Wattage Capacity of Socket Outlet

I'd like to hook up my Christmas Tree lights to be controlled by a wall switch unfortunately the wall switch does not control any outlets. If I were to use a wall lamp and screw a socket outlet into the lamp socket it would allow me to control the tree plugged into this lamp socket outlet. My concern is that if I would be overloading the lamp. Even if the socket outlet is rated for 600 Watts the lamp socket it is screwed into may only be rated for 60 watts if I was using a conventional bulb in the lamp. Which is my rate limiting step? The capacity of the lamp socket itself or the socket outlet?