Database for Exchange Server should be independent.

[mfaisal]

Microsoft Exchange is using Extensible Storage Engine DB. What if we can use DB by choice like SQL, Oracle etc.

[JanoschUlmer]

@mfaisal : Since this feedback is not related to partner Community, but rather Product related, the Microsoft feedback portal would be the right place: Feedback · Community (microsoft.com)

There is no Exchange-specific forum yet, but you can upvote the ask for it: Add forum for Exchange / Exchange online · Community (microsoft.com)