Definition. A data warehouse is an integrated data set to a subject oriented, time-varying and non-transient, which support the decision making process of government. (WH Inmon, considered the father of data warehouse). Data warehouse is a relatively new concept, aimed at handling large volumes of data from various sources, of many types. These data cover long periods of time, which brings different schemes that take the source database. The concentration of this information is geared to your analysis to support decision making timely and informed. Your name, Data warehouse (warehouse or data warehouse) is associated with a collection of large data, from operating systems and other sources, after applying the processes of analysis, selection and transfer of selected data.Its mission is, from these data and supported by sophisticated analysis tools to obtain useful information to support decision making. The Data warehousing or storage of data is the process of gathering historical information in an organization (s) stand (s) central database (s). The data will have their source in operational systems, which were selected to transfer information. These data can be stored in relational databases, hierarchical files, flat files, etc.. Because of this it is necessary to carefully analyze and define data represent the essence or philosophy of business that intends to handle and which will be important for the goal that has been determined to hold datos.La information on the imported data is stored in metadata , which are precisely those describing data from operational systems. The metadata stored information on formats, meaning and origin of the data and provide, therefore, access, navigation and data management in the cellar. These are data about data. Data Source: Operational data updated by applications OLTP (On Line Transaction Processing.Online transaction processing.). They are stored in operational databases. Integrated Database: Organized by specific interests. OLTP transactions reflecting historical information accumulated for years or in general for long periods. This differentiates it from other databases. They are usually relational databases. You could say that is the decision support server that adds value to data from sources in production. Directory Information: Lists the system which data are available, in what format and how to access them. Build your metadata from the metadata of the databases that are on the network.They are vital aid for Database Administrators DBA. Data Replication Manager: Responsible for copying and distribution of data in accordance with the design.