Experiences with Oracle DUL

Yesterday I had my first experience with Oracle DUL.

A customer had major disk damages on his RAID 5 system, but the backups he made daily were (sadly) never tested (lesson!). Recovery gave lots off errors on UNDO segments in the system table space. Only a 10 months old export was available.

Together with a consultant from Oracle we tried to get data from two damaged databases. For one DB, DUL could read the dictionary from the system data file, but could not read all the data from the user data files. The other DB also had a corrupt system data file, which meant that DUL was unable to read the dictionary and was unable to locate data from user data files. Continue reading