Experimental Evaluation of Data Warehouse Configuration Algorithms

A Data Warehouse (DW) can be seen as a set of materialized views defined over relations that are stored in remote heterogeneous database systems. When a query is posed to the DW, it is evaluated locally, using only the materialized views. The DW configuration problem is the problem of selecting an optimal set of views to materialize that answer a given set of queries. The objective is the minimization of the combination of the query evaluation and view maintenance costs. In this paper we report on the experimental evaluation of an exhaustive algorithm and we develop new greedy and heuristic algorithms that expand only a small fraction of the states produced by the exhaustive algorithm. The algorithms are described in terms of a state space search problem. Finally, we report on experimental results and discuss the observed behavior of the algorithms.