What is the difference between Data Warehouse vs Data Mart?

What is a Data Warehouse ?

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

What is Data Mart ?

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

Data Mart Diagram

Differences between Data Warehouse and Data Mart

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