Save failures after autocomplete in massive database

[dstillman]

https://forums.zotero.org/discussion/71681/zotero-stops-working-and-or-erases-meta-data

[about-code]

The sudden loss of manually typed metadata as described by the forum poster might have a similar cause like the one I desribed in #1572. In #1572 a long running background request made Zotero hit a snapshot save timeout. Before hitting the timeout I was already able to enter item meta data not knowing that there has been an ongoing transaction waiting to be completed. On the surface it seemed as if my metadata was accepted though in fact it wasn't eventually committed. So when the transaction on the item failed Zotero rolled back any intermediate DB operations which also deleted the meta data I entered.

While the situation described by the forum poster and the situation in #1572 doesn't seem to be identical the in-depth mechanisms causing metadata to disappear might be similar. So I could imagine the forum poster ran into a rollback situation like I did (maybe due to the size of his/her collection or for other reasons) when he wrote

Importing this single PDF (D1026166701) started all the trouble with disappearing meta data! After pasting – not typing – the correct author name it just returned after a while to the automatically collected – wrong – data. As written before, i never experienced autocompletion in the fields.

I tried it manually as mentioned before: Created a new entry, copy&pasted all the missing meta data in the required fields. Suddenly there was a "screen refresh" and fields were filled with crap data or data was erased.