To find out Heavy Read/Writes on the DB

SELECT DB_NAME(vfs.DbId) DatabaseName, mf.name,

mf.physical_name, vfs.BytesRead, vfs.BytesWritten,

vfs.IoStallMS, vfs.IoStallReadMS, vfs.IoStallWriteMS,

vfs.NumberReads, vfs.NumberWrites,

(Size*8)/1024 Size_MB

FROM ::fn_virtualfilestats(NULL,NULL) vfs

INNER JOIN sys.master_files mf ON mf.database_id = vfs.DbId

AND mf.FILE_ID = vfs.FileId

GO