Re: pg_start_backup and pg_stop_backup Re: Re: [COMMITTERS] pgsql: Make CheckRequiredParameterValues() depend upon correct

Heikki Linnakangas wrote:
> Tom Lane wrote:
>> Heikki Linnakangas <heikki.linnakangas@enterprisedb.com> writes:
>>> Well, it would be nice to allow using pg_start_backup() on the primary
>>> when streaming replication is enabled, even if archiving isn't.
>>> Otherwise the only way to get the base backup for the standby is to shut
>>> down primary first, or use filesystem snapshot etc.
>> I think I must be missing something: exactly how would you fire up a new
>> standby from such a base backup, if you weren't running archiving?
> 
> I was replying to Robert's thought on using pg_start/stop_backup() for
> taking a hot backup. Not for bootstrapping a standby.

Scratch that, I just reread what I wrote, and starting a streaming
replication standby from such a backup was exactly what I was describing..

>> If you aren't archiving then there's no guarantee that you'll still have
>> a continuous WAL series starting from the start of the backup.
> 
> I wasn't really thinking of this use case, but you could set
> wal_keep_segments "high enough". Not a configuration I would recommend
> for high availability, but should be fine for setting up a streaming
> replication standby for testing etc. If we don't allow
> pg_start/stop_backup() with archive_mode=off and max_wal_senders>0,
> there's no way to bootstrap a streaming replication standby without
> archiving.

This still makes sense.

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