COMP-3 (Packed Decimal) stores two digits per byte, with the final half-byte representing the sign ( C for positive, D for negative, F for unsigned). Formula for size: (Number of digits + 1) / 2 rounded up.
It includes best practices for optimizing DB2 queries and reducing JCL overhead. mainframe refresher by muthu pdf link
Single and multi-dimensional arrays using OCCURS , INDEXED BY , SEARCH , and SEARCH ALL (binary search). 5. DB2 (Database 2) COMP-3 (Packed Decimal) stores two digits per byte,