Message-ID: <67cb509e-93c7-1c7b-2388-d7e00277b344@gmail.com>
Date: Mon, 27 Mar 2023 22:00:00 +0300
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Subject: Re: BUG #17872: Dropping an attribute of a composite type breaks
 indexes over the type silently
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To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-bugs@lists.postgresql.org,
 Peter Eisentraut <peter.eisentraut@enterprisedb.com>
References: <17872-d0fbb799dc3fd85d@postgresql.org>
 <3169550.1679928579@sss.pgh.pa.us> <3182314.1679935605@sss.pgh.pa.us>
 <1aa2eec0-2017-3870-6d88-228d08c587d3@gmail.com>
 <3267914.1679941213@sss.pgh.pa.us>
From: Alexander Lakhin <exclusion@gmail.com>
In-Reply-To: <3267914.1679941213@sss.pgh.pa.us>
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27.03.2023 21:20, Tom Lane wrote:
> Alexander Lakhin <exclusion@gmail.com> writes:
>> Yes, I think something like that can resolve the issue.
>> But I would also note that the problem is not with indexes only, but also
>> with "... partition by list(comp_type_value)", for example.
> Hmm ... really?  I'd just concluded that a partitioned table is okay
> as long as it doesn't yet have any partitions.  Even if the modified
> type is a partitioning column, there's no structure yet that could
> depend on the contents of the type.  (If it does have partitions,
> we'll fail when we get to one of those.)

The following query leads to a failure on showing a partition definition:
CREATE TABLE tbl(a int, b int) PARTITION BY LIST ((tbl));
CREATE TABLE tblp PARTITION OF tbl FOR VALUES IN ('(2,4)');
ALTER TABLE tbl ALTER COLUMN a TYPE char(5);
\d+ tbl
(The effect depends on the values specified.)
It's not exactly the dependency issue but still is related to altering
a composite type.

Best regards,
Alexander