Ursula, Time Machine does work well for me. Yes, my main database usually changes many times during the day. Yes, hourly backups of the package file can use a lot os space.
Remember, though, that Time Machine doesn’t keep all of those hourly backups. As time passes, the storage space devoted to a “slice of time” drops.
I do most of my work on a ModBook, a custom Mac tablet based on a MacBook. I’m not always connected to my Time Machine backup drive, though that’s active much of the time.
My Time Machine backups are to a 500 GB hard drive for which I paid less than $0.50 per GB of capacity. That drive is handling Time Machine backups for two computers, although one of them is used infrequently. Looking at the remaining space on the drive (and Time Machine’s design), it will handle my backup chores indefinitely. I may need to make some choices from time to time (pun intended). Do I need to keep all the backup files indefinitely, or not? Are there certain files that I may want to keep indefinitely?
If I wish to obsess on keeping every file that has been downloaded on my computers, or every version of every file that has been modified, Time Machine will pretty much let me do that, year after year, decade after decade. I could use multiple hard drives to maintain such an archive of the environment of that computer over time. But I’'m not that obsessive. There are many files that I consider transient. Once in a while I throw them away. If archived, I’m still not interested in their archived storage.
There are some files that I’m rather obsessive about. I’ve lovingly built reference collections over the years. I want to preserve them. Those collections are in self-contained DT Pro databases, so I want to preserve them. Time Machine is a convenient backup system to help me do that. If something goes wrong, I can recover a database from Time Machine.
But as good as Time Machine is, it’s not enough for my most important files. For one thing, the hard drive resides at my home. Catastrophic events could occur. The hard drive(s) holding Time Machine backups could fail. My computers and drives could be stolen. My cabin could burn to the ground.
That’s why I also use the Backup Archive routine for DT Pro/DT Pro Office. It performs useful database maintenance every time it’s run. And it produces the smallest possible compressed and dated archive of a database. I can store those archives on external media. For added security, I periodically save recent archives to a DVD and store that offsite.
Finally, I don’t want to depend on scheduled backups, such as daily backups. In DT Pro Preferences > Backup I’ve set frequency to Never. Is that a bad quality assurance decision? No, if I act prudently, it’s a quality assurance plus. If I’m in the process of adding batches of hundreds or thousands of new items to a database I’m not going to wait until that night to backup my work. After each batch I’ll run Tools > Verify & Repair to make certain the database wasn’t messed up by adding corrupted files, and then Tools > Backup & Optimize to make a current internal backup (or I’ll run Backup Archive while taking a coffee break). If something goes wrong that day while I’m making major changes to a database, I’ll lose little or no data. Had I waited for a daily backup, I’d be in trouble.
I’ve had two computers fail. My TiBook’s hard drive crashed after 5 years of use. I had external copies of my databases. My Power Mac G5 blew it’s power supply a few days ago (a common problem for those computers). I’ve got external copies of the databases on that machine (but not a Time Machine backup of the 2 500 GB drives). So a computer failure for me is a minor inconvenience.