Thomas Munro <thomas.munro@gmail.com> writes:
> cfbot found another source of nondeterminism in the regression tests,
> due to the smaller shared_buffers used in this TAP test:
This failure seems related but not identical:
https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=myna&dt=2022-04-02%2004%3A00%3A26
portals.out is expecting that the "foo25ns" cursor will read
starting at the beginning of tenk1, but it's starting somewhere
else, which presumably is a syncscan effect.
I think the fundamental instability here is that this TAP test is
setting shared_buffers small enough to allow the syncscan logic
to kick in where it does not in normal testing. Maybe we should
just disable syncscan in this test script?
regards, tom lane