matches the expected partition constraint, as
     illustrated above. That way, the system will be able to skip the scan
     which is otherwise needed to validate the implicit
     partition constraint. Without the <code class="literal">CHECK</code> constraint,
     the table will be scanned to validate the partition constraint while
     holding an <code class="literal">ACCESS EXCLUSIVE</code> lock on that partition.
     It is recommended to drop the now-redundant <code class="literal">CHECK</code>
     