a></h3></div></div></div><a id="id-1.5.4.13.9.2" class="indexterm"></a><p>
    <em class="firstterm">Partition pruning</em> is a query optimization technique
    that improves performance for declaratively partitioned tables.
    As an example:

</p><pre class="programlisting">
SET enable_partition_pruning = on;                 -- the default
SELECT count(*) FROM measurement WHERE logdate &gt;= DATE '2008-01-01';
</pre><p>

    Without partition pruning, the above query would scan each of the
    partitions