I actually follow this tag, so I figured I would take the opportunity to chime in a bit.
I wrote a little SEDE query to find what other tags are being used along with database, besides the usual SQL and NoSQL culprits.
I have not spent that much time looking at each one individually, but apparently either some of them are mis-tagged with database, or there is an evident desire for a database tag that does not have anything to do with DBMS's.
My opinion would be keep it, but perhaps clean it up. Anything tagged with
'%sql%' is obviously database, so that tag would be redundant. Same with other DBMS types, such as the NoSQL mongodb so there could safely be removed. I think anything outside those should keep the tag if it is appropriate.