Oracle Database 21c : It’s New to Everyone

A few days ago Oracle made the official announcement about the release of Oracle database 21c (here). This was a rather late announcement, as the product has been available on Oracle Cloud for over a month, but that’s not the subject of this post.

With each new release I feel the need to write a post like this, so here goes…


This is a new product, so there will be a lot of people in the community writing content about it, including me. The one thing common to all those people, including me, is none of us have any real experience of this version of the database. Very few, if any, will use this version in anger for a real production system for quite some time, if ever (see innovation release). Does that mean you should ignore the content being produced at the moment? No. You just have to understand that everyone is a newbie at the moment. It will take some time for people to not only understand the basics of the functionality, but also get a feel for its relevance in the real world. Just keep that in mind.

But what about the people that were using the new features in the 20c preview release on the cloud for a year? Yep. They are all beginners too. The preview release of 20c never became generally available, so nobody got something I would consider “production experience” on that release. Even the folks at Oracle don’t have significant production experience of 21c yet. It’s only been a month. Many of the 21c new features were initially showcased in the 20c preview, but things have changed since then, so it’s likely articles you are reading that were based on 20c are out of date and need revision.

I’m not saying all this to be negative. I guess part of it is a self-protection mechanism. People will be producing content now, and as they get more experience they will hopefully revise that content to reflect their current understanding. Don’t expect to find any 21c gurus for a long time… 🙂

When will we get 21c on-prem?

The current cloud-first release of 21c is 21.1. That will bump up to 21.2 with the January patches, and 21.3 with the April patches. If we look at what happened for 18c and 19c, both were released on-prem at version X.3 some time after the release of the April patches. It’s a fair guess to say something similar will happen for 21c.

Going back to the “production experience” argument, many people won’t even start their learning experience of 21c until the on-prem version drops, even though you can get a free-tier version of 21c on Oracle Cloud today!

21c is an innovation release

Another thing to consider is 21c is an innovation release. Many people will never use this version of the database. Instead they will wait for the next long term support (LTS) release, which is likely to be Oracle 23c. Many companies can’t cope with a yearly release cycle, and will prefer to jump between LTS releases. That means you could be on 19c for another 2.5 years before you get an opportunity to move to the next on-prem LTS release. In that time features we are writing about today may have evolved substantially.

Does that mean there’s no point learning about 21c now? No. The more you know about what’s coming, the more you can prepare for it. There will be a lot to learn between 19c and 23c, so it’s better to gradually soak it up as you go along. You may also see something that makes the jump to 21c worthwhile for a specific project. I know at least one project at work that will benefit from being at 21c ASAP.

19c is where you need to be now!

Your immediate focus should be to get all your systems on to 19c, and get them all migrated to the multitentant architecture. The non-CDB architecture was deprecated in, and is desupported (that means gone) in 21c onward. If you don’t get used to the multitenant architecture now, you are going to make life really hard for yourself when you move to 23c for long term support.

Now is the time to act.

Every upgrade is potentially unique, but I have some upgrade articles that might help.

If you are new to the multitenant architecture, I’ve written a lot about it, and have a playlist on my YouTube channel.

What next?

Get playing with 21c. Learn what you love. Avoid what you dislike. Most of all, make as much noise as possible, but try to keep it constructive. Most companies are a bit short sighted where their own products are concerned. They need external people to shake them out of their navel-gazing from time to time. That’s true of Oracle as well. My first few 21c articles have resulted in people from Oracle contacting me, then raising bugs/enhancements. There are plenty of people inside Oracle who want to engage and make their products better. Help them help us!