Activate Physical Standby Database for Read/Write for Testing with Flashback to Restore Point 

Activate the standby 

Oracle Standby testing 

Oracle Standby failover
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-- On Standby

ALTER SYSTEM SET DB_RECOVERY_FILE_DEST_SIZE=25G;
ALTER SYSTEM SET DB_RECOVERY_FILE_DEST='/u01/app/oracle/flashback';
ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL;
CREATE RESTORE POINT db_standby_test GUARANTEE FLASHBACK DATABASE;
select NAME,SCN,TIME from v$restore_point;
-- On Primary for testing 
ALTER SYSTEM ARCHIVE LOG CURRENT;
ALTER SYSTEM SET LOG_ARCHIVE_DEST_STATE_2=DEFER; 
-- On Standby 
select NAME,SCN,TIME from v$restore_point;
* Activate standby 
ALTER DATABASE ACTIVATE STANDBY DATABASE;
select CONTROLFILE_TYPE from v$database;
ALTER DATABASE SET STANDBY DATABASE TO MAXIMIZE PERFORMANCE;
-- On Standby
STARTUP MOUNT FORCE;
FLASHBACK DATABASE TO RESTORE POINT db_standby_test;
select controlfile_type from v$database;
ALTER DATABASE CONVERT TO PHYSICAL STANDBY;
STARTUP MOUNT FORCE;
ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT;
select controlfile_type from v$database;
-- On Primary
ALTER SYSTEM ARCHIVE LOG CURRENT;
ALTER SYSTEM SET LOG_ARCHIVE_DEST_STATE_2=ENABLE;