If the input arguments are numeric types, the function determines which argument has the highest precedence, converts the other arguments to that data type, and returns that data type.
If the data type is DECIMAL/NUMERIC and the precision and scale of the input arguments are different, the precision and scale of the return type is set to achieve the maximum precision possible. For example, if the input arguments are DECIMAL(6,3), DECIMAL(7,4), and DECIMAL(8,7), the return type would need 3 digits to the left of the decimal point and 7 digits to the right of the decimal point to avoid any reduction in precision. In this case, the return data type is set to DECIMAL(10,7).
In cases where it is not possible to maintain the maximum precision, the data is rounded according to the DBS Control Record RoundHalfWayMagUp field. For example, if the input arguments are DECIMAL(32, 8) and DECIMAL(30, 28), the return type is DECIMAL(38,14). This allows for 24 digits to the left of the decimal point (required for the DECIMAL(32,8) argument), and 14 digits to the right of the decimal point. If the DECIMAL(30,28) input argument is the greatest value, it is rounded to 14 places to the right of the decimal point.
If the data type is fixed point NUMBER and the precision is less than or equal to 38, the precision and scale of the return type are calculated with the same method used for DECIMAL/NUMERIC. However, if the precision is greater than 38, the return type is changed to NUMBER(*) to avoid loss of accuracy. If the data type is floating point NUMBER, the return type is NUMBER(*).
If the input arguments are character types, the function converts the 2nd through 10th arguments to the data type of the 1st argument and returns the type as VARCHAR in the character set of the 1st argument.
If the input arguments are DATE types, the function returns a DATE type.
If the input arguments are TIMESTAMP types, the function returns a TIMESTAMP type. If the first parameter includes an explicit time zone, the result will also include a time zone.
If any of the input arguments is NULL, the function returns NULL.