4"
><A
NAME="AEN114280"
>E.2.3.1.3. Optimizer</A
></H4
><P
></P
><UL
><LI
><P
>        Collect and use histograms of upper and lower bounds, as well as range
        lengths, for <A
HREF="rangetypes.html"
>range types</A
>
        (Alexander Korotkov)
       </P
></LI
><LI
><P
>        Improve optimizer's cost estimation for index access (Tom Lane)
       </P
></LI
><LI
><P
>        Improve optimizer's hash table size estimate for
        doing <TT
CLASS="LITERAL"
>DISTINCT</TT
> via hash aggregation (Tom L