On Sat, Sep 17, 2022 at 02:54:27PM -0700, Nathan Bossart wrote: > On Sat, Sep 17, 2022 at 11:46:39AM +0200, Peter Eisentraut wrote: > >> > --- a/doc/src/sgml/backup.sgml > >> > +++ b/doc/src/sgml/backup.sgml > >> > @@ -691,11 +691,9 @@ test ! -f > >> > /mnt/server/archivedir/00000001000000A900000065 && cp pg_wal/0 > >> > system crashes before the server makes a durable record of > >> > archival success, > >> > the server will attempt to archive the file again after restarting > >> > (provided > >> > archiving is still enabled). When an archive library encounters a > >> > - pre-existing file, it may return <literal>true</literal> if the WAL > >> > file has > >> > + pre-existing file, it should return <literal>true</literal> if the > >> > WAL file has > >> > identical contents to the pre-existing archive and the > >> > pre-existing archive > >> > - is fully persisted to storage. Alternatively, the archive library > >> > may > >> > - return <literal>false</literal> anytime a pre-existing file is > >> > encountered, > >> > - but this will require manual action by an administrator to resolve. > >> > If a > >> > + is fully persisted to storage. If a > >> > pre-existing file contains different contents than the WAL file > >> > being > >> > archived, the archive library <emphasis>must</emphasis> return > >> > <literal>false</literal>. > >> > >> Works for me. Thanks. > > > > This documentation change only covers archive_library. How are users of > > archive_command supposed to handle this? > > I believe users of archive_command need to do something similar to what is > described here. However, it might be more reasonable to expect > archive_command users to simply return false when there is a pre-existing > file, as the deleted text notes. IIRC that is why I added that sentence > originally.
What makes the answer for archive_command diverge from the answer for archive_library?
