Implement idle timeout / revalidation? #256
Description
Ref: #119
While working on #255, I had a thought that it's also possible some of these issues are caused by connection staying idle for too long in pools.
We could consider adding an idle timeout on connection, e.g. don't try to use a connection that as been idle for more than X seconds.
This is also useful when the db is behind a proxy etc, as it makes rotations easier.