A data warehouse is a subject-oriented, integrated, time-variant and non-volatile collection of data in support of management's decision making process - Bill Inmon
A data mart is an important subset of a data warehouse. It is subject-oriented, and it is designed to meet the needs of a specific group of users. Data marts are fast and easy to use, as they make use of small amounts of data
Parameter | Data Warehouse | Data Mart |
---|---|---|
Focus | Enterprise-wide repository of disparate data sources | A single subject or functional organization area |
Data Source | Many external and internal sources from different areas of an organization | In Data Mart data comes from very few sources |
Usage | It helps to take a strategic decision | It helps to take tactical decisions for the business |
Designing | Complex in design and execution | Simple and easier to implement |
Data Handling | Data warehousing includes large area of the corporation which is why it takes a long time to process it. | Data marts are easy to use, design and implement as it can only handle small amounts of data. |
Data Storage | Designed to store enterprise-wide decision data, not just marketing data. | Dimensional modeling and star schema design employed for optimizing the performance of access layer. |
Scope | Data warehousing is more helpful as it can bring information from any department. | Data mart contains data, of a specific department of a company. There are maybe separate data marts for sales, finance, marketing, etc. Has limited usage |
Size | The size of the Data Warehouse may range from 100 GB to 1 TB+ | The Size of Data Mart is less than 100 GB. |
Implementation time | The implementation process of Data Warehouse can be extended from months to years | The implementation process of Data Mart is restricted to few months |