Re: [BUG] wrong refresh when ALTER SUBSCRIPTION ADD/DROP PUBLICATION - Mailing list pgsql-hackers

From Li Japin
Subject Re: [BUG] wrong refresh when ALTER SUBSCRIPTION ADD/DROP PUBLICATION
Date
Msg-id 96FBCE8E-45C4-45A2-8CCE-BD5526F20220@hotmail.com
Whole thread Raw
In response to Re: [BUG] wrong refresh when ALTER SUBSCRIPTION ADD/DROP PUBLICATION  (Amit Kapila <amit.kapila16@gmail.com>)
List pgsql-hackers

> On Aug 7, 2021, at 1:35 PM, Amit Kapila <amit.kapila16@gmail.com> wrote:
> 
> On Fri, Aug 6, 2021 at 9:57 PM Japin Li <japinli@hotmail.com> wrote:
>> 
>>> 
>>> Hmm yes, it cannot cover all cases. I had somehow misunderstood that
>>> the subscriber knows which relations are associated with which
>>> publications. Given that the subscriber doesn’t know which relations
>>> are associated with which publications (and the set of subscribed
>>> relations on the subscriber becomes out of date once the publication
>>> is updated), I think it's impossible to achieve that DROP PUBLICATION
>>> drops relations that are associated with only the publication being
>>> dropped.
>>> 
>>>> Do we have better ideas to fix or shall we just
>>>> say that we will refresh based on whatever current set of relations
>>>> are present in publication to be dropped?
>>> 
>>> I don't have better ideas. It seems to me that it's prudent that we
>>> accept the approach in v3 patch and refresh all publications in DROP
>>> PUBLICATION cases.
>>> 
>> 
>> Maybe refreshing all publications in PUBLICATION cases is simple way to
>> fix the problem.
>> 
> 
> Do you mean to say that do it for both Add and Drop or just for Drop?
> Actually, doing it both will make the behavior consistent but doing it
> just for Drop might be preferable by some users. I think it is better
> to be consistent here but I am fine if you and others feel it is
> better to refresh all publications only in Drop case.
> 

I prefer to refresh all PUBLICATIONS for both ADD and DROP operations, I think
this is more consistent and makes the code simple.

--
Best regards
Japin Li




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