Collections:
What Is fn_virtualfilestats()
What Is fn_virtualfilestats() function view in SQL Server?
✍: FYIcenter.com
fn_virtualfilestats() is a Transact-SQL function view that returns I/O statistics for database files, including log files. In SQL Server, this information is also available from the sys.dm_io_virtual_file_stats dynamic management view.
fn_virtualfilestats() function has the following calling syntax:
fn_virtualfilestats ( { database_id | NULL } , { file_id | NULL } )
If you call it with NULL arguments, it will return I/O statistics for all files of all databases on this server.
fn_virtualfilestats() returns the following output fields on each data files:
Among all output fields, NumberReads, BytesRead, NumberWrites and BytesWritten are very useful to helpful for us to calculate the I/O performance.
For example, the following query returns I/O statistics of the first physical files in the current database:
select * from fn_virtualfilestats(DB_ID(), 1) DBID FILEID NUMBERREADS BYTESREAD NUMBERWRITES BYTESWRITTEN ... 6 1 3 114156 41344335872 1077341 39180853248 ...
⇒ Join sys.allocation_units with fn_virtualfilestats()
⇐ Find the File IDs of a Given Table
2019-06-29, 1731🔥, 0💬
Popular Posts:
How to generate user full names? Test user names are frequently needed in testing applications that ...
How to generate MAC addresses? To help you to obtain some MAC addresses for testing purpose, FYIcent...
How to generate currency test values? Currency test values are frequently needed in testing date and...
How to valid IP addresses? In order to help your programming or testing tasks, FYIcenter.com has des...
How to generate IP Addresses? To help you to obtain some IP addresses for testing purpose, FYIcenter...