Effective Clustering of Records for Fast Query Processing

We apply a more realistic cost model than has often been used in the past to the problems of: (1) implementing join algorithms, (2) implementing relational operations which make use of multi-attribute hash les, and (3) creating better multi-attribute hash le organisations using knowledge of the queries which will be asked. This results in a substantial improvement in performance. For some problems a performance improvement of the order of 39 is achieved. We provide preliminary evidence which indicates that even better results are possible.