SQL> ALTER DATABASE CLEAR LOGFILE GROUP 5;
ALTER DATABASE CLEAR LOGFILE GROUP 5
*
ERROR at line 1:
ORA-19527: physical standby redo log must be renamed
ORA-00312: online log 5 thread 0: '/u01/app/oracle/oradata/PRODPRIM/stndby2.log'

Cause of Issue:-
This issue occurs when we don't set log_file_name_convert parameter in the standby database
SQL> sho parameter log_file

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
log_file_name_convert                string

Resolution:-
Set the LOG_FILE_NAME_CONVERT parameter in spfile
SQL>  alter system set LOG_FILE_NAME_CONVERT='/u01/app/oracle/oradata/PRODPRIM/','/u01/app/oracle/oradata/PRODPRIM/' scope=spfile;

System altered.

Shutdown the database
SQL> shu immediate
ORA-01109: database not open
Database dismounted.
ORACLE instance shut down.
Mount the standby database
SQL> startup mount
ORACLE instance started.

Total System Global Area  839282688 bytes
Fixed Size                  2217992 bytes
Variable Size             494929912 bytes
Database Buffers          339738624 bytes
Redo Buffers                2396160 bytes
Database mounted.
 
SQL> ALTER DATABASE CLEAR LOGFILE GROUP 5;

Database altered.