Tomas Vondra <tomas.vondra@enterprisedb.com> writes:
> That's unlikely, I think. The regression tests are constructed so that
> the estimates are stable. It's more likely this is some difference in
> rounding behavior, for example.
The reported delta is in the actual row count, not an estimate.
How could that be subject to roundoff issues? And there's no
delta in the Append's inputs, so this seems like it's a flat-out
miss of a row count in EXPLAIN ANALYZE.
> I wonder which msvc builds are used on
> the machines that fail/pass the tests, and if the compiler flags are the
> same.
Yeah, this might be a fruitful way to figure out "what's different
from the buildfarm".
regards, tom lane