Relational MySQL
When application developers use PHP and MySQL to build web interfaces or other data manipulation applications, they usually establish relations between tables using the underlying SQL queries. Examples of this would be queries to "get an invoice and all its items" and "get all books by an author".
In the earlier versions of phpMyAdmin, the relational data structure (how tables relate to each other) was not stored within MySQL. Tables were programmatically joined by the applications to generate meaningful results.
This was considered a shortcoming of MySQL by phpMyAdmin developers and users. Therefore, the team started to build an infrastructure to support relations for MyISAM
tables, which is now called the phpMyAdmin configuration storage. The infrastructure evolved to support a growing array of special features such as query bookmarks and MIME-based transformations.
Now-a-days, relations between tables are normally defined natively with the FOREIGN KEY
feature of the InnoDB...