Re: Reviewing freeze map code

On Mon, Jun 6, 2016 at 11:35 AM, Andres Freund  wrote:
>> We need a read-only utility which checks that the system is in a correct
>> and valid state.  There are a few of those which have been built for
>> different pieces, I believe, and we really should have one for the
>> visibility map, but I don't think it makes sense to imply in any way
>> that VACUUM can or should be used for that.
>
> Meh. This is vacuum behaviour that *has existed* up to this point. You
> essentially removed it. Sure, I'm all for adding a verification
> tool. But that's just pie in the skie at this point.  We have a complex,
> data loss threatening feature, which just about nobody can verify at
> this point. That's crazy.

FWIW, I agree with the general sentiment. Building a stress-testing
suite would have been a good idea. In general, testability is a design
goal that I'd be willing to give up other things for.

-- 
Peter Geoghegan