Using two different content db in a single web app

Hi 

I have a content db (size 190 gb). Is it advisable to continue using the same content db if size goes above 200gb (atleast tiil 4TB is it advisable)?

I was advised to use 2 different content db in same application. Is it proper?

Please help me to understand what will be the issue using a new content db i.e 2 content db in same web application (Central Admin>> Manage content db)