In this ³mutual supporting² configuration,you don¹t need additional instances just to house the ³recovery catalog² database? Your idea to house them inside the ³business² instances is quite viable, as the RMAN ³recovery catalog² is a very low-usage, low-traffic database application. ----- May I ask a quick question: why do you need to have a "recovery catalog" database at all? Running RMAN in "nocatalog" mode has exactly the same functionality as running it with a "recovery catalog" database tacked on. Reasons for using a ³recovery catalog² database instead of NOCATALOG: * storing information for periods of time longer than CONTROLFILE_RECORD_KEEP_TIME > * retaining information about READ ONLY tablespaces archived for months or > years * storing information across RESETLOGS > * to allow recovery across RESETLOGS * centralizing RMAN information from two or more ³target² databases > * redundant backup of information stored in the controlfile NOCATALOG isn¹t as risky as one might think. It is easy and very natural to be super-paranoid about controlfile backups ? flying NOCATALOG airlines just gives another reason. I¹ve always taken controlfile backups redundantly during backups (one copy to disk as well as tape), and 9i¹s CONFIGURE CONTROLFILE AUTOBACKUP just makes it easier. I think most people assume that a ³recovery catalog² is required or even a strongly recommended part of RMAN. In reality, it is just an option that is available for very specific reasons. And, like many such options, it comes at a cost in extra complexity: * now there is another database to manage and backup * upgrades from one version of RDBMS to another requires upgrade of the corresponding ³recovery catalog² repository If you don¹t intend to store recovery information for very long (i.e. Less than 30 days), then you should really consider NOCATALOG. Just my $0.02 (let the stone-throwing begin)... on 1/23/04 2:33 PM, Daniel Hanks at hanksdc@xxxxxxxxxxxxx wrote: > I'm in the process of revamping my backup procedures, and had some ideas I > wanted to filter through the wisdom/experience of the list. > > In my current setup, I have two main database machines, let's call them M1, > and M2. > > - On M1, I have 2 instances, one 'business' instance, and 1 instance which > serves as the recovery catalog for M2 (total of 2 instances). > > - On M2 I have 2 'business' instances, and 1 instance which serves as the > recovery catalog for M1 (total of 3 instances). > > So essentially M1 hosts the recovery catalog for the databases on M2, and > likewise M2 hosts the recovery catalog for the database on M1. > > My question is, would it be prudent/beneficial to put the recovery catalogs > into their own schemas in the 'business' instances, instead of maintaining > them in their own instances? > > Some benefits I see in doing this: > > - That would make 2 less instances I have to concern myself with. > - I now have (slightly) more memory/resources to allocate to the 'business' > instances. > - Backups of the recovery catalogs are now handled by the regular backups of > the 'business' instances. > > Some drawbacks to doing this: > > - The recovery catalog is now 'coupled' to the business instance. If the > business instance is down for an extended period of time (which 'should never > happen' > :-) then I'd be 'unable' to make rman backups of the other machine at least > with the catalog. > - Are there other drawbacks? > > Thanks for your thoughts and suggestions, > > -- Dan > ======================================================================== > Daniel Hanks - Systems/Database Administrator > About Inc., Web Services Division > ======================================================================== > ---------------------------------------------------------------- Please see the official ORACLE-L FAQ: http://www.orafaq.com ---------------------------------------------------------------- To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx put 'unsubscribe' in the subject line. -- Archives are at //www.freelists.org/archives/oracle-l/ FAQ is at //www.freelists.org/help/fom-serve/cache/1.html -----------------------------------------------------------------