> Read the license. Why is there a "how to buy" page?
Again MySQL Community Edition is free, it is under a GPL which states:
> This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
There are enterprise versions of MySQL that you can pay for. Telling people it is not free is misleading as it is not the case at all.
> mysql has a lot of table types - some work with transactions - some don't. Also weird.
I agree MySQL 5.1 (which came out in 2006) and earlier caused this to be an issue by making MyISAM the default engine however since MySQL 5.5 (2010). InnoDB is the default engine and is ACID compliant.
Each version of MySQL has had leaps and bounds faster subquery optimization, better foreign key support as well as much better query optimization. MySQL 5.6 and 5.7 have narrowed the gap significantly.
I didn't say that I disagree with you, yes PostgreSQL is a fantastic, performs much better and is my go to when I have the option to use it. I am simply saying that if you want to learn the basics which was the point of the post, there are significantly more resources out there for beginners to learn MySQL.
I am not trying to belittle PostgreSQL (again think its fantastic and have used it in many projects) I am simply saying that the question was asked and the volume of resources available make MySQL clear choice.
I found, it is indeed MySQL Anyway I was searching and it must be the community edition, I never paid anything nor had any issues https://www.mysql.com/products/community/ It is licensed under GPL, so I don't see an issue here. Actually I never had problems and I still used the archaic phpmyadmin to manage it
I'm going to disagree with most people here and say to go with MySQL. The documentation is extremely thorough and W3Schools is a great resource.
There's no wrong answer though. If you plan to go down this path, almost any RDMS will work. In the end you will wind up learning most if not all of them, and maybe branch out into programming languages too.
This is where I got started. The community edition. https://www.mysql.com/products/community/