title: Forcing the use of an index can improve performance?
body: <p>Imagine that we have a query like this:</p>
  
  <pre><code>select a.col1, b.col2
  from t1 a
  inner join t2 b on a.col1 = b.col2
  where a.col1 = 'abc'
  </code></pre>
  
  <p>Both <code>col1</code> and <code>col2</code> don't have any index.</p>
  
  <hr>
  
  <p>If I add another restriction on the where clause, one that is always correct but with a column with an index:</p>
  
  <pre><code>select a.col1, b.col2
  from t1 a
  inner join t2 b on a.col1 = b.col2
  where a.col1 = 'abc'
  and a.id &gt;= 0  -- column always true and with index
  </code></pre>
  
  <p><strong>May the query perform faster since it may use the index on <code>id</code> column?</strong></p>