title: Efficient way to simulate full outer join in MySQL?
body: <p>According to Google search: since MySQL does not support full outer join, it could be simulated via union and/or union all. But both of these either remove genuine duplicates or show spurious duplicates.</p>
  
  <p>What would be correct and efficient way?</p>
  
  <p>This <a href="https://stackoverflow.com/questions/989730/help-me-out-with-this-mysql-full-outer-join-or-union">question</a> seems relevant but couldn't get the answer of it.</p>