title: purpose of collate in Postgres
body: <p>I am new to Postgres. I have just started learning it from <a href="http://www.w3resource.com/PostgreSQL/pl-pgsql-declarations.php" rel="nofollow noreferrer">here</a>. I found COLLATE &quot;C&quot; from a select statement</p>
  <pre><code>SELECT not_equal(first_name, last_name COLLATE &quot;C&quot;)
  </code></pre>
  <p>What does COLLATE &quot;C&quot; do?</p>