Came here to say this. Whatever may have been true of InnoDB 20 years ago, don't follow this article's advice for any modern relational database.
To add: Not sure about MySQL, but `varchar`/`text` in PostgreSQL for short strings like those in the article is very efficient. It basically just takes up space equaling the length of the string on disk, plus one byte [1].
To add: Not sure about MySQL, but `varchar`/`text` in PostgreSQL for short strings like those in the article is very efficient. It basically just takes up space equaling the length of the string on disk, plus one byte [1].
[1] https://www.postgresql.org/docs/current/datatype-character.h...