Rule Definition
Cartesian joins which lead to cartesian products is an absolute performance killer, especially when large data sets are involved. A cartesian join is a multiple-table query that does not explicitly state a join condition among the tables, it creates a Cartesian product. A Cartesian product consists of every possible combination of rows from the tables. This result set is usually extremely large and unwieldy, killing application performance. In addition, most of the time, this is also a functional bug.

Remediation
Check the statement and if so, add a join's clause between the tables.

Violation Code Sample

Select * from table1, table2

other exemple:

hypothsis
Select count(*) from publishers
->3 rows
Select count(*) from roysched
->87 rows
Select count(*) from Titles
-> 18 rows
example of cartesian  product 
 
Select p.pub_name, p.city, t.title, r.royalty
From
 publishers p,
 titles t,
 roysched r
--> 4698 rows( 87 x 18 x 3)
 
Select p.pub_name, p.city, t.title, r.royalty
From
 publishers p,
 titles t,
 roysched r 
Where
 p.pub_id = t.pub_id
--> 1566 rows ( 87 x 18)
 
Select p.pub_name, p.city, t.title, r.royalty
From
 publishers p,
 titles t,
 roysched r 
Where
 p.pub_id = t.pub_id AND
 r.royalty = 14 
--> 252 rows

Fixed Code Sample

Select * from table1 T1 inner join table2 T2 on (T1.C = T2.C)

example of non cartesian product:
Select p.pub_name, p.city, t.title, r.royalty
From
 publishers p,
 titles t,
 roysched r 
Where
 p.pub_id = t.pub_id AND
 t.title_id = r.title_id
--> 87 rows