MySQL


 * MySQL: the Comic Sans of databases. Except Comic Sans has uses.
 * -- David Gerard

MySQL is a popular open-source database system using the SQL query language. Its files are traditionally stored with the field definitions in .frm files, the data in .myd files, and indexes in .myi files. The newer InnoDB storage engine replaces the .myd and .myi files with a shared "ibdata1" file, and in most cases an .ibd file for each database.

UTF-8 in MySQL
To use the proper UTF-8 standard for character encoding, you need to designate the character set parameter as utf8mb4, because the more appropriate 'utf8' was already used to designate a subset of this standard which encompasses only the BMP characters (in the range U+0000 to U+FFFF), not the supplementary characters at higher code points, which take four bytes to express in UTF-8.

File format information

 * .frm files (archived)
 * .myd and .myi files (archived)

Other links

 * Wikipedia article
 * Official site
 * Why MySQL is not my favourite database.
 * Do Not Pass This Way Again