Never once have I lost data due to software errors, and after many hard landings the database always manages to come back online after wading through the redo logs and make sure the data remains consistent.
I have been working as a DBA at sites where some decided to do maintenance on their UPS, the SAN, the network, or whatever in peak hours, resulting in hard landings that many databases won't recover from. The worst nightmare for a DBA is to lose data. Yes, we have backups, and we spend time learning disaster recovery. But nothing beats the relief when you initiate "startup" after a crash and Oracle after a little while responds with "Database opened". You may say I've been lucky; software errors that corrupt data do exists, but after thousands of databases and many years with Oracle Database administration, not losing data remains my favourite feature.
My second favourite is all the instrumentation in there, the ability to figure out what is going on when someone complains. The database instrumentation is frequently a good starting place, even when the fault is outside somewhere, like in a badly designed application in another layer.
Thank you, OTN, for the support, information, articles, easy downloads, the ACE program, events, and much more. Have a great Appreciation Day!