Re: XLogArchivingActive

On Thu, 2006-05-25 at 17:25 +0200, Andreas Pflug wrote:
> Tom Lane wrote:
> > Andreas Pflug <pgadmin(at)pse-consulting(dot)de> writes:
> >
> >>I propose to introduce a GUC "permanent_archiving" or so, to select
> >>whether wal archiving happens permanently or only when a backup is in
> >>progress (i.e. between pg_start_backup and pg_stop_backup).
> >
> >
> > This is silly. Why not just turn archiving on and off?
>
> Not quite. I want online backup, but no archiving.

I can see what you want and why you want it. It's good to have the
option of a physical online backup as opposed to the logical online
backup that pg_dump offers.

> Currently, I have to
> edit postgresql.conf and SIGHUP to "turn on archiving" configuring a
> (hopefully) writable directory, do the backup, edit postgresql.conf and
> SIGHUP again. Not too convenient...

You're doing this for pgAdmin right?

My understanding was that we had the tools now to edit the
postgresql.conf programmatically?

Seems like its not too convenient to change the way the server operates
to do this, as long as we solve the SIGHUP/postgresql.conf problem. I'm
also not that happy about curtailing people's options on backup either:
if people decided they wanted to have a mixture of isolated on-line
backup (as you suggest), plus active archiving at other times they would
still have the problems you suggest.

Not sure what the edit commands are offhand, but we would need the
following program:

- edit postgresql.conf
- pg_reload_conf()
- wait 30
- pg_start_backup('blah')
- backup
- pg_stop_backup()
- unedit postgresql.conf
- pg_reload_conf()

Which could then be wrapped even more simply as

- pg_start_backup_online('blah')
- backup
- pg_stop_backup_online()

Which overall seems lots easier than changing the server and adding
another parameter.

--
Simon Riggs
EnterpriseDB http://www.enterprisedb.com