Doing the same thing to 100 databases is usually easy to automate.
I managed a group that had a dozen customers on a single multi-tenant database and some migrations took more than a day - we needed to set maintenance windows on weekends (and once we had to roll back after an error).
Having a dozen databases we could roll out updates to on a client per client basis would have saved us from some enormous headaches.
I managed a group that had a dozen customers on a single multi-tenant database and some migrations took more than a day - we needed to set maintenance windows on weekends (and once we had to roll back after an error).
Having a dozen databases we could roll out updates to on a client per client basis would have saved us from some enormous headaches.
OTOH, no two companies are alike. You do you.