Re: backup options

"Sean M" <smckeown_at_earthlink.net> wrote in message news:3D12BE3B.FA8C7CBA_at_earthlink.net...
> "Howard J. Rogers" wrote:
> >
> > "tshen" <tshen01_at_hotmail.com> wrote in message
> >
> > > Is oracle 8.1.7 allows DBA to put DB back into standby mode after
> > > bring it up?
> >
> > Nope, utterly 100% absolutely impossible. Activating the standby causes
a
> > resetlogs to be issued, therefore it can never again becoem the standby.
You
> > are supposed to fix your old primary and turn that into the new standby.
> > Again, if you want the ability to flip-flop between primary and standby
> > roles, you need 9i.
>
> This isn't entirely true... you can, if you're *very* careful and fully
> understand the Oracle recovery concepts, flip-flop between production ->
> standby -> production ad infinitum in pre-9i releases (back to 7.3 I
> believe). The process is too complex to describe in detail here, but if
> you do a search on "Graceful Switchover and Switchback for Oracle
> Standby Databases" in Metalink you'll find a white paper, written by
> Lawrence To, that describes a fully supported method of doing this. The
> basic idea is that the standby database is a exact backup of your
> primary. If you shutdown your primary cleanly, move the primary's
> online redo logs and recreate the standby's controlfile to look just
> like the primary's, and apply all archives, you can "fake out" Oracle
> into thinking the whole database has moved to a new machine. You never
> issue an "activate standby database" command, you never issue an "open
> resetlogs" command, so you don't have to rebuild/recopy anything.
>

Which is certainly possible (I've done it, once). But there's a hell of a kerfuffle getting the old primary to now be the standby and direct all the redo from the new primary back to it. Not exactly flip-flop if I remember... more like a "kerflunk, damn, blast, kerfloffle, plonk, ah! damn, bummer, "get me a beer", bink!, ping!, sodit".

I'm sure the whitepaper puts it more elegantly!

I do *try* not to be hyperbolically didactic. Sometimes I flunk it. Still reckon the gist was more or less right, though.

Regards
HJR
> This paper effectively describes how to manually accomplish what 9i DG
> graceful switchover does for you automatically.
>
> Regards,
> Sean M
Received on Fri Jun 21 2002 - 01:51:06 CDT