I’ve already shown you how to upgrade a single PDB to Oracle AI Database 26ai using refreshable clone PDB.

But what about Data Guard? Refreshable clone PDB supports only deferred recovery, which means I must restore the PDB after the upgrade.

Let’s see how it works.

Upgrade

For the upgrade, I follow the procedure for a non-Data Guard upgrade.

• In my AutoUpgrade config file, I must either:
  • Omit manage_standbys_clause.
  • Or, set it to manage_standbys_clause=none.
• Both methods trigger AutoUpgrade to plug in with deferred recovery, which is the only supported option when using refreshable clone PDB.

Once the upgrade completes, I can proceed and restore the PDB to my standby database.

Standby Database

• I execute all commands on the same host – the standby system.

• On the standby, I verify that recovery status is disabled:

  SQL> select open_mode, recovery_status
       from v$pdbs where name='NEWPDB1';
  
  OPEN_MODE    RECOVERY_STATUS
  ____________ __________________
  MOUNTED      DISABLED
  

  • This means that I plugged in with deferred recovery.
  • The standby is not protecting this PDB.

• Next, I connect to the standby using RMAN, and I restore the PDB:

  connect target /
  run{
     allocate channel disk1 device type disk;
     allocate channel disk2 device type disk;
  
     set newname for pluggable database NEWPDB1 to new;
  
     restore pluggable database NEWPDB1
        from service <primary_service>
        section size 64G;
  }
  

  • You can add more channels depending on your hardware.
  • Replace NEWPDB1 with the name of your PDB.
  • <primary_service> is a connect string to the primary database.

• Next, I connect to the standby database using Data Guard broker and turn off redo apply:

  edit database <stdby_unique_name> set state='apply-off';
  

• Back in RMAN, still connected to the standby, I switch to the newly restored data files:

  switch pluggable database NEWPDB1 to copy;
  

• Then, I connect to the standby and generate a list of commands that will online all the data files:

  alter session set container=NEWPDB1;
  select 'alter database datafile '||''''||name||''''||' online;' from v$datafile;
  

  • Save the commands for later.
  • There should be one row for each data file.

• If my standby is an Active Data Guard, I must restart it into MOUNT mode.

  alter session set container=CDB$ROOT;
  shutdown immediate
  startup mount
  

• Now, I can re-enable recovery and online the data files:

  alter session set container=NEWPDB1;
  alter pluggable database enable recovery;
  alter database datafile <file1> online;
  alter database datafile <file2> online;
  ...
  alter database datafile <filen> online;
  

  • I must connect to the PDB.
  • I must execute the alter database datafile ... online command for each data file.

• I turn on redo apply:

  edit database <stdby_unique_name> set state='apply-on';
  

• At this point, the standby protects my PDB.

• After a minute or two, I check the Data Guard config:

  validate database <stdby_unique_name>;
  

• Once my standby is in sync, I can do a switchover as the ultimate test:

  switchover to <stdby_unique_name>;
  

• Now, I connect to the new primary and ensure the PDB opens in read write mode and unrestricted:

  select open_mode, restricted
  from v$pdbs
  where name='NEWPDB1';
  
  OPEN_MODE     RESTRICTED
  _____________ _____________
  READ WRITE    NO
  

• You can find the full procedure in Making Use Deferred PDB Recovery and the STANDBYS=NONE Feature with Oracle Multitenant (KB90519). Check sections Steps for Preparing to enable recovery of the PDB and Steps required for enabling recovery on the PDB after the files have been copied.

That’s It!

Refreshable clone PDB is a great way of upgrading a single PDB. It’s very easy, but you must take care of your standby afterward.

Check the other blog posts related to upgrade to Oracle AI Database 26ai.

Happy upgrading!

Appendix

Multiple Standby Databases

You must restore the PDB to each standby database.

If you have multiple standby databases, it’s a lot of work for the primary to handle the restore pluggable database command from all standbys.

Imagine we have three standby databases. Here’s an alternative approach:

• First, Standby 1 restores from primary.
• Next, standby 2 restores from standby 1.
• At the same time, standby 3 restores from primary.
• This spreads the load throughout your databases, allowing you to complete faster.

What If My Database Is Encrypted

AutoUpgrade handles the keys in the primary database.

After the upgrade, but before you begin the restore, you must copy the database keystore from the primary to the standby.

What If My Database Is A RAC Database?

Works on Oracle RAC Database as well.