What is the Difference Between Dependent and Independent Data Marts

The main difference between dependent and independent data marts is that the dependent data marts get data from an already created data warehouse while the independent data marts get data directly from an operational source and/or external source.

In brief, a data warehouse is a system that helps to analyse data, create reports and visualize them to make business decisions. An organization has multiple data sources. Data warehouses collect this data and help to analyze them to take business insights. A data mart is a subset of data stored in a data warehouse. These data marts provide more security and data integrity. Furthermore, there are two types of data marts as dependent and independent data marts.

Key Areas Covered

1. What is Dependent Data Marts
     – Definition, Functionality
2. What is Independent Data Marts
     – Definition, Functionality
3. What is the Difference Between Dependent and Independent Data Marts
     – Comparison of Key Differences

Key Terms

Data Mart, Data Warehouse, Dependent Data Mart, Independent Data Marts

What are Dependent Data Marts

A dependent data mart obtains data from a data warehouse. It improves data centralization.  Furthermore, if it is necessary to develop one or more physical data marts, it is possible to configure them as dependent data marts.

There are two approaches to consider when building a dependent data mart. First, it is possible to build it in a way that the user can access both the data mart and the data warehouse depending on the requirement. Secondly, the user can only get accessibility to handle the data in the data mart.

What are Independent Data Marts

An independent data mart does not get data from the central or the main data warehouse. Therefore, an independent data mart does not have any association with the main data warehouse or other data marts. Hence, storing and performing analytics on each data mart is a separate task. Mostly, this data mart type is suitable for small groups or sections within an organization. 

Figure 1: Data Marts

In addition to dependent and independent data marts, there is another data mart called hybrid data mart. It combines input from sources other than the central data warehouse. It requires minimum data cleansing. Furthermore, it supports large storage structures.

Difference Between Dependent and Independent Data Marts

Definition

A dependent data mart is a logical subset or a physical subset of a larger data warehouse. In contrast, an independent data mart is a type of data mart that draws data from different sources without using the central data warehouse. Thus, this explains the fundamental difference between dependent and independent data marts.

Method of Obtaining Data

Dependent data marts get data from a central data warehouse that has already been created. However, independent data marts get data directly from operational sources or external sources of data or both.

Functionality

In addition, dependent data marts obtain data by aggregating, restricting and summarizing the data of the data warehouse while independent data marts get data from multiple transaction systems in one subject area or department to support specific business needs. Hence, this is a major difference between dependent and independent data marts.

Dependability

Moreover, dependent data marts depend on the central data warehouse while dependent data marts are standalone data marts and do not depend on the central data warehouse.

Security

Another difference between dependent and independent data marts is that the independent data marts are more secure than dependent data marts.

Control on Data

Furthermore, we can identify a difference between dependent and independent data marts based on control. Independent data marts have more control over their data than dependent data marts.

Conclusion

In breif, a data mart is a subset of a data warehouse that focuses on a single functional area or an organization. There are two types of data marts as dependent and independent data marts. The difference between dependent and independent data marts is that the dependent data marts get data from already created data warehouse while the independent data marts get data directly from an operational, external source or both.

Reference:

1. “20 Data Marts.” Oracle8i Data Warehousing Guide, Available here.
2. “Data Mart Tutorial: What Is Data Mart, Types & Example.” Meet Guru99 – Free Training Tutorials & Video for IT Courses, Available here.
3. “Data Mart – Stand-Alone and Dependent Data Marts.” ZenTut, Available here.

Image Courtesy:

1. “Data Warehouse Feeding Data Mart” By Jerry vlntn at English Wikibooks – Transferred from en.wikibooks to Commons (Public Domain) via Commons Wikimedia