October 22, 2014 \ Ananth TM Target Data Target data can be stored in: Single data warehouse Data marts with logical data chunks Both data warehouse and data marts The data warehouse has all the information of the enterprise in a historical archival. Data Marts are proposed as logical subsets of the complete DW. They should be consistent in their data representation in order to assure DW robustness. Data warehouses are used where interdependency of data marts is needed. Data marts are used for analysis of components The data models that are used for DWs are Multidimensional Model and Relational Model. Two different approaches for Relational DW design: one that applies dimensional modelling techniques, and another that bases mainly in the concept of materialized views. Dimensional models represent data with a “cube” structure , making more compatible logical data representation with OLAP data management. The objectives of dimensional modelling are: To produce database structures that are easy for end-users to understand and write queries against, and To maximise the efficiency of queries. It achieves these objectives by minimising the number of tables and relationships between them.