Query Not Executing.

hello,

Here is the query.

select Count(*)

from

(select Datepart(yyyy,Activitydate) [Year], Month(ActivityDate) [Month] ,DataCenter, Farm

from Daily

where DATEPART(yyyy, ActivityDate) = DATEPART(yyyy, getdate()) and Month(ActivityDate) = 3

Group By Datepart(yy,Activitydate), Month(ActivityDate), DataCenter, Farm

) A

INNER JOIN

(SELECT *

from Monthly

where Year = DATEPART(yyyy, getdate())
) B

ON

A.Year = B.Year and

A.Month = B.Month and

A.DataCenter = B.DataCenter and

A.Farm = B.Farm


Above query executes fine giving output as 3519; that too in 1sec.
However when i try to apply criteria on Monthly table of Month=3, query just keeps executing for hours..


Following query does not work.


select Count(*)

from

(select Datepart(yyyy,Activitydate) [Year], Month(ActivityDate) [Month] ,DataCenter, Farm

from Daily

where DATEPART(yyyy, ActivityDate) = DATEPART(yyyy, getdate()) and Month(ActivityDate) = 3

Group By Datepart(yy,Activitydate), Month(ActivityDate), DataCenter, Farm

) A

INNER JOIN

(SELECT *

from Monthly

where Year = DATEPART(yyyy, getdate()) and [Month] = 3

) B

ON

A.Year = B.Year and

A.Month = B.Month and

A.DataCenter = B.DataCenter and

A.Farm = B.Farm



I am confused on what could be the problem.
Please suggest.

Thanks
Sandeep.