Today the headline [The 32-Bit Dog Ate 16 Million Kids' CS Homework](https://news.slashdot.org/story/17/01/22/1940249/the-32-bit-dog-ate-16-million-kids-cs-homework). Quote from [blog.code.org](http://blog.code.org/post/156133016748/this-mornings-technical-difficulties-on-code)

> 
> The way we store student coding activity is in a table that until
>  today had a 32-bit index. What this means is that the database table
>  could only store 4 billion rows of coding activity information. We
>  didn’t realize we were running up to the limit, and the table got
>  full. We have now made a new student activity table that is storing
>  progress by students. With the new table, we are switching to a 64-bit
>  index which will hold up to 18 quintillion rows of information. On the
>  plus side, this new table will be able to store student coding
>  information for millions of years. On the down side, until we’ve moved
>  everything over to the new table, some students’ code from before
>  today may temporarily not appear, so please be patient with us as we
>  fix it.
> 
> 
> 

We now suppose the use MariaDB/MySQL. Can you explain me in detail (with SQL statements and error messages) this issue? I don't understand this data loss very well.