After reading this Devonian Times article https://www.devontechnologies.com/blog/20210914-devonthink-database-archive, I chose File > Export > Database Archive for backup.
And one of the database archives seems to go beyond the icloud file size limit (it’s 87GB),
so, in this case, can I zip the database into many splitting zip to upload it to the iCloud? I know that uploading a single zip file is safe for databases, but I’m not sure about splitting zip files.
This really is outside DEVONthink’s world.
You have a zip file which you use a tool to split it into individual zip files. Assuming using this or another tool and then recover the entire zip file file into one, then I can’t see a problem, theoretically. Software to do this has been around for decades, but it is dependant on you selecting and using reliable software.
I recommend you try out your idea.
Make a big zip, split it. send up to the third party cloud service, bring it back, combine it, unzip and open as a new database in DEVONthink. As long as the round trip results in a file just like started, that’s what it’s supposed to do. Do it routinely, say once a month, to make sure your files aren’t getting corrupted.
My hunch is the weak link in this plan is using the third party cloud service and its technology for reliably up- and down-loading these big files without corruption.
I rely on TimeMachine (supplemented by Backblaze) to make backups of these backups and most everything else. Because of anecdotal evidence (have not researched completely, and don’t plan to) I would never consider using iCloud for backup. That’s just me.