Earlier quoted context omitted.
Whenever anyone talks about “the application,” I immediately ask “what about all the other applications?” I promise you that you will find customer service and accounting and biz dev have also built stuff that uses the database to get their jobs done (probably not with the same ORM or even the same language) unless you have taken draconian measures to prevent them.
My assumption (with modern applications!) is that nothing but the role directly owning the data will access the data. The development and DBA teams will likely have a role they can assume after performing a carefully-audited breakglass procedure to use in an emergency (rare) or to fulfill audit tasks. At least in my org this is a well-known problem with legacy applications sharing databases. Limit access to the datab…
One particularly interesting Oracle problem is:
ORA-00060: deadlock detected while waiting for resource
"Oracle considers deadlocks to be so rare, so unusual, that it creates a trace file on the server each and every time one does occur... The number one cause of deadlocks in the Oracle database, in my experience, is un-indexed foreign keys."
For another perspective, add to this a default setting in every SQLite database:
$ sqlite3 verynew.db
SQLite version 3.34.1 2021-01-20 14:10:07
Enter ".help" for usage hints.
sqlite> .dump
PRAGMA foreign_keys=OFF;
BEGIN TRANSACTION;
COMMIT;