Data Warehouse is a relational database management system (RDBMS) construct to meet the requirement of transaction processing systems. It can be defined as any centralized data repositories which provide multidimensional benefits for storing, analysing and interpreting the whole data of an enterprise. It provides a platform to provide unified repository to satisfy information oriented requirements of decision makers. Data Warehouse environment contains an extraction, transportation, and loading (ETL) solution, an online analytical processing (OLAP) engine, customer analysis tools, and other applications that handle the process of gathering information and delivering it to business users. This book explains the basic concepts and underlying architectures of the building a data ware, which in turn will serve as a base for various data mining applications.