MULTIPLE VIEWS ON LINE MAINTENANCE IN DATA WAREHOUSE ENVIRONMENT

Views on line maintenance in data warehouse environment means that the refresh ments of materialized views are synchronized with that of data sources without disturbing user’s normal use with data warehouse at the same time. Data warehouse base （DWbase） in data warehouse architecture and 3VPA（three version painting algorithm） are presented to solve the consistency problem between multiple views on line maintenance and drill down query. The introduction of DWbase not only improves the scalability of data warehouse system but also provides better support for drill down query. The combined control of DWbase and 3VPA, which uses compensating, synchronization, and version control techniques, ensures data consistency of multiple views on line maintenance and drill down query.