> On May 19, 2026, at 19:00, Alexander Korotkov <[email protected]> wrote:
>
> Hi, Chao!
>
> On Tue, May 19, 2026 at 5:50 AM Chao Li <[email protected]> wrote:
>>> On May 18, 2026, at 20:04, Alexander Korotkov <[email protected]> wrote:
>>>
>>> On Mon, May 18, 2026 at 2:57 PM Chao Li <[email protected]> wrote:
>>>>> <v3-0003-Clarify-SPLIT-PARTITION-bound-requirements-in-doc.patch><v3-0001-Fix-SPLIT-PARTITION-range-bound-validation-with-D.patch><v3-0002-Fix-SPLIT-PARTITION-hint-for-DEFAULT-partition-bo.patch><v3-0004-Reject-degenerate-SPLIT-PARTITION-with-DEFAULT-pa.patch>
>>>>
>>>> v3-0001 through v3-0003 look good to me.
>>>>
>>>> For v3-0004, I have a suspicion, but it's late here and my brain is
>>>> getting slow, so I would like to study it more tomorrow.
>>>
>>> Sure, take your time.
>>>
>>> ------
>>> Regards,
>>> Alexander Korotkov
>>> Supabase
>>
>> My suspicion was that check_split_partition_not_same_bound() now has two
>> paths. The RANGE path honors collation, while the LIST path does not. So I
>> spent some time creating a test that uses a case-insensitive collation:
>> ```
>> evantest=# create collation case_insensitive (provider=icu,
>> locale='und-u-ks-level2', deterministic = false);
>> CREATE COLLATION
>> evantest=# create table t (b text collate case_insensitive) partition by
>> list (b);
>> CREATE TABLE
>> evantest=# create table tp_ab partition of t for values in ('a', 'b');
>> CREATE TABLE
>> evantest=# alter table t split partition tp_ab into
>> evantest-# (partition tp_a for values in ('a', 'A'),
>> evantest(# partition tp_default default);
>> ERROR: cannot split partition "tp_ab" only to add a DEFAULT partition
>> LINE 2: (partition tp_a for values in ('a', 'A'),
>> ^
>> DETAIL: The non-DEFAULT partition would keep the same partition bound.
>> HINT: Use CREATE TABLE ... PARTITION OF ... DEFAULT to add a DEFAULT
>> partition.
>> ```
>>
>> In this test, the split partition’s bound is ('a', 'b'), and the new
>> partition’s bound is ('a', 'A'). Their list lengths are both 2, but the two
>> bounds are actually different, because 'a' and 'A' are considered equal by
>> the collation.
>>
>> So, in the LIST path, since check_partition_bounds_for_split_list() has
>> already ensured that the new partition’s bound is contained within the split
>> partition’s bound, we need to check the reverse direction as well. Whether
>> the split partition’s bound is also contained in the new partition’s bound.
>> If yes, the two bounds are identical.
>>
>> See the attached v4 for my changes for 0004. 0001-0003 are unchanged. Since
>> 0001 and 0003 are independent of 0004, maybe they can be pushed first.
>
> I've pushed 0001-0003.
Thanks for pushing them.
> Thank you for discovering the collation issue
> in 0004. Note that original approach of using
> partition_bounds_equal() can't handle different collations too (as it
> internally uses datumIsEqual()).
Yes, I realized that while reviewing v3. That’s reason I didn’t get back v2 and
only worked again based on v3.
> I've revised the remaining patch:
> made function header comment a bit more detailed
This part looks good to me.
> and added additional
> regression tests. Please, check.
>
But I don’t see any change for regression test between v4 and v5. Maybe you
forgot to save your changes?
Best regards,
--
Chao Li (Evan)
HighGo Software Co., Ltd.
https://www.highgo.com/
