The object which describes a single file contains either a
   Path key or an Encoded-Path key.
   Normally, the Path key will be present. The
   associated string value is the path of the file relative to the root
   of the backup directory. Files located in a user-defined tablespace
   will have paths whose first two components are pg_tblspc and the OID
   of the tablespace. If the path is not a string that is legal in UTF-8,
   or if the user requests that encoded paths be used for all files, then
   the Encoded-Path key will be present instead.  This
   stores the same data, but it is encoded as a string of hexadecimal
   digits. Each pair of hexadecimal digits in the string represents a
   single octet.
  
The following two keys are always present:
SizeThe expected size of this file, as an integer.
Last-ModifiedThe 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 pg_verifybackup. It is included only for informational purposes.
If the backup was taken with file checksums enabled, the following keys will be present:
Checksum-Algorithm
      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 CRC32C,
      SHA224,
      SHA256,
      SHA384, and
      SHA512.
     
ChecksumThe checksum computed for this file, stored as a series of hexadecimal characters, two for each byte of the checksum.