A dataware house is a decision support database for organisational needs.It is subject oriented,non volatile,integrated ,time varient collect of data.

               ODS(Operational Data Source) is a integrated collection of related information . it contains maximum 90 days information.

An operational data store (or "ODS") is a database designed to integrate data from multiple sources to facilitate operations, analysis and reporting. Because the data originates from multiple sources, the integration often involves cleaning, redundancy resolution and business rule enforcement. An ODS is usually designed to contain low level or atomic (indivisible) data such as transactions and prices as opposed to aggregated or summarized data such as net contributions. Aggregated data is usually stored in the Data warehouse.