techblog 

In theory it should be entirely possible to open your physical standby database read-write, perform some testing and then use Oracle flashback database to get back to being a physical standby again. Unfortunately in a RAC environment things don’t quite go according to the manual:

STANDBY_SQL> CREATE RESTORE POINT pre_test GUARANTEE FLASHBACK DATABASE;

PRIMARY_SQL> ALTER SYSTEM ARCHIVE LOG CURRENT;

STANDBY_SQL> ALTER DATABASE ACTIVATE STANDBY DATABASE;

STANDBY_SQL> ALTER DATABASE OPEN;

WOOPS! This is what we see when attempting this:

ALTER DATABASE  OPEN;

ORA-03113: end-of-file on communication channel

ORA-00600:  internal error code, arguments: [3705], [1], [8], [3], [8]

Fortunately (I think) this is a known issue: Bug 4479323 OPEN RESETLOGS can fail with OERI[3705] in RAC. That is to say it is NOT just related to a physical standby but could be a recovery issue in any RAC database. The workarounds suggested in the Metalink note 4479323.8 did not work for me. This issue is meant to be fixed in 10.2.0.3 which is imminent for Linux x86-64. Unfortunately the one-off patch seems to just be for 10.1.0.4.

I should point out that I was unable to restore the database back to a physical standby and had to completely reinstate it from scratch.