Using a Projection Node
A Projection node is one of the most popular nodes and they 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.