Because with USING, you're precluded from using the full table.column identifier in your JOIN condition. Without that, a future ALTER TABLE that adds another "b

Because with USING, you're precluded from using the full table.column identifier in your JOIN condition. Without that, a future ALTER TABLE that adds another "bar" column to an existing table in the FROM-list will cause a previously-working query to break. https://gist.github.com/AdamG/1128b86fdafca1e53a4bd5253a6882a2 https://gist.github.com/AdamG/1128b86fdafca1e53a4bd5253a6882...