Re: Online base backup from the hot-standby

On 31.05.2011 07:46, Jun Ishiduka wrote:
>> I don't much like that approach. The standby would need to be able to
>> write the backup history file to the archive at the end of backup, and
>> we'd have to reintroduce the code to fetch it from archive and, when
>> streaming, from the master. At the moment, the archiver doesn't even run
>> in the standby.
>
> Please teach the reason for "The standby would need to be able to write
> the backup history file to the archive at the end of backup" .
> (I'd like to know why "to only pg_xlog" is wrong .)

If the backup history file is not archived, the postgres process won't
find it when you try to restore from the base backup. The new server has
no access to the standby's pg_xlog directory.

> Because there is the opinion of "Cascade replication" , I don't want to
> realize the function with the method which the standby requests to execute
> it on the primary server .
>
> (The opinion of "Cascade replication"：
> http://archives.postgresql.org/pgsql-hackers/2011-05/msg01150.php)

I don't see how this helps.

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com