SQL memory usage

 SELECT object_name, counter_name, cntr_value/1024/1024 AS 'Total Server Memory (KB)'

FROM sys.dm_os_performance_counters

WHERE counter_name = 'Total Server Memory (KB)'

SELECT (physical_memory_in_use_kb / 1024) AS CurrentlyUsedMemorybySQLServer

    ,(locked_page_allocations_kb / 1024) AS Locked_pages_used_Sqlserver_MB

    ,(total_virtual_address_space_kb / 1024) AS Total_VAS_in_MB

    ,process_physical_memory_low

    ,process_virtual_memory_low

FROM sys.dm_os_process_memory;