A subset of the data resource, usually oriented to a specific purpose or major data subject, that may be distributed to support business needs. The concept of a data mart can apply to any data whether they are operational data, evaluational data, spatial data, or metadata.
Usually sponsored at the department level and developed with a specific issue or subject in mind, a Data Mart is a data warehouse with a focused objective. The scope of data in a data mart is limited to data supporting the target objective. In this sense, the data mart is more structured than a general-purpose data warehouse. Data mart's are now generally recognized as the most cost-effective approach to data warehousing.
A small, single-subject warehouse used by individual departments or groups of users.