Umm.. virtually no join on tables with more than a handful of rows is done as a cartesian product. A suitable set of columns is used to sort or hash each side o

Umm.. virtually no join on tables with more than a handful of rows is done as a cartesian product. A suitable set of columns is used to sort or hash each side of the join, such that the actual join logic is basically linear performance (each row in table A is probably only ever paired with approximately 1 row in table B when evaluating the predicates). A cartesian product would involve testing the predicates on every combination of A and B (each row in table A being paired with each row in table B) (Note when I say linear performance, I mean the join predicate is executed a linear amount of times, but the initial sort/hash operation was probably more like O(n log n))