[Dave_Rosenthal]

> Serializing access ... fundamentally requires some serial execution.

This is true, but I don't think this requirement limits scalability because the serial part can be arbitrarily cheap (e.g. approve ordered batches of work).

You also say that many databases could implement serializable transactions but don't because of the "higher costs" and that "weak isolation is slower". This sounds like a tradeoff to me so, of course, there will never be one right answer. Well, maybe someday for problems that permit I-confluence :)

However, the article attests to the high costs of sacrificing serializability in programmer productivity and system complexity. Those are serious downsides that need to be weighed very carefully against any actual, measured, performance advantages that are on the table.