Run no-conversion load jobs with tables with hidden columns

If you run no-conversion jobs, the physical image of the table in the load file must match the physical image of the target table and all columns must exist in the same order and be of the same type.

By default a no-conversion unload job does not contain the hidden columns, because the job resulted from unloading a "SELECT *" query and this type of SELECT query does not return any hidden columns. Under these circumstances, the target table where the load will occur must not contain any hidden columns. If it does contain hidden columns, the image of the file will not be a match.

If your application requires that the unload file contains the hidden columns (for example, if the target table has hidden columns and it is not possible to alter the table to remove the columns while the load occurs) , you must use a SELECT statement that explicitly indicates the columns in the select list.

The target table should not contain hidden columns, because these columns retain internal information for internal activities of the engine. Loading hidden columns can create unexpected results.

Hidden columns tables include but are not restricted to fragmented tables with rowid columns, tables with VERCOLS, and tables with CRCOLS. Also fragmented tables with rowid columns do not support no-conversion jobs.

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