Start from here:
Explanation: When the system detects an error in internal IBM DATABASE 2 (DB2Â¦) processing, it will abnormally end a connected user task (TCB) or one of its own internal tasks. For information about the reason codes associated with this abend code, see DB2 Messages and Codes.
System Action: The system abnormally ends the connected user task or the DB2 internal task.
Application Programmer Response: Check register 15 of the SDWA section'General Purpose Registers at Time of Error', and locate the accompanying reason code. In addition, check the information displayed at the user's terminal, and in the corresponding logrec data set entry.
System Programmer Response: If the error recurs and the program is not in error, look at the messages in the job log for more information. Search problem reporting data bases for a fix for the problem. If no fix exists, contact the IBM Support Center. Provide the SYSOUT output for the job and the logrec data set error record.
If you want to know about this abend out of curiosity, suggest you get familir with manuals. If there is an actual abend, it might have some other reason/s too; e.g. once the problem was with a module referencing outside the array bounds. Since the SSRANGE option was not on, this was not being handled causing the program to fail at some other point with a S04E.