title: BigQuery Full outer join producing "left join" results
body: <p>I have 2 tables, both of which contain distinct id values.  Some of the id values might occur in both tables and some are unique to each table.  Table1 has 10,910 rows and Table2 has 11,304 rows</p>
  
  <p>When running a left join query:</p>
  
  <pre><code>SELECT COUNT(DISTINCT a.id)
  FROM table1 a
  JOIN table2 b on a.id = b.id
  </code></pre>
  
  <p>I get a total of 10,896 rows or 10,896 ids shared across both tables.</p>
  
  <p>However, when I run a <code>FULL OUTER JOIN</code> on the 2 tables like this:</p>
  
  <pre><code>SELECT COUNT(DISTINCT a.id)
  FROM table1 a
  FULL OUTER JOIN EACH table2 b on a.id = b.id
  </code></pre>
  
  <p>I get total of 10,896 rows, but I was expecting all 10,910 rows from table1.</p>
  
  <p>I am wondering if there is an issue with my query syntax.</p>