Incomplete Recovery

>> Not true, Norman. If you have all redo from the point of the last
>> checkpoint onwards, then shutdown abort will pose no greater
 difficulty than
>> any other form of shutdown.

True - and lets face it, isn't this what instance recovery is all about when you startup after an abort or imediate shutdown - all the redo is present, so the instance recovers. But at times (in noarchive mode - which you brought up) the failure could take place when some of the redo has been overwritten - so no recovery. In archivelog mode, no worries - all the redo is available.

>> When do you recover binary backups of control files, Norman? Er,
 never...
>> not unless you've lost a tablespace in the meantime, anyway. Or
 unless you
>> have a deathwish.

I have no need for a deathwish thanks, alter database backup controlfile to trace does me fine !
On my first day in the job as a trainee DBA I was told to 'delete that file because the tablespace that used to use it is no longer there', so I did. Trouble was, the tablespace *was* still there - database running in noarchivelog mode, 120 developers waiting to get their source database back up and running - me in a stew ! Talk about a baptism of fire. I got it all back though ! (At 02:00 in the morning !) I learned all about backup to trace that day !

>> I can show you a dozen ways of breaking a *database*

Oops, wrong terminology - the sort of thing I am always telling my developers off about, hoist by my own petard !

>> Maybe if they taught you the difference between a database and an
instance,
They did, honest, I typed it wrong.
Instance - memory structures (SGA) & background processes. Database - control, redo & datafiles.

>> I might trust your comments a good deal more).

You can trust what you like :o)

>> I only mention this because I have spent the afternoon doing
 incomplete
>> recoveries on a database that was repeatedly shutdown 'abort'. Nary
 a one
>> went wrong (which I agree is some kind of record for me and my
demos).

Sounds like a fun day then. I shall go away and set up an instance and a database :o) and try to break the database by doing incomplete recovery after an abort - just to satisfy my own curiosity.

Regards, Norman. Received on Tue Jan 30 2001 - 05:53:23 CST