Add a note to the documentation to clarify that even when

"autovacuum = off", the system may still periodically start autovacuum
processes to prevent XID wraparound. Patch from David Fetter, with
editorializing.

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 4a148f7a939e5b168b2a6b91e071e0f0fc1dd360..b5794f918eaf6904dd244782adc9604c8e9db784 100644 (file)
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -3148,6 +3148,12 @@ SELECT * FROM parent WHERE key = 2400;
         This parameter can only be set in the <filename>postgresql.conf</>
         file or on the server command line.
        </para>
+       <para>
+        Note that even when this parameter is disabled, the system
+        will periodically launch autovacuum processes in order to
+        prevent transaction ID wraparound.  See <xref
+        linkend="vacuum-for-wraparound"> for more information.
+       </para>
       </listitem>
      </varlistentry>