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From: jian he <jian.universality@gmail.com>
Date: Fri, 19 Sep 2025 22:53:35 +0800
Message-ID: 
 <CACJufxET9Qe-=zJtjGrKPr7-1QbVcP9y-vJU9CMEDfPGt_dbyg@mail.gmail.com>
Subject: Re: Add SPLIT PARTITION/MERGE PARTITIONS commands
To: Dmitry Koval <d.koval@postgrespro.ru>
Cc: Chao Li <li.evan.chao@gmail.com>, pgsql-hackers@lists.postgresql.org
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Precedence: bulk

hi. about v59.

check_partitions_not_overlap_list
            overlap =3D list_intersection(sps1->bound->listdatums,
                                        sps2->bound->listdatums);
            if (list_length(overlap) > 0)
            {
                Const       *val =3D (Const *) lfirst(list_head(overlap));
                ereport(ERROR,
                        errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                        errmsg("new partition \"%s\" would overlap
with another new partition \"%s\"",
                               sps1->name->relname, sps2->name->relname),
                        parser_errposition(pstate, exprLocation((Node *) va=
l)));
            }

list_intersection seems not right, how can we be sure it deals with
collation correctly?

It failed to deal with numeric special value (0.0).
demo:
CREATE TABLE t (a numeric) PARTITION BY LIST (a);
CREATE TABLE t1 PARTITION OF t FOR VALUES in  ('0', '1');
ALTER TABLE t SPLIT PARTITION t1 INTO
  (PARTITION x  FOR VALUES in  ('0'),
  PARTITION x1 FOR VALUES IN ('0.0', '1'));

I=E2=80=99ll think about the solution later; for now, I just wanted to poin=
t
out this problem.