Also… I’ve been issues in MySQL repeatable read mode where a single SELECT, selecting a single row, returned impossible results. I think it was:
SELECT min(value), max(value) FROM table WHERE id = 1;
This isn't CONCAT-specific, BTW--we just use CONCAT because it allows us to infer anomalies in linear, rather than exponential time. Same kinds of behaviors manifest with plain old read/write registers.
Also… I’ve been issues in MySQL repeatable read mode where a single SELECT, selecting a single row, returned impossible results. I think it was:
where id is a primary key. I got two different values for min and max. That was a fun one.