Performance hit if I create multiple DBs on same instance

Hi:

11.3 on linux

I've come up with a plan to archive data from my main DB which involves creating other DBs on the same server.  But even though there will be zero activity on the archive DBs in terms of insert/update/delete, and almost no activity in terms of select, I'm still worried that the mere existence of these other DBs will steal resources away from the instance and degrade performance in my main DB. So my question is whether or not that worry is valid or not.

Thanks in Advance for any help !