Re: Skipping logical replication transactions on subscriber side

On 03.12.21 03:53, Amit Kapila wrote:
>> I don't know how difficult it would be, but allowing multiple xids might
>> be desirable.
>
> Are there many cases where there could be multiple xid failures that
> the user can skip? Apply worker always keeps looping at the same error
> failure so the user wouldn't know of the second xid failure (if any)
> till the first failure is resolved.

Yeah, nevermind, doesn't make sense.

> Yeah, I also think so. BTW, what do you think of providing extra
> flexibility of giving other options like 'operation', 'rel' along with
> xid? I think such options could be useful for large transactions that
> operate on multiple tables as it is quite possible that only a
> particular operation from the entire transaction is the cause of
> failure. Now, on one side, we can argue that skipping the entire
> transaction is better from the consistency point of view but I think
> it is already possible that we just skip a particular update/delete
> (if the corresponding tuple doesn't exist on the subscriber). For the
> sake of simplicity, we can just allow providing xid at this stage and
> then extend it later as required but I am not very sure of that point.

Skipping transactions partially sounds dangerous, especially when
exposed as an option to users. Needs more careful thought.