APPLIES TO:

Oracle Database - Enterprise Edition - Version 12.1.0.1 and later
Information in this document applies to any platform.
GOAL

Running 12c database and need to configure archive log, shall we configure it in PDB or CDB?

SOLUTION

All PDBs share the same redo log files, so it‘s not possible to enable archivelog mode only for a specific PDB. 
All PDBs share the archivelog mode of CDB.
Remember that PDBs themselves don‘t have a dedicated instance (processes and memory areas) so they share CDB‘s ones.

Configuring of archivelog mode should be implemented in CDB.

For more details on how to configure this feature, please refer to below doc:

測試
<roidb01:cdb1:/home/oracle>$sqlplus / as sysdba

SQL*Plus: Release 12.1.0.2.0 Production on Sat Mar 10 12:34:59 2018

Copyright (c) 1982, 2014, Oracle.  All rights reserved.

Connected to:
Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production
With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options

SQL> show pdbs

    CON_ID CON_NAME                       OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
         2 PDB$SEED                       READ ONLY  NO
         3 PDB11                          READ WRITE NO

SQL> 
SQL> archive log list;
Database log mode              No Archive Mode
Automatic archival             Disabled
Archive destination            /u01/app/oracle/product/12.1.0/dbhome_1/dbs/arch
Oldest online log sequence     32
Current log sequence           34
SQL> 
SQL> alter system set log_archive_dest_1=‘location=/u01/app/oracle/product/12.1.0/dbhome_1/dbs/arch‘;

System altered.

SQL> archive log list;
Database log mode              No Archive Mode
Automatic archival             Disabled
Archive destination            /u01/app/oracle/product/12.1.0/dbhome_1/dbs/arch
Oldest online log sequence     32
Current log sequence           34
SQL>     

SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount;
ORACLE instance started.

Total System Global Area 1174405120 bytes
Fixed Size                  2923680 bytes
Variable Size             436208480 bytes
Database Buffers          721420288 bytes
Redo Buffers               13852672 bytes
Database mounted.
SQL> alter database archivelog ;

Database altered.

SQL> alter database open;

Database altered.

SQL> 

SQL> alter system switch logfile;

System altered.

SQL> !ls -l /u01/app/oracle/product/12.1.0/dbhome_1/dbs/arch
total 4
-rw-r----- 1 oracle oinstall 1024 Mar 10 17:37 1_35_965910550.dbf

SQL> 

SQL> show pdbs

    CON_ID CON_NAME                       OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
         2 PDB$SEED                       READ ONLY  NO
         3 PDB11                          MOUNTED
SQL> alter session set container=PDB11;

Session altered.

SQL> archive log list;
Database log mode              Archive Mode
Automatic archival             Enabled
Archive destination            /u01/app/oracle/product/12.1.0/dbhome_1/dbs/arch
Oldest online log sequence     34
Next log sequence to archive   36
Current log sequence           36
SQL> alter system switch logfile;
alter system switch logfile
*
ERROR at line 1:
ORA-65040: operation not allowed from within a pluggable database
 

CDB or PDB打開歸檔