some notes shrinking while syncing
I recently took extensive notes on a book using the 'Notes' section, while offline. Later I synced Zotero and half of my notes disappeared. Even though I was offline the whole time I was writing, only the first half of what I wrote now appears - this is true on the original device, on the new device, and in the online library. Is there any way to restore previous material? Thanks.
The problem with getting the note content back is that the only way (and even that I don't really see) I could imagine them getting lost is if they were never written to the database, so they literally never existed for Zotero purposes, so I have no thoughts on getting these back.
Obviously this should never happen, but absent a replicable instance, I'm not quite sure how to go about troubleshooting what happened.
I really wish I had something better for you, but there's just no way to find a problem that's supposed to be impossible to occur at a technical level, that occurs incredibly rarely, and that can't be made to occur reliably.
What does it mean for them not to be written to the database?
as you type a note, you're typing in an editor and the text exists in that editor only.
Zotero saves all text content -- all metadata, all notes -- in a database file (an sqlite database file, to be precise).
When you you type into a Zotero field, it saves what you typed to the field the moment you switch to a different field (or item).
It also does that when you write a note: when you switch away from the note, Zotero will write the content to the database. But that's obviously not enough, since you might be spending significant time on a note, so it also writes what you have written to the database every couple of seconds. My only idea for how what you describe could be happening is if that process somehow stopped working (which, again, it never should).
A couple other ideas for getting your data back (if you haven't rewritten it yet):
1) You can check the zotero.sqlite.bak and zotero.sqlite.1.bak files in your Zotero data directory. If there's a timestamp that looks at all promising, make a copy of that file immediately. Then see Restoring from the Last Automatic Backup.
2) If you're on a Mac and use Time Machine, even if you didn't have it plugged in, Time Machine might have a local snapshot of the database from the relevant time. So you could check that.