Rails query speed

Just discovered strange behavior:

Model.includes(:another).all
Model.includes(:another)

The first one is 5 times faster than开发者_如何学运维 the second, could you explain it?

How to achieve first method's speed but returning Relation instance for use with Kaminari?

It is probably only virtual difference, just on logs. When checked it in Firebug, loading speed was identical.