During a file import, data is first loaded to a staging table and then mapped into the associated fact table. As part of the import process, the staging table will be truncated before loading to the table.
The staging table must be created prior to configuring a new File Import. The structure of the staging table must be compatible with the data file to be imported.
For example, if your import file contains columns for Account, Date, Entity, Currency and Amount, then your staging table must also contain these columns as shown below:
Sample Data Import File
Staging Table Editor corresponding to Sample Data Import File above
For more information, refer to Staging Table Management.