Re: Question about StartLogicalReplication() error path

Hi,

On 2021-06-11 16:05:10 -0400, Robert Haas wrote:
> You seem to see this as some kind of major problem and I guess I don't
> agree. I think it's pretty clear what the motivation was for the
> current behavior, because I believe it's well-explained by the comment
> and the three people who have tried to answer your question. I also
> think it's pretty clear why somebody might find it surprising: someone
> might think that fast-forwarding is harmful and risky rather than a
> useful convenience. As evidence for the fact that someone might think
> that, I offer the fact that you seem to think exactly that thing. I
> also think that there's pretty good evidence that the behavior as it
> exists is not really so bad. As far as I know, and I certainly might
> have missed something, you're the first one to complain about behavior
> that we've had for quite a long time now, and you seem to be saying
> that it might cause problems for somebody, not that you know it
> actually did. So, I don't know, I'm not opposed to talking about
> potential improvements here, but to the extent that you're suggesting
> this is unreasonable behavior, I think that's too harsh.

Yea. I think it'd be a different matter if streaming logical decoding
had been added this cycle and we'd started out with supporting queries
over replication connection - but it's been long enough that it's likely
that people rely on the current behaviour, and I don't see the gain in
reliability outweigh the compat issues.

Your argument that one can just check kinda goes both ways - you can do
that with the current behaviour too...

Greetings,

Andres Freund