Exactly. Exceptions prove the rule. But this applies to everything, not just databases. Never write your own OS, unless you are faced with an exception where you have to.
If you have a special case where RDBMs can't fill your need, then you obviously have to build your own. But these cases are so rare that it proves the rule.
If you have a special case where RDBMs can't fill your need, then you obviously have to build your own. But these cases are so rare that it proves the rule.