MySQL 8.4 Release Notes
        
Note
            format_bytes() is deprecated,
            and subject to removal in a future MySQL version.
            Applications that use it should be migrated to use the
            built-in FORMAT_BYTES()
            function instead. See
            Section 14.21, “Performance Schema Functions”
          Given a byte count, converts it to human-readable format and
          returns a string consisting of a value and a units indicator.
          Depending on the size of the value, the units part is
          bytes, KiB (kibibytes),
          MiB (mebibytes), GiB
          (gibibytes), TiB (tebibytes), or
          PiB (pebibytes).
mysql> SELECT sys.format_bytes(512), sys.format_bytes(18446644073709551615);
+-----------------------+----------------------------------------+
| sys.format_bytes(512) | sys.format_bytes(18446644073709551615) |
+-----------------------+----------------------------------------+
| 512 bytes             | 16383.91 PiB                           |
+-----------------------+----------------------------------------+