforms recomputation of XML views.