Dhara Shah

Data Warehouse
- Data Mart


What is Data Warehousing ?

  • Like a conventional ware house where excess inventory is stored for easy access of items and can be requested by users on as-need-be basis; the digital information is stored in data warehouses(DW).
  • The same concept of storing data and its availability as a conventional physical warehouse can crystallize the concept.
  • DW is the channelizing of data from various sources into one streamlined , easy to manipulate fashion where data can be used to determine trends from the past. Generally accepted methods of accessing data include queries,analysis and reporting. Since a single database is created , there can be numerous sources  to input data.It is the large database in the end that is manipulated by users to gather required information.
  • Companies depend on data warehousing  to analyze trends over time. The Top Data Warehousing Companies use data warehousing  to learn more about the day-to-day operations but more importantly analyze trends over time but its main functionality lies in facilitating strategic planning resulting from long-term  overviews.
  • The data is mostly read-only since its objective is present an overview-like reporting.If any changes are required to the data stored in in the DW, a query needs to be generated.
  • DW is specifically designed to assist in decision making for the management that depicts a collective picture of the everything related to business at a single given time.

Where is Data Warehousing and Data Mart being used today?

Examples include:
  • Facebook
  • Amazon
  • eBay
  • Google

The companies use the data to research the customers preferences extensively and to sell/utilize the information gathered third-parties who then use this information for future product development and/or to up-sale their existing products.

The digital information brings companies like the above mentioned, very close to understanding its customers and clients alike which is immensely beneficial.

YouTube Video

YouTube Video



Data Warehouse vs Data Mart

Data Warehouse

Data Mart

A data structure that is optimized for distribution

A data structure that is optimized for access

It collects and stores integrated sets of historical data from multiple operational systems and feeds them to one or more data marts.

It is designed to facilitate end-user analysis of data.

It may also provide end-user access to support enterprise views of data

It typically supports a single, analytic used by a distinct set of workers

Associated with enterprise-wide business processes and decisions

Targets a specific business segment of that enterprise

Easier to understand Data Mart as a subset of Data Warehouse but not a universally accepted concept.


Data Warehouse

Picture taken from http://en.wikipedia.org/wiki/File:Data_warehouse_overview.JPG

Data Mart

Picture taken from http://data-warehouses.net/architecture/datamarts.html

Key Functions :ETL based Data Warehouse

 Staging Layer It stores raw extracted data from different sources of data.
 Integration Layer It transforms the data from the staging layer while storing it in an ODS ( operational data store) database. It is later stored in an hierarchy or groups based on priority, called dimensions
 Access Layer It makes the data accessible to the users to retrieve the necessary data


Emerging Data Warehousing Strategies