Checksums 

Definition

A checksum is a number calculated by the system for each of the segments in the extracted sequential file. The system calculates the checksum when writing the data into the extract file.

You can use checksums to verify the integrity of the sequential file containing a data extract. Verifying checksums of an extract file ensures that the file has not been corrupted or that it has not been changed manually by someone since the data was extracted.

While checksums help you verify the integrity of the file containing the data extract, Control total figures help you verify the integrity of the data extracted based on its contents.