Message-ID: <78a13f951a03bf325027f8dcfb32b1b5089cdb14.camel@cybertec.at>
Subject: Re: pg_restore with --disable-triggers discards ENABLE ALWAYS
From: Laurenz Albe <laurenz.albe@cybertec.at>
To: Duncan Sands <duncan.sands@deepbluecap.com>,
	pgsql-bugs@lists.postgresql.org
Date: Thu, 12 Sep 2024 22:02:01 +0200
In-Reply-To: <d374b6fc-4217-48a9-8639-2c9b4d3a92d0@deepbluecap.com>
References: <d374b6fc-4217-48a9-8639-2c9b4d3a92d0@deepbluecap.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
User-Agent: Evolution 3.52.4 (3.52.4-1.fc40) 
MIME-Version: 1.0
Archived-At: 
 <https://www.postgresql.org/message-id/78a13f951a03bf325027f8dcfb32b1b5089cdb14.camel%40cybertec.at>
Precedence: bulk

On Thu, 2024-09-12 at 10:27 +0200, Duncan Sands wrote:
> CREATE TABLE test_table(x int);
> CREATE FUNCTION test_function() RETURNS trigger AS $$ BEGIN RETURN NULL; =
END; $$=20
> LANGUAGE plpgsql;
> CREATE TRIGGER test_trigger AFTER UPDATE ON test_table FOR EACH ROW EXECU=
TE=20
> FUNCTION test_function();
> ALTER TABLE test_table ENABLE ALWAYS TRIGGER test_trigger;
>=20
> Checking the table:
>=20
> duncan=3D> \d test_table
> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0 Table "public.test_table"
> =C2=A0 Column |=C2=A0 Type=C2=A0=C2=A0 | Collation | Nullable | Default
> --------+---------+-----------+----------+---------
> =C2=A0 x=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 | integer |=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 |=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0 |
> Triggers firing always:
> =C2=A0=C2=A0=C2=A0=C2=A0 test_trigger AFTER UPDATE ON test_table FOR EACH=
 ROW EXECUTE FUNCTION=20
> test_function()
>=20
> ^ Observe "Triggers firing always".
>=20
>=20
> Now for the dump + restore:
>=20
> pg_dump -f dump.custom -Fc --table test_table
> pg_restore --data-only --disable-triggers --dbname duncan dump.custom
>=20
> Checking the table:
>=20
> duncan=3D> \d test_table
> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0 Table "public.test_table"
> =C2=A0 Column |=C2=A0 Type=C2=A0=C2=A0 | Collation | Nullable | Default
> --------+---------+-----------+----------+---------
> =C2=A0 x=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 | integer |=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 |=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0 |
> Triggers:
> =C2=A0=C2=A0=C2=A0=C2=A0 test_trigger AFTER UPDATE ON test_table FOR EACH=
 ROW EXECUTE FUNCTION=20
> test_function()
>=20
> ^ Observe that "Triggers firing always" has disappeared.

This looks like a user error to me.
If you restore with --data-only, the table and constraint definitions
are not restored at all.  So the table "test_table" in database "duncan"
must already have existed before the restore, and the trigger was already
defined like that.

Yours,
Laurenz Albe