Re: Standby database question

"Howard J. Rogers" <howardjr2000_at_yahoo.com.au> wrote in message news:4kyz9.74020$g9.208056_at_newsfeeds.bigpond.com...
> Well, a simple question, and it seems to have stirred up all sorts of
> confusion in the replies!!
>
> Somewhere in all of the replies is the truth.
>
> The paths to datafiles can be different, because there's an init.ora
> parameter that will do a transparent conversion from '/bing/bong/x.dbf' on
> primary to '/blah/bong/x.dbf' on standby.
>
> The O/S must be the same on primary and standby. You can't ship redo from
a
> Unix box to an NT standby, for example. Neither can you ship Solaris redo
to
> an HP standby. Can an HP10.10 box ship redo to an HP10.20 standby?
> Perhaps... but it would be unsupported, and would be the first thing
Oracle
> Support would pick up on if asked. As such, it's certainly not
recommended.
> The requirement for the O/S to be the same is true even of the new
'logical
> standby' facility in 9iR2.
>
> The *number* of datafiles (and their size etc) must be identical on both
> primary and standby. You can *NOT* have a subset of your datafiles as a
> standby. If you've 100 datafiles on primary, each of 500MB, you must have
> 100 datafiles on standby, each of 500MB. The reason? You'll be shipping
> redo from primary to standby, and redo contains instructions such as "on
> file 3, block 650, row 4, change column 4 to 600". So if you don't have a
> file 3, or if file 3 is smaller on standby, such that it doesn't have a
> block 650, the whole thing is going to go down the drain.

Hi Howard

This question has raised some confusion.

You *CAN* have a subset of your datafiles on the standby DB.

You can make datafiles on the standby database "offline" which means that these files do not have to be copied across, are not recovered (the redo is simply ignored, it doesn't cause any failures) and effectively results in a subset of the datafiles being maintained on the standby.

When you open the standby database, you simply drop the now stuffed tablespace and you're away.

Cheers

Richard Received on Sun Nov 10 2002 - 17:44:18 CST