Hey, you're an author!
I expect perfection, grace and infallibility. ;) Jared On Monday 18 March 2002 07:33, Freeman, Robert wrote: > And hey, it was Sunday morning at 0700 something... what do you > expect from me anyways??? :-))))))) > > RF > > Robert G. Freeman - Oracle8i OCP > Oracle DBA Technical Lead > CSX Midtier Database Administration > > The Cigarette Smoking Man: Anyone who can appease a man's conscience can > take his freedom away from him. > > > > -----Original Message----- > Sent: Sunday, March 17, 2002 6:43 PM > To: Multiple recipients of list ORACLE-L > > On Sunday 17 March 2002 07:53, Freeman, Robert wrote: > > 1. You do not open the database to users until AFTER you do a backup (hot > > or cold, dosen't mater) at point t2. > > Well, yeah, that was the point. It doesn't have to be a cold backup, but > since you can't do any work, it may as well be a cold backup. > > Jared > > > 2. There is a method of recovering a database (8i +) after RESETLOGS has > > been > > issued with archived redo logs. I discussed it in my DBA World Tour > > backup and > > recovery presentation. To do this, you MUST have the control file for the > > database from BEFORE the resetlogs operation, and backup of the control > > file from AFTER the same operation. I've done this about 3 times in > > testing > > > and it works fine but it very very picky about the control file images. > > > > RF > > > > Robert G. Freeman - Oracle8i OCP > > Oracle DBA Technical Lead > > CSX Midtier Database Administration > > > > The Cigarette Smoking Man: Anyone who can appease a man's conscience can > > take his freedom away from him. > > > > > > > > -----Original Message----- > > Sent: Friday, March 15, 2002 7:28 PM > > To: Multiple recipients of list ORACLE-L > > > > > > Hi Jared, > > > > > > * You *have* to take a COLD backup of the database after using > > > > > > resetlogs. > > > > > > > (Not required - a Hot backup and archive logs is adequate. All hot > > > > > > backups / > > > > > > > archive logs prior to that are invalid, though...) > > > > > > Consider the following: > > > > > > Time: > > > > > > t0: database restored > > > t1: database opened with RESETLOGS > > > t2: hot backup started ( database in archive log mode ) > > > t3: users input very important transactions > > > t4: database crashes, and must be restored > > > > > > How will you recover the transactions from time t3? > > > > As long as the online redologs are available, this should be no problem. > > I have successfully recovered databases where a log switch did not occur > > and recovery had to use an online redo log. (I am assuming that the lost > > datafiles will be restored from this hot backup fresh off the tapes) > > > > On the other hand, if the online redolog is hosed you have lost the > > transactions anyway, _regardless_ of the fact that a Cold backup was > > taken. > > > Then you will have to go back to the _previous_ incarnation and redo the > > restore and then perform a ccf/resetlogs (i.e. back to square one). If > > you have a Cold backup, you restore the cold backup and go on with life. > > I.e. in both cases (availability of cold or hot backup, lost online redo > > log), you have lost transactions... > > > > Additionally, with a Hot backup and depending on what was lost, you can > > at least perform tablespace/datafile recovery . With a cold backup, you > > will have to restore the whole database.... > > > > The point I was trying to make was that a Cold backup after a RESETLOGS > > does not serve anything. Maybe there is still a gotcha I have not been > > able > > > to figure out, so Backup/restore Gurus: take a bash at this logic! I > > would love to be corrected. > > > > (Btw, the previous recovery scenario was on 7.3.4 - things could have > > changed since, and I have not been able to test that out...) > > > > > > John Kanagaraj > > Oracle Applications DBA > > DBSoft Inc > > (W): 408-970-7002 > > > > Grace - Getting something we don't deserve > > Mercy - NOT getting something we deserve > > > > Click on 'http://www.needhim.org' for Grace and Mercy that is freely > > available! > > > > ** The opinions and statements above are entirely my own and not those of > > my employer or clients ** -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Jared Still INET: [EMAIL PROTECTED] Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
