- You can not use the MSI installer to install two MySQL servers on the same box. If the installer seems an old installation, it insists on upgrading it if you are installing a newer version, and if you are installing an older version, well, that will be refused.
- You cannot, using the MSI installer, install both 32 and 64-bit versions on the same box. If you try that, even if the versions are the same, the second install insists that what you have already installed is newer than the one you are installing, although the have the same version number, but one is 32 bit and one is 64 bit.
- In the Instance configurator when it comes to the data directory location, if you select "Installation path" you might think that the data directory will be placed where you are installing MySQL right now. Think again, this is not so. What this means is that if you install MySQL on the box, and MySQL hasn't been installed there before, then Installation path means just that, So let's assume that you choose to install MySQL in C:\foo, then the data directory will be C:\foo\data. Which is fine. If you then uninstall this version of MySQL and then install some other version of it, this time in, say, C:\bar, then you would image that the data directory would be C:\bar\data, but it will still be C:\foo\data. I'm not sure where this is stored, but it is somewhere and it's really annoying.
Will the MySQL Installer help then? That is a 201 Mb package that contains, according to the download page "All MySQL Products. For all Windows Platforms. In one package." Right, that should do the trick then? Nope, once you have made the choice to install MySQL Server, be it 32 or 64 bit, you can only install one of them.
Look, I'm trying hard not to be a grumpy old man here, but it is difficult (partly because I'm getting old I guess). I am aware that I can always download and unpack the ZIP archive (which is what I will do now), but please folks, this is on Windows and I'd rather stay away from that on that platform. And Oracle / MySQL took the effort to create not just one, but 2 installers, but none of them allow you to install 2 MySQL servers on the same machine, which is too bad.
And by the way, no just because I am installing MySQL and then uninstalling it, and then installing it again, doesn't mean I want to use the same data. It just doesn't.
And I am afraid that if you think MariaDB is any better, think again, that is NOT the case. Too bad.