ownCloud is not supported on mac, so there is no testing and if something breaks you are on your own. I would follow the steps for a manual upgrade:
Please note that downgrades are not supported. So do a full backup before that you can go back in case something goes wrong.
In general, performance with mySQL is much better and on Linux I would recommend that if you can install it. As mac is not supported, it could be that one option works better than the other.
Consider migrating to a supported OS, until then avoid all non-standard US-ASCII because there have been several issues with UTF-8 encoding on mac.