Stage 3. Sum (Optional)

The sum stage is an integral part of the reconciliation process that facilitates the processing of large files by producing summary records. This stage can be performed on one or more files, depending on the Preparation function previously used. If the WRITE function was used with two files, unmatched summary records can be detected.

The output of this stage can be

• unmatched records, for example, records that appear in one file but not the other
• all records, for example, both matched and unmatched records, sorted in key order

The sum stage is performed using the SUM function (all summary records are included in the output) or SUMX (the user can request separate output files for matched and unmatched records). These functions are explained in Reconciliation Functions.