Message-ID: <c8b162966097d43e7d77f39f7a9f206f64a0572f.camel@cybertec.at>
Subject: Re: Serializable Transaction Anomoly
From: Laurenz Albe <laurenz.albe@cybertec.at>
To: Daniel Bickler <daniel.bickler@goprominent.com>,
 "pgsql-docs@lists.postgresql.org"
	 <pgsql-docs@lists.postgresql.org>
Date: Tue, 05 Nov 2024 20:17:04 +0100
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On Tue, 2024-11-05 at 18:41 +0000, Daniel Bickler wrote:
> The way I interpreted the documentation, the example I ran into was a fal=
se negative
> according to the definition of a serialization anomaly, because it=E2=80=
=99s serial in one
> ordering but not the other which seems incorrect with =E2=80=9Call possib=
le=E2=80=9D.
> =C2=A0
> I think where I don=E2=80=99t fully understand is the documentation seems=
 to imply all serial
> orderings must be valid to commit a SERIALIZABLE transaction but it seems=
 like just
> one serial ordering must be valid?

You seem to think that transactions are serializable if their result is con=
sistent
with all possible serial execution orders.  But that is not so.

What the documentation says is:
It is an serialization anomaly (that is, not serializable) if the execution=
 is
*in*consistent will all possible serial executions.

That implies: It is serializable if the execution is consistent with one se=
rial
execution.

Yours,
Laurenz Albe