SELECT COUNT(*) AS [Nb_Total_Plans]
,SUM(c.size_in_bytes)/(1024*1024) AS [Total_Cache_Size_Mo]
FROM sys.dm_exec_cached_plans c 
CROSS APPLY sys.dm_exec_sql_text(plan_handle) s

SELECT COUNT(*) AS [Nb_Total_Plans]
,SUM(c.size_in_bytes)/(1024*1024) AS [Total_Cache_Size_Mo]
FROM sys.dm_exec_cached_plans c