You let SQL Server do that for you, meaning you don't necessarily control 8GB goes to db1, and the rest is split between db2 and db3.

SQL Server is going to maintain which databases get a certain amount of memory based on data being queried. You can take note of the amount of dirty and clean pages with a query from John Sansom HERE[/url]. An MSSQLTips.com article by Aaron Betrand provides a query to dig down to an object level per database HERE[/url].