Re: select_parallel test failure: gather sometimes losing tuples (maybe during rescans)?

Thomas Munro wrote:
> On Sun, Mar 4, 2018 at 10:46 PM, Magnus Hagander <magnus@hagander.net> wrote:
> > Um. Have you actually seen the "mail archive app" cut long threads off in
> > other cases? Because it's certainly not supposed to do that...
> 
> Hi Magnus,
> 
> I mean the "flat" thread view:
> 
> https://www.postgresql.org/message-id/flat/CAFjFpRfQ8GrQvzp3jA2wnLqrHmaXna-urjm_UY9BqXj=EaDTSA@mail.gmail.com
> 
> The final message on that page is not the final message that appears
> in my mail client for the thread.  I guessed that might have been cut
> off due to some hard-coded limit, but perhaps there is some other
> reason (different heuristics for thread following?)

You're thinking of message
https://www.postgresql.org/message-id/CAFjFpRfa6_n10cn3vXjN9hdTqneH6A1rfnLXy0PnCP63T2putw@mail.gmail.com
but that is not the same thread -- it doesn't have the References or
In-Reply-To headers (see "raw"; user/pwd is archives/antispam).  Don't
know why though -- maybe Gmail trimmed References because it no longer
fit in the DKIM signature?  Yours had a long one:
https://www.postgresql.org/message-id/raw/CAEepm%3D0VCrC-WfzZkq3YSvJXf225rDnp1ypjv%2BrjKO5d0%3DXqFg%40mail.gmail.com

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services