Fix some documentation in pg_rewind

michaelpq · michaelpq · commit 4b482e94a006 · 2019-04-05T10:38:26.000+09:00
A confusion which comes a lot from users is that it is necessary to issue a checkpoint on a freshly-promoted standby so as its control file has up-to-date timeline information which is used by pg_rewind to validate the operation. Let's document that properly. This is back-patched down to 9.5 where pg_rewind has been introduced. Author: Michael Paquier Reviewed-by: Magnus Hagander Discussion: https://postgr.es/m/CABUevEz5bpvbwVsYCaSMV80CBZ5-82nkMzbb+Bu=h1m=rLdn=g@mail.gmail.com Backpatch-through: 9.5
diff --git a/doc/src/sgml/ref/pg_rewind.sgml b/doc/src/sgml/ref/pg_rewind.sgml
@@ -221,6 +221,15 @@ PostgreSQL documentation
  <refsect1>
   <title>Notes</title>
 
+  <para>
+   When executing <application>pg_rewind</application> using an online
+   cluster as source which has been recently promoted, it is necessary
+   to execute a <command>CHECKPOINT</command> after promotion so as its
+   control file reflects up-to-date timeline information, which is used by
+   <application>pg_rewind</application> to check if the target cluster
+   can be rewound using the designated source cluster.
+  </para>
+
   <refsect2>
    <title>How it works</title>
 
