Message-ID: <10b34e0a0963e01bec1a34200eadc0f024f598cd.camel@cybertec.at>
Subject: Re: Function not found while creating partial index
From: Laurenz Albe <laurenz.albe@cybertec.at>
To: Chris Hanks <christopher.m.hanks@gmail.com>, 
	pgsql-bugs@lists.postgresql.org
Date: Mon, 02 Feb 2026 13:22:53 +0100
In-Reply-To: <CAK7KUdB48U+Q2MTV1+M+0sXe2sqMhfWF=EAcFtZDFsOyunPzsA@mail.gmail.com>
References: 
	<CAK7KUdB48U+Q2MTV1+M+0sXe2sqMhfWF=EAcFtZDFsOyunPzsA@mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
User-Agent: Evolution 3.58.2 (3.58.2-1.fc43) 
MIME-Version: 1.0
Archived-At: <https://www.postgresql.org/message-id/10b34e0a0963e01bec1a34200eadc0f024f598cd.camel%40cybertec.at>
Precedence: bulk

On Sun, 2026-02-01 at 13:56 -0500, Chris Hanks wrote:
> Hello! The following series of statements results in an unexpected (to me=
) error on 18.0 and 18.1:
>=20
> CREATE FUNCTION my_function_1(n integer) RETURNS integer AS 'SELECT n' LA=
NGUAGE SQL IMMUTABLE;
> CREATE FUNCTION my_function_2(n integer) RETURNS integer AS 'SELECT my_fu=
nction_1(n)' LANGUAGE SQL IMMUTABLE;
> CREATE SCHEMA my_schema;
> CREATE TABLE my_schema.my_table (my_number integer);
> CREATE INDEX my_index ON my_schema.my_table (my_number) WHERE my_function=
_2(my_number) =3D 4;
>=20
> The CREATE INDEX fails with the following error:
>=20
> ERROR: =C2=A0function my_function_1(integer) does not exist
> LINE 1: SELECT my_function_1(n)
> =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0^
> HINT: =C2=A0No function matches the given name and argument types. You mi=
ght need to add explicit type casts.
> QUERY: =C2=A0SELECT my_function_1(n)
> CONTEXT: =C2=A0SQL function "my_function_2" during inlining=20
>=20
> SQL state: 42883
>=20
> If I change the definition of my_function_2 to 'SELECT public.my_function=
_1(n)' then the index builds successfully, so that's my current workaround.

That's not the workaround, that's the proper solution.

See the documentation (https://www.postgresql.org/docs/current/sql-createin=
dex.html):

> While CREATE INDEX is running, the search_path is temporarily changed to =
pg_catalog, pg_temp.

Yours,
Laurenz Albe