Finally, my true question was
whether Postgres would support something like worm with the
performance benefits of UNLOGGED, but not the inconveniences
of auto truncates.
There are a lot of downsides to this:� file_fdw tables are
read-only, so you have to update the external file through some
other means.� Also, I've never used file_fdw, so I'm not sure
whether you can create indexes on the tables - and even if you can,
you would need to manually recreate the indexes periodically because
Postgresql won't see your updates.