Oracle - What is correlated
sub-query? - August 11, 2008 at 15:00 PM by Amit Satpute
What is correlated sub-query?
In a simple SubQuery, the
result retrieved by the inner query is fed to the outer query. The outer query
takes the result as its input and processes it to produce its output.
However, in a corelated sub query, a correlated sub-query is dependent upon the
The outer query and the sub-query are related typically through a WHERE
statement located in the sub-query.
The sub query gives a reference to the outer query. Then the outer query
executes and the result is returned to the sub query. Finally the sub query is
executed for every row that is selected by the outer query