Guest

• Jan 9th, 2007

 

when a join condition is omited when getting  result from two tables then that kind of query gives us Cartesian product, in which all combination of rows displayed. All rows in the first table is joined to all rows of second table......

Ajay Nerumati

 Profile Answers by Ajay Nerumati 

• Jan 29th, 2007

 

Hi All,It is a common requirement in Oracle to join tables using join syntax, you end up getting a cartesian product 1. when a join condition is ommited .2. The condition is not a valid condition.Under such curcumstances all rows of table 'A' are mapped to table 'N', resulting in A*N number or rows.Thank you,Ajay Nerumati.Oracle DBA

g_sidhu

 Profile 

• Feb 12th, 2008

 

Cartesian Products: If two tables in a join query have no join condition, Oracle returns their Cartesian product. Oracle combines each row of one table with each row of the other. A Cartesian product always generates many rows and is rarely useful.• A Cartesian product is formed when:– A join condition is omitted– A join condition is invalid– All rows in the first table are joined to all rows in the second table

• To avoid a Cartesian product, always include a valid join condition in a WHERE clause.

safdar

 Profile Answers by safdar 

• Feb 14th, 2008

 

hi
we have two table emp and dept in scott user
emp have 14 rows and dept have 5 rows
if we write this query
select emp.ename,emp.sal,dept.dname from emp,dept;
this query provide you 70 rows
this called cartesian product 14*5

sampra

 Profile Answers by sampra 

• Feb 26th, 2008

 

when a join condition is omited when getting  result from two tables then that kind of query gives us Cartesian product, in which all combination of rows displayed. All rows in the first table is joined to all rows of second table......

jomarie

• Sep 2nd, 2014

 

this is formed when join conditions is omitted or invalid