Re: Oracle Data Guard

Comments inline

At 13:34 8-12-03 -0800, you wrote:
>Hi Tanel,
>
>
>Much appreciated, The fact is I am interested in
>Logical standby rather than physical.
>
> Our 30-50% of our Production data needs to be
>replicated to another database and where they will
>have their processing and batches.

It all depends on the amount of redolog you generate. When that's pretty much, you waste some resources by transporting online/archived redologs you actually don't need.

> Now We didn't go to Snapshot because It is on
>multiple tables (where we didnot have PK's and many
>tables) and due to performance issue I didn't want to
>use Snapshots (they did not want any tables to be
>truncate before being loaded even via snapshots).

So, they don't like nologging operations like truncate, not even on the standby database?

> The best option I think is Logical Standby Database.
>Or Can you please suggest me any other means.
>
> Replication should be quicker like once in
>every 20 minutes, Even Transportable tablespacs does
>not work here since they need all tables to 24*7.

LSB might work, but do not consider the option of failing over to it. Be aware that, altough in maximum protection mode your redolog arrives at the SB system within the transaction, it doesn't get applied there instantly. SQL Application takes place _after_ the log-switch on the Primary. When you take 10 minutes of redolog, and perform a logswitch, the SQL Apply process might even take longer than 10 minutes to complete processing of the redologfile. There is a risk that not every transaction arrives within 20 minutes at the LSB. So, your log-switching frequency and the amount of redo you generate per unit of time both play a major role in the refresh rate of the LSB.

I'll send you the PDF of a DG Special I did in Kista a few months ago.

Regards, Carel-Jan

• There will allwasy be another 10 last bugs --

>Any suggestion would be more helpful.
>
>with thanks,
>Vi.
>
>
>
>--- Tanel Poder <tanel.poder.003_at_mail.ee> wrote: > >
>Hi All,
> > >
> > > can any one let me know kindly the following info.
> > >
> > > 1) Has any one used the Oracle 9i Data Guard?
> >
> > Yes, physical standby and successfully.
> >
> > > 2) If yes then, is there any performance impact
> > on
> > > Target/Source server database.
> >
> > Your database has to be in archivelog mode, but when
> > you are thinking such
> > solutions as DG, then you probably are already
> > running archivelog anyway.
> >
> > If you run in maximum protection or maximum
> > availability, yes there is. The
> > impact depends mainly on network connection between
> > primary and standby(s)
> > and the speed of redolog disks. You could tune these
> > by using faster
> > network, enabling jumbo frames and SDU size if using
> > Gbit ethernet, also
> > setting lgwr and log apply processes priority higher
> > than others.
> >
> > > 3) any drawbacks using Data Guard.
> >
> > You should set your database or critical tablespaces
> > to force logging mode
> > in order to transfer all changes to standby in
> > physical standby. That means,
> > performance improvements which take advantage of
> > nologging operations (such
> > insert append nologging etc), will not run that fast
> > anymore.
> > In logical standby, I think there's no such
> > requirement, but I don't
> > recommend you to use logical stby yet, it's more
> > like a prototype currently,
> > not exactly a working product.
> >
> > Tanel.
> >
> >
> > --
> > Please see the official ORACLE-L FAQ:
> > http://www.orafaq.net
> > --
> > Author: Tanel Poder
> > INET: tanel.poder.003_at_mail.ee
> >
> > Fat City Network Services -- 858-538-5051
> > http://www.fatcity.com
> > San Diego, California -- Mailing list and web
> > hosting services
> >
>---------------------------------------------------------------------
> > To REMOVE yourself from this mailing list, send an
> > E-Mail message
> > to: ListGuru_at_fatcity.com (note EXACT spelling of
> > 'ListGuru') and in
> > the message BODY, include a line containing: UNSUB
> > ORACLE-L
> > (or the name of mailing list you want to be removed
> > from). You may
> > also send the HELP command for other information
> > (like subscribing).
>
>________________________________________________________________________
>BT Yahoo! Broadband - Save £80 when you order online today. Hurry! Offer
>ends 21st December 2003. The way the internet was meant to be.
>http://uk.rd.yahoo.com/evt=21064/*http://btyahoo.yahoo.co.uk
>--
>Please see the official ORACLE-L FAQ: http://www.orafaq.net
>--
>Author: =?iso-8859-1?q?Nalla=20Ravi?=
> INET: vvnrk2001_at_yahoo.co.uk
>
>Fat City Network Services -- 858-538-5051 http://www.fatcity.com
>San Diego, California -- Mailing list and web hosting services
>---------------------------------------------------------------------
>To REMOVE yourself from this mailing list, send an E-Mail message
>to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
>the message BODY, include a line containing: UNSUB ORACLE-L
>(or the name of mailing list you want to be removed from). You may
>also send the HELP command for other information (like subscribing).

-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.net
-- 
Author: Carel-Jan Engel
  INET: cjpengel.dbalert_at_xs4all.nl

Fat City Network Services    -- 858-538-5051 http://www.fatcity.com
San Diego, California        -- Mailing list and web hosting services
---------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB ORACLE-L
(or the name of mailing list you want to be removed from).  You may
also send the HELP command for other information (like subscribing).