Pentaho® Solutions: Business Intelligence and Data Warehousing with Pentaho and MySQL®

Chapter 15. OLAP Solutions Using Pentaho Analysis Services

Pentaho Analysis Services provides the OLAP capabilities of the Pentaho Platform. Chapter 8 briefly introduced the concepts OLAP, ROLAP, MOLAP, and HOLAP. This chapter is devoted to getting (R)OLAP solutions up and running on the Pentaho BI platform using Pentaho Analysis Services (PAS). PAS allows you to interactively analyze data from the data warehouse by providing a crosstab-style interface on which different dimensions such as time, product, and customer can be placed. Unlike a reporting tool, there is no need to first define a query, retrieve the results and format these, although this is possible if desired. An OLAP front end provides an intuitive point-and-click or drag-and-drop interface that will automatically retrieve and format data based on the selection made by a user. It allows for fast zooming in on certain parts of the data cube, also called drill down, or aggregating details to a summary level, also called drill up. You can apply conditions to only look at parts of a cube, which is also called slicing. Swapping information from rows to columns or vice versa finally is like turning the cube and look at it from different angles, which is also called dicing. Performing drill up, drill down, slice and dice, and doing all of this in a high speed, interactive manner is what distinguishes OLAP from other kinds of analysis and reporting and allows a user to quickly analyze data and find exceptions or gain insight ...