A data warehouse is an information provider that collects necessary data from individual source databases to support the analytical processing of decision-support functions. In the past, research on data warehouses primarily focused on relational data models. In this paper, A new data model, called the composite data model, is proposed to store the data in the object-oriented data warehouse. The data model forms new classes consisting of the attributes listed in the definitions of views and copies necessary class structure from the data source. The query performance of the data warehouse can thus be improved. The corresponding view creation and deletion algorithms are also proposed.