Thanks for reply....

the main difference i have seen in these are

Left Join: i need to prepare the query as table (Temporary Table) and actual join will be provided after filtering of data using "ON"

Cross Apply: i can prepare the Temporary Table in that i can make use of my parent table reference.

Example:

Left Join:

Select r.Name, r.EmailID, ISNULL(j.Employer) as PresentEmployer From CandidateInfo r WITH (NOLOCK)

LEFT JOIN (Select CandID, Employer From JOB_EMPLOYER WITH (NOLOCK)) as j ON j.CandID = r.ID

OUTER APPLY:

Select r.Name, r.EmailID, ISNULL(j.Employer) as PresentEmployer From CandidateInfo r WITH (NOLOCK)

OUTER APPLY (Select Employer From JOB_EMPLOYER WITH (NOLOCK) Where CandID = r.ID) as j

These two sample queries are examples in which i actually use Pivot output as table and that will be joining with parent table for getting details.

As per my observation in SQL Server 2005, i was not seen any greater performance when i user CROSS APPLY but query output was faster and worker table load was also pretty low when i user CROSS APPLY in SQL Server 2008.

But same query was not performing properly if use this logic for other combination.

So i want to know that is there any dependency or specific formation where and when we can use CROSS APPLY.