Manual:$wgDBTableOptions

Details
MySQL table options to use during installation or update. $wgDBTableOptions will be set in the LocalSettings.php file generated by the installer. You can choose one of the following options resulting in the according values:


 * MySQL binary: ENGINE=InnoDB, DEFAULT CHARSET=binary
 * MySQL UTF-8: ENGINE=InnoDB, DEFAULT CHARSET=utf8
 * MySQL 4.0 backwards-compatible UTF-8: TYPE=InnoDB

No matter which value is selected here, internally MediaWiki always produces data in UTF-8 encoding to be saved in the database, so that a conversion is never needed. Since binary charsets prevent MySQL from doing charset conversions, which otherwise might take place, but are unnecessary, the advised value is "ENGINE=InnoDB, DEFAULT CHARSET=binary".