[Spivak]

You're absolutely right but I think the advantage is that to the users of the database it doesn't really feel like there's any locking going on and it's this implicit thing that's constructed from the history.

Like for a hypothetical ticket selling platform you just get a log like

    00:00 RESERVE AAA FOR xxx, 5 min
    00:02 BUY     BBB FOR qqq
    00:15 RESERVE AAA FOR yyy, 5 min
    00:23 CONFIRM AAA FOR xxx
    00:25 CONFIRM BBB for qqq
    00:27 REJECT  AAA FOR yyy, "already reserved"
    05:16 RESERVE AAA FOR zzz, 5 min
    05:34 CONFIRM AAA FOR zzz

So although there's "locking" going on here enforced by the consumer sending the confirms the producer just sends intents/events and sees whether they're successful or not and both producer and consumer are stateless.

I guess it just depends on which model you think is more a PITA to work with.