tariq_oracle

 Profile Answers by tariq_oracle 

• Apr 13th, 2008

 

subquery: required in those cases where requisted data are not known
                  and always depend on inner query

correlated subquery: outer depend on  inner query and inner query depend on                                   outer query

krishnaindia2007

 Profile Answers by krishnaindia2007 

• Jun 20th, 2008

 

In sub query the inner query is executed only once. Depeding upon the results of inner query , outer query is evaluated.

In correlated subquery the inner query is evaluated once for each row processed by the parent statement or outer query.