Re: tablecmds: reject CLUSTER ON for partitioned tables earlier

> On Jan 27, 2026, at 01:26, Zsolt Parragi <zsolt.parragi@percona.com> wrote:
> 
> +ALTER TABLE nonpartitioned INHERIT partitioned; -- ok
> ERROR:  cannot inherit from partitioned table "partitioned"
> -- cannot add NO INHERIT constraint to partitioned tables
> 
> That comment should be fail

Fixed.

> 
> Otherwise the patches look good.
> 

Thanks a lot for confirming.


> The rest is about the two checks that seem redundant to me - I don't
> have a problem with leaving them as is, but they do seem redundant to
> me.
> 
>> So, I would leave the check there, maybe use a separate discussion for removal of the check.
> 
> I tried to find a way to trigger it and couldn't figure out anything,
> to me it seems unreachable.
> 
>> However, there is a call path: vacuum -> vacuum_rel -> cluster_rel -> rebuild_relation -> mark_index_clustered. I am not sure if the check plays some role there.
> 
> VACUUM FULL always passes InvalidOid to the cluster_rel for the index
> parameter, so we can't hit the error.
> 
> CLUSTER is more difficult to follow, but to me that also seems like to
> never hit this error, and the behavior I see is also described in the
> documentation (mark_index_clustered is only called for leaf
> partitions, where it works). Following the calls in the code also
> shows the same to me, that this method is now only called for
> partitions.

I will need more investigation on this, so let’s leave it for a seperate discussion.

> 
>> No, the check is not redundant. It checks for child partitions, while ATPrepChangeInherit only blocks partitioned tables.
> 
> And I have the same issue with this one: I modified that error in
> ATExecDropInherit to an assertion locally. The test suite had no new
> failures, I also tried to write a few tests manually, but I wasn't
> able to trigger it. Maybe I'm missing something, but I think it's
> redundant now.

I added two new test cases in 0002 that trigger the check.

BTW, this is the CF entry: https://commitfest.postgresql.org/patch/6415/. You may mark yourself as a reviewer, and once you consider the patch is ready to go, would you mind change the status to Ready For Committer?

PFA v6.


Best regards,
--
Chao Li (Evan)
HighGo Software Co., Ltd.
https://www.highgo.com/