Oracle Natural Joins and Count(1)

Question

Does anyone know why in Oracle 11g when you do a Count(1) with more than one natural join it does a cartesian join and throws the count way off?

Such as

<         


        

Answer 1

My advice would be to NOT use NATURAL JOIN. Explicitly define your join conditions to avoid confusion and "hidden bugs". Here is the official NATURAL JOIN Oracle documentation and more discussion about this subject.