Data warehouse refreshment is often viewed as a problem of maintaining materialized views over operational sources. In this paper, we show that the data warehouse refreshment process is a complex process comprising several tasks, e.g., monitoring, extracting, transforming, integrating and cleaning operational data, deriving new data, building histories and loading the data warehouse. We propose a novel approach for defining and executing the refreshment process based on specifications stored in an object-oriented metadata repository. Our approach considers the multidimensional character of OLAP data and can be used in conjunction with various operational sources and target data warehouses.
Athanasios Vavouras, Stella Gatziu, Klaus R. Dittr