Message-ID: <7edb8a57-5e50-dd77-7953-454d6686779e@gmail.com>
Date: Mon, 15 Apr 2024 18:00:00 +0300
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Subject: Re: Add SPLIT PARTITION/MERGE PARTITIONS commands
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To: Robert Haas <robertmhaas@gmail.com>,
 Alexander Korotkov <aekorotkov@gmail.com>
Cc: Dmitry Koval <d.koval@postgrespro.ru>,
 PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
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From: Alexander Lakhin <exclusion@gmail.com>
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Hello Robert,

15.04.2024 17:30, Robert Haas wrote:
> On Sat, Apr 13, 2024 at 6:05 AM Alexander Korotkov <aekorotkov@gmail.com> wrote:
>> Please, find a my version of this fix attached.  I think we need to
>> check relpersistence in a similar way ATTACH PARTITION or CREATE TABLE
>> ... PARTITION OF do.  I'm going to polish this a little bit more.
> + errmsg("\"%s\" is not an ordinary table",
>
> This is not a phrasing that we use in any other error message. We
> always just say "is not a table".

Initially I was confused by that message, because of:
CREATE TABLE t (i int) PARTITION BY RANGE (i);
CREATE FOREIGN TABLE ftp_0_1 PARTITION OF t
   FOR VALUES FROM (0) TO (1)
   SERVER loopback OPTIONS (table_name 'lt_0_1');
CREATE FOREIGN TABLE ftp_1_2 PARTITION OF t
   FOR VALUES FROM (1) TO (2)
   SERVER loopback OPTIONS (table_name 'lt_1_2');
ALTER TABLE t MERGE PARTITIONS (ftp_0_1, ftp_1_2) INTO ftp_0_2;
ERROR:  "ftp_0_1" is not a table
(Isn't a foreign table a table?)

And also:
CREATE TABLE t (i int) PARTITION BY RANGE (i);
CREATE TABLE tp_0_1 PARTITION OF t
   FOR VALUES FROM (0) TO (1);
CREATE TABLE t2 (i int) PARTITION BY RANGE (i);
ALTER TABLE t MERGE PARTITIONS (tp_0_1, t2) INTO tpn;
ERROR:  "t2" is not a table
(Isn't a partitioned table a table?)

And in fact, an ordinary table is not suitable for MERGE anyway:
CREATE TABLE t (i int) PARTITION BY RANGE (i);
CREATE TABLE tp_0_1 PARTITION OF t
   FOR VALUES FROM (0) TO (1);
CREATE TABLE t2 (i int);
ALTER TABLE t MERGE PARTITIONS (tp_0_1, t2) INTO tpn;
ERROR:  "t2" is not a partition

So I don't think that "an ordinary table" is a good (unambiguous) term
either.

Best regards,
Alexander