Re: Should we remove vacuum_defer_cleanup_age?

On 4/13/23 11:32 AM, Jonathan S. Katz wrote:
> On 4/12/23 11:34 PM, Amit Kapila wrote:
>> On Tue, Apr 11, 2023 at 11:50 PM Andres Freund <andres@anarazel.de> 

>> +1 to do one of the above. I think there is a good chance that
>> somebody might be doing more harm by using it so removing this
>> shouldn't be a problem. Personally, I have not heard of people using
>> it but OTOH it is difficult to predict so giving some time is also not
>> a bad idea.
>>
>> Do others have any opinion/suggestion on this matter?
> 
> I need a bit more time to study this before formulating an opinion on 
> whether we should remove it for v16. In any case, I'm not against 
> documentation.

(didn't need too much more time).

[RMT hat]

+1 for removing.

I looked at some data and it doesn't seem like vacuum_defer_cleanup_age 
is used in any significant way, whereas hot_standby_feedback is much 
more widely used. Given this, and all the problems + arguments made in 
the thread, we should just get rid of it for v16.

There are cases where we should deprecate before removing, but I don't 
think this one based upon usage and having a better alternative.

Per [1] it does sound like we can make some improvements to 
hot_standby_feedback, but those can wait to v17.

We should probably set $DATE to finish this, too. I don't think it's a 
rush, but we should give enough time before Beta 1.

Jonathan

[1] 
https://www.postgresql.org/message-id/20230317230930.nhsgk3qfk7f4axls%40awork3.anarazel.de