Re: Migration

"Howard J. Rogers" <hjr_at_dizwell.com> wrote in message news:3fa97f91$0$9607$afc38c87_at_news.optusnet.com.au...
>
> "A. Teles" <ateles_at_netcabo.pt> wrote in message
> news:3fa97f03$0$6606$a729d347_at_news.telepac.pt...
> > Hi,
> >
> > Could someone please help me?
> >
> > Assumption situation - Platform migration of Oracle DW on Oracle DB
(data
> > volume 3.5 TB) from HP-UX to IBM-AIX
> >
> > 1.. DB migration; it is correct to use Export/Import technique/method
in
> > the above assumption?
>
> Since you are crossing platforms, then Export/Import is the only way to go
> (unless you create an empty database on AIX and use database links to pull
> the data across... but that's going to be fiddly).
>
> > 2.. Witch is the time frame in a worst case for this (how many hours,
> > days or weeks!!)?
>
> Worst case? Weeks. That's a lot of data to shift. However you do it, it's
> going to take days, minimum, I would have said.
>
> > 3.. It is possible to apply the mentioned technique or some other
(witch
> > one?) in uptime, totally or partially?
>
> Export is merely selecting against the database, so it doesn't require
> downtime. And likewise importing onto a second box shouldn't have any
impact
> on the availability of the first box. But, export with CONSISTENT=Y is
going
> to want to take (effectively) a snapshot of the entire database as it was
> the moment the export started. And that means it's going to rely pretty
> heavily on rollback/undo to create the read consistent images of the data
it
> will require.Given you're a data warehouse, one presumes there is not too
> much DML activity on the database, so that oughtn't to be a problem for
you,
> but if there is DML, then it might be.
>

Hi Howard,

Even if you have sufficient undo space, without a downtime, how do you carry the changes across that occur during the export/import ?

Cheers

Richard Received on Thu Nov 06 2003 - 06:40:19 CST