title: Check value if exists in column
body: <p>I'd like to know how to maximize speed when querying for the presence of a <code>varchar</code> value in a column in a specific table. I don't need to know where it is, or how many occurrences there are, I just want a <code>true</code>/<code>false</code>. Of course, the column has an index.</p>
  
  <p>Now, I have this:</p>
  
  <pre><code>SELECT exists (SELECT 1 FROM table WHERE column = &lt;value&gt; LIMIT 1);
  </code></pre>