Got a pretty big instance on a one-week backup cycle with an incremental (differential) strategy .. or rather, that's what it was supposed to be. Somehow the daily differentials seem to come out as cumulative!? The size of our instance means that this is a bit of a problem - daily backup window in excess of 3 hours is not acceptable at the end of the week.
Our schedule: Once every week we do an
backup incremental level 0 as copy tag 'sometag' skip readonly database;
and once a day
backup incremental level 1 for recover of copy tag 'sometag' database plus archivelog;
We've configured block-change-tracking for the database
The problem is, that the result is a cumulative incremental backup, which means an increasing backup-window every day, with a reset in the weekends.
What are we doing wrong?
- Change Tracking is getting screwed up?
- Strategy incompatible with image copies?