Tom Lane wrote:
...planner is actually going to choose based on the ultimate join cost,
not on the subplan costs...
In this explanation, the reason for the change in plans over time could
be a change in the statistics for the other table. Is "facets" more
dynamic than "point_features"?
In total rows changing it's more dynamic, but percentage-wise, it's
less dynamic (point_features probably turns round 50% of it's rows
in a day -- while facets turns over about 3% per day -- but facets
is 1000X larger).
Facets is a big table with rather odd distributions of values.
Many of the values in the indexed columns show up only
once, others show up hundreds-of-thousands of times. Perhaps
an analyze ran and just randomly sampled differently creating
different stats on that table?
