Re: snapshot too old issues, first around wraparound and then more.

On Wed, Apr 1, 2020 at 10:28 AM Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> Sure, but not all levels of risk are equal. Jumping out of a plane
> carries some risk of death whether or not you have a parachute, but
> that does not mean that we shouldn't worry about whether you have one
> or not before you jump.
>
> In this case, I think it is pretty clear that hard-disabling the
> feature by always setting old_snapshot_threshold to -1 carries less
> risk of breaking unrelated things than removing code that caters to
> the feature all over the code base. Perhaps it is not quite as
> dramatic as my parachute example, but I think it is pretty clear all
> the same that one is a lot more likely to introduce new bugs than the
> other. A carefully targeted modification of a few lines of code in 1
> file just about has to carry less risk than ~1k lines of code spread
> across 40 or so files.

Yeah, that's certainly true. But is that fine point really what
anybody disagrees about? I didn't think that Andres was focussed on
literally ripping it out over just disabling it.

> Is there any chance that you're planning to look into the details?
> That would certainly be welcome from my perspective.

I had a few other things that I was going to work on this week, but
those seems less urgent. I'll take a look into it, and report back
what I find.

--
Peter Geoghegan