The numeric EXTERNAL data types are the numeric data types (INTEGER, FLOAT, DECIMAL, and ZONED) specified as EXTERNAL, with optional length and delimiter specifications. The length is in bytes unless character-length semantics are used for the data file. In that case, the length is in characters. See "Character-Length Semantics".
These data types are the human-readable, character form of numeric data. The same rules that apply to CHAR data regarding length, position, and delimiters apply to numeric EXTERNAL data. See "CHAR" for a complete description of these rules.
The syntax for the numeric EXTERNAL data types is shown as part of "datatype_spec".
The data is a number in character form, not binary representation. Therefore, these data types are identical to CHAR and are treated identically, except for the use of DEFAULTIF. If you want the default to be null, then use CHAR; if you want it to be zero, then use EXTERNAL. See "Using the WHEN_ NULLIF_ and DEFAULTIF Clauses".
FLOAT EXTERNAL data can be given in either scientific or regular notation. Both "5.33" and "533E-2" are valid representations of the same value.