So far, two main scenarios have been discussed in this book:

Both scenarios are highly useful and can serve people's needs nicely. However, what happens if databases, and especially change volumes, start being really large? What if a 20 TB database has produced 10 TB of changes and something drastic happens? Somebody might have accidentally dropped a table or deleted a couple of million rows, or maybe somebody set data to a wrong value. Taking a base backup and performing a recovery might be way too time consuming, because the amount of data is just too large to be handled nicely.

The same applies to performing frequent base backups. Creating a 20 TB base backup is just too large, and storing all those backups might be pretty space consuming. Of course, there is always the possibility of getting around...