My favorite feature to date has to be Oracle RMAN (Recovery Manager). Why? Well I really believe that at the end of the day the most important job of the DBA (and there are many!) is to ensure that the data is protected. If you lose an organization’s data not only will you most likely lose your job but you could potentially cause some serious financial issues (not to mention bad reputation) for that organization.
I may have a different appreciation for RMAN than those who may have not had an opportunity to work with the Oracle database prior to version 8. I first started using Oracle database version 7.3.2 and to make a backup you would do something like this:
ALTER TABLESPACE TBS1 BEGIN BACKUP; Backup all datafiles for this tablespace ALTER TABLESPACE TBS1 END BACKUP;
Now you had to do this for every tablespace in your database and every time you added a new datafile you would need to remember to add that to your backup script (you could get savvy and create a dynamic script). The point being it was too easy to miss backing up a database file which would cause you some trouble in the event you needed to restore. Not to mention knowing when files were backed up and how long they were retained for.
Along comes RMAN which simplified the entire backup, restore and recovery process for the DBA. The simplest example to backup a database with RMAN?
BACKUP DATABASE PLUS ARCHIVELOG;
Pretty easy! It backups all my database files including my archived redo logs. Don’t be fooled, RMAN can be as simple or as advanced as you want it to be. The features of RMAN only get better with each release. You can check out those new features by starting at OTN and taking a look at the latest Oracle database documentation.