One of the versions[1] of the 5.6 documentation[2] has a comment regarding that.
> This configuration differs from another popular MySQL NoSQL solution, HandlerSocket, by skipping even the Handler API layer and directly accessing the InnoDB storage engine through low-level APIs, making the code path even shorter and more efficient.
> This configuration differs from another popular MySQL NoSQL solution, HandlerSocket, by skipping even the Handler API layer and directly accessing the InnoDB storage engine through low-level APIs, making the code path even shorter and more efficient.
[1] http://www.oszone.co.kr/reference/refman-5.6-en.html-chapter...
[2] http://dev.mysql.com/doc/refman/5.6/en/innodb-memcached-bene...