Plesk package install a instance of MySQL. Not sure it's the latest version of MYSQL, if I'd like to install additonal MySQL myself, will it be managed by Plesk? Then how the connection string will be formed? For example, usually, it will be host name, dbname that is used to connect to a instance of MySQL, as it is with Plesk's installation. If I installed additional MySQL instance, how to resolve the host name and dbname? How to differentiate the instance from each other from web program?

I found this may be a good approach than simply use the mysql instance comes with Plesk, that mysql instance is better off kept clean and simple, as it's used by Plesk for whatever the reason.

Although configure and set mysql database/user via plesk is easy, it's mostly for the non-GUI OS. In case of windows, using remote desktop, MySQL.com has a wonderful administrator and query GUI tool set that come close to be on par with Microsoft SQL's. The GUI tool make most of important settng of MySQL a piece of cake now.

Add a new instance of MySQL and tune it to how you want it to be, use a different port number for it, a differnt instance name than "MySQL" used by Plesk's mysql. On command line connection, add --port=xxxx to designate the target instance.

I just have to share this as I am really tired of hearing people telling me MySQL only runs best on Linux. I like Linux but I hate manipulation.

If you run a php web application, use "localhost:port" instead of "localhost" in the mysql host name setting.