Document that autovacuum cannot vacuum or analyze temporary tables.

doc/src/sgml/maintenance.sgml

-<!-- $PostgreSQL: pgsql/doc/src/sgml/maintenance.sgml,v 1.102 2010/04/03 07:22:55 petere Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/maintenance.sgml,v 1.103 2010/04/16 02:22:33 momjian Exp $ -->
 
 <chapter id="maintenance">
  <title>Routine Database Maintenance Tasks</title>
@@ -642,6 +642,12 @@ analyze threshold = analyze base threshold + analyze scale factor * number of tu
     since the last <command>ANALYZE</command>.
    </para>
 
+   <para>
+    Temporary tables cannot be accessed by autovacuum.  Therefore,
+    appropriate vacuum and analyze operations should be performed via
+    session SQL commands.
+   </para>
+
    <para>
     The default thresholds and scale factors are taken from
     <filename>postgresql.conf</filename>, but it is possible to override them

doc/src/sgml/ref/create_table.sgml

 <!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/create_table.sgml,v 1.125 2010/04/03 07:23:00 petere Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/create_table.sgml,v 1.126 2010/04/16 02:22:33 momjian Exp $
 PostgreSQL documentation
 -->
 
@@ -144,6 +144,15 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } ] TABLE <replaceable class="PAR
       table are automatically temporary as well.
      </para>
 
+     <para>
+      The <link linkend="autovacuum">autovacuum daemon</link> cannot
+      access and therefore cannot vacuum or analyze temporary tables.
+      For this reason, appropriate vacuum and analyze operations should be
+      performed via session SQL commands.  For example, if a temporary
+      table is going to be used in complex queries, it is wise to run
+      <command>ANALYZE</> on the temporary table after it is populated.
+     </para>
+      
      <para>
       Optionally, <literal>GLOBAL</literal> or <literal>LOCAL</literal>
       can be written before <literal>TEMPORARY</> or <literal>TEMP</>.