Doc: Update the documentation for spilled transaction statistics.

Amit Kapila · Amit Kapila · commit e641b2a995ab · 2020-06-02T11:35:14.000+05:30
Reported-by: Sawada Masahiko Author: Sawada Masahiko, Amit Kapila Reviewed-by: Amit Kapila Discussion: https://postgr.es/m/CA+fd4k4vNg7dRO5ECHdtQXXf1=Q4M98pfLW0dU7BKD8h79pkqA@mail.gmail.com
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
@@ -2518,6 +2518,12 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i
    mechanism will simply display NULL lag.
   </para>
 
+  <para>
+   Tracking of spilled transactions works only for logical replication.  In
+   physical replication, the tracking mechanism will display 0 for spilled
+   statistics.
+  </para>
+
   <note>
    <para>
     The reported lag times are not predictions of how long it will take for
