Multi-objective materialized view selection using NSGA-II

Data warehouse is constructed with the purpose of supporting decision making. Decision making queries, being long and complex, consume a lot of time in processing against a continuously growing data warehouse. View materialization is one of the alternative ways of improving the response time of such analytical or decision making queries. This involves selection and materialization of views that minimize the analytical query response times while adhering to the resource constraints. This is referred to as the view selection problem, which is a NP-Hard problem. The view selection problem is concerned with simultaneously minimizing the cost of evaluating materialized and non-materialized views. This being a bi-objective optimization problem is addressed using NSGA-II in this paper. The proposed approach aims to achieve an acceptable trade-off between the afore-mentioned two objectives.