Building a Virtual Cube

To quickly and easily build a virtual cube, use the Virtual Cube wizard. The wizard takes you through steps to specify your virtual cube’s:

• Cubes.

  Select the cubes that contain the data you want in your virtual cube. A cube is a set of data organized and summarized into a multidimensional structure defined by measures and dimensions. The virtual cube creates a combined view of your selected cubes by including their measures and dimensions that you select.

• Measures.

  Select the measures to be available to users of your virtual cube. A measure contains numerical data (for example, Sales) viewed and analyzed by users. Each measure corresponds to a column in the fact table in a selected cube. This column supplies the measure’s values.

• Dimensions.

  Select the dimensions to be available to users of your virtual cube. Dimensions are descriptive categories by which the measures can be separated for analysis. In tabular browsers, they provide the column headings, row headings, and subheadings by which the measures are separated and displayed to cube users. (In graphical browsers, they provide other types of descriptive labels but with the same function as in tabular browsers.) For example, the measure is Sales, and the dimensions are Time, Location, and Product. Users can separate Sales into various categories of Time, Location, and Product. Time provides headings for individual years and subheadings for months. Location and Product also supply a variety of headings and subheadings.

  Each dimension is created from one or more columns in a dimension table. These columns supply the dimension’s values which produce the column headings, row headings, and subheadings seen by virtual cube users.

For more information about virtual cubes, see Virtual Cubes.

To start the Virtual Cube wizard

1. In the OLAP Manager tree view, expand a database.
2. Right-click the Virtual Cubes folder, and then click New Virtual Cube.

The last step of the wizard gives you the option to process your virtual cube now or later. You must process it before you and users can view its data. Depending on the size of the unprocessed cubes in your virtual cube, processing may take considerable time. If all the cubes in your virtual cube have been processed, virtual cube processing is much faster. If you decide to process later, refer to Processing Cubes Using the OLAP Manager for more information.

Note Newly processed virtual cubes are visible to client users only after they reconnect to the server computer.

After you make nonstructural changes to a cube, you must process dependent virtual cubes to provide users continuing access to them. (This processing is much faster than processing the component cubes if the component cubes’ structures have not changed since their last processing.) These changes include adding or changing a calculated member, changing security roles, and changing the Description property value. When you make a nonstructural change, virtual cube users connected to the server computer are unaffected as long as they remain connected. However, until you process the dependant virtual cubes, users who connect will be unable to see them.