Difference between Data Mart and Data warehousing
What is the difference between Data Mart and Data warehousing?
Firstly, Data mart represents the programs, data, software and hardware of a specific department. For example, there is separate data mart for finance, production, marketing and sales department.
None of the data mart resembles with any other data mart. However, it is possible to coordinate the data of various departments. Data mart of a specific department is completely focused on individual needs, requirements and desires. Data in data mart is highly indexed but is not suitable to support huge data as it is designed for a particular department.
Whenever the data mart database is to be designed, the requirements of all users in the department are gathered. In most of the cases, we use star-join structure database in data mart. Data marts are basically of two types, independent data mart and dependent data mart. Data warehouse is used as a source by a dependent data mart. Dependent data mart is structurally and architecturally strong. Independent data mart on the other hand is not structurally and architecturally strong. Moreover, they are not useful for organization until you create multiple independent data marts.
Data warehousing is not limited to a department of office. It represents the database of a complete corporate organization. Subject areas of data warehousing includes all corporate subject areas of corporate data model. Data warehousing is neither bounded to have relations between subject areas of departments nor with subject areas of corporation. Detailed data is stored in the database of data warehousing unlike data mart which stores only aggregated or summarized data. Data in the data warehouse is indexed lightly as it has to manage large volume of data. It would be wise to say that there is very little difference in data structure and content of data mart and data warehouse.
Data warehouse is built iteratively as it is not possible to create the complete data warehouse and then implement it. Data warehouse is a vast concept that covers various aspects of a corporate world. In contrast, data mart can be easily and quickly designed and implemented for end users use.
Many people think that they can create data marts for various departments and then integrate them into a data warehouse but this is not possible. Data mart only concentrates on individual department requirements and not on collective need of an entire organization. Moreover, various other factors such as granularity or level of data used, data structure etc. is also different in data mart and data warehousing. Data warehouses are an expensive deal and require a lot of time, investment, planning, managing volumes of data, data integration complexities etc. compared to a data mart.
Data mart is therefore useful for small organizations with very few departments or at places that requires data management for a specific business requirement whereas data warehousing is suitable to support an entire corporate environment.