Tag Archives: files

How to move and or rename Database files in SQL Server

An example use case for the process below could be you need to move database files to a new drive. Another example might be your organisation intends to run a legacy database along side a new updated database with both sharing the same database name in the same instance with the files located in the same directory with the same names. Obviously this cannot be done and requires the database names to differ and the files to be renamed or not exist in the same directory.

For example AdventureWorks might become AdventureWorks_Legacy while a new and improved AdventureWorks database retains the original database name. The associated database file names would also need to be changed/moved to reflect this.

Someone might also want to do something like this for test purposes but obviously having test resources in a live environment would not be recommended if avoidable.

The first step to moving and renaming the files is to copy and modify the script below. Note the script below assumes you want to move and change the names of the files. To avoid any database conflicts you only need to do one or the other.

/* 
Find & Replace DbName with the name of the Database you are working with
*/
USE [DbName];

/*
Changing Physical names and paths
Replace 'C:\...\NewDbName.mdf' with full path of new Db file to be used
*/
ALTER DATABASE DbName MODIFY FILE (
	NAME = ' DbName '
	,FILENAME = 'C:\...\NewDbName.mdf'
	);

/*
Replace 'C:\...\NewDbName_log.ldf' with full path of new Db log file to be used
*/
ALTER DATABASE DbName MODIFY FILE (
	NAME = ' DbName _log'
	,FILENAME = 'C:\...\NewDbName_log.ldf'
	);

/*
Changing logical names
*/
ALTER DATABASE DbName MODIFY FILE (
	NAME = DbName
	,NEWNAME = NewDbName
	);

ALTER DATABASE DbName MODIFY FILE (
	NAME = DbName_log
	,NEWNAME = NewDbName_log
	);
Once the script has been set up as desired follow the steps below:
  1. Open Microsoft SQL Server Management Studio (SSMS).
  2. Connect to the server that houses the Db you are working with.
  3. Run the modified script
  4. Right click on the Db in SSMS and select Tasks > Take Offline
  5. If you are moving the database files log into the server that houses the database files and copy and move the MDF and LDF files to the location you specified in first two alter commands. If the script specifies new names rename the copied files to match the names given in the script exactly.
  6. Go back to SSMS and right click on the Db and select Tasks > Bring Online.
  7. If you have moved the files once the database is back online and confirmed working as expected the unused original files can be deleted.
  8. Now you can rename the Db to the new name if you wish using SSMS.

How to demonstrate the fill ratio of separate tempdb files of equal size in SQL Server

This topic reminds of me this little quiz of which jug will fill first.

Pretty much all of the documentation and recommendations out there say to keep the tempdb data files the same size so that the round-robin data flow works properly, i.e. the tempdb data files fill up evenly. This means that the data for a large temp table is actually split across the files and does not reside in one file.

Below is the code necessary to prove this scenario.

I tested this process on Microsoft SQL Server 2012 – Service Pack 1.

If working with a default installation of SQL Server Express The below script should print out the code to generate four equally sized (500 Mb) tempdb data files with no auto growth.

Run the script against the instance, review the print out and then copy/paste and run it against the instance

SET NOCOUNT ON

IF OBJECT_ID('tempdb..#sfs') IS NOT NULL
	DROP TABLE #sfs;
	
DECLARE @TempDbDirectory VARCHAR(MAX)
DECLARE @Sql VARCHAR(MAX)

CREATE TABLE #sfs (
	fileid TINYINT
	,filegroupid TINYINT
	,totalextents INT
	,usedextents INT
	,dbfilename SYSNAME
	,physfile VARCHAR(255)
	);

INSERT INTO #sfs
EXEC ('USE  tempdb; DBCC showfilestats;');

SET @TempDbDirectory = (
		SELECT REPLACE(physfile, 'tempdb.ndf', '')
		FROM #sfs
		WHERE dbfilename = 'tempdev'
		)

SET @Sql = '
USE [tempdb]
GO

DBCC SHRINKFILE (
		N''tempdev''
		,100
		)
GO

USE [tempdb]
GO

ALTER DATABASE [tempdb] MODIFY FILE (
	NAME = N''tempdev''
	,NEWNAME = N''tempdev1''
	)
GO

USE [master]
GO

ALTER DATABASE [tempdb] MODIFY FILE (
	NAME = N''tempdev1''
	,FILENAME = N''' + @TempDbDirectory + 'tempdb.ndf''
	,SIZE = 512000 KB
	,FILEGROWTH = 0
	)
GO

ALTER DATABASE [tempdb] ADD FILE (
	NAME = N''tempdev2''
	,FILENAME = N''' + @TempDbDirectory + 'tempdb2.ndf''
	,SIZE = 512000 KB
		,FILEGROWTH = 0
	)
GO

ALTER DATABASE [tempdb] ADD FILE (
	NAME = N''tempdev3''
	,FILENAME = N''' + @TempDbDirectory + 'tempdb3.ndf''
	,SIZE = 512000 KB
		,FILEGROWTH = 0
	)
GO

ALTER DATABASE [tempdb] ADD FILE (
	NAME = N''tempdev4''
	,FILENAME = N''' + @TempDbDirectory + 'tempdb4.ndf''
	,SIZE = 512000 KB
		,FILEGROWTH = 0

	)
GO

ALTER DATABASE [tempdb] MODIFY FILE (
	NAME = N''templog''
	,FILEGROWTH = 512000 KB
	)
GO
'

PRINT @Sql
Once the script has run restart the server so the changes can take effect.
Once restarted when you look in the SSMS object explorer for the properties of the tempdb you should see a window like below showing the 4 tempdb data files.
tempdbFiles
Because SQL Server has just restarted nothing should be in these files.
You can test this by running the script below. Which return results like this. As you can see GB_Used is 0 for the 4 tempdb data files.
empty Temp Db

/*
Credit for this script goes to:
DAVE TURPIN
http://www.daveturpin.com/2011/07/how-to-drop-a-tempdb-database-file/
*/

-- Is there data in the second file of tempdb?
--drop table #sfs
--drop table #fixed_drives
--drop table #output_table
--drop table #databases
--drop table #dbf
--drop table #fg


IF OBJECT_ID('tempdb..#sfs') IS NOT NULL
	DROP TABLE #sfs;

IF OBJECT_ID('tempdb..#fixed_drives') IS NOT NULL
	DROP TABLE #fixed_drives;

IF OBJECT_ID('tempdb..#output_table') IS NOT NULL
	DROP TABLE #output_table;

IF OBJECT_ID('tempdb..#databases') IS NOT NULL
	DROP TABLE #databases;

IF OBJECT_ID('tempdb..#dbf') IS NOT NULL
	DROP TABLE #dbf;

IF OBJECT_ID('tempdb..#fg') IS NOT NULL
	DROP TABLE #fg;

--------------------------
-- Save result set from showfilestats
--------------------------
CREATE TABLE #sfs (
	fileid TINYINT
	,filegroupid TINYINT
	,totalextents INT
	,usedextents INT
	,dbfilename SYSNAME
	,physfile VARCHAR(255)
	);

------------------------------
-- Save result set from sys.database_files
------------------------------
CREATE TABLE #dbf (
	[file_id] INT
	,file_guid UNIQUEIDENTIFIER
	,[type] TINYINT
	,type_desc NVARCHAR(60)
	,data_space_id INT
	,[name] SYSNAME
	,physical_name NVARCHAR(260)
	,[state] TINYINT
	,state_desc NVARCHAR(60)
	,size INT
	,max_size INT
	,growth INT
	,is_media_ro BIT
	,is_ro BIT
	,is_sparse BIT
	,is_percent_growth BIT
	,is_name_reserved BIT
	,create_lsn NUMERIC(25, 0)
	,drop_lsn NUMERIC(25, 0)
	,read_only_lsn NUMERIC(25, 0)
	,read_write_lsn NUMERIC(25, 0)
	,diff_base_lsn NUMERIC(25, 0)
	,diff_base_guid UNIQUEIDENTIFIER
	,diff_base_time DATETIME
	,redo_start_lsn NUMERIC(25, 0)
	,redo_start_fork_guid UNIQUEIDENTIFIER
	,redo_target_lsn NUMERIC(25, 0)
	,redo_target_fork_guid UNIQUEIDENTIFIER
	,back_lsn NUMERIC(25, 0)
	);

------------------------------
-- Save result set from sys.filegroups select * from sys.filegroups
------------------------------
CREATE TABLE #fg (
	[name] SYSNAME
	,data_space_id INT
	,[type] CHAR(2)
	,type_desc NVARCHAR(60)
	,is_default BIT
	,is_system BIT
	,[filegroup_id] UNIQUEIDENTIFIER
	,log_filegroup_id INT
	,is_read_only BIT
	);

-- Populate #disk_free_space with data 
CREATE TABLE #fixed_drives (
	DriveLetter CHAR(1) NOT NULL
	,FreeMB INT NOT NULL
	);

INSERT INTO #fixed_drives
EXEC master..xp_fixeddrives;

CREATE TABLE #output_table (
	DatabaseName SYSNAME
	,FG_Name SYSNAME
	,GB_Allocated NUMERIC(8, 2)
	,GB_Used NUMERIC(8, 2)
	,GB_Available NUMERIC(8, 2)
	,DBFilename SYSNAME
	,PhysicalFile SYSNAME
	,Free_GB_on_Drive NUMERIC(8, 2)
	);

SELECT NAME AS DBName
INTO #databases
FROM sys.databases
WHERE database_id <= 4
	AND state_desc = 'ONLINE';

DECLARE @dbname SYSNAME;

SELECT @dbname = (
		SELECT TOP (1) DBName
		FROM #databases
		);

DELETE
FROM #databases
WHERE DBName = @dbname;

WHILE @dbname IS NOT NULL
BEGIN
	-- Get the file group data
	INSERT INTO #sfs
	EXEC ('USE ' + @dbname + '; DBCC showfilestats;');

	INSERT INTO #dbf
	EXEC ('USE ' + @dbname + '; SELECT * FROM sys.database_files;');

	INSERT INTO #fg
	EXEC ('USE ' + @dbname + '; SELECT * FROM sys.filegroups;');

	-- Wrap it up!
	INSERT INTO #output_table (
		DatabaseName
		,FG_Name
		,GB_Allocated
		,GB_Used
		,GB_Available
		,DBFilename
		,PhysicalFile
		,Free_GB_on_Drive
		)
	SELECT @dbname AS DATABASE_NAME
		,fg.NAME AS [File Group Name]
		,CAST(((sfs.totalextents * 64.0) / 1024000.0) AS NUMERIC(8, 2)) AS GB_Allocated
		,CAST(((sfs.usedextents * 64.0) / 1024000.0) AS NUMERIC(8, 2)) AS GB_Used
		,CAST((((sfs.totalextents - sfs.usedextents) * 64.0) / 1024000.0) AS NUMERIC(8, 2)) AS GB_Available
		,sfs.dbfilename
		,sfs.physfile
		,CAST((fd.FreeMB / 1000.0) AS NUMERIC(8, 2)) AS Free_GB_on_Drive
	FROM #sfs sfs
	INNER JOIN #dbf dbf ON dbf.[file_id] = sfs.fileid
	INNER JOIN #fg fg ON fg.data_space_id = sfs.filegroupid
	INNER JOIN #fixed_drives fd ON fd.DriveLetter = SUBSTRING(sfs.physfile, 1, 1);

	SELECT @dbname = (
			SELECT TOP (1) DBName
			FROM #databases
			);

	IF @dbname IS NOT NULL
		DELETE
		FROM #databases
		WHERE DBName = @dbname;

	TRUNCATE TABLE #sfs;

	TRUNCATE TABLE #dbf;

	TRUNCATE TABLE #fg;
END

SELECT CONVERT(INT, CONVERT(CHAR, current_timestamp, 112)) AS CaptureDate
	,DatabaseName
	,FG_Name
	,GB_Allocated
	,GB_Used
	,GB_Available
	,DBFilename
	,PhysicalFile
	,Free_GB_on_Drive
FROM #output_table
ORDER BY DatabaseName
	,FG_Name
To test how the files fill you can run the script below which will create a temp table and write 6,553,599 rows of 1 into the table which should reserve over 100 Mb worth of space.

SET NOCOUNT ON; 

DECLARE @x INT

SET @x = 1

CREATE TABLE #MyTempTable (id BIGINT)

WHILE @x < 6553600
BEGIN
		;

	INSERT INTO #MyTempTable (id)
	VALUES (1)

	SET @x = @x + 1
END;
Once it has complete if you run the script above to test the tempdb fill usage again you should see the files have been filled evenly.
Image of evenly filled temp db files

 

How to run multiple SQL scripts automatically in order.

If you’ve been working towards a new deployment to a live database chances are you have written several scripts (possibly dozens) that have been developed/tested against the the development server.

Now the time has come to put the update live. Which would require executing each script against the live database.

This task can be automated by using a very handy batch script to run against the directory the files are saved in.

Caveat: This process does not take into account error handling or rollbacks, it’s just a simple example people can build on.

In order for this to work the files must have been named in a manner that the necessary order of execution corresponds to ascii sort order, i.e. 001_CreateTable.sql, 002_PopulateTable etc. This is standard practice for sql file naming conventions.

Simply create a .BAT file with the following command:
(Swap servername and databaseName for your required server and database names, TIP: SELECT @@servername can provide you with the full server name.)

for %%G in (*.sql) do sqlcmd /S servername /d databaseName -E -i"%%G"
pause

Place this .BAT file in the directory from which you want the .SQL files to be executed, double click the .BAT file and the command will loop and execute every SQL script in the folder.

How to copy only files from a folder and respective subfolders using a batch script

Ok so here’s a nifty little batch script that will loop through all the directories in a directory to gather all the subsequent files into a new directory. (Code at bottom of the page)

(For those of you that don’t know what a batch script is here’s a quick definition. A batch file is a text file that contains a sequence of commands for a computer operating system. It’s called a batch file because it batches (bundles or packages) into a single file a set of commands that would otherwise have to be presented to the system interactively from a keyboard one at a time.)

Here’s a diagram explaining how the batch script provided at the bottom of the page works. (Note that the folders aren’t copied just the files.)

diagram of process

So why would you use this?

Lets say you’re dealing with a system that has outputted thousands of folders into a single folder and each folder contains files.

You could be looking at millions of files to be gathered, a process that cannot be done manually.

Or a simpler use case might be you’ve downloaded thousands of movies and each was put into a separate folder. Now you just want the media files in one location.

How to use:

Open the program notepad.

Copy the code below and past it into notepad saving the file with the extension .bat

Place the batch file in the parent folder, i.e. the folder all the other folders are in.

Double click the batch file.

The batch file will create a folder one directory level above where the parent folder is located and copy all the files to this location.

An example of how to use the file is as follows:

If you had the parent folder “My Movies” on your desktop.

Pasting the batch file into this folder, and double clicking on it, would copy every movie into a folder called “Copied from My Movies” on your desktop.

And here’s the code,
Adiós.