> ... if dual-licensed GPL was the best way to go, it wouldn't be the case that entities outside of MySQL/Oracle (e.g. AWS) were capturing a huge amount of MySQL's value/revenue ... Why else would development be shifted to the managed-service-only, closed-source MySQL Heatwave product?

And do you realise that you are comparing corporates with two completely different philosophies and business model? It's absolutely in character for Oracle to use the loophole in the older GPL (that has since been fixed by the AGPL) to try to make MySQL closed-source again by offering it through a SaaS infrastructure. Oracle has never been a champion of the opensource movement, while the original owners of MySQL were. It is the same with IBM, who are now the owners of Red Hat Linux. And that shows in how they ran / run their business.

We are discussing about opensource software business models only. Not open-source and closed-source ones (it should be a no-brainer that closed-source software business models are the most successful and profitable ones).

> I mentioned several concerns specifically about MariaDB in my previous reply and you did not address those at all.

Simply because it is irrelevant to our discussion. The success or failures of MySQL or MariaDB or Oracle's MySQL was/is not just solely because of its license and there are many other factors behind it (for example, MariaDB earned a lot of scorn from open source developers because they felt betrayed after its original source - MySQL - ended up in Oracle's hand). Nevertheless, MySQL is a great example of a commercially successful example of a dual-licensed GPL product.

I have enough business experience, and a good understanding of open source software to understand its strength and limitation in a commercial setting. Honestly, you do need a lecture for not being able to see the obvious:

1. As per your own confessions, a competitor was able to use your open source code without sharing subsequent work on the codebase. This would obviously have never happened with the AGPL license, as the license compels others who distribute the software (even as SaaS) to share the source code.

2. You tried to change the codebase and / or license to make it more difficult for them to fork your code and use it. This shows your own confusion regarding the open source philosophy and your business model. Your code was used by others in the spirit of the open source license you chose. And yet, you continue to assert you are the wronged party?

3. It is also easy to see that you (wrongly) chose a permissive opensource license out of self-interest to your business (hoping to attract more developer contributions and then close source the product later when it becomes profitable, just as your competitor did) than out of an equal commitment to the open source philosophy. Your competitor outwitted you because you weren't knowledgable about licenses, your own business goals and business model.