Re: Question on RAC user-managed recovery

From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: 2006-01-12 23:54:48
Message-id: 006601c617cb$3069d540$0200a8c0@Primary

It's just part of the way that RAC works.

You have three nodes that are independent; they re-synchronize their SCNs very frequently - but in principle could delay re-synchronization for about 3 seconds. So if you happened to have three transactions take place one the three separate nodes just after a re-synch, then all three nodes would have to commit at the same SCN.

Regards

Jonathan Lewis

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Original Message ----- From: "Hameed, Amir" To: "ORACLE-L" ; Sent: Thursday, January 12, 2006 10:37 PM Subject: Question on RAC user-managed recovery

Folks,
I am running some time-based database instance recovery tests in the lab on a three-node RAC environment. The following command was issued from one RAC instance while the others were down. I am trying to understand the way the change number (change 7286467501233) is being displayed on the first line of each of the first three threads below. Why is this number common here? After that, this number is distinct in each subsequent archived log file. I would appreciate if someone can explain/clarify it for me.

Thank you
Amir

SQL> recover database until time '2006-01-12:15:20:00' using backup controlfile
ORA-00279: change 7286467501233 generated at 01/11/2006 14:38:59 needed for thread 1
ORA-00289: suggestion : /u107/oradata/archives/e52rac/log_1_778.dbf ORA-00280: change 7286467501233 for thread 1 is in sequence #778

Specify log: {=suggested | filename | AUTO | CANCEL}

ORA-00279: change 7286467501233 generated at 01/11/2006 14:38:35 needed for thread 2
ORA-00289: suggestion : /u107/oradata/archives/e52rac/log_2_463.dbf ORA-00280: change 7286467501233 for thread 2 is in sequence #463

Specify log: {=suggested | filename | AUTO | CANCEL}

ORA-00279: change 7286467501233 generated at 01/11/2006 14:38:37 needed for thread 3
ORA-00289: suggestion : /u107/oradata/archives/e52rac/log_3_408.dbf ORA-00280: change 7286467501233 for thread 3 is in sequence #408

Specify log: {=suggested | filename | AUTO | CANCEL}

ORA-00279: change 7286467508134 generated at 01/11/2006 14:43:27 needed for thread 2

ORA-00289: suggestion : /u107/oradata/archives/e52rac/log_2_464.dbf
ORA-00280: change 7286467508134 for thread 2 is in sequence #464
ORA-00278: log file '/u107/oradata/archives/e52rac/log_2_463.dbf' no

longer needed for this recovery
..
..

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Received on Thu Jan 12 2006 - 23:54:48 CST