 In real life, a real database such as Wikipedia's may be edited thousands of times per hour, and references are virtually always spread throughout the file and can number into the millions, billions, or more.A sequential "copy" backup would literally contain so many small corruptions that the backup would be completely unusable without a lengthy repair process which could provide no guarantee as to the completeness of what has been recovered.A backup process which properly accounts for data consistency ensures that the backup is a snapshot of how the entire database looked at a single moment.