Oracle Database : A Bigfile and Shrink Wishlist

A few days ago I mentioned a couple of new features related to bigfile tablespaces in Oracle database 23ai.

Having played with these new features, a couple of things were added to my wish list.

Convert Smallfile to Bigfile Tablespaces

If would be awesome if we could convert smallfile tablespaces to bigfile tablespaces. At the moment we have to create a new bigfile tablespace and move everything to it. It would be nice if we had some type of simple convert option instead.

I don’t know if this would be possible with some internal jiggery-pokery, or if it would just hide the manual process of moving everything from us. Either way it would be cool.

Being able to convert a smallfile tablespace to bigfile tablespace gives us the option to use the new shrink tablespace functionality, assuming the process of converting didn’t already achieve this for us. 🙂

As much as I like the new bigfile defaults, we don’t create a lot of new databases these days. We are mostly supporting existing databases, so being able to do an easy convert would be really handy.

Smallfile Shrink Tablespace

As much as I love the new shrink tablespace functionality for bigfile tablespaces, I have loads of existing smallfile tablespaces that could benefit from a shrink operation. I know how to manually reclaim free space, as described here, but it is a pain. It would be much better if the shrink tablespace could support smallfile tablespaces as well.

Of course, I’m happy to ignore this if the conversion from smallfile to bigfile tablespaces were possible, as that would solve my issue via a different route. 🙂

Why do I care?

I’m not a fan of randomly shrinking things, but we do get incidents that leave us in a position where a big clean up is necessary. I recently wrote a post called When Auditing Attacks, where I mentioned how we accidentally generated loads of auditing records. Having a no-brainer way to clean this stuff up would be so useful!



The Dunning–Kruger Effect 

I’m starting to feel like the Dunning-Kruger Effect should be mentioned in every piece of media.

What is it?

“The Dunning–Kruger effect is a cognitive bias in which people with limited competence in a particular domain overestimate their abilities.”


I see examples of this all the time and it drives me crazy.

Uneducated People

We have the stereotypes of drunk and lazy students, but the process of deep-diving a subject teaches you a lot more than just that subject. If education is done well it teaches you how to learn. I must admit my undergraduate degree didn’t really teach me to learn. That all happened during my PhD.

I think higher education also gives you a different perspective. At each level of education I realized how simple the previous level was. If I had never experienced the next level, I would never have had this realization. It also made me question what more I might be missing.

Aristotle wrote, “The more you know, the more you realize you don’t know.” The converse of this seems to be true also.

You don’t have to go to university of have this perspective, but it’s rare I see it from people who haven’t.

Educated Idiots

Even educated people can fall prey to the Dunning–Kruger effect. Being educated in one subject doesn’t qualify you as an expert in every other subject. You may have the tools to research a new subject area better than someone with limited education, but have you really done the research, or have you just read the headlines?

In the UK an undergraduate degree is 3 years, and a PhD is a minimum of 3 years. Did you really commit 3-6 years to this new subject you are claiming expertise at? I’m not saying every topic of conversation needs that amount of time and rigor, but you should have enough self awareness to know you have not done the time, so you don’t know what you don’t know.

Despite this some educated people seem to think their PhD qualifies them to speak on any subject as an expert. You see these people doing the rounds on popular podcasts talking like they are a world leading expert on something they have no background in. It drives me nuts.

Critical Thinking

Unfortunately it all comes back to critical thinking, which seems to be sadly lacking in many people. I wrote about this here.


Please just engage your brain. If the people speaking are not self-aware enough to realize they are talking crap, at least you can be self-aware enough to fact check their rubbish.



Fedora 40 and Oracle

Fedora 40 was released over a month ago. Here comes the standard warning.

Here are the usual suspects.

I like messing about with this stuff, as explained in the first link.

I pushed Vagrant builds to my GitHub.

If you want to try these you will need to build a Fedora 40 box. You can do that using Packer. There is an example of that here.

What’s New?

So what’s new with Fedora 40? You can read about it here.