Data marts contain repositories of summarized data collected for analysis on a specific sector or unit within an organization. They are a subset of data stored in a data warehouse and are often seen as small slices of the data warehouse. The key objective for data marts is to provide the business user with the data that is most relevant, in the shortest possible time. They may contain millions of records and require gigabytes of storage. There are five steps in implementing a data mart: designing, constructing, populating, accessing and managing. According to the Yellowbrick ITDM data warehousing survey, 37% respondents had multiple data warehouses & data marts that are not connected & 26% respondents had connected multiple data warehouses & data marts.
