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

Tom Lane wrote:
> Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)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.

> 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.

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