InnoDB (and MyISAM) has been the backend MySQL engine up until now, but Oracle’s purchase of InnoDB could threaten that. MySQL has wasted little time in search for replacement options. InnoDB is open source, but there is the threat that Oracle could work a change in the license and make it an “unattractive choice” for MySQL to use as a backend engine. The purchase itself doesn’t automatically disqualify InnoDB, but what Oracle decides to do with it may.