You can add a checksum column to your data by adding a Checksum stage to your data flow.

1. Drag a Checksum stage to your canvas and position it so that it receives data from your data source, and writes it to your data target.
2. Double-click the stage to open the stage editor. Optionally, supply values for the following properties:

   Option	Description
   Computation Mode	By default set to Use all columns. You can also choose to explicitly exclude columns, or explicitly include them. If you choose either of these options, then you must fill in additional properties to specify the columns to exclude, or to include.
   Buffer Output Column Name	By default this property is not set. You can use the property to specify that the buffer used in the generation of the checksum should be included in an additional column with the output data. The buffer contains the actual values in the columns used to generate the checksum.
   Checksum Output Column Name	By default, the output column that contains the checksum value is named Checksum, but you can specify an alternative name in this property.

3. On the Output tab, click Edit in the columns section and specify how your output columns are derived from your input columns and the data generated by the stage.