Add note that autovacuum can use up several times maintenance_work_mem,

with warning against setting it too high.

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index cf992c7fdc395a6faee9927c5aebf39fa4be6a37..cb0aabd7dd7eb1200a4d27764b1fb618c8521651 100644 (file)
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -860,6 +860,11 @@ SET ENABLE_SEQSCAN TO OFF;
         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>