We had several discussions on the internal mailing lists the other day about cloning with Pluggable Databases in Oracle 18c (or 220.127.116.11). And I blogged about this topic a while ago but realized I may need to refresh this a bit.
My example from the old blog post still works fine. But I realized that I switched my database into read-only mode. Hence, I like to repeat it and check different options.
Cloning a 12.1 PDB into Oracle 18c
In the source CDB1 I create a fresh PDB first, then open it and create a cloning user with the necessary privileges.
create pluggable database pdb3 admin user pdb3 identified by pdb3 file_name_convert=('/u02/oradata/CDB1/pdbseed','/u02/oradata/CDB1/pdb3'); alter pluggable database pdb3 open; alter session set container=PDB3; create user hugo identified by hugo; grant create session, create pluggable database to hugo; exit
In the destination CDB2 I create a database link to the source PDB using the user’s context – and then I clone without setting the source into read-only mode. This can be done when my destination CDB2 has LOCAL UNDO on.
create database link sourcedblink connect to hugo identified by hugo using 'PDB3'; create pluggable database CDB2_PDB3 from pdb3@sourcedblink file_name_convert=('/u02/oradata/CDB1/pdb3', '/u02/oradata/CDB2/pdb3'); alter pluggable database CDB2_PDB3 open;
As the CDB2_PDB3 opens with errors only I need to check PDB_PLUG_IN_VIOLATIONS:
column name format a9 column cause format a20 column message format a50 column action format a36 set line 200 set pages 1000 select name, cause, message, action from PDB_PLUG_IN_VIOLATIONS where status<>'RESOLVED' and CON_ID=4 order by time; NAME CAUSE MESSAGE ACTION --------- -------------------- -------------------------------------------------- ------------------------------------ CDB2_PDB1 VSN not match PDB's version does not match CDB's version: PDB's Either upgrade the PDB or reload the version 18.104.22.168.0. CDB's version 22.214.171.124.0. components in the PDB.
Obviously I will have to upgrade my PDB now.
You can find a “howto” here: Unplug a 12.2 PDB and plug into the 18c Cloud
Cloning a 12.1 non-CDB into Oracle 18c
In my DB12 non-CDB source environment I add a cloning user:
create user hugo identified by hugo; grant create session, create pluggable database to hugo;
And then I clone the database directly into a PDB into CDB2. I don’t do the usual compatibility check as it has issues in Oracle 18c.
create database link sourcedblinkDB12 connect to hugo identified by hugo using 'DB12'; create pluggable database CDB2_PDB2 from NON$CDB@sourcedblinkDB12 file_name_convert=('/u02/oradata/DB12','/u02/oradata/CDB2/db12');
Unfortunately this raises an
ORA-65353: The undo tablespace is missing from the XML metadata file error which I found documented nowhere except somebody asking the same question in the Oracle Community.
This is not a bug. The error code is just very misleading. Simple explanation:
You can either clone a PDB that needs to be upgraded or a non-cdb that doesn’t need to be upgraded.
The above steps will certainly work with a same-version non-CDB. I filed a bug to have the error message either changed or more explanatory. And also to have this requirement added to the docs.
Source database has to be:
- at least Oracle 126.96.36.199
- same Endianness
- at the same (equal) version as the container database (this part is not documented)
- and script
noncdb_to_pdb.sqlneeds to be run
- Cloning a PDB from Oracle 12.1 to Oracle 12.2
- Unplug a 12.2 PDB and plug into the Oracle 18c Cloud
- Oracle 18.3.0 Multitenant: Compatibility Check does not work
- Create a PDB directly from a non-CDB
- Bug 28502219 – CREATE PLUGGABLE DATABASE FROM NON$CDB: ORA-65353: THE UNDO TABLESPACE IS MISSIN