Himanshu M Gupta

US Patent:

6484159, Nov 19, 2002

Filed:

May 20, 1999

Appl. No.:

09/315161

Inventors:

Inderpal Singh Mumick - Berkeley Heights NJ
Himanshu Gupta - Mountain View CA

Assignee:

ATT Corp. - New York NY
Savera Systems, Inc. - Murray Hill NJ

International Classification:

G06F 1730

US Classification:

707 2, 707100

Abstract:

The present invention is a method and system for incrementally maintaining a database having at least one materialized view based on at least one table. When changes to the table are received, a change table based on the received changes is generated. The generated change table is propagated upwards to form a higher-level change table and the materialized view is updated by applying the higher-level change table to the materialized view using a refresh operation. In one aspect, the change table includes a plurality of tuples representing the changes and the materialized view includes a plurality of tuples. The refresh operation has two parameters, a join condition and an update function specification. The materialized view is updated by finding all tuples in the materialized view that match the tuple in the change table, using the join condition, for each tuple in the change table and updating each found tuple in the materialized view by performing operations indicated by the update function specification.