May 18, 2014 by Ozgur Ozden
OLAP (online analytical processing) is a software tool which analyzes the data stored in a database and uses multidimensional view to access data faster. OLAP is the backbone of data mining but not as big as data warehouse. Integral part of the OLAP system is the OLAP server which is located between the client and the Database Management System and contains detailed information about the database information structure. At the heart of the OLAP system there lies an “OLAP Cube” which is a multidimensional data.
There are many advantages of OLAP system such as
1- Processing the multidimensional data is easier with OLAP systems. It is easier because system uses aggregations which is computing all the dimensions for example adding up all the products to have total inventory.
2- OLAP systems provide more complicated solutions that are difficult to obtain by standard SQL queries.
3- Multidimensional view of the data increases the data interpretation and decision making in the business.
4- OLAP can be used in many platforms.
Typical OLAP architecture consists of the following components or layers.
1- End-user Layer: This module is located at the client side because this is the visual interaction point between the server and the end-user. It is the interface where client send his queries to the data warehouse. In this layer end-user can receive the data calculated and use it in various forms to analyze it such as in its multidimensional form or view the standardized reports.
2- Data Source: can contain information from various places such as web pages, flat tables, archived and live databases, or multidimensional cubes.
3- OLAP Server: is responsible for performing the complex processing needed for the business including comparing data by periods, multiple dimensional data, data gathering, etc… It is capable of processing multidimensional data with multi user input. There are different types of OLAP systems as Multidimensional OLAP (MOLAP), Hybrid OLAP (HOLAP), and Relational OLAP (ROLAP)
4- Data Warehouse: This module mainly placed at the server because it converts the data requests to data objects. Data in a warehouse can be stored as dimensional or normalized. OLAP cube data is formed by using the tables in the database with dimensional approach. Star or Snowflake schema can be used to form tables in the warehouse. There are many advantages of data warehouse such as collecting data from various sources, perform different kind of analyses, reduced cost and time saved etc…
1- Overview of Online Analytical Processing (n.d) (online) Available at: http://office.microsoft.com/en-001/excel-help/overview-of-online-analytical-processing-olap-HP010177437.aspx [Accessed at: 25.10.2013]
2- Elena et al. ARCHITECTURE ON-LINE ANALYTICAL PROCESSING (online) Available at:http://fse.tibiscus.ro/anale/Lucrari2011/125.pdf [Accessed at: 25.10.2013]
3- Introduction to OLAP (n.d) (online) Available at: http://www.newagetraining.com/lessons/Intro_to_OLAP.pdf [Accessed at: 25.10.2013]