Multidimensional index structures in relational databases

Efficient query processing is one of the basic needs for data mining algori thms. Clustering algorithms, association rule mining algorithms and OLAP to ols all rely on efficient query processors being able to deal with high-dim ensional data. Inside such a query processor, multidimensional index struct ures are used as a basic technique. As the implementation of such an index structure is a difficult and time-consuming task, we propose a new approach to implement an index structure on top of a commercial relational database system. In particular, we map the index structure to a relational database design and simulate the behavior of the index structure using triggers and stored procedures. This can be easily done for a very large class of multi dimensional index structures. To demonstrate the feasibility and efficiency , we implemented an X-tree on top of Oracle8. We ran several experiments on large databases and recorded a performance improvement up to a factor of 1 1.5 compared to a sequential scan of the database.