The different data for the intelligence information system are stored intermediately in a place called data warehouse.
The data warehouse is therefore the only place where all enterprise data are consolidated. The creator of the Data Warehouse concept, Bill Inmon, defines it as follows:
"A data warehouse is a collection of thematic, integrated, non-volatile and historized data for decision-making."
Its main characteristics are therefore as follows:
- The data warehouse is subject-oriented, this means that the data collected must be "business" oriented and therefore sorted by topic.
- The data warehouse consists of integrated data, i.e. preliminary "cleaning" of the data is necessary to ensure rationalization and standardization.
- The data of the data warehouse are non-volatile, which means that a datum entered into the warehouse remains there permanently and can not be suppressed.
- The data of the data warehouse must be historized, i.e. dated.
The term Datamart refers to a subentity of data warehouses containing the data of the data warehouse for a particular sector of the company (department, division, service, product line, etc.). For example, there is a DataMart Marketing, DataMart Commercial, etc.