Re: [ovirt-users] upgrade to 4.1

Le 23 avr. 2017 à 07:59, Yedidyah Bar David <didi(a)redhat.com&gt; a écrit :

The main reason we require this is for pg_dump/pg_restore which are ran during setup/rollback (if needed). pg_dump can't know for sure that all the changes in the db were done using a client of its own version (that is, current machine usually), and if indeed a newer client was used, it might have used features that pg_dump of the lower version doesn't know how to back up (and especially pg_restore does not know how to restore). See also [1]. I seem to have tested there (can't remember anymore, see comment 13) 9.2 client with 9.5 server and it didn't work. pg_dump(1) manpage says: Because pg_dump is used to transfer data to newer versions of PostgreSQL, the output of pg_dump can be expected to load into PostgreSQL server versions newer than pg_dump's version. pg_dump can also dump from PostgreSQL servers older than its own version. (Currently, servers back to version 7.0 are supported.) However, pg_dump cannot dump from PostgreSQL servers newer than its own major version; it will refuse to even try, rather than risk making an invalid dump. Also, it is not guaranteed that pg_dump's output can be loaded into a server of an older major version — not even if the dump was taken from a server of that version. Loading a dump file into an older server may require manual editing of the dump file to remove syntax not understood by the older server. Use of the --quote-all-identifiers option is recommended in cross-version cases, as it can prevent problems arising from varying reserved-word lists in different PostgreSQL versions.