Re: CREATE SCHEMA ... CREATE DOMAIN support

On 04/09/2026 22:30, Tom Lane wrote:
> Noah Misch <noah(at)leadboat(dot)com> writes:
>> On Fri, Sep 04, 2026 at 10:21:52AM -0400, Tom Lane wrote:
>>> What would you have us do differently?
>
>> I recommend reverting the v19 CREATE SCHEMA changes, unfortunately. The
>> thread started with what smelled like low-hanging fruit: let users write
>> "CREATE SCHEMA myschema CREATE DOMAIN mydomain" instead of "CREATE SCHEMA
>> myschema; CREATE DOMAIN myschema.mydomain". That led to a9c350d silently
>> changing the meaning of CREATE SCHEMA statements that v18 already accepts.
>> Since the benefit of supporting "CREATE SCHEMA myschema CREATE DOMAIN
>> mydomain" is so modest, it doesn't take much of a problem to outweigh that
>> benefit.
>
> Well, you have a point. There's pretty nearly nothing that's
> well-designed about CREATE SCHEMA subcommands: as you say, the syntax
> is shaky, and the namespace visible to subcommands is unclear, and
> the whole business of re-ordering subcommands is debatable, and even
> if all those things were fixed the benefit of the entire feature is
> marginal. So maybe we should just say that our legacy implementation
> is what it is and we will mark it deprecated rather than putting any
> effort into improving it. I'd like to see more than one vote in favor
> of that before I do it, though.

Reverting seems like the safest thing to do. This is a really niche
thing, but whatever behavior we pick, we'll be stuck with it for a long
time. If we're not 100% certain about the new behavior, better to take a
step back and discuss and design it with more time.

- Heikki