select 
* 
from
( select DIM_year, DIM_COSTCENTER, data  from
ODI_STAGE.dbo.T_LOAD_DATA_DEVPLAN  where SESSION_ID=3353 and DIM_ACCOUNT='AC.DP.15009' ) 
n 
left join
( select DIM_year, DIM_COSTCENTER, data  from
ODI_STAGE.dbo.T_LOAD_DATA_DEVPLAN  where SESSION_ID=3307 and DIM_ACCOUNT='AC.DP.15009')
 o
on n.DIM_COSTCENTER=o.DIM_COSTCENTER and n.dim_year=o.DIM_YEAR and n.DATA=o.DATA
where 
 n.DATA<>o.DATA or (o.DATA is null or  n.DATA is null)