The data type specification of a field tells SQL*Loader how to interpret the data in the field. For example, a data type of INTEGER specifies binary data, while INTEGER EXTERNAL specifies character data that represents a number. A CHAR field can contain any character data.
Only one data type can be specified for each field; if a data type is not specified, then CHAR is assumed.
"SQL*Loader Data Types" describes how SQL*Loader data types are converted into Oracle data types and gives detailed information about each SQL*Loader data type.
Before you specify the data type, you must specify the position of the field.