411 REFERENCE · Wikibooks
RAC Attack - Oracle Cluster Database at Home/Flashback Database
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
Before opening the database, enable flashback database.
SQL> alter database flashback on;
Database altered.
SQL> alter database open;
Database altered.
SQL> select flashback_on from v$database;
FLASHBACK_ON
------------------
YES
SQL> select oldest_flashback_scn,flashback_size from v$flashback_database_log;
OLDEST_FLASHBACK_SCN FLASHBACK_SIZE
-------------------- --------------
610425 8192000Now, login to collabn2 and startup the database from sqlplus. You will get an error message.
collabn2:/home/oracle[RAC2]$ ss
SQL*Plus: Release 11.1.0.6.0 - Production on Mon May 4 09:21:25 2009
SQL> startup
ORACLE instance started.
Total System Global Area 318054400 bytes
Fixed Size 1299624 bytes
Variable Size 142609240 bytes
Database Buffers 167772160 bytes
Redo Buffers 6373376 bytes
Database mounted.
ORA-38760: This database instance failed to turn on flashback database
SQL> select flashback_on from v$database;
FLASHBACK_ON
------------------
YES
SQL> select oldest_flashback_scn,flashback_size from v$flashback_database_log;
OLDEST_FLASHBACK_SCN FLASHBACK_SIZE
-------------------- --------------
0 16384000Interestingly, the database seems to be running alright. Investigate the alert log for error messages.
collabn2:/home/oracle[RAC2]$ cdd
collabn2:/u01/app/oracle/diag[RAC2]$ cd rdbms/rac/RAC2/trace/
collabn2:/u01/app/oracle/diag/rdbms/rac/RAC2/trace[RAC2]$ less alert_RAC2.log
Mon May 04 09:22:07 2009
Errors in file /u01/app/oracle/diag/rdbms/rac/RAC2/trace/RAC2_ora_22856.trc:
ORA-38701: Flashback database log 1 seq 1 thread 1: "/u01/app/oradata/RAC/flashb
ack/o1_mf_4zxxs99n_.flb"
ORA-27037: unable to obtain file status
Linux Error: 2: No such file or directory
Additional information: 3Investigate the alert log on collabn1 – do any error messages appear here? Do any other problems occur?
You might have to wait for a few minutes. Check the output of "srvctl status database -d RAC" too.Disable flashback database. You do not need to shutdown for the disable operation.
SQL> alter database flashback off;
Database altered.
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