Using a Projection Node
The Projection node is one of the most popular node types. Projection nodes usually appear in most calculation views of all types. They provide many useful features that most calculation views require.
A Projection node is typically used to achieve the following:
To select only the required columns from a data source.
To define calculated columns.
To define parameters that request values at run-time, such as user-prompts.
To apply a filter on the data source.