Message-ID: <a6b7545b-a99a-7009-8161-0ac149efec3f@gmail.com>
Date: Fri, 25 Oct 2024 17:00:00 +0300
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Subject: Re: [BUG] Fix DETACH with FK pointing to a partitioned table fails
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From: Alexander Lakhin <exclusion@gmail.com>
To: Alvaro Herrera <alvherre@alvh.no-ip.org>, Tender Wang <tndrwang@gmail.com>
Cc: Jehan-Guillaume de Rorthais <jgdr@dalibo.com>,
 Junwang Zhao <zhjwpku@gmail.com>,
 "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>,
 Guillaume Lelarge <guillaume@lelarge.info>,
 Michael Paquier <michael@paquier.xyz>
References: <202410221432.3qtqbk2q6o7q@alvherre.pgsql>
 <461e9c26-2076-8224-e119-84998b6a784e@gmail.com>
In-Reply-To: <461e9c26-2076-8224-e119-84998b6a784e@gmail.com>
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Hello Alvaro and Tender Wang,

24.10.2024 17:00, Alexander Lakhin wrote:
> Please look at a new anomaly introduced with 53af9491a. When running the
> following script:
> CREATE TABLE t (a int, b int, PRIMARY KEY (a, b));
> CREATE TABLE pt (a int, b int, FOREIGN KEY (a, b) REFERENCES t(a, b))
>  PARTITION BY LIST (a);
>
> CREATE TABLE tp1 (x int, a int, b int);
> ALTER TABLE tp1 DROP COLUMN x;
>
> ALTER TABLE pt ATTACH PARTITION tp1 FOR VALUES IN (1);
>
> ALTER TABLE pt DETACH PARTITION tp1;

I've also discovered another anomaly with a similar setup, but it's not
related to 53af9491a.

CREATE TABLE t (a int, PRIMARY KEY (a));
INSERT INTO t VALUES (1);

CREATE TABLE pt (b int, a int) PARTITION BY RANGE (a);
ALTER TABLE pt DROP COLUMN b;
ALTER TABLE pt ADD FOREIGN KEY (a) REFERENCES t ON DELETE SET DEFAULT (a);

CREATE TABLE tp1 PARTITION OF pt FOR VALUES FROM (1) TO (2);
ALTER TABLE pt DETACH PARTITION tp1;

DELETE FROM t;
\d+ t

This script ends up with:
ERROR:  invalid attribute number 2
ERROR:  cache lookup failed for attribute 2 of relation 16398

(Perhaps it deserves a separate discussion.)

Best regards,
Alexander