Is NATURAL (JOIN) considered harmful in production environment?

Question

I am reading about NATURAL shorthand form for SQL joins and I see some traps:

• it just takes automatically all same named column-pairs (use USI

Answer 1

Adding an extra reason not listed in any of the answers above. In postgres (not sure if this the case for other databases) if no column names are found in common between the two tables when using NATURAL JOIN then a CROSS JOIN is performed. This means that if you had an existing query and then you were to subsequently change one of the column names in a table, you would still get a set of rows returned from the query rather than an error. If instead you used the JOIN ... USING(...) syntax you would get an error if the joining column was no longer there.

The postgres documentation has a note to this effect:

Note: USING is reasonably safe from column changes in the joined relations since only the listed columns are combined. NATURAL is considerably more risky since any schema changes to either relation that cause a new matching column name to be present will cause the join to combine that new column as well.