title: Interval hour type for a postgres column doesn't send error when inserting minute or second
body: <p>I defined one of my column as follow</p>
  <pre><code>  ALTER TABLE toto
      ADD COLUMN period INTERVAL HOUR DEFAULT '24 hour',
      ADD CONSTRAINT check_period CHECK (period BETWEEN INTERVAL '0 hour' AND INTERVAL '48 hour');`
  </code></pre>
  <p>The thing I want is to send an error when the interval that I want to insert is not an hour.</p>