You can create dynamic ports in a transformation to receive new or changed columns from an upstream transformation. A dynamic port receives one or more columns and generates ports based on input rules. The input rules determine the columns that a dynamic port receives and generates.
Use dynamic ports to perform the following tasks:
Receive new and changed columns.
To get data from a dynamic source or a parameterized source, create a dynamic port in the downstream transformations to receive new and changed columns. If a mapping contains from a dynamic source, the dynamic ports in the downstream transformations automatically get any new or changed columns. For example, if a new column "title" is added to the dynamic source, the Read transformation passes the new column to the dynamic port and the dynamic port creates a generated port for the "title" column.
Filter columns based on input rules.
To process only a certain type of column in a transformation, create a dynamic port and define input rules to filter columns. For example, a mapping source has columns with decimal, string, and date/time data types. You need to process data only for columns of decimal data type. Create a dynamic port and define input rules to include only decimal columns.
Repeat a calculation for more than one port in an Expression transformation
To perform the same calculation on more than one port, use dynamic ports in dynamic expressions. A dynamic expression runs one time for each port in the dynamic port and returns the result to a dynamic output port.
The following image shows a dynamic port named From_Read_Employee and the generated ports: