t=37.75..37.76 rows=1 width=8)
   -&gt;  Seq Scan on measurement_y2008m01  (cost=0.00..33.12 rows=617 width=0)
         Filter: (logdate &gt;= '2008-01-01'::date)
</pre><p>
   </p><p>
    Note that partition pruning is driven only by the constraints defined
    implicitly by the partition keys, not by the presence of indexes.
    Therefore it isn't necessary to define indexes on the key columns.
    Whether an index needs to be created for a given partition depends on
    whether you expect that queries tha