Is Oracle RMAN catalog DB mandatory ?

In case of disaster, we need to restore the catalog database first and then do a restore. So this is a two step process.

Also you have to check if the catalog db is in sync with Networker.

So, using catalog db creates more work for you.
That is why I ask about non catalog db environment.
We do not have a dba that we can ask about RMAN.

So, anyone else got some other ideas/experience with NMO ?

I think the best way is to ask you DBA about it. Everyone seems to have a different "best" approach to this. If you catalog database is as safe as the others databases, why not use it? As far as I know, it helps a lot during the recover.

Took a look in the module for Oracle documentation, and it says "For more information on the Recovery Catalog, including the implications of
not using it for backups and restores, refer to the Oracle Recovery Manager
documentation."

So, it's up to you. I've always used the catalog database, but if you don't see any good reason to use this, simply don't. As you said, you'll be avoiding one possible point of failure.

It's not mandatory. Even today, most DBAs will run away from RMAN catalog if they never worked with it and will try to use control file instead (which makes a bit more complex restores and you have retention limit).

If RMAN DB is lost, you can use (not always obvisouly) controlfile. As anything else, you need to have backup of RMAN catalog database as well. We have a script which shuts it down and then we do fs backup of it. Hanfling backups and restore is much easier with catalog in my opinion, but I guess it takes time to get used to it.

You can easily add a line in RMAN script to take a backup of control file also.
Could you give me some more details how to do a restore with and without the catalog DB?
We can assume that the CatalogDB is online.

There is really book on this subject which I can't find these days... I'll just have to do inventory of things I pushed under the bed:
http://www.amazon.com/Oracle-Database-RMAN-Backup-Recovery/dp/0072263172

There is also ebook I guess for 11g called RMAN recipes which I found to be available for free pdf download (which I believe is illegal, but it is up to you what you do).

While I didn't check second one entirely, I know that first one contains exactly what you asked and it is really good reading which I would recommend to everyone.

Thanks for the links I will definetly get one of those books but I need to set up an Oracle backup and I want to know which one would be better. It is going to take a while to get those books and I just need a simple answer which method is better. I know how to take the backups but I am not copletely comfortable with restores.

Thanks for the help in advance.

From my point of view it is much easier with catalog database. Creating catalog database is not an issue. There is simple guide on metalink I believe. After you just register database with catalog, include connect string in your RMAN script with user/pass for rman user and that's it.

Restore is should not be an issue either... you also connect to db and catalog and you restore until time, SCN or whatever you prefer. Single tablespace restore is a bit difficult if I remember correctly as, at least in past, you were required to have auxiliary database. But in most case you will find that restoring from archive logs or even FRA will be all that you need and will be handled by Oracle itself.