  This article addresses the generation of the ETL
operators(Extract-Transform-Load) for supplying a Data Warehouse from a
relational data source. As a first step, we add new rules to those proposed by
the authors of [1], these rules deal with the combination of ETL operators. In
a second step, we propose an automatic approach based on model transformations
to generate the ETL operations needed for loading a data warehouse. This
approach offers the possibility to set some designer requirements for loading.
