METHOD AND APPARATUS FOR AGGREGATION OF DATA IN A DATABASE MANAGEMENT SYSTEM

摘要

An aggregation engine for a data warehouse which provides an indexing technique which allows the measures in a fact table data entry to be added to the appropriate aggregate bucket by mapping the each of the dimension keys to an aggregate index within a level in that dimension and then calculating an overall index using the aggregate index from each dimension which is then mapped onto the aggregate bucket in question. A rolling cache is also provided allowing frequently or recently used aggregate buckets to be represented in memory rather than in a file, and merged with the equivalent bucket in an aggregate file when necessary, so that the slower access to the address file and the aggregate files can be avoided.