SELECT	CASE counter_name 
			WHEN 'Target Server Memory (KB)' THEN 'MemoryAssignedToSQLServer'
			WHEN 'Total Server Memory (KB)' THEN 'MemoryUsedBySQLServer'
		END AS Property,
		(cntr_value/1024) AS Value_MB
FROM	sys.dm_os_performance_counters
WHERE	counter_name IN ('Target Server Memory (KB)','Total Server Memory (KB)')

We walk in the dark places no others will enter
We stand on the bridge and no one may pass