For some user-defined datatypes, you must specify additional parameters for lengh, precision, and scale.
The char, nchar, varchar, nvarchar, binary, and varbinary datatypes expect a length in parentheses. If you do not supply one, SAP ASE assumes the default length of 1 character.
The float datatype expects a precision in parentheses. If you do not supply one, SAP ASE uses the default precision for your platform.
The numeric and decimal datatypes expect a precision and scale, in parentheses and separated by a comma. If you do not supply them, SAP ASE uses a default precision of 18 and scale of 0.
You cannot change a user-defined datatype’s length, precision, or scale when you include it in a create table statement.