mysql数据库

Question

could you guys please explain for me HOW these databases ARE CREATED :

• mysql
• phpmyadmin
• information_schema
• performance_schema

I know it's a novice question, I might GUESS the answer for some of them, for example "the reason phpmyadmin database is created" IS because I installed phpmyadmin and this database was created alongside . That's not for sure, so I just need some clarification.

Thank you !

Answer 1

Mysql is a database server. It serves access to databases. It runs on a machine as a service.

Phpmyadmin is a php based tool you install for managing mysql from a web page.

The last two are databases that can be created by an application, such as phpmyadmin, for storing schema information about the rest of the database or tables of a database.

Answer 2

These are the standard set of databases shown when you execute SHOW DATABASES on a clean MySQL install.

• mysql - this is created at install of the MySQL server, either by the package management system of your operating system or the script provided as part of the MySQL package
• information_schema - meta database, it does not exist on the disk
• performance_schema - meta database, but it does store some files on the disk

Any other databases are user/application created.