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?

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