Date: Tue, 7 Jul 2026 16:58:39 -0700
From: Noah Misch <noah@leadboat.com>
To: Alexander Korotkov <aekorotkov@gmail.com>
Cc: d.koval@postgrespro.ru, pgsql-hackers@postgresql.org
Subject: Re: SPLIT/MERGE use of is_internal=true
Message-ID: <20260707235839.5f.noahmisch@microsoft.com>
References: <20260707185751.f9.noahmisch@microsoft.com>
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On Wed, Jul 08, 2026 at 02:49:45AM +0300, Alexander Korotkov wrote:
> On Tue, Jul 7, 2026 at 9:57 PM Noah Misch <noah@leadboat.com> wrote:
> > This and other places in the SPLIT/MERGE patches pass is_internal=true, which
> > ultimately flows to hooks with the following meaning:
> >
> >         /*
> >          * If this flag is set, the user hasn't requested that the object be
> >          * altered, but we're doing it anyway for some internal reason.
> >          * Permissions-checking hooks may want to skip checks if, say, we're alter
> >          * the constraints of a temporary heap during CLUSTER.
> >          */
> >         bool            is_internal;
> >
> > SPLIT/MERGE constitute user requests to create and/or drop tables, so they're
> > not like a CLUSTER temporary heap.  They should pass is_internal=false, like
> > when the user runs CREATE/DROP directly.
> 
> Thank you for catching this.  For sure, we shouldn't pass
> is_internal=true here.  Attached patch fixes this.  I'm going to push
> it if no objections.

> Subject: [PATCH v1] Don't create SPLIT/MERGE partitions as internal relations
> 
> createPartitionTable(), which builds the new partitions for ALTER TABLE
> ... SPLIT PARTITION and ALTER TABLE ... MERGE PARTITIONS, passed
> is_internal=true to heap_create_with_catalog().  These relations are
> created at the explicit request of the user, just like a plain CREATE
> TABLE, so pass is_internal=false instead.  The is_internal flag is meant
> for objects created as an internal implementation detail (for example, a
> transient heap built during CLUSTER), and it is observed by
> object-access hooks.
> 
> Reported-by: Noah Misch <noah@leadboat.com>
> Discussion: https://postgr.es/m/20260707185751.f9.noahmisch@microsoft.com

Log should have a "Backpatch-through: 19" line.

> ---
>  src/backend/commands/tablecmds.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
> index 95abaf4890c..0b6a84b32b7 100644
> --- a/src/backend/commands/tablecmds.c
> +++ b/src/backend/commands/tablecmds.c
> @@ -23137,7 +23137,7 @@ createPartitionTable(List **wqueue, RangeVar *newPartName,
>  										(Datum) 0,
>  										true,
>  										allowSystemTableMods,
> -										true,
> +										false,	/* is_internal */
>  										InvalidOid,
>  										NULL);

The edit looks fine for this code site.  As I mentioned above, other
SPLIT/MERGE code sites need the same change.