[stickfigure]

> I never saw serializable being set in actual production systems

Every major prod system I've worked on in the last 15 years ran in serializable, including my current charge which processes tens of billions of dollars annually. YMMV but this is quite common in serious production systems. Google's Spanner only runs in serializable.

It doesn't matter though. I could write the sequence out with a SELECT FOR UPDATE and the second request will block instead of retry. The client experience is the same; the "second" request blocks. @pdonis wanted an example so I picked one.