DBA Maestro - Helpful DBA tips

I was recently involved in DR testing involving two standby databases.  For the testing, I simply converted the 2 standby databases from physical standbys to snapshot standbys.   After the testing had ended from an application perspective, I started to convert the standby databases from snapshot standby back to physical standby.  In the process of doing so, I received the following ORA-0600 error. SQL > ALTER DATABASE CONVERT TO PHYSICAL STANDBY * ERROR at line 1: ORA-00600: internal error code, arguments: [krhahws_02], [], [], [], [], [], [], [], [], [], [], [] Oh no!  Never fear, I thought...  I went to Oracle Support to research this issue and found the following resolution: 1. set disk_asynch_io=FALSE in the init.ora (this setting is just going to be temporary for repeating the "flashback database"). 2. shutdown then "startup mount" the database, to pick up the new parameter setting for disk_asynch_io 3. verify the disk_a...

Completing full backup/restore from RMAN backup or cold backup should now be a "thing of the past" due to flashback technology.  It is highly suggested to create a guaranteed restore point (GRP) in 10g/11g Oracle database without enabling flashback logging; the reason this would be beneficial is if you are not concerned with being able to flashback the database to a particular point-in-time AFTER the GRP was setup in the database.  If you would like to be able to flashback the database to any point in time AFTER the GRP was setup in the database, you WOULD need to enable flashback logging. Both GRP without flashback logging and flashback logging will generate flashback logs; however, without flashback logging enabled, the amount of flashback logs will be much less and much smaller than if flashback logging were enabled. Starting with Oracle 11gR2, you can now enable/disable flashback logging and create/drop GRPs at will WITHOUT requiring a database outage. I will go...

Flashback database and backup scenario: ------------------------------------------------ If you flashback a database to a GRP (Guaranteed Restore Point) that has been set in the database, all backups that were taken after the GRP was created can no longer be used.  You can however restore the database to a point in time prior to the GRP creation. SQL> shutdown immediate startup mount flashback database to restore point TEST; Total System Global Area  384143360 bytes Fixed Size                  2154016 bytes Variable Size             301990368 bytes Database Buffers           75497472 bytes Redo Buffers                4501504 bytes Database mounted. SQL> Flashback complete. SQL> alter database open resetlogs; Database altered. Now you can restore and recover the database from any backup taken BEFORE the GR...