title: HIVE WHERE NOT EXISTS doesn't compare NULLS
body: <p>I am trying to select only the rows where some of the column values differ. My problem is that if I use =, it doesn't compare columns with null values and if I replace = with Like, I get the following error, Any suggestions? Both tables have columns that are equivalent</p>
  
  <blockquote>
    <p>Unsupported SubQuery Expression SubQuery expression refers to both Parent and SubQuery expressions and is not a valid join condition. (state=42000,code=10249)</p>
  </blockquote>
  
  <pre><code>SELECT * 
  FROM table1 t
  where not exists(
  select * from table2 l where t.loco_id=l.loco_id and
  t.a=l.a and
  t.b=l.b
  );
  </code></pre>