According to docs/database.txt (thanks Tim for writing this useful text), database reads should use wfGetDB( DB_SLAVE ). However, when browsing through the code, I found the following definition of Article::getDB() : /** * Get the database which should be used for reads * * @return Database */ function &getDB() { $ret =& wfGetDB( DB_MASTER ); return $ret; } As far as I can see, the Database object returned by this function is used to load the contents of the article. Why is DB_MASTER used instead of DB_SLAVE? Jitse