Restrict SQL Server Login –SQL Server 2005

There is always a need to restrict the user logins into the SQL Server databases. Many DBA’s face this difficulty, as the restriction of logins has to be done for different users with different requirements. SQL Server 2005 introduces an option called “LOGON” triggers which is an easy way restrict the number of user logins as per our requirements.

This Logon trigger is created directly on the database server and registered on the master database. The below sample demonstrates the use of login triggers to restrict the user “john” from accessing the database using “SQL Query Analyzer” window.


USE master
GO
CREATE TRIGGER trgRestrictUser
ON ALL SERVER WITH EXECUTE AS 'sa'
FOR LOGON
AS
BEGIN
IF (ORIGINAL_LOGIN()= 'john' AND APP_NAME() = 'Microsoft SQL Server Management Studio - Query')
ROLLBACK;
END;

This logon trigger can be used for various auditing purposes in SQL Server. This is a new feature introduced in the SQL Sever 2005 Service Pack 2.We need to upgrade to SP2 to use this feature.

Below links can give more information about Logon triggers
http://msdn2.microsoft.com/en-us/library/bb326598.aspx

SQL Server TempDB useful tips

Moving Temp Database Files
Step 1:
Move the tempdb files to a new physical location (mostly on disk drive in RAID protection 1, 1 + 0 or 5 )
use master
GO
Alter database tempdb modify file (name = tempdev, filename = '\tempdev.mdf')
GO
Alter database tempdb modify file (name = templog, filename = '\templog.ldf')
GO
Step 2:
Restart the SQL Server service
Step 3:
On Restart the tempdb will be created with the new location specified
Step 4:
Remove the data and log file of the tempdb from the old location

Starting SQL Server without TempDB
SQL Server cannot operate with out the tempdb database.When the tempdb filesare corrupted / deleted accidentaly we can restart the SQL Server using the following commandline utlitity
SQLSERVER.exe –s -f -c -T3609

TempDB Best Practices
The below link explains some of the best practices on using the tempdb
http://www.mssqltips.com/tip.asp?tip=1432