i did a test to backup a set of data, and then restore to an empty database. Before the backup, data are put with a WritePolicy(sendKey=true), and the key can be retrieved. After the restore, it seems the userKey is lost.
The [backup file format] (http://www.aerospike.com/docs/tools/backup/file_format.html) seems to keep DIGEST only for record.
Should backup support userKey?