Nice example of a bug caused by weak isolation. FWIW, Postgres has an interesting implementation of "serializable" which takes far fewer locks than MySQL, so may give you better performance while retaining the same isolation level.

Yes: it is the relatively new approach by Cahill et al in 2008, known as SSI: https://courses.cs.washington.edu/courses/cse444/08au/544M/R...

Which, as far as production-common database implementations go, is lightspeed for implementing new academic work (9.1, the first version with the feature, was released in 2011).