I'm not sure what attack vector they're going to uncover from knowing the database you use, given there is a relatively small number of databases anyway—they're already in a position to guess (brute force) themselves into your system if just knowing the database was enough.
Maybe you think they are looking to get your guard down and then ask the juicier questions?
In this case I’d wager they’re just looking to sell to us. If they were malicious however, replying to the email would let the sender know about my position within the organization and how inclined I am to sharing information.
At the end of the day there’s no upside to either me nor my organization to respond to cold emails beyond politeness.
Maybe you think they are looking to get your guard down and then ask the juicier questions?