Re: Hardware Replication vs DataGuard

On Sun, 04 Dec 2005 19:47:36 +0000, Rodrick Brown wrote:

> Putting costs aside what do most people think about using hardware san
> replication technologies like SRDF/Truecopy etc.. for replicating Oracle
> volumes at a block level to a remote instance of Oracle ? vs using something
> like dataguard, I know dataguard allows you to have read only access to that
> data which I think is its biggest plus, but for disaster recovery reasons
> only what would be a better solution.

SRDF (later replaced by the Truecopy) and BCV's are a great thing to have, especially for backups and reporting purposes. At the time when I was using them, RMAN didn't support BCV's, but by splitting the volumes a duplicate database (the original was 1.1TB) was created in minutes. All tablespaces had to be put in backup mode, split was done, and then archived logs were copied over and the database was recovered and open to serve as a reporting database or backed up to tape so that I/O caused by backup doesn't interfere with I/O caused by the customers. It's not a replacement for standby, it's a supplement. You can create standby extremely quickly, you can have a logical standby for reporting purposes, there are many uses.
On the other hand, if you want to use the remote replication, I'm not sure how would you configure a database to open it? It would have to be properly scripted, to duplicate the log transport services provided by Oracle. It would be cumbersome, it would require high level of skills and it would be completely unnecessary.

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