query SQL CPU and I/O utilization

-- Get CPU utilization by database

WITH DB_CPU_Stats
AS
(SELECT DatabaseID, DB_Name(DatabaseID) AS [DatabaseName], SUM(total_worker_time) AS [CPU_Time_Ms]
 FROM sys.dm_exec_query_stats AS qs
 CROSS APPLY (SELECT CONVERT(int, value) AS [DatabaseID]
              FROM sys.dm_exec_plan_attributes(qs.plan_handle)
              WHERE attribute = N'dbid') AS F_DB
 GROUP BY DatabaseID)
SELECT ROW_NUMBER() OVER(ORDER BY [CPU_Time_Ms] DESC) AS [row_num],
       DatabaseName, [CPU_Time_Ms],
       CAST([CPU_Time_Ms] * 1.0 / SUM([CPU_Time_Ms]) OVER() * 100.0 AS DECIMAL(5, 2)) AS [CPUPercent]
FROM DB_CPU_Stats
WHERE DatabaseID > 4 -- system databases
AND DatabaseID <> 32767 -- ResourceDB
ORDER BY row_num OPTION (RECOMPILE);

-- Helps determine which database is using the most CPU resources on the instance


-- Get I/O utilization by database
WITH Aggregate_IO_Statistics
AS
(SELECT DB_NAME(database_id) AS [Database Name],
CAST(SUM(num_of_bytes_read + num_of_bytes_written)/1048576 AS DECIMAL(12, 2)) AS io_in_mb
FROM sys.dm_io_virtual_file_stats(NULL, NULL) AS [DM_IO_STATS]
GROUP BY database_id)
SELECT ROW_NUMBER() OVER(ORDER BY io_in_mb DESC) AS [I/O Rank], [Database Name], io_in_mb AS [Total I/O (MB)],
       CAST(io_in_mb/ SUM(io_in_mb) OVER() * 100.0 AS DECIMAL(5,2)) AS [I/O Percent]
FROM Aggregate_IO_Statistics
ORDER BY [I/O Rank] OPTION (RECOMPILE);

-- Helps determine which database is using the most I/O resources on the instance