Do you remember? At OOW 2019 in San Francisco, we announced that Oracle Database 20c will be the first CDB-only database release. But at this time we didn’t present this in written form. We told you, once the Oracle Database 20c documentation is available, you will see it. Oracle Database 20c – The first CDB-only release.
Oracle 20c is the first CDB-only release
Typically you will find deprecation and desupport notes in the Database Upgrade Guide. And there you will see also this note:
Starting with Oracle Database 20c, installation of non-CDB Oracle Database architecture is no longer supported.
The non-CDB architecture was deprecated in Oracle Database 12c. It is desupported in Oracle Database 20c. Oracle Universal Installer can no longer be used to create non-CDB Oracle Database instances.
What does this mean for you?
At first, most of you will move to Oracle Database 19c right now. So you may not care about Oracle Database 20c yet. In Oracle Database 19c, the non-CDB and the CDB architecture stand side-by-side, you can choose either one. And since Oracle Database 19c, 3 PDBs are included. Just make sure you use
max_pdbs=3 in your SPFILE.
Hence, nothing changes right now.
As of now, MOS Note:742060.1 – Release Schedule of Current Database Releases hasn’t been updated yet. But it is expected that Oracle 20c will get only a shorter support time frame as the terminal release of the release family. I assume that you will consider 20c only to test out certain development features but you will target the next terminal release of the 20c family as the one you will upgrade to.
But when you attempt this move, this means you will migrate your database unless it isn’t a CDB/PDB already. And when you plan this, please browse through the blog posts I wrote a few months ago. Some things may need extra consideration. And I may extend the list of things to know over time.
I just would like to quote Tim Hall here:
Further Information and Links
- Oracle Database 20c – Documentation and Cloud availability
- 3 PDBs included – and non-CDB architecture desupported
- Database Migration from non-CDB to PDB – An Overview
- Upgrade, plug in, convert (noncdb_to_pdb.sql) – 184.108.40.206 and higher
- Plugin, upgrade, convert (noncdb_to_pdb.sql) – 220.127.116.11 and higher
- Clone via NON$CDB, upgrade, convert – 18.104.22.168 and higher
- 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