doc: Add description of "filename" for pg_walsummary

This command requires an input file (WAL summary file), that has to be
specified without an option name.  The shape of the command and how to
use this parameter is implied in its synopsis.  However, this page
lacked a description of the parameter.  Listing parameters that do
not require an option is a common practice across the docs.  See for
example pg_dump, pg_restore, etc.

Author: Peter Smith <smithpb2250@gmail.com>
Discussion: https://postgr.es/m/CAHut+PtbQi8Dw_0upS9dd=Oh9OqfOdAo=0_DOKG=YSRT_a+0Fw@mail.gmail.com

diff --git a/doc/src/sgml/ref/pg_walsummary.sgml b/doc/src/sgml/ref/pg_walsummary.sgml
index 57b2d24650cf12b3c76c26d0d2505a9d7329eb0d..3f3c5ae16a293728e312e34d6aaa44972e9bf885 100644 (file)
--- a/doc/src/sgml/ref/pg_walsummary.sgml
+++ b/doc/src/sgml/ref/pg_walsummary.sgml
@@ -23,7 +23,7 @@ PostgreSQL documentation
   <cmdsynopsis>
    <command>pg_walsummary</command>
    <arg rep="repeat" choice="opt"><replaceable>option</replaceable></arg>
-   <arg rep="repeat"><replaceable>file</replaceable></arg>
+   <arg rep="repeat"><replaceable>filename</replaceable></arg>
   </cmdsynopsis>
  </refsynopsisdiv>
 
@@ -56,6 +56,16 @@ PostgreSQL documentation
 
    <para>
     <variablelist>
+     <varlistentry>
+      <term><replaceable class="parameter">filename</replaceable></term>
+      <listitem>
+       <para>
+        Specifies the name of a WAL summary file, found in the
+        <literal>pg_wal/summaries</literal> subdirectory of the data directory.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-i</option></term>
       <term><option>--individual</option></term>