Listing 1: Calculating the Total I/O for Each Database 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; 1