Processing and Browsing a Cube

Processing a dimension and processing a cube are two separate tasks. When you process a dimension, Analysis Services reads in the information from the dimension tables and constructs a map of the dimension. Within the map, each member is stored, fully qualified, using all levels of the hierarchy for the dimension. For example, suppose that Washington is a member in the State dimension. It’s a unique state; no other state has the same name. The map, however, still stores the entire hierarchy for the state: All State→USA→North West→Washington. By storing the entire hierarchy for each member in the dimension map, Analysis Services can use the map to quickly find relationships between members when you query the cube. Of course, the dimension map is compressed and very efficient.

When you process a cube, Analysis Services first combines the dimension maps from all the dimensions used in the cube into a multidimensional cube map. It then reads the detail records from the warehouse fact table, storing detail values in a data storage area. The data storage area is efficiently organized and does not take up any room for key combinations that do not contain a value.

Process a Cube

When you process a cube, the Analysis server automatically processes any dimensions that are used in the cube that have not yet been processed. So, to process the cube and all its dimensions, you need to execute only one command.

1.	Expand the Cubes folder of the Chapter 2 database, right-click the newly created Sales cube, and click Process. [View full size image] The Process A Cube dialog box shows you that the only available option is to completely process the cube.
2.	Click OK to begin processing. A log appears showing the progress. As each dimension is processed, a group of entries appears in the log. As the cube is processed, another group of entries appears in the log. [View full size image]
3.	Scroll up and down the log to see the steps involved in processing dimensions and a cube. To see the full text of an entry in the log, select the line and click View Details. (If you do view an entry, close the small window before continuing.)
4.	Click Close to close the Process log window.

When you processed the cube, Analysis Services copied the detail values from the fact table into a proprietary data structures. It did not store any aggregated values. For a small cube such as this one, the lack of aggregations will not hinder your ability to browse the cube.

Browse Cube Data

You can use the simple browser provided by Analysis Manager to view the values in the Sales cube.

1.	Right-click the Sales cube in the Chapter 2 database, and click Browse Data. You can maximize the Cube Browser window by double-clicking the caption bar, or you can resize the window by dragging any edge of it. The Cube Browser window displays a data grid with measures across the top in the column area, and the first dimension (sorted alphabetically by name) down the left side in the row area. Remaining dimensions appear at the top of the browser in the slicer area. Cube slicers are sometimes called filters or page fields. [View full size image]
2.	In the row or column areas, a plus sign (+) indicates that you can expand the hierarchy and view more detail, and a minus sign (–) indicates that you can collapse the hierarchy to view less detail. Double-click the Sheri Nowmer label to see her subordinates. [View full size image]
3.	Double-click the Sheri Nowmer label again to collapse the hierarchy.
4.	Drag the State button from the slicer area over the top of the Level 02 label in the row area. When the mouse pointer icon includes a double-headed arrow, release the mouse button. The browser swaps, or pivots, the two dimensions. [View full size image]
5.	Then double-click the Country label (the column heading) to expand all three countries at one time. [View full size image] You can change the size of the slicer area by dragging its bottom border.
6.	Double-click the Country label again to collapse the countries.
7.	Drag the Product button from the slicer area over the top of the Canada label. When the mouse pointer icon does not include a double-headed arrow, release the mouse button. The browser combines both dimensions within the row headings. [View full size image]
8.	Click the drop-down arrow next to the Time button in the slicer area. In the dimension tree, click the plus sign next to All Time, click the plus sign next to 1997, and then click Quarter 3. Clicking a plus or minus sign expands or contracts the tree. Clicking a label selects that member. [View full size image]
9.	Click Close or press Escape to close the Cube Browser window.

Now you have used the Analysis Manager to create an OLAP database, dimensions, and a cube. With a cleanly designed data warehouse, you can use the Cube Wizard and the Dimension Wizard to easily create cubes and dimensions. The cubes and dimensions you create by using the wizards, however, might not be precisely what you need. In Chapters 3 and 4, you’ll learn how to use advanced properties to get complete control over the design of new or existing objects.