Problem Description

Oracle 12.2 RAC ADG switchover primary/standby switch.
After the original primary issued alter database switchover to escfsdb;, the new primary started normally.
The new standby (original primary) started MRP and reported the following error:

MRP0:Background Media Recovery terminated with error 46952
2023-09-17T00:09:43.472636+08:00
Errors in file /u01/app/oracle/diag/rdbms/ef/ef1/trace/ef1_pr00_221142.trc:
ORA-46952:standby database format mismtch for password file '+DATAC1/ef/PASSWORD/pwdef.359.1001353187'

Analysis

Primary, DB alert log

Starting ORACLE instance (normal) (OS id: 214994)
2023-09-17T00:08:51.478593+08:00
CLI notifier numLatches:131 maxDescs:5068
2023-09-17T00:08:51.481305+08:00

2023-09-17T00:08:51.481378+08:00
Dump of system resources acquired for SHARED GLOBAL AREA (SGA)

...

2023-09-17T00:09:22.805928+08:00
replication_dependency_tracking turned off (no async multimaster replication found)
Physical standby database opened for read only access.
Completed: ALTER DATABASE OPEN /* db agent *//* {1:25046:29480} */

...

2023-09-17T00:09:42.104231+08:00
Archived Log entry 747327 added for thread 1 sequence 187866 rlc 1001353316 ID 0xf03f7b79 LAD2 :
2023-09-17T00:09:42.454884+08:00
Completed: alter database recover managed standby database using current logfile disconnect from session
2023-09-17T00:09:42.510539+08:00

...

2023-09-17T00:09:43.353601+08:00
Media Recovery Waiting for thread 2 sequence 184825 (in transit)
2023-09-17T00:09:43.357045+08:00
Recovery of Online Redo Log: Thread 2 Group 31 Seq 184825 Reading mem 0
Mem# 0: +DATAC1/ef/ONLINELOG/group_31.443.1011206587
MRP0: Background Media Recovery terminated with error 46952
2023-09-17T00:09:43.472636+08:00
Errors in file /u01/app/oracle/diag/rdbms/ef/ef1/trace/ef1_pr00_221142.trc:
ORA-46952: standby database format mismatch for password file '+DATAC1/ef/PASSWORD/pwdef.359.1001353187' <<<<<<< Here
2023-09-17T00:09:43.474426+08:00
Managed Standby Recovery not using Real Time Apply
2023-09-17T00:09:43.755738+08:00
Clearing online redo logfile 3 complete
Clearing online redo logfile 4 +DATAC1/ef/ONLINELOG/group_4.372.1001353523

This phenomenon of ours is a good match for “Standby Database MRP Fails With ORA-46952: Standby Database Format Mismatch For Password ( Doc ID 2503352.1 )”. The final solution is to copy the password file from the primary database to the standby database.

Solution

1- Rename all password files on standby.
2- Start the archive apply:

SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT FROM SESSION;

3- Copy the password file from production node 1 to standby.
Since version 12.2 is already out of premier support, it is recommended to upgrade to version 19c as soon as possible. Thank you.

REFERENCE INFORMATION

Standby Database MRP Fails With ORA-46952: Standby Database Format Mismatch For Password (Doc ID 2503352.1)