Re: Skipping logical replication transactions on subscriber side

On Fri, Oct 1, 2021 at 5:32 PM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>
> On Fri, Oct 1, 2021 at 6:30 AM Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
> >
> > On Fri, Oct 1, 2021 at 5:05 AM Peter Eisentraut
> > <peter(dot)eisentraut(at)enterprisedb(dot)com> wrote:
> > >
> > > On 30.09.21 07:45, Masahiko Sawada wrote:
> > > > I've attached updated patches that incorporate all comments I got so
> > > > far. Please review them.
> > >
> > > I'm uneasy about the way the xids-to-be-skipped are presented as
> > > subscriptions options, similar to settings such as "binary". I see how
> > > that is convenient, but it's not really the same thing, in how you use
> > > it, is it? Even if we share some details internally, I feel that there
> > > should be a separate syntax somehow.
> >
> > Since I was thinking that ALTER SUBSCRIPTION ... SET is used to alter
> > parameters originally set by CREATE SUBSCRIPTION, in the first several
> > version patches it added a separate syntax for this feature like ALTER
> > SUBSCRIPTION ... SET SKIP TRANSACTION xxx. But Amit was concerned
> > about an additional syntax and consistency with disable_on_error[1]
> > which is proposed by Mark Diliger[2], so I’ve changed it to a
> > subscription option.
> >
>
> Yeah, the basic idea is that this is not the only option we will
> support for taking actions on error/conflict. For example, we might
> want to disable subscriptions or allow skipping transactions based on
> XID, LSN, etc.

I guess disabling subscriptions on error/conflict and skipping the
particular transactions are somewhat different types of functions.
Disabling subscriptions on error/conflict seems likes a setting
parameter of subscriptions. The users might want to specify this
option at creation time. Whereas, skipping the particular transaction
is a repair function that the user might want to use on the spot in
case of a failure. I’m concerned a bit that combining these functions
to one syntax could confuse the users.

Regards,

--
Masahiko Sawada
EDB: https://www.enterprisedb.com/