but it is encoded as a string of hexadecimal
   digits. Each pair of hexadecimal digits in the string represents a
   single octet.
  </para>

  <para>
   The following two keys are always present:
  </para>

  <variablelist>
   <varlistentry>
    <term><literal>Size</literal></term>
    <listitem>
     <para>
      The expected size of this file, as an integer.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><literal>Last-Modified</literal></term>
    <listitem>
     <para>
      The last modification time of the file as reported by the server at
      the time of the backup. Unlike the other fields stored in the backup,
      this field is not used by <xref linkend="app-pgverifybackup" />.
      It is included only for informational purposes.
     </para>
    </listitem>
   </varlistentry>
  </variablelist>

  <para>
   If the backup was taken with file checksums enabled, the following
   keys will be present:
  </para>

  <variablelist>
   <varlistentry>
    <term><literal>Checksum-Algorithm</literal></term>
    <listitem>
     <para>
      The checksum algorithm used to compute a checksum for this file.
      Currently, this will be the same for every file in the backup
      manifest, but this may change in future releases. At present, the
      supported checksum algorithms are <literal>CRC32C</literal>,
      <literal>SHA224</literal>,
      <literal>SHA256</literal>,
      <literal>SHA384</literal>, and
      <literal>SHA512</literal>.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><literal>Checksum</literal></term>
    <listitem>
     <para>
      The checksum computed for this file, stored as a series of
      hexadecimal characters, two for each byte of the checksum.
     </para>
    </listitem>
   </varlistentry>
  </variablelist>
 </sect1>

 <sect1 id="backup-manifest-wal-ranges">
  <title>Backup Manifest WAL Range Object</title>

  <para>
   The object which describes a WAL range always has three keys:
  </para>

  <variablelist>
   <varlistentry>
    <term><literal>Timeline</literal></term>
    <listitem>
     <para>
      The timeline for this range of WAL records, as an integer.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><literal>Start-LSN</literal></term>
    <listitem>
     <para>
      The LSN at which replay must begin on the indicated timeline in order to
      make use of this backup.  The LSN is stored in the format normally used
      by <productname>PostgreSQL</productname>; that is, it is a string
      consisting of two strings of hexadecimal characters, each with a length
      of between 1 and 8, separated by a slash.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><literal>End-LSN</literal></term>
    <listitem>
     <para>
      The earliest LSN at which replay on the indicated timeline may end when
      making use of this backup. This is stored in the same format as
      <literal>Start-LSN</literal>.
     </para>
    </listitem>
   </varlistentry>
  </variablelist>

  <para>
   Ordinarily, there will be only a single WAL range. However, if a backup is
   taken from a standby which switches timelines during the backup due to an
   upstream promotion, it is possible for multiple ranges to be present, each
   with a different timeline. There will never be multiple WAL ranges present
   for the same timeline.
  </para>
 </sect1>
</chapter>