Concept of OLAP ?

hello everyone,

What is the concept of OLAP in database systems ?
Can anyone provide me necessary and useful information about this ?
thank you...

OLAP means OnLine Analytical Processing.

OLAP is an approach to quickly answer multi-dimensional analytical queries. OLAP is part of the broader category of business intelligence, which also encompasses relational reporting and data mining.
The typical applications of OLAP are in business reporting for sales, marketing, management reporting, business process management (BPM), budgeting and forecasting, financial reporting and similar areas. The term OLAP was created as a slight modification of the traditional database term OLTP (Online Transaction Processing).

Databases configured for OLAP use a multidimensional data model, allowing for complex analytical and ad-hoc queries with a rapid execution time.
They borrow aspects of navigational databases and hierarchical databases that are faster than relational databases.

Concept

In the core of any OLAP system, there is a concept of an OLAP cube (also called a multidimensional cube or a hypercube). It consists of numeric facts called measures which are categorized by dimensions. The cube metadata is typically created from a star schema or snowflake schema of tables in a relational database. Measures are derived from the records in the fact table and dimensions are derived from the dimension tables.

Each measure can be thought of as having a set of labels, or meta-data associated with it. A dimension is what describes these labels; it provides information about the measure.

A simple example would be a cube that contains a store's sales as a measure, and Date/Time as a dimension. Each Sale has a Date/Time label that describes more about that sale.

Any number of dimensions can be added to the structure such as Store, Cashier, or Customer by adding a column to the fact table. This allows an analyst to view the measures along any combination of the dimensions.

Well, the concept of OLAP was not included in the traditional database systems....It became useful in the Advanced Database Systems.

The application of OLAP became highly useful in multidimensional relational databases.

• Multidimensional structure is defined as “a variation of the relational model that uses multidimensional structures to organize data and express the relationships between data”.
• The structure is broken into cubes and the cubes are able to store and access data within the confines of each cube. “Each cell within a multidimensional structure contains aggregated data related to elements along each of its dimensions”.
• Even when data is manipulated it is still easy to access as well as be a compact type of database. The data still remains interrelated. Multidimensional structure is quite popular for analytical databases that use online analytical processing (OLAP) applications.
• Analytical databases use these databases because of their ability to deliver answers quickly to complex business queries.
• Data can be seen from different ways, which gives a broader picture of a problem unlike other models.

Online analytical processing (OLAP) is in my opinion a highly abused term that has lost much of its original meaning. In its original guise, dating from the early 1990’s, the term was used to describe a class of computer systems that were designed and optimized for analysis. This is still true of Oracle OLAP but not for many of the other proprietary solutions currently available in the marketplace.
You can gain the basic knowledge of OLAP through a great book.The book is available on Amazon & you can buy an e-book directly from the publisher by writing