*** doc/src/sgml/config.sgml
--- doc/src/sgml/config.sgml
***************
*** 881,886 **** SET ENABLE_SEQSCAN TO OFF;
--- 881,891 ----
          than <varname>work_mem</varname>.  Larger settings might improve
          performance for vacuuming and for restoring database dumps.
         </para>
+        <para>
+         Note that when autovacuum runs, up to
+         <xref linkend="guc-autovacuum-max-workers"> times this memory may be
+         allocated, so be careful not to set the default value too high.
+        </para>
        </listitem>
       </varlistentry>