The DEFINE command:
- Describes the fields in a record of input data that are inserted in the Teradata FastLoad table
- Identifies the name of the input data source or use of an INMOD routine
Teradata FastLoad translates the DEFINE command specifications into a Teradata SQL USING clause, and links the USING clause with a subsequent INSERT statement. The Teradata FastLoad job must include DEFINE specifications for each field in a record from the input data source before executing an INSERT statement.
Though every field used in an INSERT statement must have been previously defined in a DEFINE command, every field so defined need not be used in an INSERT statement.
Teradata FastLoad also uses the DEFINE command data type specifications to determine the format and record length of stored data.