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Home -> Community -> Mailing Lists -> Oracle-L -> Re: Upgrade DB with no downtime
It is possible to establish master-master replication between different
versions of oracle. In theory, you could set up the "upgraded" database as
a replicated environment, then stop the original master at some point and
go forward on the new "master" at the new release version. I tried this a
few years ago going from 8.1.7 to 9.1 and had it about 90% stable when
management decided to just take the downtime it. I had never worked with
advanced replication at the time and have no doubts about that being a
contributing factor to the timeline. Note, the really wouldn't be an
"upgrade" in the traditional since, the new version is just built at that
level, the data replicated, and the old instance shut down. There are
still steps that effectively lock the primary system, but these were
relatively short, from what I can remember, and easily fit in the 30 min or
so of downtime allowed at night for cycling servers and the like.
At any rate, I _think_ it is possible, but it is not easy or quick. Timeframe and management patience to get everything working 100% in development is key (and my management only gave me about two months, wedged in with all my normal activities, to implement before yanking the idea).
FWIW,
John P Weatherman
Oracle DBA
Advance America
> [Original Message]
> > The database needs to be available in read-write mode when we do the
upgrade
> > from 8i to 9i or 9i to 10G. Hardware is not an issue as long as we can
> > achieve zero downtime during the upgrade. Not sure how we can achieve
that.
> > Anyone has any experience or suggestions?
-- Archives are at http://www.freelists.org/archives/oracle-l/ FAQ is at http://www.freelists.org/help/fom-serve/cache/1.html -----------------------------------------------------------------Received on Thu May 27 2004 - 08:28:21 CDT
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