| SHUTDOWN ABORT questions [message #59752] |
Sun, 21 December 2003 15:23  |
scott
Messages: 73
Registered: September 1999
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Member |
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Hi All,
This one also quailfies as a question of academic interest.
Oracle Docs says
SHUTDOWN ABORT
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(1)Current SQL Statements being processed by the Oracle Sever are immediately terminated
(2)Oracle does not wait for users currently connected to the database to disconnect
(3)UNCOMMITED Transactions are not rolled back
(4)The instance is terminated without closing the files
(5)The database is NOT closed or dismounted
(6)The next startup REQUIRES Instance recovery
My question:
If the redo lof buffers have not been written to the redo log files then how will SMON go through the process of forward recovery?
It says that the database is not closed or dismounted which possibly means that the Instance is still alive. (Which might answer question no 1). But if the machine is given a reboot at this time will there be a Instance Recovery?
Thanks
Scott
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| Re: SHUTDOWN ABORT questions [message #59755 is a reply to message #59752] |
Sun, 21 December 2003 15:49  |
Thiru
Messages: 1089
Registered: May 2002
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Senior Member |
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Scott,
ALL committed transactions have been written to the online redolog files already and so they are safe.The state of the uncommited transactions are known from the rollback segments which is also written to the online redolog files. All dirty buffers whose SCN is <= the last checkpoint SCN already reside in the datafiles and so SMON has to just apply those transactions from the online redolog files since that SCN (to do rollforward recovery that covers the commited transactions that were not written to the datafiles when the instance crashed becos of shutdown abort) .The uncommitted transactions are removed during the roll backward recovery.
The Instance is not alive after the shutdown abort. It just means that the database is not closed cleanly .
Hope this clarifies
Thiru
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