doc: Clarify how to generate backup files with non-exclusive backups

michaelpq · michaelpq · commit cc7416f3b679 · 2021-04-02T16:37:28.000+09:00
The current instructions describing how to write the backup_label and tablespace_map files are confusing. For example, opening a file in text mode on Windows and copy-pasting the file's contents would result in a failure at recovery because of the extra CRLF characters generated. The documentation was not stating that clearly, and per discussion this is not considered as a supported scenario. This commit extends a bit the documentation to mention that it may be required to open the file in binary mode before writing its data. Reported-by: Wang Shenhao Author: David Steele Reviewed-by: Andrew Dunstan, Magnus Hagander Discussion: https://postgr.es/m/8373f61426074f2cb6be92e02f838389@G08CNEXMBPEKD06.g08.fujitsu.local Backpatch-through: 9.6
diff --git a/doc/src/sgml/backup.sgml b/doc/src/sgml/backup.sgml
@@ -903,7 +903,8 @@ SELECT * FROM pg_stop_backup(false);
      <filename>backup_label</> in the root directory of the backup. The
      third field should be written to a file named
      <filename>tablespace_map</> unless the field is empty. These files are
-     vital to the backup working, and must be written without modification.
+     vital to the backup working and must be written byte for byte without 
+     modification, which may require opening the file in binary mode.
     </para>
    </listitem>
    <listitem>
