Materialized view selection under the maintenance time constraint

A data warehouse is a data repository which collects and maintains a large amount of data from multiple distributed, autonomous and possibly heterogen eous data sources. Often the data is stored in the form of materialized vie ws in order to provide fast access to the integrated data. One of the most important decisions in designing a data warehouse is the selection of views for materialization. The objective is to select an appropriate set of view s that minimizes the total query response time with the constraint that the total maintenance time for these materialized views is within a given boun d. This view selection problem is totally different from the view selection problem under the disk space constraint. In this paper the view selection problem under the maintenance time constraint is investigated. Two efficien t, heuristic algorithms for the problem are proposed. The key to devising t he proposed algorithms is to define good heuristic functions and to reduce the problem to some well-solved optimization problems. As a result, an appr oximate solution of the known optimization problem will give a feasible sol ution of the original problem. (C) 2001 Elsevier Science B.V. All rights re served.