OLAP stands for OnLine Analytical Processing and it deals with Historical Data or Archival Data. Historical data are those data that are archived over a long period of time. OLAP helps to answer multi-dimensional analytical (MDA) queries in a fast manner.
Both Bill Inmon and Ralph Kimball are stalwarts of data warehousing and business intelligence industry, they have contributed immensely to define standards and frameworks. They each have defined methods to design data warehouse for any company. Both philosophies have their own advantages and differentiating factors, and enterprises continue to use either of these.
Today it is not just the large organizations, be it a small company or a midsized firm - every moden company needs some kind of business intelligence solution to be competitive in the market.
Term ETL refers to methods access and manipulate source data and load it into target data. ETL is the abbreviation of three words Extract, Transform and Load.
Purpose of ETL process is to extract data, mostly from different types of systems, transform it into a structure that’s more appropriate for reporting and analysis and then finally load it into the target database, usually a data warehouse.
Assume that you are the manager of a large retail store where your customers want range of products including cosmetics, soft drinks, toiletries, Over-the-counter drugs, toys, processed foods and more. How does your customer feel when you have cosmetics in a separate store and then processed foods in another store in a far away distance. In reality, such a retail store does not serve the purpose of one stop shopping. This will create inconvinience to the customer as well loose the sales for the store owner.