...
> This would make it impossible for SET to have any persistent effect
> at all. (Every SQL command is inside a transaction --- an
> implicitly-established one if necesary, but there is one.)
Of course the behavior would need to be defined from the user's
viewpoint, not from a literal description of how the internals work.
There *is* a difference from a user's PoV between explicit transactions
and single queries, no matter how that is implemented in the PostgreSQL
backend...
Let's not let trivial english semantics divert the discussion please.
- Thomas