Database Software

Hello all,

I'm still trying to get a grip on this concept for RMAN backup planning.

I recently ran into a situation as follows.

I have the backups set to a redundancy of 1.

I have instance1, which had GRID jobs to run RMAN backups as follows

Incremental database level=0 weekly at Wed at 2:30am
I have daily backups, incremental level=1 each evening
I have archive log backups through the day.

What happened, was that apparently on a Tues some time, the development team deleted data from almost every table in their schema.
The didn't discover this till midday or so on Wednesday.

I went to try to restore...and RMAN couldn't do it. I had found a SCN for early the Tues they did it...but I got the following error:

RMAN> RUN
2> {
3> SET UNTIL SCN 4590383198282;
4> RESTORE DATABASE;
5> RECOVER DATABASE;
6> }

executing command: SET until clause

Starting restore at 28-APR-10
allocated channel: ORA_SBT_TAPE_1
channel ORA_SBT_TAPE_1: SID=639 device type=SBT_TAPE
channel ORA_SBT_TAPE_1: NMO v4.5.0.0
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=638 device type=DISK

creating datafile file number=1 name=+DATADG/instance1/datafile/system.284.697137287
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of restore command at 04/28/2010 15:53:00
ORA-01180: can not create datafile 1
ORA-01110: data file 1: '+DATADG/instance1/datafile/system.284.697137287'

From what research I did...it appears that since I did not have a level=0 incremental from before, it could not reset the database back in time. The previous one had been deleted since, I guess I had a redundancy of 1.

So, I thought I had a week backup they way I have it set..but that assumes that errors are found pretty quickly before the next level=0 backup.

I want at least 1 to 1.5 weeks worth of backups. I do have the problem that we do not have many tapes in rotation, so I cannot go for too long...may 2x weeks tops.

I'm trying to rethink my strategy, but I'm confused as I read as to the difference between setting RMAN retention with redundancy vs recovery window.

Can someone give me an explanation how you understand it? I'm reading on the web and in oracle books, and for some reason, it just isn't clear to me what is the best way to go....especially when I see that redundancy and recovery window might both be set??

Thank you in advance,

cayenne