Message-ID: <249fa239-3e30-6060-087d-394f36c498f6@postgrespro.ru>
Date: Tue, 13 Dec 2022 09:58:12 +0300
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Subject: Re: BUG #17706: ALTER TYPE leads to crash
To: Richard Guo <guofenglinux@gmail.com>,
 "David G. Johnston" <david.g.johnston@gmail.com>
Cc: pgsql-bugs@lists.postgresql.org
References: <17706-fa10a46c1ac9ce5a@postgresql.org>
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 <CAMbWs48eGK9YwbSprdwN4jWGeeC7xLLehb1ymFeZKFsTO9BmOg@mail.gmail.com>
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From: Sergey Shinderuk <s.shinderuk@postgrespro.ru>
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On 13.12.2022 05:58, Richard Guo wrote:
> If we create a table using type foo, the alter
> operation would error out like that.
> 
> create table t (a foo);
> 
> alter type foo alter attribute b type text;
> ERROR:  cannot alter type "foo" because column "t.a" uses it
> 
> Maybe we can likewise record the dependencies for the type if it's being
> used in other more scenarios besides as a column in some table?


Just in case, ALTER TABLE can also trigger the crash:

create table t (a int, b int);

create function f() returns t as $$
declare
	r t = (1, 2^30);
begin
	alter table t alter b type text;
	return r;
end;
$$ language plpgsql;

postgres=# select f();
server closed the connection unexpectedly


-- 
Sergey Shinderuk		https://postgrespro.com/