"Kevin Grittner" <Kevin.Grittner@wicourts.gov> writes:
> It's easy to see how it resolves the column references; but the syntax
> is still not compliant with the SQL standard. The FROM clause is
> required. We could call it a PostgreSQL extension, but I'm curious if
> anyone actually finds it useful.
You've never done "SELECT some_expression" ?
regards, tom lane