I'd like to make add_missing_from=false the default for 8.1. Any objections?
I think the only reason not to do this is for backward compatibility
with previous releases of PostgreSQL, but I don't find that too
compelling: it is easy to fix up queries that rely on the old behavior,
and the old behavior if not compliant with the SQL spec. Also, the admin
can always enable add_missing_from locally if they can't afford to
update their applications. Per usual, we should mention the change
prominently in the "Incompatibilities" section of the release notes.
Barring any objections, I'll send in a patch that implements this soon.
-Neil