</TT
>.  Larger values increase the time needed to
        do <TT
CLASS="COMMAND"
>ANALYZE</TT
>, but might improve the quality of the
        planner's estimates. The default is 100. For more information
        on the use of statistics by the <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
>
        query planner, refer to <A
HREF="planner-stats.html"
>Section 14.2</A
>.
       </P
></DD
><DT
><A
NAME="GUC-CONSTRAINT-EXCLUSION"
></A
><TT
CLASS="VARNAME"
>constraint_exclusion</TT
> (<TT
CLASS="TYPE"
>enum</TT
