As first blog post of this series about Database Migration from non-CDB to PDB – Upgrade, plug in, convert I will explain the most straight forward approach of going to Single- or Multitenant. But you have other options as well. which I’ll showcase in the other blog posts. I demonstrated this technique on the blog already a while ago. But since Oracle 18.104.22.168, there are a few other options available.
High Level Overview
|Endianness change possible:||No|
|Source database versions:||Oracle 22.214.171.124 or newer|
|Characteristic:||Upgrade non-CDB first|
|Upgrade necessary:||Yes, before plugin|
||Upgrade, plugin, copy (optional) and
|Minimal downtime option(s):||Oracle GoldenGate|
|Process overview:||Upgrade to matching version of CDB, then plugin non-CDB as PDB, and finally convert it to a PDB|
|Fallback after plugin:
||Data Pump – optional: Oracle GoldenGate|
Database Migration from non-CDB to PDB – Upgrade, plug in, convert
As of now, you can’t plugin an Oracle 11.2 database. When your source is Oracle 126.96.36.199 or higher, you have more freedom if you’d like to plugin at first, and then upgrade, or if you upgrade first, and then plugin. I prefer the latter solution which I describe in this article for the simple reason that there’s proven fallback for the upgrade case whereas there’s no easy fallback once you plugged in. But I leave it to you to choose your preferred option.
Your non-CDB has a data dictionary. And this data dictionary must be adjusted to match the dictionary version of the receiving CDB. Whether you do this at first or after plugin, is up to you. But here, I will upgrade my 188.8.131.52 and 184.108.40.206 non-CDB databases in our Hands-On Lab at first. And of course, I will use the AutoUpgrade. If you plan to do this exercise without the new AutoUpgrade, you can either follow my blog post or one of the use case scenarios in the Oracle Documentation.
autoupgrade.jar I’m using the following config file:
global.autoupg_log_dir=/home/oracle/logs upg1.dbname=DB12 upg1.start_time=NOW upg1.source_home=/u01/app/oracle/product/220.127.116.11 upg1.target_home=/u01/app/oracle/product/19 upg1.sid=DB12 upg1.log_dir=/home/oracle/logs upg1.upgrade_node=localhost upg1.target_version=19 upg2.dbname=FTEX upg2.start_time=NOW upg2.source_home=/u01/app/oracle/product/18.104.22.168 upg2.target_home=/u01/app/oracle/product/19 upg2.sid=FTEX upg2.log_dir=/home/oracle/logs upg2.upgrade_node=localhost upg2.target_version=19
Following best practices, I’m running the
analyze mode at first, followed by
java -jar $OH19/rdbms/admin/autoupgrade.jar -config DB12_FTEX.cfg -mode analyze java -jar $OH19/rdbms/admin/autoupgrade.jar -config DB12_FTEX.cfg -mode deploy
An hour later, my two databases,
DB12, are both upgraded to Oracle Database 19c and ready to be plugged in.
Plugin Check Operation
For the plugin operation, I need to create an XML manifest file. Once the XML manifest file has been created, I can connect to my CDB and plug in
I will have to repeat the same step with the DB12 database.
Once I created the two XML manifest files, I need to execute the recommended plugin-compatibility check in my CDB.
set serveroutput on DECLARE compatible CONSTANT VARCHAR2(3) := CASE DBMS_PDB.CHECK_PLUG_COMPATIBILITY( pdb_descr_file => '/home/oracle/FTEX.xml', pdb_name => 'FTEX') WHEN TRUE THEN 'YES' ELSE 'NO' END; BEGIN DBMS_OUTPUT.PUT_LINE('Is the future PDB compatible? ==> ' || compatible); END; /
A typical result is this here in the lab:
SQL> start ftex_compatible.sql Is the future PDB compatible? ==> YES PL/SQL procedure successfully completed. SQL> start db12_compatible.sql Is the future PDB compatible? ==> NO PL/SQL procedure successfully completed.
One gets a “
FTEX), the other one a “
DB12). You will need to check now PDB_PLUG_IN_VIOLATIONS for the reason why
DB12 is not compatible to be plugged into
CDB2. I use this query to check what I need to fix:
set pages 2000 column message format a50 column status format a9 column type format a9 column con_id format 9 column name format a8 select con_id, name, type, message, status from PDB_PLUG_IN_VIOLATIONS where status<>'RESOLVED' order by name,time;
And the result is interesting:
CON_ID NAME TYPE MESSAGE STATUS ------ -------- --------- -------------------------------------------------- --------- 1 DB12 WARNING PDB plugged in is a non-CDB, requires noncdb_to_pd PENDING b.sql be run. 1 DB12 ERROR Database option CATJAVA mismatch: PDB installed ve PENDING rsion 22.214.171.124.0. CDB installed version NULL. 1 DB12 ERROR Database option JAVAVM mismatch: PDB installed ver PENDING sion 126.96.36.199.0. CDB installed version NULL. 1 DB12 ERROR Database option ORDIM mismatch: PDB installed vers PENDING ion 188.8.131.52.0. CDB installed version NULL. 1 DB12 ERROR Database option XML mismatch: PDB installed versio PENDING n 184.108.40.206.0. CDB installed version NULL. 1 DB12 WARNING CDB parameter sga_target mismatch: Previous 1200M PENDING Current 1504M 1 DB12 WARNING CDB parameter compatible mismatch: Previous '12.2. PENDING 0' Current '19.0.0' 1 DB12 WARNING CDB parameter _fix_control mismatch: Previous '201 PENDING 07874:1', '23249829:1', '25120742:1', '25405100:1' , '25476149:1', '26019148:1', '26423085:1', '26536 320:1', '26986173:1', '27321179:1', '27466597:1', '28072567:1' Current NULL 1 DB12 WARNING CDB parameter pga_aggregate_target mismatch: Previ PENDING ous 120M Current 200M 1 FTEX WARNING PDB plugged in is a non-CDB, requires noncdb_to_pd PENDING b.sql be run. 1 FTEX WARNING Database option OLS mismatch: PDB installed versio PENDING n NULL. CDB installed version 220.127.116.11.0. 1 FTEX WARNING Database option OWM mismatch: PDB installed versio PENDING n NULL. CDB installed version 18.104.22.168.0. 1 FTEX WARNING CDB parameter sga_target mismatch: Previous 1104M PENDING Current 1504M 1 FTEX WARNING CDB parameter compatible mismatch: Previous '11.2. PENDING 0.4.0' Current '19.0.0' 1 FTEX WARNING CDB parameter pga_aggregate_target mismatch: Previ PENDING ous 120M Current 200M
Quite a long list. For
FTEX I received only
WARNINGs. But the
ERROR conditions for
DB12 will block the plugin operation. You see that these are serious errors. The CDB does not contain options which exist in DB12. I could now either install these options into CDB2 – or I remove them from DB12. I remove them following these ideas. Installing them into my CDB may have implications on future PDBs. But before removing these options you should check if the components are in use.
Once I removed the components ORDIM, JAVA and XML from my DB12 database, I create the manifest file again and repeat the compatibility check:
SQL> start db Is the future PDB compatible? ==> YES PL/SQL procedure successfully completed.
I can safely ignore the other warnings except the one which tells me to execute
Now, as everything seems to be ok, I can login to my CDB and plug both databases in:
create pluggable database FTEX using '/home/oracle/FTEX.xml' file_name_convert=('FTEX','CDB2/FTEX'); create pluggable database DB12 using '/home/oracle/DB12.xml' file_name_convert=('DB12','CDB2/DB12');
SQL> show pdbs CON_ID CON_NAME OPEN MODE RESTRICTED ---------- ------------------------------ ---------- ---------- 2 PDB$SEED READ ONLY NO 4 FTEX MOUNTED 5 DB12 MOUNTED
I will open the PDBs but they will open
RESTRICTED only of course as they need to assimilated as “real” PDBs.
SQL> alter pluggable database all open; Warning: PDB altered with errors. SQL> show pdbs CON_ID CON_NAME OPEN MODE RESTRICTED ---------- ------------------------------ ---------- ---------- 2 PDB$SEED READ ONLY NO 4 FTEX READ WRITE YES 5 DB12 READ WRITE YES
I did not specify any command option such as
NOCOPY with the
create pluggable database command. Hence, the default –
COPY – will be used. This has the advantage of keeping my source untouched in case anything fails during the plugin operation. But the downside clearly is that I need twice as much disk space. And in case the database is large, the
COPY operation may take longer.
SQL> select con_id, file_name, tablespace_name from cdb_data_files order by con_id, relative_fno; CON_ID FILE_NAME TABLESPACE ------ ------------------------------------------ ---------- 1 /u02/oradata/CDB2/system01.dbf SYSTEM 1 /u02/oradata/CDB2/sysaux01.dbf SYSAUX 1 /u02/oradata/CDB2/undotbs01.dbf UNDOTBS1 1 /u02/oradata/CDB2/users01.dbf USERS 2 /u02/oradata/CDB2/pdbseed/system01.dbf SYSTEM 2 /u02/oradata/CDB2/pdbseed/sysaux01.dbf SYSAUX 2 /u02/oradata/CDB2/pdbseed/undotbs01.dbf UNDOTBS1 4 /u02/oradata/CDB2/FTEX/system01.dbf SYSTEM 4 /u02/oradata/CDB2/FTEX/sysaux01.dbf SYSAUX 4 /u02/oradata/CDB2/FTEX/users01.dbf USERS 4 /u02/oradata/CDB2/FTEX/undotbs100.dbf UNDOTBS100 5 /u02/oradata/CDB2/DB12/system01.dbf SYSTEM 5 /u02/oradata/CDB2/DB12/sysaux01.dbf SYSAUX 5 /u02/oradata/CDB2/DB12/undotbs01.dbf UNDOTBS1 5 /u02/oradata/CDB2/DB12/users01.dbf USERS
Another positive side effect of the
COPY operation: The files will be under one directory tree. Of course you could move them afterwards with the online datafile move feature we include since Oracle 22.214.171.124. as well.
The final part of the entire migration is the execution of
noncdb_to_pdb.sql. Unfortunately the runtime of this once-in-a-lifetime-of-a-database script is unpredictable. It depends a lot on the dictionary content and especially on the objects requiring recompilation.
SQL> alter session set container=FTEX; Session altered. SQL> set timing on SQL> set serverout on SQL> set echo on SQL> set termout on SQL> spool /home/oracle/logs/ftex_noncdbtopdb.log SQL> start ?/rdbms/admin/noncdb_to_pdb.sql
In my example it takes almost exactly 10 minutes for each database to complete.
Be aware that these are only toy databases with no user data in it.
STARTUP the PDBs as
noncdb_to_pdb.sql puts them into
RESTRICTED mode again after completion.
SQL> show pdbs CON_ID CON_NAME OPEN MODE RESTRICTED ---------- ------------------------------ ---------- ---------- 2 PDB$SEED READ ONLY NO 4 FTEX READ WRITE NO 5 DB12 READ WRITE NO
An important topic you need to plan for in all your upgrade and migration tasks are the various fallback opportunities. In the above case, for the upgrade itself, the fallback is very straight forward. When you use the AutoUpgrade and your database is in
ARCHIVELOG mode, then a guaranteed restore point (GRP) gets created. You can easily flashback. Or you can downgrade in case you deleted the GRP and went live. As long as
COMPATIBLE remains on the pre-upgrade value, downgrade is a viable and fast option.
But as soon as you invoke the plugin command, there is no easy fallback. Hence, you need to test this carefully. As you see, in the above plugin operation I didn’t specify
NOCOPY on purpose. This mean, all my files get copied to the destination defined in
COPY is the default and the safer command here in this case. Your source database remains untouched in case the plugin or any subsequent operation fails.
Another pitfall you should be aware of – and it happens in our Hands-On Lab as well:
Once I plugin, the only AFTER upgrade fallback is an export and import with Oracle Data Pump. Transportable Tablespaces can’t be used as TTS works only within the same or to a higher version. If you seek for minimal downtime you can use Oracle GoldenGate on top. I’m not aware of any other fallback options once you started production on the plugged in PDB.
Further Information and Links
- The new AutoUpgrade Blog Post Series
- Oracle Database 19c Hands-On Lab
- Hand-On Lab: Plugin UPGR into CDB2
- Plugin 18c – Compatibility Check does not work – August 14, 2018
- Cloning with Pluggable Database in 18c – August 16, 2018
- noncdb_to_pdb.sql – Why does it take so long – June 8, 2017
- Upgrade to Oracle Database 12.2 and plugin into a 12.2 CDB – March 8, 2017
- 9 Upgrade and Migration Scenarios – August 1, 2018
Typical Plugin Issues and Workarounds
- Typical Plugin Issues and Workarounds
- The Compatible Pitfall
- The Time Zone Pitfall
- The Component Pitfall
- The Patch Level Pitfall
- Various Pitfalls
- The Fallback Challenge
- The Minimal Downtime Challenge
- Upgrade, plug in, convert (noncdb_to_pdb.sql) – 126.96.36.199 and higher
- Plugin, upgrade, convert (noncdb_to_pdb.sql) – 188.8.131.52 and higher
- Clone via NON$CDB, upgrade, convert – 184.108.40.206 and higher