[Fire-Dragon-DoL]

Sorry for my inexperience in this kind of implementation but wouldn't an sql transaction achieve something similar? And with table partitioning (at least on postgres) you should be able to go quite far, instead of neediness a new db (and a lot of related stuff to study)

[BillinghamJ]

No because in a distributed system, you can't rely on SQL transactions. i.e. if you need to make one API request to start the transaction and a second API request to commit it/rollback - you can't hold the SQL transaction open between those.