If you want to restore a table from backups then you start with the latest (or target) full backup and then you restore the latest differential backup. If the incremental backups are being used then you have to restore all increments since the last full backup.
SnowMirror is able to backup ServiceNow tables into two formats: CSV and native ServiceNow XML. These formats are the same or very similar to those created by ServiceNow export features. Depending on a backup format the restore strategies are different.
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