Re: Serializable wrong?

On Fri, Jun 12, 2020 at 6:58 PM Joshua Drake <jd(at)commandprompt(dot)com> wrote:

> -Hackers,
>
> I came across this today [1], "
> 3 Results
>
> In most respects, PostgreSQL behaved as expected: both read uncommitted
> and read committed prevent write skew and aborted reads. We observed no
> internal consistency violations. However, we have two surprising results to
> report. The first is that PostgreSQL’s “repeatable read” is weaker than
> repeatable read, at least as defined by Berenson, Adya, Bailis, et al. This
> is not necessarily wrong: the ANSI SQL standard is ambiguous. The second
> result, which is definitely wrong, is that PostgreSQL’s “serializable”
> isolation level isn’t serializable: it allows G2-item during normal
> operation. "
>
> Thanks!
>
> JD
>
> 1. https://jepsen.io/analyses/postgresql-12.3
>

Yes, this has been reported and is under discussion in pgsql-bugs list:

https://www.postgresql.org/message-id/db7b729d-0226-d162-a126-8a8ab2dc4443%40jepsen.io