(2018/04/07 4:17), Andres Freund wrote:
On 2018-03-05 17:07:10 -0500, Tom Lane wrote:
Meanwhile, I'm back to wondering what could possibly have affected
the planner's estimates, if pg_proc and pg_statistic didn't change.
I confess bafflement ... but we've now eliminated the autovacuum-
did-it theory entirely, so it's time to start looking someplace else.
I wonder if something in the postgres_fdw remote join machinery
is not as deterministic as it should be.
I wonder if temporarily changing postgres_fdw's test to specify an extra
config that installs auto_explain in full aggressiveness (i.e. including
costs etc) and enables debug3 logging could help narrow this down?
+1 because we cannot deny the possibility that the plan instability is
caused by such an unexpected behavior of postgres_fdw.