Re: Conflict Detection and Resolution

On Mon, Aug 26, 2024 at 2:23 PM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>
> On Thu, Aug 22, 2024 at 3:45 PM shveta malik <shveta(dot)malik(at)gmail(dot)com> wrote:
> >
> > On Wed, Aug 21, 2024 at 4:08 PM Nisha Moond <nisha(dot)moond412(at)gmail(dot)com> wrote:
> > >
> > > The patches have been rebased on the latest pgHead following the merge
> > > of the conflict detection patch [1].
> >
> > Thanks for working on patches.
> >
> > Summarizing the issues which need some suggestions/thoughts.
> >
> > 1)
> > For subscription based resolvers, currently the syntax implemented is:
> >
> > 1a)
> > CREATE SUBSCRIPTION <subname>
> > CONNECTION <conninfo> PUBLICATION <pubname>
> > CONFLICT RESOLVER
> > (conflict_type1 = resolver1, conflict_type2 = resolver2,
> > conflict_type3 = resolver3,...);
> >
> > 1b)
> > ALTER SUBSCRIPTION <subname> CONFLICT RESOLVER
> > (conflict_type1 = resolver1, conflict_type2 = resolver2,
> > conflict_type3 = resolver3,...);
> >
> > Earlier the syntax suggested in [1] was:
> > CREATE SUBSCRIPTION <subname> CONNECTION <conninfo> PUBLICATION <pubname>
> > CONFLICT RESOLVER 'conflict_resolver1' FOR 'conflict_type1',
> > CONFLICT RESOLVER 'conflict_resolver2' FOR 'conflict_type2';
> >
> > I think the currently implemented syntax is good as it has less
> > repetition, unless others think otherwise.
> >
> > ~~
> >
> > 2)
> > For subscription based resolvers, do we need a RESET command to reset
> > resolvers to default? Any one of below or both?
> >
> > 2a) reset all at once:
> > ALTER SUBSCRIPTION <name> RESET CONFLICT RESOLVERS
> >
> > 2b) reset one at a time:
> > ALTER SUBSCRIPTION <name> RESET CONFLICT RESOLVER for 'conflict_type';
> >
> > The issue I see here is, to implement 1a and 1b, we have introduced
> > the 'RESOLVER' keyword. If we want to implement 2a, we will have to
> > introduce the 'RESOLVERS' keyword as well. But we can come up with
> > some alternative syntax if we plan to implement these. Thoughts?
> >
>
> It makes sense to have a RESET on the lines of (a) and (b). At this
> stage, we should do minimal in extending the syntax. How about RESET
> CONFLICT RESOLVER ALL for (a)?
>

Done, v11 implements the suggested RESET command.

> > ~~
> >

--
Thanks,
Nisha