Manual:$wgDBconnection/ja

詳細
DefaultSettings.php 内で '' を設定されていますが、まったく使用されていません.

It was used to store a MySQL link identifier (return value of mysql-connect).

Since MediaWiki 1.2, this variable was unused.

In MediaWiki 1.17 (a060794480fe), it was removed from DefaultSettings.php.