Data mart
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A data mart is a specialized version of a data warehouse. Like data warehouses, data marts contain a snapshot of operational data that helps business people to strategize based on analyses of past trends and experiences. The key difference is that the creation of a data mart is predicated on a specific, predefined need for a certain grouping and configuration of select data. Since data mart configuration emphasizes easy access to relevant information, the star schema is a fairly popular design choice, as it enables a relational database to emulate the analytical functionality of a multidimensional database.
A dependent data mart is a logical subset (view) or a physical subset (extract) of a larger data warehouse, isolated for one of the following reasons:
- A need for a special data model or schema: e.g., to restructure for OLAP
- Performance: to offload the data mart to a separate computer for greater efficiency or to obviate the need to manage that workload on the centralized data warehouse.
- Security: to separate an authorized data subset selectively
- Expediency: to bypass the data governance and authorizations required to incorporate a new application on the Enterprise Data Warehouse
- Proving Ground: to demonstrate the viability and ROI (return on investment) potential of an application prior to migrating it to the Enterprise Data Warehouse
- Politics: a coping strategy for IT (Information Technology) in situations where a user group has more influence than funding or is not a good citizen on the centralized data warehouse.
- Politics: a coping strategy for consumers of data in situations where a data warehouse team is inept and unable to create a usable data warehouse.
Tradeoffs inherent with datamarts include limited scalability, duplicaton of data, data inconsistency with other silos of information, and inability to leverage enterprise sources of data.de:Data Mart fr:Datamart it:Data mart nl:Datamart pt:Data mart ru:Витрина данных