SELECT
   Total_Rows= SUM(st.row_count)
FROM
   sys.dm_db_partition_stats st
WHERE
    object_name(object_id) = 'T' AND (index_id < 2);


select COUNT(*) from T;

SELECT COUNT(*)AS CNTT FROM TABLEA(WITH NOLOCK)

SELECT  s.name AS [schema], t.name TableName,   p.rows 
from sys.objects t     -- with (nolock)
JOIN sys.schemas s 
     ON t.schema_id=s.schema_id
	 JOIN sys.partitions  p 
	        ON p.object_id = t.object_id 
			JOIN sys.indexes i 
			ON i.index_id=p.index_id AND t.object_id=i.object_id
			WHERE 
			t.type = 'U' and i.type_desc in ('CLUSTERED','HEAP')  
			order by  3 desc