FreeLists / oracle-l / RE: Shutdown Abort

["Baumgartel, Paul" <paul.baumgartel@xxxxxxxxxxxxxxxxx>]

Well said, and I hope the definitive word on this topic, to be dusted off 
whenever someone revives this discussion.
 
Does anyone really think that Oracle could have succeeded if power failures or 
other sudden, unplanned instance terminations threatened data integrity?

Paul Baumgartel 
CREDIT SUISSE 
Information Technology 
Securities Processing Databases Americas 
One Madison Avenue 
New York, NY 10010 
USA 
Phone 212.538.1143 
paul.baumgartel@xxxxxxxxxxxxxxxxx 
www.credit-suisse.com 

 

  _____  

From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On 
Behalf Of Robert Freeman
Sent: Tuesday, July 03, 2007 12:13 PM
To: oracle-l@xxxxxxxxxxxxx
Subject: RE: Shutdown Abort


Anything is possible given the right set of conditions. Clearly there is an 
issue with fsck in AIX5L that can cause problems with temporary tablespace temp 
files. This same problem would seem to exist when doing a shutdown immediate 
too. So if one were to do a shutdown abort, and reboot the system and have this 
failure occur, one might well jump to the conclusion that it's a problem with 
shutdown abort, when in fact it is not.
 
So there may be other OS interactions that happen in very odd cases that might 
cause it appear that a shutdown abort is the issue when it is, in reality, 
something else. Also there could be bugs present anywhere in the configuration 
(OS, firmware, etc..) that could cause IO corruption given the right 
conditions. Then there is the possibility of something running in the 
background of the OS that caused the problem, who is to know? The bottom line 
is that you are supposed to be able to pull the PLUG on the thing, and expect 
that it will come up without help *every* *single* time (assuming that pulling 
the plug didn't take out a physical disk for some reason). 
 
I think you are spot on that this was not a controlled test, so anything could 
have caused it. In my mind, if it's not reproducable, then there is something 
about the test that was not controlled. The exact set of conditions needs to be 
known and reproducable to call a test controlled. 
 
The OP's problem might well have happened with a shutdown immediate, there is 
no way of telling and so blaming shutdown abort is jumping to conclusions that 
are not supported by any hard facts other than the fact that one of the actions 
performed was a shutdown abort. How do we know it wasn't the startup command 
that was at fault?? This test makes shutdown abort a suspect but not a 
criminal. If you can replicate the problem consistently, then we have something 
to work with, and I'd LOVE to see your results.
 
I guess my point of view is that you are as likely to find a bug with shutdown 
immediate as you are with shutdown abort, so do we just not shutdown the 
database at all because there  *might* be a bug? All other things being equal, 
shutdown abort should not have negative impacts on your database, and if it 
does, it's a bug. Besides, by the time I go production on any given system, 
I've done a shutdown abort enough times on test and development that it should 
be exercised pretty well. You can't spend your life worrying about the bugs 
that *might* be there (there are enough real ones to contend with!!), that is 
what backup strategies are for. 
 
Finally the *body* of experience here seems to be that shutdown abort works, 
and is perfectly safe. I've yet to see one case where anyone can reliably 
replicate a shutdown abort bug in 9i or 10g that is exclusive to shutdown 
abort. If anyone can provide a reproducible test case of shutdown abort 
failure, please let me know.
 
RF
 
 

Robert G. Freeman
Oracle Consultant/DBA/Author
Principal Engineer/Team Manager
The Church of Jesus Christ of Latter-Day Saints
Father of Five, Husband of One,
Author of various geeky computer titles
from Osborne/McGraw Hill (Oracle Press)
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-----Original Message-----
From: Joel.Patterson@xxxxxxxxxxx [mailto:Joel.Patterson@xxxxxxxxxxx]
Sent: Tuesday, July 03, 2007 9:47 AM
To: robertgfreeman@xxxxxxxxx; oracle-l@xxxxxxxxxxxxx
Subject: RE: Shutdown Abort



I agree.   It was very unusual - but apparently possible.    My original note 
sided with immediate, but if that was unacceptable, I would use abort.     ...  
If Randy claims it has to be a controlled test, then so be it.   I would think 
it quite hard to find exactly what was happening and make it happen.   

 

Joel Patterson 
Database Administrator 
joel.patterson@xxxxxxxxxxx 
x72546 
904  727-2546 

 


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