SQL Server 2008 Features For The Database Administrator (DBA)

Author: Mike Weiner

Contributor: Burzin Patel,Sanjay Mishra

Reviewers: Lubor Kollar, Kevin Cox, Bill Emmert, Greg Husemeier, Paul Burpo, Joseph Sack, Denny Lee, Lindsey Allen, Mark Souza

Microsoft SQL Server 2008 provides a number of enhancements and new functionality, building on previous versions. Administration, database maintenance, manageability, availability, security, and performance, among others, all fall into the roles and responsibilities of the database administrator. This article provides the top ten new features of SQL Server 2008 (referenced in alphabetical order) that can help DBAs fulfill their responsibilities. In addition to a brief description of each feature, we include how this feature can help and some important use considerations.

Activity Monitor

When troubleshooting a performance issue or monitoring a server in real time, it is common for the DBA to execute a number of scripts or check a number of sources to collect general information about what processes are executing and where the problem may be. SQL Server 2008 Activity Monitor consolidates this information by detailing running and recently executed processes, graphically. The display gives the DBA a high-level view and the ability to drill down on processes and view wait statistics to help understand and resolve problems.

To open up Activity Monitor, just right-click on the registered server name in Object Explorer and then click Activity Monitor, or utilize the standard toolbar icon in SQL Server Management Studio. Activity Monitor provides the DBA with an overview section producing output similar to Windows Task Manager and drilldown components to look at specific processes, resource waits, data file I/Os, and recent expensive queries, as noted in Figure 1.

Figure 1: Display of SQL Server 2008 Activity Monitor view from Management Studio

NOTE: There is a refresh interval setting accessed by right-clicking on the Activity Monitor. Setting this value to a low threshold, under 10 seconds, in a high-volume production system can impact overall system performance.

DBAs can also use Activity Monitor to perform the following tasks:

Pause and resume Activity Monitor with a simple right-click. This can help the DBA to “save” a particular point-in-time for further investigation without it being refreshed or overwritten. However, be careful, because if you manually refresh, expand, or collapse a section, the data will be refreshed.

Right-click a line item to display the full query text or graphical execution plan via Recent Expensive Queries.

Execute a Profiler trace or kill a process from the Processes view. Profiler events include RPC:Completed, SQL:BatchStarting, and SQL:BatchCompleted events, and Audit Login and Audit Logout.

Activity Monitor also provides the ability to monitor activity on any SQL Server 2005 instance, local or remote, registered in SQL Server Management Studio.

[SQL Server] Audit

Having the ability to monitor and log events, such as who is accessing objects, what changes occurred, and what time changes occurred, can help the DBA to meet compliance standards for regulatory or organizational security requirements. Gaining insight into the events occurring within their environment can also help the DBA in creating a risk mitigation plan to keep the environment secure.

Within SQL Server 2008 (Enterprise and Developer editions only), SQL Server Audit provides automation that allows the DBA and others to enable, store, and view audits on various server and database components. The feature allows for auditing at a granularity of the server and/or database level.

There are server-level audit action groups, such as:

FAILED_LOGIN_GROUP, which tracks failed logins.

BACKUP_RESTORE_GROUP, which shows when a database was backed up or restored.

DATABASE_CHANGE_GROUP, which audits when a database is created, altered, or dropped.

Database-level audit action groups include:

DATABASE_OBJECT_ACCESS_GROUP, which is raised whenever a CREATE, ALTER, or DROP statement is executed on database objects.

DATABASE_OBJECT_PERMISSION_CHANGE_GROUP, which is raised when GRANT, REVOKE, or DENY is utilized for database objects.

There are also audit actions, such as SELECT, DELETE, or EXECUTE. For more information, including a full list of the audit groups and actions, see SQL Server Audit Action Groups and Actions.

Audit results can be sent to a file or event log (Windows Security or System) for viewing. Audit information is created utilizing Extended Events, another new SQL Server 2008 feature.

By using SQL Server 2008 audits, the DBA can now answer questions that were previously very difficult to retroactively determine, such as “Who dropped this index?”, “When was the stored procedure modified?”, “What changed which might not be allowing this user to access this table?”, or even “Who ran SELECT or UPDATE statements against the [dbo.Payroll] table?”

For more information about using SQL Server Audit and some examples of implementation, see the SQL Server 2008 Compliance Guide.

Backup Compression

This feature has long been a popular request of DBAs for SQL Server. The wait is finally over, and just in time! Many factors, including increased data retention periods and the need to physically store more data have contributed to the recent explosion in database size. Backing up a large database can require a significant time window to be allotted to backup operations and a large amount of disk space allocated for use by the backup file(s).

With SQL Server 2008 backup compression, the backup file is compressed as it is written out, thereby requiring less storage, less disk I/O, and less time. In lab tests conducted with real customer data, we observed in many cases a reduction in the backup file size between 70% and 85%. Testing also revealed around a 45% reduction in the backup and restore time. It is important to note that the additional processing results in higher processor utilization. To help segregate the CPU intensive backup and minimize its effect on other processes, one might consider utilizing another feature mentioned in this paper, Resource Governor.

The compression is achieved by specifying the WITH COMPRESSION clause in the BACKUP command (for more information, see SQL Server Books Online) or by selecting it in the Options page in the Back Up Database dialog box. To prevent having to modify all existing backup scripts, there is also a global setting to enable compressing all backups taken on a server instance by default. (This setting is accessed by using the Database Settings page of the Server Properties dialog box or by running sp_configure with backup compression default set to 1.) While the compression option on the backup command needs to be explicitly specified, the restore command automatically detects that a backup is compressed and decompresses it during the restore operation.

Backup compression is a very useful feature that can help the DBA save space and time. For more information about tuning backup compression, see the technical note on Tuning the Performance of Backup Compression in SQL Server 2008. NOTE: Creating compressed backups is only supported in SQL Server 2008 Enterprise and Developer editions; however, every SQL Server 2008 edition allows for a compressed backup to be restored.

Central Management Servers

DBAs are frequently responsible for managing not one but many SQL Server instances in their environment. Having the ability to centralize the management and administration of a number of SQL Server instances from a single source can allow the DBA to save significant time and effort. The Central Management Servers implementation, which is accessed via the Registered Servers component in SQL Server Management Studio, allows the DBA to perform a number of administrative tasks on SQL Servers within the environment, from a single management console.

Central Management Servers allow the DBA to register a group of servers and apply functionality to the servers, as a group, such as:

Multiserver query execution: A script can now be executed from one source, across multiple SQL Servers, and be returned to that source, without the need to distinctly log into every server. This can be extremely helpful in cases where data from tables on two or more SQL Servers needs to be viewed or compared without the execution of a distributed query. Also, as long as the syntax is supported in earlier server versions, a query executed from the Query Editor in SQL Server 2008 can run against SQL Server 2005 and SQL Server 2000 instances as well. For more information, see the SQL Server Manageability Team Blog, specifically Multiple Server Query Execution in SQL Server 2008 .

Import and evaluate policies across servers: As part of Policy-Based Management (another new SQL Server 2008 feature discussed in this article), SQL Server 2008 provides the ability to import policy files into particular Central Management Server Groups and allows policies to be evaluated across all of the servers registered in the group

Control Services and bring up SQL Server Configuration Manager: Central Management Servers help provide a central place where DBAs can view service status and even change status for the services, assuming

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