In business intelligence ODS system is different from data mart system which again is different from data warehouse system. These three systems differ in their business purpose as well as technical design.

Operational data store(ODS)

ODS is layer of repository that resides between a data warehouse and the source system. The current, detailed data from disparate source systems is integrated, grouped subject areas wise in the ODS. The ODS is updated more frequently than a data warehouse. The updates happen shortly after a source system data changes.

There are two objectives of an ODS:

1. Source DWH with detailed, integrated data.
2. Provide organization with operational Integration.

Data mart

When we restrict the scope of a data warehouse to a sub set of business process or subject area we call it a Data Mart.

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

Data warehouse

A data warehouse (DW) is a database used for reporting and analysis. Data warehouse refers to enterprise level data warehouse system.

The data stored in the warehouse is uploaded from the operational systems. The data may pass through an operational data store for additional operations before it is used in the DW for reporting.