The following table describes the things to consider when using the HELP TABLE command.
|Using DEFINE Commands||If the HELP TABLE command is used to define field names, a DEFINE command must still be used to specify the input data source name or INMOD routine.|
If the table contains a UDT column, an external representation of the UDT is returned.
For example, if the user defines a USDollar data type as Decimal(13,2) and defines a column as USDollar type in the table, Decimal(13,2) is returned as the data type of this column.
|Using a CLEAR Command||
When using two HELP TABLE commands in the same Teradata FastLoad job, using a CLEAR command before the second one cancels the first. The following command example produces a list of only the Department table:
HELP TABLE Employee ; CLEAR ; HELP TABLE Department ;
Entering the two HELP TABLE commands without a CLEAR command, as in the following example, produces a list of both the Employee and Department tables:
HELP TABLE Employee ; HELP TABLE Department ;
|Unicode Session Character Set Limitation||
Teradata FastLoad uses the number of bytes of storage returned from the database to construct the USING clause of a load operation. Therefore, when the session character set is UTF-8 or UTF-16, the MAX LENGTH returned from the database is not the actual byte count for the Unicode column, meaning that the internally generated USING clause does not properly reflect the structure of the input data stream.
Instead of using HELP TABLE to describe the structure of input data, use the DEFINE command when the session character set is UTF-8 or UTF-16.