Data mart

Data mart

A data mart (DM) is the access layer of the data warehouse (DW) environment that is used to get data out to the users. The DM is a subset of the DW, usually oriented to a specific business line or team.

Contents

Terminology

There can be multiple data marts inside a single corporation; each one relevant to one or more business units for which it was designed. DMs may or may not be dependent or related to other data marts in a single corporation. If the data marts are designed using conformed facts and dimensions, then they will be related. In some deployments, each department or business unit is considered the owner of its data mart including all the hardware, software and data.[1] This enables each department to use, manipulate and develop their data any way they see fit; without altering information inside other data marts or the data warehouse. In other deployments where conformed dimensions are used, this business unit ownership will not hold true for shared dimensions like customer, product, etc.

The related term spreadmart describes the situation that occurs when one or more business analysts develop a system of linked spreadsheets to perform a business analysis, then grow it to a size and degree of complexity that makes it nearly impossible to maintain.

Design schemas

Reasons for creating a data mart

  • Easy access to frequently needed data
  • Creates collective view by a group of users
  • Improves end-user response time
  • Ease of creation
  • Lower cost than implementing a full data warehouse
  • Potential users are more clearly defined than in a full data warehouse

Dependent data mart

According to the Inmon school of data warehousing, 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 refreshment 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 unable to create a usable data warehouse.

According to the Inmon school of data warehousing, tradeoffs inherent with data marts include limited scalability, duplication of data, data inconsistency with other silos of information, and inability to leverage enterprise sources of data.

See also

References

Bibliography

External links


Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • Data mart — Saltar a navegación, búsqueda Un Data mart es una versión especial de almacén de datos (data warehouse). Son subconjuntos de datos con el propósito de ayudar a que un área específica dentro del negocio pueda tomar mejores decisiones. Los datos… …   Wikipedia Español

  • Data-Mart — Ein Data Mart ist eine Kopie von ein oder mehreren Teildatenbeständen des Data Warehouse, die für einen bestimmten Organisationsbereich oder eine bestimmte Anwendung, Analyse (siehe unten) erstellt wird. Man kann es auch als Teilansicht auf das… …   Deutsch Wikipedia

  • Data Mart — Ein Data Mart ist ein langfristig gehaltener Datenbestand innerhalb eines Data Warehouse (Datenlager) oder die Kopie eines Teilbereichs des Data Warehouse, die für einen bestimmten Organisationsbereich oder eine bestimmte Anwendung geschaffen… …   Deutsch Wikipedia

  • Data Mart — Abteilungsdatenbank; physikalisch getrennter Auszug aus einem Data Warehouse, dessen Datenbestand einer Fachabteilung für ihre spezifischen Auswertungen (z.B. durch OLAP oder ⇡ Data Mining Werkzeuge) zur Verfügung steht …   Lexikon der Economics

  • Data warehouse — Overview In computing, a data warehouse (DW) is a database used for reporting and analysis. The data stored in the warehouse is uploaded from the operational systems. The data may pass through an operational data store for additional operations… …   Wikipedia

  • Mart — may mean: Data mart Shoppers Drug Mart Mart (given name) Mart (Syriac), Syriac title for women saints Montachusett Regional Transit Authority Mart, Texas mArt, a local broadcasting station in Amsterdam. Museum of Modern and Contemporary Art of… …   Wikipedia

  • Data Vault Modeling — is a database modeling method that is designed to provide historical storage of data coming in from multiple operational systems. It is also a method of looking at historical data that, apart from the modeling aspect, deals with issues such as… …   Wikipedia

  • Data management — comprises all the disciplines related to managing data as a valuable resource. Contents 1 Overview 2 Topics in Data Management 3 Body Of Knowledge 4 Usage …   Wikipedia

  • Data transformation — Data transformation/Source transformation Concepts metadata · data mapping data transformation · model transf …   Wikipedia

  • Data Mining Extensions — (DMX) is a query language for Data Mining Models supported by Microsoft s SQL Server Analysis Services product. Like SQL, it supports a data definition language, data manipulation language and a data query language, all three with SQL like syntax …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”