Re: BUG #17220: ALTER INDEX ALTER COLUMN SET (..) with an optionless opclass makes index and table unusable

On 10/13/21 2:06 AM, Bossart, Nathan wrote:
> On 10/11/21, 11:03 AM, "Vik Fearing" <vik@postgresfriends.org> wrote:
>> On 10/11/21 5:25 PM, PG Bug reporting form wrote:
>>>
>>> User 'musttu' on IRC reported the following bug: After running "ALTER INDEX
>>> some_idx ALTER COLUMN expr SET (n_distinct=100)", the index and table become
>>> unusable. All further statements involving the table result in: "ERROR:
>>> operator class text_ops has no options".
>>>
>>> They reported this on the RDS version of 13.3, but I've been able to
>>> reproduce this on Debian with 13.4 and 14.0. It does not reproduce on 12.8,
>>> all statements succeed on that version.
>>
>> This was broken by 911e702077 (Implement operator class parameters).
> 
> Moving to pgsql-hackers@.
> 
> At first glance, it looks like ALTER INDEX .. ALTER COLUMN ... SET
> uses the wrong validation function.  I've attached a patch where I've
> attempted to fix that and added some tests.

Ah, thank you.  I was in the (slow) process of writing basically this
exact patch.  So I'll stop now and endorse yours.
-- 
Vik Fearing