ode>
    constraints — which gives it its name — whereas partition
    pruning uses the table's partition bounds, which exist only in the
    case of declarative partitioning.  Another difference is that
    constraint exclusion is only applied at plan time; there is no attempt
    to remove partitions at execution time.
   </p><p>
    The fact that constraint exclusion uses <code class="literal">CHECK</code>
    constraints, which makes it slow compared to partition pruning, can
    sometimes be used a