SQL*Loader express mode lets you quickly perform a load by specifying only a table name when the table columns are all character, number, or datetime data types, and the input data files contain only delimited character data.
In express mode, a SQL*Loader control file is not used. Instead, SQL*Loader uses the table column definitions found in the ALL_TAB_COLUMNS view to determine the input field order and data types. For most other settings, it assumes default values which you can override with command-line parameters.