Hi,
Some days ago, i tried to beat the Mysql 5.7 optimizer in the challenge launched by Morgan Tocker in this blog post : http://www.tocker.ca/2015/07/15/the-mysql-5-7-optimizer-challenge.html
And i beat it ! So i won a polo and put my name close to great people that i follow every working day in this blog post from Oracle : https://blogs.oracle.com/MySQL/entry/mysql_5_7_community_contributor
😛