When you add data items to crosstabs, you create crosstab nodes and crosstab node members. These objects allow you to easily create crosstabs, by dragging data items to crosstabs.
Crosstabs are dimensional objects that have row edges and column edges. Each edge is composed of a set of crosstab nodes. Each crosstab node contains the following:
One or more crosstab node members.
Zero or one nested crosstab node, which contains one or more crosstab node members or nested crosstab nodes.
Each crosstab node member refers to a data item that contains an expression to define the members in the crosstab.
The following crosstab contains four crosstab nodes.
Crosstab node 1 contains a single node member for the total. This node refers to the data item Total(Product line).
Crosstab node 2 contains a crosstab node member that refers to the data item Product line. This member has a nested crosstab node containing a crosstab node member that refers to the data item Product type.
Crosstab node 3 contains a single node member for the average. This node refers to the data item Average(Product line).
Crosstab node 4 contains a crosstab node member that refers to the data item Order year. This member has two nested crosstab nodes. The first node contains a crosstab node member that refers to the data item Order month. The second node contains a crosstab node member for the total. This node refers to the data item Total(Order month).
Tip: Nodes are also created when you add data items to charts.
Crosstab nodes can be placed anywhere in the crosstab. For example, in the previous diagram, you can drag Order month under Average(Product line) to create a row edge.
To move nested items from one edge to another, ensure that you
select the crosstab node and not the crosstab node member. For example,
in the previous diagram, you want to move Product line and Product
type to the column edge. To do this, click Product
line and, in the Properties pane,
click the select ancestor button 
and click Crosstab
Node. Both Product line and Product
type are selected.
In the Structure menu, the Create Crosstab Nodes option affects the drag-and-drop behavior in crosstabs. When the option is turned on and you add a data item to a crosstab, the item is created as a crosstab node. If the option is turned off, the item is created as a crosstab node member to an existing crosstab node.
For example, in the previous diagram, if the option is turned on and you drag Country from the Insertable Objects pane to beneath Product line, Country becomes a new peer node to Product line. If the option is turned off, Country becomes a new peer node to Product line and has Product type as a nested crosstab node. This happens because instead of adding a new node, you are adding a new member to the existing node that already contains Product line.
Tip: To create discontinuous crosstabs 
,
turn the Create Crosstab Nodes option on. If
you want the items on the edges of crosstabs to be related (contain
the same nested items), turn the Create Crosstab Nodes option
off.
