Cumulative Problem

Question

Hi all,
We have a table of incidents with a Date Opened and a Date Closed.
The report needed is a cumulative report month by month giving the number of open incidents from the start of the current year
So - we need to start with all open (open date before 1st Jan but no close date) incidents.
Then there will be calls opened in January, and some calls closed in January (and some of these will be calls that were from last year) - so the January cumulative total is (Original) + (Calls opened in Jan) - (Calls closed in Jan) .
SImilarly for Feb, March and up to date.
I'm sure this must be a common request, but I can't think of a way of getting these figures into a report - preferably a cross-tab so we can get a nice bar chart of the totals.
Thanks
Malcolm

Answer 1

I've never actually used incremental backups with a RETENTION POLICY of 'REDUNDANCY', always with a RECOVERY WINDOW.
REDUNDANCY 1 will aim to keep one copy of each backup it takes (as far as I'm aware), therefore it won't really have any awareness of the recovery sequentials involved, i.e., since you're deleting manually it will only check that it has a single copy of each backup for those backups that haven't expired.
On the other hand, if you were operating with a RECOVERY WINDOW of, say, 3 days, you wouldn't need the CROSSCHECK and DELETE EXPIRED, just the DELETE OBSOLETE, and that would retain only what it needs to effect a recovery from the backups from any time over the last 3 days (incomplete) to the present (complete).
Therefore, it would automatically know which level 0s and 1s to keep for that purpose, but the oldest one would never be a level 1, it would always have to be a level 0 plus the subsequent level1s. So say that you take a weekly level 0, and a level 1 on the days in between, on the 6th day after the level 0, you will have one level 0, plus each incremental since then to satisfy the RECOVERY WINDOW of 3 days.
You could also look at taking level 2s, to reduce your backup footprint even further, i.e, weekly level 0, followed by a level 1, followed by a level 2, followed by a level 1, etc...
Here's an example of a cumulative-incremental backup strategy:
[Multi-level RMAN Backup Strategy|http://download.oracle.com/docs/cd/B10501_01/server.920/a96566/rcmconc1.htm]