This is the sixth article of the series, Introduction to MSSQL Server 2000 Analysis Services. As I stated in the first article, Creating Our First Cube, the primary focus of this series is an introduction to the practical creation and manipulation of multidimensional OLAP cubes. The series is designed to provide hands-on application of the fundamentals of MS SQL Server 2000 Analysis Services ("Analysis Services"), with each installment progressively adding features designed to meet specific real - world needs. For more information on the series, as well as the hardware/software requirements to prepare for the exercises we will undertake, please see my initial article, Creating Our First Cube.

Introduction

In the first article of the series, we used the Cube Wizard to build an initial cube with the assistance of the Dimension Wizard. We progressed through subsequent articles, creating similar dimensions to those we built with the Wizard, focusing largely in our second article on using the Dimension Editor to illustrate options for building a more customized cube. We continued this examination of dimensions in Article Three, where we recreated the calendar time dimension, this time focusing on the process through which the Dimension Wizard converts existing time/date fields to a time dimension, along with its hierarchy of levels and members. Article Three also exposed ways to customize the predefined, time-related properties that the wizard establishes in building the time dimension, suggesting options for customization of these properties to enhance the cube, from the dual perspectives of user-friendliness and the reporting needs of the organization. We created an example of an alternate time dimension for fiscal time reporting, and then we discussed some of the considerations surrounding the simultaneous housing of both hierarchies in the same OLAP cube structure.

In Article Four, we examined another special type of dimension, the Parent-Child dimension, and explored the attributes that make it different from a regular dimension. We discussed the considerations that surround Parent-Child dimensions, such as the recursive nature of their data sources, and various actions that must be handled differently in their creation and maintenance. We created a parent-child dimension using the Dimension Wizard, within which we worked with levels and properties. Finally, we enabled values at the parent level of our newly created parent-child dimension. In Article Five, Working with the Cube Editor, we reviewed, summarized and integrated many of the concepts and components that we had previously constructed individually in earlier lessons. We undertook a complete cube build "from scratch," pulling together all that we had learned, to demonstrate the assembly of a cube more sophisticated than the cube we generated in our first lesson with the Cube Wizard.

In this article, Exploring Virtual Cubes, we will introduce the concept of virtual cubes, and practice their creation and use. We will discuss the options that virtual cubes provide, from the intermingling perspectives of consolidation of multiple data sources, presentation enhancement and control, and other functionality.

In this article, we will:

• Discuss potential uses of virtual cubes to offer options that extend the functionality and capabilities of individual OLAP cubes;
• Create virtual cubes to practice their development for:
• Consolidation of data within multiple OLAP cubes;
• Comparison of data between individual cubes;
• Control /customization of information presentation.
• Modify the structure of a virtual cube;
• Add a calculated member within a virtual cube;
• Discuss limitations and strengths in the use of virtual cubes where appropriate.