Online analytical processing (OLAP) is a category of software technology that enables analysts, managers, and executives to gain insight into data through fast, consistent, interactive access to a wide variety of possible views of information that has been transformed from raw data to reflect the real dimensionality of the enterprise as understood by the user.

Kinds of OLAP

ROLAP- relational OLAP using relational databases; a star schema is used

MOLAP- multidimensional OLAP using multidimensional databases

DOLAP- desktop OLAP Other variations

Example: Olap Usage of an Automobile Marketer

The StoryAn automobile marketer wants to improve business activity. Therefore he wants to view sales figures from different perspectives.

A QuestionWhat is the trend in sales volumes over a period of time for a specific model and color across a specific group of dealerships ?

The Data NeedsSales by model

Sales by dealership

Sales by color

Sales over time

etc.

Example: The Multidimensional View of the Data

Sales Volumes

Blue Red White

Van

Coupe

Sedan

Miller

Clyde

Smith

COLOR

DEALERSHIP

MOD E L

OLAP Features: “Slicing and Dicing“ the Data

Sales Volumes

Blue

Red White

Van

Coupe

Sedan

Miller

Clyde

Smith

COLOR

DEALERSHIP

MOD E L

• Color: Blue and White• Model: Coupe only• Dealership: Clyde only

Clyde

Blue

White

Coupe

“Sliced and Diced“ Data

Choosing a range out of each dimension:

OLAP Features: Rotating the Data

Sales Volumes

Blue Red White

Van

Coupe

Sedan

COLOR

MOD E L

View of the Account Manager

Rotate the data cube by 90°

DEALERSHIP

Sales Volumes

Miller

Smith

Clyde

Van

Coupe

Sedan

MOD E L

View of the Product Manager

Different users will require different views of the multidimensional cube – OLAP allows easy rotation of data

OLAP Features: Drill-Down and Roll-Up

Data can be disaggregated and aggregated along a dimension according to their natural hierarchy

Drill-Down

Roll-Up

State

Region

Dealership Miller Smith

Clyde Lucas Gleason

Atlanta Athens

Georgia

Sales Volumes by Organization Dimension

- three level hierarchy -