not always choose
        the optimal join order, advanced users can elect to
        temporarily set this variable to 1, and then specify the join
        order they desire explicitly.
        For more information see <A
HREF="explicit-joins.html"
>Section 14.3</A
>.
       </P
><P
>        Setting this value to <A
HREF="runtime-config-query.html#GUC-GEQO-THRESHOLD"
>geqo_threshold</A
> or more
        may trigger use of the GEQO planner, resulting in non-optimal
        plans.  See <A
HREF="runtime-config