title: does ruby on rails automatically lock active record associations when locking the active record?
body: <p>Pretty basic question:</p>
  
  <p>I have a model x that has_many y, and model y belong_to x. </p>
  
  <p>If I lock an instance of model x with id x_id, does it also lock the associated rows in the table for model y which has has value x_id under the join column?</p>
  
  <p>Or does ror locking just lock the active record and does not care about its associations?</p>
  
  <p>Thanks!</p>