Algebra-Based Optimization of XML-Extended OLAP Queries

In today’s OLAP systems, integrating fast changing data physically into a cube is complex and time-consuming. Our solution, the “OLAP-XML Federation System, ” makes it possible to reference the fast changing data in XML format in OLAP queries without physical integration. In this paper, we introduce the novel query optimization techniques specialized for the federation system including a query optimizer and plan transformation rules. We also show the experimental results which suggest that our approach, unlike the physical integration, is a practical solution for integrating fast changing data into OLAP systems.