Data Warehouse:
- Holds multiple subject areas
- Holds very detailed information
- Works to integrate all data sources
- Does not necessarily use a dimensional model but feeds dimensional models.
Data Mart
- Often holds only one subject area- for example, Finance, or Sales
- May hold more summarised data (although many hold full detail)
- Concentrates on integrating information from a given subject area or set of source systems
- Is built focused on a dimensional model using a star schema.
Summary
- Data mart and data warehousing are tools to assist management to come up with relevant information about the organization at any point of time
- While data marts are limited for use of a department only, data warehousing applies to an entire organization
- Data marts are easy to design and use while data warehousing is complex and difficult to manage
- Data warehousing is more useful as it can come up with information from any department.