Re: [PATCH] Fix duplicate errmsg in ALTER TABLE SPLIT PARTITION - Mailing list pgsql-hackers

On Wed, Apr 29, 2026 at 5:03 PM Ayush Tiwari
<ayushtiwari.slg01@gmail.com> wrote:
>   - For SPLIT, switch the adjacency error to
>         errmsg("cannot split partition \"%s\"",
>                get_rel_name(splitPartOid)),
>     so it names the old partition, matching the merge wording style.
>     To make splitPartOid available there, I added an Oid splitPartOid
>     parameter to check_two_partitions_bounds_range() and pass
>     InvalidOid from the merge call site (where is_merge is true so
>     the parameter is unused).

If we have splitPartOid, then the boolean is_merge is redundant and
can be removed, right? To keep the intent clear we can add a local
variable

bool is_merge = (splitPartOid == NULL ? true : false);

Other than that, both patches LGTM.

Thanks for reviewing.

v6 attached, addressing the remaining point.  In 0001,
check_two_partitions_bounds_range() no longer takes an is_merge
argument.  The merge call site passes InvalidOid, the split call site
passes splitPartOid, and the helper derives a local is_merge value from
that.  I used OidIsValid(splitPartOid) rather than a NULL comparison,

If there are two errmsg's back-to-back, only the second one displays.
Maybe some automated tooling can detect cases like this going forward?