Scalar type is a type whose values have no elements. Scalar types consist of enumeration types, integer types, physical types, and floating point types. Enumeration types and integer types are called discrete types. Integer types, floating point types, and physical types are called numeric types. All scalar types are ordered; that is, all relational operators are predefined for their values.
scalar_type_definition ::= enumeration_type_definition
The scalar type values cannot contain any composite elements. All values in a specific scalar type are ordered. Due to this feature all relational operators are predefined for those types. Also, each value of a discrete or physical type has a position number.
All numeric types (i.e. integer, floating point and physical) can be specified with a range which constrains the set of possible values.
Please refer to respective topics for more information on different scalar types (enumeration type, integer type, floating point type, physical type).