Re: Assertion failing in master, predicate.c

On 11/22/19 11:07 AM, Tom Lane wrote:
> Mark Dilger <hornschnorter(at)gmail(dot)com> writes:
>> On 11/21/19 8:03 PM, Tom Lane wrote:
>>> I also confirm that it only happens in HEAD, not v12. I've not
>>> actually bisected, but a look at the git history for predicate.c
>>> sure makes it look like db2687d1f ("Optimize PredicateLockTuple")
>>> must be to blame.
>
>> `git bisect` shows the problem occurs earlier than that, and by
>> chance the first bad commit was one of yours. I'm not surprised
>> that your commit was regarding LISTEN/NOTIFY, as the error is
>> always triggered with a LISTEN statement. (I've now hit this
>> many times in many tests of multiple SQL statements, and the
>> last statement before the error is always a LISTEN.)
>
> Oh my, that's interesting! I had wondered a bit about the LISTEN
> changes, but it's hard to see how those could have any connection
> to serializable mode. This will be an entertaining debugging
> exercise ...

predicate.c was changed a few times after REL_12_STABLE was
branched from master but before Thomas's change that you
initially thought might be to blame. I checked whether
rolling back the changes in predicate.c while keeping your
LISTEN/NOTIFY changes might fix the bug, but alas the bug
is still present.

I'll go familiarize myself with your LISTEN/NOTIFY changes
now....

--
Mark Dilger