From: "Michel SALAIS" <msalais@msym.fr>
To: "'Holger Jakobs'" <holger@jakobs.com>,
	<pgsql-admin@lists.postgresql.org>
References: <548f2ed6-3209-705d-09e2-a5afbc6fb71c@quadratum-braccas.com>
 <bc177652-b317-0f78-cc82-466f24315549@gmail.com>
 <6bfd5d91-bb06-1b56-f4f8-cc8f90307a35@jakobs.com>
In-Reply-To: <6bfd5d91-bb06-1b56-f4f8-cc8f90307a35@jakobs.com>
Subject: RE: set autocommit only for select statements
Date: Tue, 12 Apr 2022 11:01:13 +0200
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-----Message d'origine-----
De : Holger Jakobs <holger@jakobs.com>=20
Envoy=C3=A9 : mardi 12 avril 2022 08:31
=C3=80 : pgsql-admin@lists.postgresql.org
Objet : Re: set autocommit only for select statements

Am 12.04.22 um 03:53 schrieb Mladen Gogala:
>
> The "autocommit" is a tool option which tells the tool whether to add=20
> "COMMIT" statement after each and every SQL. The RDBMS server only=20
> knows about transactions, as mandated by the ACID compliance. What the =

> "autocommit" option of tools like psql actually does is to turn each=20
> of your SQL statements into a separate transaction.
>
What you write about psql sending a COMMIT statement after each =
statement is wrong. It may be true for other database systems.

PostgreSQL as a server commits each statement automatically unless the =
client has started a transaction with BEGIN or START TRANSACTION =
statements.

This can be proved easily by not using psql as a client, but some =
programming language.

Regards,

Holger


-- Holger Jakobs, Bergisch Gladbach, Tel. +49-178-9759012
-------------------------------------------------------------------------=
----------


Hi,
It is a little more "complex" :-)
A session can be put in AUTOCOMMIT mode or transaction mode. Tool "psql" =
is by default in AUTOCOMMIT mode and can be put in transaction mode =
using=20
\set AUTOCOMMIT off

Pay attention to the variable case. It should be in capital letters. =
When this is done, You don't need to start transactions explicitly and =
the server behaves like Oracle but it is not an identical behavior. =
Other points matter like the reaction to errors when in a transaction... =


Other programming environments could choose another default operating =
mode and however can offer to choose the operating mode at connection.


Michel SALAIS