What are the components of a data warehouse?

The major components of a data warehouse are as follows −

Data Sources − Data sources define an electronic repository of records that includes data of interest for administration use or analytics. The mainframe of databases (e.g. IBM DB2, ISAM, Adabas, Teradata, etc.), client-server databases (e.g. Teradata, IBM DB2, Oracle database, Informix, Microsoft SQL Server, etc.), PC databases (e.g. Microsoft Access, Alpha Five), spreadsheets (e.g. Microsoft Excel) and any other electronic storage of data.

Data Warehouse − The data warehouse is normally a relational database. It should be organized to hold data in a structure that best supports not only query and documenting but also advanced analysis techniques, such as data mining.

Reporting − The data in the data warehouse must be available to the organisations staff if the data warehouse is to be useful. There is a huge number of software applications that execute this function, or reporting can be custom-developed. Reporting tools includes are as follows:

• Business intelligence tools − These are software applications that clarify the process of development and production of business documents based on data warehouse information.

• Executive information systems (known more widely as Dashboard (business) − These are software applications that are used to display complex business metrics and information graphically to allow rapid understanding.

• Data Mining − Data mining tools are software that enables users to implement detailed numerical and statistical calculations on detailed data warehouse data to detect trends, identify design and analyze data.

Metadata − Metadata is data about the data which is needed by the users. It is used not only to instruct operators and users of the data warehouse about its status and the data held inside the data warehouse but also as a means of integration of incoming information and a tool to upgrade and refine the basic data warehouse model.

Operations − A data warehouse operation is consists of the processes of loading, manipulating, and extracting information from the data warehouse. Operations also cover user management, security, capacity management, and related functions.

Optional Components − There are the following components exist in some data warehouses which are as follows −

• Dependent Data Marts − A dependent data mart is a physical database (either on the same hardware as the data warehouse or on a separate hardware platform) that receives all its information from the data warehouse.

• Logical Data Marts − A logical data mart is a filtered view of the main data warehouse but does not physically exist as an independent data copy.

• Operational Data Store − An ODS is an integrated database of operational data. Its sources contain legacy systems, and it includes current or near-term information.