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In-Reply-To: <944307.1775420103@sss.pgh.pa.us>
From: jian he <jian.universality@gmail.com>
Date: Mon, 6 Apr 2026 10:29:05 +0800
Message-ID: 
 <CACJufxEwkAJuCutLQdsxCOJkAvDS=9KgbphMVkXtQP8te=nciA@mail.gmail.com>
Subject: Re: CREATE SCHEMA ... CREATE DOMAIN support
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Kirill Reshke <reshkekirill@gmail.com>,
 Peter Eisentraut <peter@eisentraut.org>,
	PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
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On Mon, Apr 6, 2026 at 4:15=E2=80=AFAM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>
> Here's a revised patchset that I think is pretty close to committable.
> I reorganized it some compared to v11: 0001 is still about the same,
> but the business with allowing circular foreign keys is now in 0002,
> because it seems like that bears directly on whether we should
> consider 0001 acceptable.  And then I squashed all the object-type
> additions into 0003, because dealing with them all at once seemed
> simpler.
>
> I rewrote 0002 rather heavily, mainly because it assumed it could
> scribble on the input query tree which I don't think is okay.
> The functionality is still the same though.
>

transformCreateSchemaStmtElements you mentioned

 * Note it's important that we not modify the input data structure.  We cre=
ate
 * a new result List, and we copy any CREATE TABLE subcommands that we migh=
t
 * modify.

But there is still no explanation about why it's not ok to scribble on
the input query tree.
V13-0002 looks great, and it is way more intuitive than my approach!
Thanks!

+ DeconstructQualifiedName(qualified_name, &obj_schema, &obj_name);
+ if (obj_schema !=3D NULL &&
+ strcmp(context_schema, obj_schema) !=3D 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_SCHEMA_DEFINITION),
+ errmsg("CREATE specifies a schema (%s) "
+ "different from the one being created (%s)",
+ obj_schema, context_schema)));

There is no tests for the above. It would be better to have one dummy
test verify the error message.

it would be better change to
+ errmsg("CREATE specifies a schema (%s) different from the one being
created (%s)",
It's better for regex pattern searching, for new line you need to know
how to escape.

+ (errcode(ERRCODE_INVALID_SCHEMA_DEFINITION),
The leading parenthesis is not needed.

> I was kind of sad that 0003 didn't support functions/procedures,
> because (a) the SQL spec requires those in CREATE SCHEMA, and
> (b) they are a flagship feature for Postgres, mainly because they
> are such a critical aspect of extendability.  So I added that,
> which only required adding CreateFunctionStmt to the set of
> supported node types in transformCreateSchemaStmtElements.
>

I guess at the time, I wasn't aggressive enough to consider CREATE
SCHEMA CREATE FUNCTION.

I saw the "Author" line in commit messages v13-0002 and v13-0003.
You should be added as an author on both v13-0002 and v13-0003.
Your changes simplified 0002 a lot, and you added the other CREATE
SCHEMA subcommands to 0003.

Except for the above issue, v13 all looks good to me.


--
jian
https://www.enterprisedb.com/