Re: Transferring a DB to a new platform WITHOUT export/import

"Rick Denoire" <100.17706_at_germanynet.de> wrote in message news:va6ccvg8t3pgdp8rt4lorlbd3289ibgn9e_at_4ax.com...
> Bill Mitchell <agmitch_at_xcharter.net> wrote:
>
>
> >If using export, check for LONG and LONG RAWs. These tables will import
> >VERY slowly (perhaps 10 to 20 times more slowly). You should definitely
> >transfer these in parallel if possible. Also check for custom SYS
objects
> >and grants to SYS objects, as they probably won't be transferred in the
> >export.
>
> How can the import be parallelized?
>
> >Another option might be to upgrade to Oracle 9i. Then set up a standby
> >database using the new sql apply method (can't remember what it is
called).
> >You could then have nearly instantaneous switch-over.
>
> YEAH!! That's it, the perfect method. I assumed that a standby DB
> would only work for databases of the same version. The source is
> 8.1.7-3, the target will be 9.2.0. Are you sure that this will work??
>
> Why did other people not come up with this idea?

Because it won't work when you are dealing with different versions of the database (nor with different O/Ses, or with different patch versions of the O/S). And those restrictions apply to the Logical Standby method which Bill was referring to as well as to ye olde physical standby.

And (I might be wrong), if you do have LONGS or LONG RAWs, I'm pretty certain they won't replicate to the standby... you need CLOBS and BLOBS for that.

>
> **** INSTANTANEOUS SWITCH OVER ****
>

Yeah, but don't go beserk just yet. First, the switchover won't be instantaneous: you still have to propogate the SQL to the standby database. Second, if you choose to propogate the SQL to the standby in more or less real time, there are some very serious performance implications for your initial database.

> I love that idea.

No good idea ever comes without costs. And the better the idea, quite often, the heavier the costs.

Regards
HJR
>
> Thanks a lot
>
> Rick Denoire
Received on Sat May 17 2003 - 07:26:11 CDT