doc: Document reopen of output file via SIGHUP in pg_recvlogical.

When pg_recvlogical receives a SIGHUP signal, it closes the current
output file and reopens a new one. This is useful since it allows us to
rotate the output file by renaming the current file and sending a SIGHUP.

This behavior was previously undocumented. This commit adds
the missing documentation.

Back-patch to all supported versions.

Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Shinya Kato <shinya11.kato@gmail.com>
Discussion: https://postgr.es/m/0977fc4f-1523-4ecd-8a0e-391af4976367@oss.nttdata.com
Backpatch-through: 13

diff --git a/doc/src/sgml/ref/pg_recvlogical.sgml b/doc/src/sgml/ref/pg_recvlogical.sgml
index 648d3f0f62c185774b0cafe27fa2badda620567e..0af2343b87bdc2931b01e50036e5975c93501557 100644 (file)
--- a/doc/src/sgml/ref/pg_recvlogical.sgml
+++ b/doc/src/sgml/ref/pg_recvlogical.sgml
@@ -53,6 +53,16 @@ PostgreSQL documentation
    (<keycombo action="simul"><keycap>Control</keycap><keycap>C</keycap></keycombo>)
    or <systemitem>SIGTERM</systemitem> signal.
   </para>
+
+  <para>
+   When <application>pg_recvlogical</application> receives
+   a <systemitem>SIGHUP</systemitem> signal, it closes the current output file
+   and opens a new one using the filename specified by
+   the <option>--file</option> option.  This allows us to rotate
+   the output file by first renaming the current file and then sending
+   a <systemitem>SIGHUP</systemitem> signal to
+   <application>pg_recvlogical</application>.
+  </para>
  </refsect1>
 
  <refsect1>