Message-ID: <52a74da36f9c7601e944dc5ba9648368816f22ee.camel@cybertec.at>
Subject: Re: please define 'statement' in the glossary
From: Laurenz Albe <laurenz.albe@cybertec.at>
To: Tom Lane <tgl@sss.pgh.pa.us>, "David G. Johnston"
	 <david.g.johnston@gmail.com>
Cc: petermittere@gmail.com, pgsql-docs@lists.postgresql.org
Date: Tue, 15 Jul 2025 07:36:13 +0200
In-Reply-To: <697664.1752512964@sss.pgh.pa.us>
References: 
	<175223006802.3157505.14764328206246105568@wrigleys.postgresql.org>
	 <15139c5d218754350e4870062f90ff0e85490290.camel@cybertec.at>
	 <270191.1752420426@sss.pgh.pa.us>
	 <097e693ea6cc3541cbcd72c915d7d492c26930c0.camel@cybertec.at>
	 <456003.1752442676@sss.pgh.pa.us> <458204.1752443813@sss.pgh.pa.us>
	 <CAKFQuwa4VMoHehuN5qCX5Jv15ZahTJ00jxMu4mbtYNHbJ4PXOA@mail.gmail.com>
	 <ec1e6bb700f9eefceea0648656b38ab223c14c54.camel@cybertec.at>
	 <685003.1752506254@sss.pgh.pa.us>
	 <CAKFQuwYzod+L_vjOuWz8OAte2SoS5V5ByOGfhDx1-ubvHTb11g@mail.gmail.com>
	 <CAKFQuwYC-p=2pr__2Gu65HR5E=4fmiwHhacKBrxRYmB2GEqtGw@mail.gmail.com>
	 <690858.1752509326@sss.pgh.pa.us>
	 <CAKFQuwa2gDZTJm5hkrqubcn1=A3aTDR7HxX-NfF-9fKrp28f+A@mail.gmail.com>
	 <697664.1752512964@sss.pgh.pa.us>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
User-Agent: Evolution 3.56.2 (3.56.2-1.fc42) 
MIME-Version: 1.0
Archived-At: 
 <https://www.postgresql.org/message-id/52a74da36f9c7601e944dc5ba9648368816f22ee.camel%40cybertec.at>
Precedence: bulk

On Mon, 2025-07-14 at 13:09 -0400, Tom Lane wrote:
> "David G. Johnston" <david.g.johnston@gmail.com> writes:
> > Ok.  That explains why "statement_timestamp() and transaction_timestamp=
()
> > return the same value during the first command of a transaction," isn't
> > just stating the obvious.  transaction_timestamp() literally returns th=
e
> > value statement_timestamp().
>=20
> Right.  I'm tempted to be more explicit about that, along the lines of
>=20
>      <function>statement_timestamp()</function> and <function>transaction=
_timestamp()</function>
> -    return the same value during the first statement of a transaction, b=
ut might
> -    differ during subsequent statements.
> +    return the same value during the first statement of a transaction,
> +    because the transaction timestamp is set by copying the statement
> +    timestamp when a new transaction starts.
>=20
> I didn't include that change below though; perhaps it has too much
> whiff of implementation detail.
>=20
> > I'm fine with this entire section assuming/stating that extended protoc=
ol
> > is in effect and that 53.2.2.1 explains how these behave when executing=
 a
> > multi-statement simple protocol "script".
>=20
> It's incorrect to claim that this only applies to extended protocol,
> and besides I thought you didn't want to mention protocol details
> here.  I can't argue with documenting it in the protocol chapter
> though.  So about like this?

+1

This thread doesn't look like we're going to find a wording that will
make everyone happy, but I believe that this patch is a clear improvement.

Quite contrary to David, I would have liked the word "protocol" with
the message, because it gives me personally the right idea, but I am
fine with "message" alone.  After all, a message in PostgreSQL jargon
is a protocol message.

Yours,
Laurenz Albe