WordPress has, of course, the lion's share of MySQL deployments by server count if not by row count. Yes, WordPress isn't the latest and greatest stuff. Yes, it

WordPress has, of course, the lion's share of MySQL deployments by server count if not by row count. Yes, WordPress isn't the latest and greatest stuff. Yes, it's <bad thing> and <another bad thing>. But such is the curse of the customer base. They upgraded everybody from utf8 to utf8mb4 (excluding some users of ancient versions of MySQL) with their version 4.2. It went live on April 23, 2015. They announced the upgrade at the beginning of April 2015 here. https://make.wordpress.org/core/2015/04/02/the-utf8mb4-upgrade/ https://make.wordpress.org/core/2015/04/02/the-utf8mb4-upgra... There's some interesting stuff in there about the practical difficulties of the upgrade. The biggest issue was, and still is, the need for prefix indexes. With respect to Adam Hooper, his article was stale when it appeared just over a year after the WordPress schema upgrade. Here's right of course. But the biggest user base was well on their way to abandoning utfmb3 by that time.