From: Tom Lane <tgl@sss.pgh.pa.us>
To: pgsql-hackers@lists.postgresql.org
Subject: MERGE lacks ruleutils.c decompiling support!?
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-ID: <3579736.1683293801.1@sss.pgh.pa.us>
Date: Fri, 05 May 2023 09:36:41 -0400
Message-ID: <3579737.1683293801@sss.pgh.pa.us>
Archived-At: <https://www.postgresql.org/message-id/3579737.1683293801%40sss.pgh.pa.us>
Precedence: bulk

I made this function:

CREATE OR REPLACE FUNCTION test_fun()
RETURNS void
LANGUAGE SQL
BEGIN ATOMIC
MERGE INTO target
USING source s on s.id = target.id
WHEN MATCHED THEN
  UPDATE SET data = s.data
WHEN NOT MATCHED THEN
  INSERT VALUES (s.id, s.data);
end;

It appears to work fine, but:

regression=# \sf+ test_fun()
ERROR:  unrecognized query command type: 5

and it also breaks pg_dump.  Somebody screwed up pretty badly
here.  Is there any hope of fixing it for Monday's releases?

(I'd guess that decompiling the WHEN clause would take a nontrivial
amount of new code, so maybe fixing it on such short notice is
impractical.  But ugh.)

			regards, tom lane