Problem.

When running MFJSORT (i.e. PGM=SORT) in JCL, the following message is produced.

SORT230I: OVERFLOW DURING SUMMATION - RC0

Resolution.

The overflow message SORT230I is produced when internal fields used to calculate SUM results are too large to be written to a single record and needs additional storage.

The message is written to help debug in case of failures, and is normal MFJSORT behaviour which can safely be ignored.