Tutorials
Reporting ServicesMatrix provides a similar functionality (roughly speaking rows against columns) to cross-tab reports in MS Access (Resource Link) and Pivot Table dynamic views (Resource Link). The matrix should have at least one row group and one column group. The matrix can expand both ways to accommodate the data, horizontally for column groups and vertically for row groups. The matrix cells (intersection of rows and columns) display summary information (aggregates).
When you click on Insert Matrix in the Insert menu and drop it on the design area of Report Builder 2.0, it gets displayed as shown in the next figure.

Now if you click inside the boundary of the (2x2) empty matrix you will see more features of the matrix as shown in the following screenshot. The basic elements are the ColumnGroup (Column Groups), the RowGroup (Row Groups), and the Data. The group information is also displayed as shown by overlaid lines pointing to them. There needs to be a minimum of one group and one column for the matrix and there could be a hierarchy of column and row groups.

The row and column group cells have their own properties which can be displayed when you right-click on them as shown in the next screenshot for the row group. When you right-click on the cell marked Rows, the following drop-down menu pops up.

In addition to the properties that you can set for the textbox in that cell, you have additional submenu items that work with the grouping and totaling. These are part of representing data in a matrix. Each of the Tablix for the Rows and Columns has the additional submenu items which are shown here for the Rows. Similar ones apply for the Columns as well.
These are useful when you want to create nested groups as you shall see in the hands-on exercises in Chapter 7. With the Matrix design interface in SQL Server 2005 this would not have been possible.
In addition to the above, each of the items Rows and Columns cells has the following items as well. These specify how new columns and rows are inserted with reference to the current cell as shown. The differences are due to the geometrical positions that are allowed for the new columns or rows as shown.
For the "Columns" cell:
For the "Rows" cell:
Besides using a cell as a starting point, one could also use the rows as a whole or column as a whole to add further structure as shown in the next figure. Of course you need to use the proper submenu option to arrive at a particular matrix structure. Clicking at the indicated points would let you choose the structure you want for your matrix. If you click at the location shown for the Tablix you could choose to the delete the whole matrix. The Tablix graphical arrangement gives you the maximum flexibility in extending the matrix in 2-dimensions.
