INCREMENTAL MAINTENANCE OF AGGREGATED AND JOIN SUMMARY TABLES

A method, apparatus, and article of manufacture for incrementally maintaining a summary table derived from a plurality of base tables in a database stored on the computer. A plurality of modifications are applied to the base tables, and the applied modifications are then propagated to the summary table. The propagated modifications include an associated tag column containing a tag value, and the tag value indicates per row of the propagated modifications how many rows are to be added to or deleted from the summary table.