Over at the work blog, I wrote about what the true maximum number of columns in MySQL is as well as the minimum maximum. Basically, the FRM file is ass and places bizarre arbitrary limits on things due to what can only be seen as “limitations” in 1980s computing and automatically generated interfaces for entering rows on a 80×24 character VT100 terminal.

Full post here: https://www.percona.com/blog/understanding-the-maximum-number-of-columns-in-a-mysql-table/