During audience execution, if the audience's definition is configured to generate backfill files, they are generated at workflow (in Test and/or Production mode, as specified). The backfill query type is INSERT, and separate files are generated for offer history ('[Table name]__[GUID]') and offer history meta ('[Table name]_[GUID]') tables (note the double underscore at the former). Files match the selected export template's basic settings and contain data as per a given table's structure.
In addition, an offer history details backfill file is generated in Production mode only.
When an audience instance is rolled back, if the audience's definition is configured to generate backfill files, such a file is generated at workflow rollback. The backfill query type is DELETE a file is generated for offer history ('[Table name]_Rollback_[GUID]') only. The file contains RPContactID, ChannelExecutionID and RowCounter fields.
In addition, an offer history details backfill file is generated to reflect the rollback.
Note that backfill files are also generated at receipt of records by a queue listener, if the activity is configured to generate offer history. Offer history meta backfill files are not generated in this context.
For more information on backfill files, please see the Audience Definitions section in the Configuration documentation.
In addition, the Export backfill state data system task generates offer history states and channel execution results backfill files. For more information, please see the Operations interface documentation.