In the context of relational data warehouses administration, the use of optimization techniques is an issue to provide decision-making information within a reasonable time. The authors can cite indexes, materialized views, data partitioning, etc. The selection of optimal instances of these structures is NP-complete problem. Researchers often use approximate methods or algorithms to reduce the complexity of the selection problem of these optimization techniques. Among these methods, they find, for example those based on genetic algorithm and ant colony.