Drill Metastore executes many operations in transaction including delete. Currently Iceberg creates orphan files when executing delete in transaction and these files cannot be expired and keep pilling up. Iceberg issue - https://github.com/apache/incubator-iceberg/issues/330. When #330 is fixed, we need to update Iceberg commit to ensure these issue is resolved in Drill as well.
PR with the fix - https://github.com/apache/incubator-iceberg/pull/352