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In-Reply-To: <232439a3-af7a-4a13-82ae-33da5520d4bf@postgrespro.ru>
From: Alexander Korotkov <aekorotkov@gmail.com>
Date: Fri, 26 Jun 2026 22:50:36 +0300
Message-ID: 
 <CAPpHfdsao-VXZYN8-vRm543EFUE7=4tq+hcTh5iEc6ikqWq_cQ@mail.gmail.com>
Subject: Re: Add SPLIT PARTITION/MERGE PARTITIONS commands
To: Dmitry Koval <d.koval@postgrespro.ru>
Cc: Pavel Borisov <pashkin.elfe@gmail.com>,
 Justin Pryzby <pryzby@telsasoft.com>,
	pgsql-hackers@lists.postgresql.org
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On Fri, Jun 26, 2026 at 6:20=E2=80=AFPM Dmitry Koval <d.koval@postgrespro.r=
u> wrote:
> If we exclude case with DEFAULT partition, MERGE PARTITIONS command was
> intended to be used when an incorrect table partitioning was chosen.
> For example, a table was initially partitioned by month, but later we
> needed to change table partitioning by quarter. In this case, MERGE
> PARTITIONS command should merge several adjacent partitions into one.
> Current checks are made for this case.
>
>  >- If there's *no* default partition, then I think the check should be
>  >relaxed; it's sufficient to verify that the bounds of the merged
>  >partition do not overlap with any partition which is not being merged;
>
> It's probably possible to do this. But in this case, the command will
> not exactly be "MERGE PARTITIONS" ("MERGE PARTITIONS & EXPAND"?).

+1,
We can implement a support for this for 20.  For 19, I propose to
state the restriction more explicit in the docs.  See the attached
patch.

------
Regards,
Alexander Korotkov
Supabase

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