Subject: [PATCH] pg_get_domain_ddl: DDL reconstruction function for CREATE DOMAIN statement

From: "zengman" <[email-masked]>
Date: Thu, 20 Nov 2025 14:42:15 +0800

Hello everyone, 

I have tested the v4 patch and observed that the following scenario requires support. Accordingly, I have prepared version v5: v5-0001 is fully consistent with the v4 patch, and v5-0002 restricts input to domains exclusively, with an additional simple test case attached.

```sql
postgres=# create table test_table(a int);
CREATE TABLE
postgres=# SELECT pg_get_domain_ddl('test_table');
ERROR:  cache lookup failed for type 0
```

-- 
Regrads,
Man Zeng