Re: (9i) Logical standby database

"Sybrand Bakker" <postbus_at_sybrandb.demon.nl> wrote in message news:ugsm85sie3dv3e_at_corp.supernews.com...
>
> "Daniel" <wiechczd_at_poczta.onet.pl> wrote in message
> news:aek8r1$dbg$1_at_news.tpi.pl...
> > Hi,
> > 9i introduce new possibilities in ensuring of database availability
> > - logical standby database, where the updates are made using SQL
> statements
> > regenerated from logged changes to the primary database
> >
> > Question is - is it posible to implement a environoment (2 separate
sites)
> > where the logical standby database resides on different OS (f.ex.
Windows
> > 2000) platform than the production database (primary)
> > - UNIX.
> >
> > Please help, it's very important..
> > Thanks in Advance
> > Daniel
> >
> >
> That is already possible in Oracle 8i with the standby database feature.
> Obviously you will need the Enterprise Edition. By this I mean that
> homegrown scripts, pumping over the redologs, are not going to work. The
key
> to this all is net8.

It may have a lot to do with Net8, but it also has to do with the redo log format, and going across O/Ses in 8i is definitely not possible. It was a requirement in both 8i and 9i release 1 that the standby database be physically identical to the original (same number of datafiles, same size of datafiles and so on), though the exact file layout could be different (u01/app/blah/data01.dbf on primary, u02/blahstdby/data01.dbf on standby for example).

The logical standby suggests O/S independence, since a SQL statement is a SQL statement, regardless of the platform. But whilst it certainly means that the physical characteristics of the primary and standby can be different (different numbers and sizes of datafiles), you are still transmitting redo. And the format in which redo is stored (and hene transmitted to the standby) is platform specific, and therefore O/S independence is NOT permitted. If it's AIX on the primary, it has to be AIX on the standby.

Regards
HJR
>
> Hth
>
>
> --
> Sybrand Bakker
> Senior Oracle DBA
>
> to reply remove '-verwijderdit' from my e-mail address
>
>
>
>
Received on Mon Jun 17 2002 - 18:05:42 CDT