Db2 decoding for numeric data in edit and validation routines

Db2 stores numeric data in a specially encoded Db2-coded format.

To retrieve numeric data in its original form, you must Db2-decode it according to its data type.

Table 1. Db2 decoding procedure according to data type
Data type	Db2 decoding procedure	Decoding examples
SMALLINT	Invert the sign bit (high-order bit).	Stored value: 8001 Decoded value: 0001 (+1 decimal) Stored value: 7FF3 Decoded value: FFF3 (-13 decimal)
INTEGER	Invert the sign bit (high-order bit).	Stored value: 800001F2 Decoded value: 000001F2 (+498 decimal) Stored value: 7FFFFF85 Decoded value: FFFFFF85 (-123 decimal)
FLOAT	If the sign bit (high-order bit) is 1, invert only that bit. Otherwise, invert all bits.	Stored value: C110000000000000 Decoded value: 4110000000000000 (+1.0 decimal) Stored value: 3EEFFFFFFFFFFFFF Decoded value: C110000000000000 (-1.0 decimal)
DECIMAL	Save the high-order hexadecimal digit (sign digit). Shift the number to the left one hexadecimal digit. If the sign digit is X'F', put X'C' in the low-order position. Otherwise, invert all bits in the number and put X'D' in the low-order position.	Stored value: F001 Decoded value: 001C (+1) Stored value: 0FFE Decoded value: 001D (-1)
BIGINT	Invert the sign bit (high order bit).	Stored value: 8000000000000854 Decoded value: 0000000000000854 (2132 decimal) Stored value: 7FFFFFFFFFFFFFE0 Decoded value: FFFFFFFFFFFFFFE0 (-32 decimal)
DECFLOAT	See the information on sortable decimal formats in Db2 12 for z/OS licensed diagnosis information.	Stored value: D8F77D00000000000C Decoded value: 222C000000001E80 (+7.500 decimal floating-point) Stored value: 270882FFFFFFFFFFF2 Decoded value: A2300000000003D0 (-7.50 decimal floating-point)