There's Something about SQL! : SQL Server

SQL Server Support, Failover Clustering and Virtualization

beatrice — Fri, 22 May 2009 12:47:00 GMT

On May 19th, Microsoft has updated the Support Policy for Microsoft SQL Server products that are running in a hardware virtualization environment, which you can find at the following link: http://support.microsoft.com/kb/956893/en-us

The main update is related to guest failover clustering, therefore when you create a SQL Server failover cluster inside a virtual machine where the nodes are running as a virtual machine.

In particular:

Guest Failover Clustering is supported for SQL Server 2005 and SQL Server 2008 in a virtual machine for Windows Server 2008 with Hyper-V, Microsoft Hyper-V Server 2008, and SVVP certified configurations provided both of the following requirements are met:

The Operating System running in the virtual machine (the “Guest Operating System”) is Windows Server 2008 or higher

The virtualization environment meets the requirements of Windows 2008 Failover Clustering as documented at The Microsoft Support Policy for Windows Server 2008 Failover Clusters, as documented in the following Microsoft Knowledge Base article:
943984 The Microsoft Support Policy for Windows Server 2008 Failover Clusters

- Beatrice Nicolini -

Whitepaper - Disk Partition Alignment Best Practices for SQL Server

beatrice — Wed, 20 May 2009 10:09:00 GMT

I've blogged some time ago about Microsoft recommendations for maximizing the performances of your disks subsystem for a SQL Server implementation:

SQL Server - Speed up your Disks!

http://blogs.technet.com/beatrice/archive/2008/06/09/sql-server-speed-up-your-disks.aspx

Collection of SQL Server Storage Best Practices

http://blogs.technet.com/beatrice/archive/2008/04/07/collection-of-sql-server-storage-best-practices.aspx

Finally there's available directly from the SQL CAT Team a new whitepaper stating which are the Microsoft guidelines concerning disk partition alignment.

"Disk partition alignment is a powerful tool for improving SQL Server performance. Configuring optimal disk performance is often viewed as much art as science. A best practice that is essential yet often overlooked is disk partition alignment. Windows Server 2008 attempts to align new partitions out-of-the-box, yet disk partition alignment remains a relevant technology for partitions created on prior versions of Windows.

This paper documents performance for aligned and nonaligned storage and why nonaligned partitions can negatively impact I/O performance; it explains disk partition alignment for storage configured on Windows Server 2003, including analysis, diagnosis, and remediation; and it describes how Windows Server 2008 attempts to remedy challenges related to partition alignment for new partitions yet does not correct the configuration of preexisting partitions.

The following topics are also included: background information, implementation, vendor considerations, two essential correlations, valid starting partition offsets, and the simple protocol to align partitions, define file allocation unit size, and assign drive letters. It includes results from tests that show how partition alignment can affect performance for SQL Server 2008"

You can find it here:

http://sqlcat.com/whitepapers/archive/2009/05/11/disk-partition-alignment-best-practices-for-sql-server.aspx

- Beatrice Nicolini -

Old MPS Reports Dismissed - New Version Ready!

beatrice — Tue, 19 May 2009 10:17:00 GMT

A new version of MPS Reports has been released late April, at the following link:

Microsoft Product Support Reports

http://www.microsoft.com/downloads/details.aspx?FamilyId=CEBF3C7C-7CA5-408F-88B7-F9C79B7306C0&displaylang=en

Amongst the main differences:

With the new MPS reports, there is only one download, based on your system architecture (x86 or x64).
The supported Operating Systems for the new tool are Windows XP, Windows Server 2003, Windows Vista and Windows Server 2008.
There are some prerequisites for running the new tool:

Microsoft .NET Framework 2.0
Windows Powershell 1.0
Windows Installer 3.1
Microsoft Core XML Services (MSXML) 6.0

For specific information for running the new version, you can refer to this article form the

Ask The Performance Team:

Two Minute Drill: The New MPS Reports

http://blogs.technet.com/askperf/archive/2009/05/01/two-minute-drill-the-new-mps-reports.aspx

If instead you prefer the old school way, and still like to run the old versions, refer to Tristank blog:

Old MPSReports

http://blogs.technet.com/tristank/archive/2009/05/12/old-mpsreports.aspx

- Beatrice Nicolini -

SQL Server 2005 Service Pack 2 is not successfully updated when you try to install or to uninstall a security update

beatrice — Thu, 19 Feb 2009 13:50:00 GMT

If you recently found yourself in installing latest SQL Server 2005 Security Update (you did installed it right?):

Microsoft Security Bulletin MS09-004 – Important

http://www.microsoft.com/technet/security/bulletin/MS09-004.mspx

..and had a look to the known issues page...

You might have had a heart attack (as I did at first) in seeing the following:

SQL Server 2005 Service Pack 2 is not successfully updated when you try to install or to uninstall a security update

http://support.microsoft.com/kb/957008

"When you try to install a security update for Microsoft SQL Server 2005 Service Pack 2, Microsoft SQL Server 2005 is not successfully updated. This issue occurs because the rollback process for the security updates incorrectly removes the SQL Server 2005 service accounts from the respective local SQL Server service groups. "

You can guess my reaction when immediately I thought: "oh my, so not just this but all previous SQL Server 2005 SP2 Security Updates which I've applied were not successful" :-S!!!

Ok now, did I scare you off? :-)

You can just relax as the title and the description are a bit misleading. Nothing too bad out there (and in fact, title and description are in the process of being updated...)

This issue triggers if and only if for any reason the rollback process is started.

If the build was installed successfully without a rollback (which you can check by verifying the build number), then the security update was installed correctly.

If you check at the end of the process your instance build number (anyway, it is best practice to do so :)) and it matches the Security Update build number - then you are safe.

- Beatrice Nicolini -

DBCC DBREINDEX (aka INDEX REBUILD in 2005) and Statistics Update

beatrice — Fri, 13 Feb 2009 20:09:00 GMT

So - today I've been made this question.

"I have a DB, AUTO_UPDATE_STATISTICS option OFF (very bad idea, anyway :-)), I rebuild my indexes every week. I do not have major changes in my database. As update statistics with fullscan is a side effect of DBCC DBREINDEX (aka INDEX REBUILD in 2005), can I say all my statistics are fine and up to date?"

Well... No :-(

In fact, statistics created from DBCC DBREINDEX (aka INDEX REBUILD in 2005) are only statistics over indexed columns. Statistics over non-indexed column (the ones named something like _WA_sys) are not managed from these operations. Therefore, if you want these to be up to date you need to turn AUTO_UPDATE_SATTISTICS ON or to schedule their management in other way.

More info can be found at:

Is statistics over non-indexed columns updated by index rebuild?

http://sqlblog.com/blogs/tibor_karaszi/archive/2007/08/09/is-statistics-over-non-indexed-columns-updated-by-index-rebuild.aspx

- Beatrice Nicolini -

Microsoft Security Bulletin MS09-004 – Important

beatrice — Wed, 11 Feb 2009 13:30:00 GMT

For your joy (and especially for the joy of my customer :)) yesterday Microsoft has released a new Security Bulletin for SQL Server:

Microsoft Security Bulletin MS09-004 – Important

http://www.microsoft.com/technet/security/bulletin/MS09-004.mspx

This update is marked as important, which stands for: “A vulnerability whose exploitation could result in compromise of the confidentiality, integrity, or availability of users data, or of the integrity or availability of processing resources”.

Systems with SQL Server 7.0 Service Pack 4, SQL Server 2005 Service Pack 3, and SQL Server 2008 are not affected by this issue.

This update will take your implementations at the following build levels:

- SQL 2005 SP2: 3077 (GDR) or 3310 (QFE).

Please note the security update is not included in CU11, which is on build 3301.

Next cumulative update for SQL Server 2005 (ie, CU 12 ETA mid Feb) will include this GDR.

- SQL Server 2000 SP4: 2282 (QFE).

For future reference, The Severity Rating System defines the following levels for vulnerabilities:

Rating	Definition
Critical	A vulnerability whose exploitation could allow the propagation of an Internet worm without user action.
Important	A vulnerability whose exploitation could result in compromise of the confidentiality, integrity, or availability of users data, or of the integrity or availability of processing resources.
Moderate	Exploitability is mitigated to a significant degree by factors such as default configuration, auditing, or difficulty of exploitation.
Low	A vulnerability whose exploitation is extremely difficult, or whose impact is minimal.

- Beatrice Nicolini -

Best Practices for installing SQL Server service packs, hotfixes, cumulative updates

beatrice — Tue, 10 Feb 2009 12:15:00 GMT

There isn't much information around (other than the readme for service packs) on which are the best practices on installing Service Packs, Cumulative Updates, Hotfixes on SQL Server installation.

...well till today really :-)

This is nothing official from Microsoft but still the following are the best practices recommended from my PFE colleague Uttam (which has kindly agreed for me to copy in my blog without any copyright request :) - Txs Uttam) .

Best practices for installing service packs, cumulative updates and hotfixes for SQL Server

Test on a test/dev SQL Server first and only after you have confirmed that all applications are working as expected then install it on a production SQL Server.
Review the Readme for Service Pack/cumulative update/hotfix. Any concerns/recommendations will be found in the readme.
Run DBCC CHECKDB on ALL databases (user and system databases) and ensure that there were no errors reported.
Backup ALL databases (user and system databases) and full-text catalogs (if applicable). This is NOT required but highly recommended.
Stop Monitoring and Anti-virus services
Make sure you have the proper permissions to install (administrative privilege on server/cluster node)
The below points are for clustered SQL Server instance

Make sure ALL SQL resources come online on ALL cluster nodes
Make sure that ALL disk resources (even the ones that not being used by SQL Server) are online and not in failed state.
Verify that there are no dependencies other than those created by the SQL Server setup on any SQL Server cluster resources.
Run MPSRPT_SQL.exe on all cluster nodes (not required but recommended)
Make sure all remote desktop connections are closed. You can connect to the node (you are running the setup from) using remote desktop connections but you should disconnect any remote connections to other cluster nodes.

- Beatrice Nicolini & the real contributor :-) - Uttam Parui -

Are you based in Manchester? Two upcoming FREE SQL events for your agenda!

beatrice — Thu, 22 Jan 2009 14:02:00 GMT

If you are based in Manchester or nearby, there are two interesting FREE SQL Server events planned in town!

5th February: UK SQL Server Usergroup

Agenda has still to be confirmed, and will be posted here: http://www.sqlserverfaq.com/events/147/Manchester-SQL-User-Group-Meeting.aspx

28th March: SQL Bits IV

Agenda (once again) has still to be confirmed, but keep the website monitored for all upcoming news:

http://sqlbits.com/

Both cases - remember to register as soon as possible! Places are limited.

- Beatrice Nicolini -

How To - Proactively Know Upcoming SQL Server CUs and SPs

beatrice — Tue, 13 Jan 2009 18:44:00 GMT

Umh, it has been a long time since my last post. I must admit, I've had brilliant holidays (relax and skiing) followed by a very bad flue, which summed up with all the XMas parties of 2008 makes 3 weeks without any post on my professional blog :-).

Well, if anybody out there had missed me, here I am back on track :-P

So - just a tip for today.

A RSS feed you should consider subscribing to if you want to be always up to date with the upcoming SQL Service Pack or Cumulative Updates.

All you have to do is go to

Microsoft SQL Server Release Services

and subscribe!

Enjoy!

- Beatrice Nicolini -

Released - Cumulative Update Package 1 for SQL Server 2005 Service Pack 3

beatrice — Sat, 20 Dec 2008 13:35:00 GMT

Microsoft has just shipped the first Cumulative Update for SQL Server 2005 SP3.

This CU contains only hotfixes that were released in Cumulative Update 10 for SQL Server 2005 Service Pack 2 and Cumulative Update 11 for SQL Server 2005 Service Pack 2.

These hotfixes are not included in SQL Server 2005 Service Pack 3.

CU1 for SQL 2005 SP3 is only intended as a post service pack rollup for SP2 CU10 and SP2 CU11 customers who plan to upgrade to SP3 and still keep the hotfixes from SQL 2005 SP2 CU10 and SQL 2005 SP2 CU11. No new hotfixes have been included in this Cumulative Update other than the hotfixes that were already released in CU10 and CU11.

For more info and to download the CU: http://support.microsoft.com/kb/959195/en-us

- Beatrice Nicolini -

Data & Backup Compression (Part 3) - Tests, Numbers and Tuning Tips

beatrice — Wed, 03 Dec 2008 16:18:00 GMT

One of the most common question I've received regarding data and backup compression in SQL Server 2008 is related to achievable results in terms of performance and compressio-ratio on very large databases.

I've just found some interesting data published by Unisys which you can review at:

Microsoft SQL Server 2008 Data and Backup Compression

http://www.unisys.com/eprise/main/admin/corporate/doc/41371394.pdf

This document presents the results achieved by tests performed on a 2TB database, representative of a modern OLTP financial environment, on a dual-core machine with 128 GB of RAM, installed on SQL Server 2008 64-bit.

Tests include:

Data compression (ROW and PAGE, with different granularity combinations)
Backup Compression (on data-uncompressed database, on ROW compressed database, on PAGE compressed database)

Very interesting are the results related to Backup Compression.

In particular, you can easily notice how data-compression can influence backup-compression compressio-ratio, and how it impacts elapsed time and CPU utilization.

As you can see, backup compression on a data uncompressed database gives you a compressio-ratio of 2.95%, reduces by 36% backup runtime (from 6,937 secs to 2,358 secs) but increases CPU utilization by nearly the 55% (from 1.42 to 77.26).

How you can tune the performances of your backup compression.

1) We've already discussed how you can take advantage of Resource Governor to minimize the amount of CPU used (http://blogs.technet.com/beatrice/archive/2008/11/10/resource-governor-how-to-get-started.aspx).

2) Additionally Performance of backup operations may be increased by utilizing multiple backup devices and/or increasing BUFFERCOUNT.

This will have the effect of increasing the parallelism and overall CPU usage across all CPUs in the server, allowing to achieve an even more reduced backup time.

On the other hand, reducing the number of backup devices or BUFFERCOUNT may reduce the overall CPU used by the backup operation, leaving more CPU resources for other workloads.

More information can be found on the SQL CAT blog:

Tuning the Performance of Backup Compression in SQL Server 2008

http://sqlcat.com/technicalnotes/archive/2008/04/21/tuning-the-performance-of-backup-compression-in-sql-server-2008.aspx

Interesting would be to test resource governor together with increased buffercount, this should allow you to control the CPU utilization and on the same time to speedup the backup operation.

- Beatrice Nicolini -

How to: Troubleshoot SQL Server 2008 Features

beatrice — Tue, 02 Dec 2008 15:54:00 GMT

This is a nice section in 2008 Books On Line which I just found and wanted to blog about - mainly for my reference so that I can quickly find it when needed ;-)

I've found it whilst looking for recommendations to troubleshoot Resource Governor, but there are actually many other troubleshooting how-to's which I might need very soon whilst playing with the new features in SQL Server 2008 - and also it includes other general troubleshooting tips which you can easily adapt to 2000 and 2005.

For example you can find:

But also

..and so on.

You can find all this at

Troubleshooting Concepts (Database Engine)

http://msdn.microsoft.com/en-us/library/bb522471.aspx

- Beatrice Nicolini -

SQL Server 2008 Upgrade Technical Reference Guide

beatrice — Thu, 27 Nov 2008 18:59:00 GMT

The SQL Server 2008 Upgrade Technical Reference Guide is now Live and available to download.

It is a 490-page white paper (hold on, do not get scared, you don't need to read it all :-)) which covers the essential phases and steps to upgrade existing instances of SQL Server 2000 and 2005 to SQL Server 2008 by using best practices.

These include preparation tasks, upgrade tasks, and post-upgrade tasks. It is intended to be a supplement to SQL Server 2008 Books Online.

More info:

- Beatrice Nicolini -

X64, Lock Pages in Memory and AWE - Should I or Should I Not?

beatrice — Wed, 26 Nov 2008 13:28:00 GMT

I've heard this question thousands of times so I've thought to try to summarize some recommendation in this blog post.

For 32 bits, things are pretty straight-forward.

If they are not, I've posted some comments some time ago:

\3GB \PAE and AWE - Taking away (some) confusion

http://blogs.technet.com/beatrice/archive/2008/08/29/3gb-pae-and-awe-taking-away-some-confusion.aspx

For 64 bits, things are a bit more complicated.

First of all -simple things first - you don't need to enable AWE on a x64 machine, as the option is actually ignored.

What you can do, is to enable the Lock Pages in Memory Option.

This in the policy which determines which accounts can use a process to keep data in physical memory, preventing the system from paging the data to virtual memory on disk.

So - should you enable this option?

If you look on BOL (Books on Line) Microsoft recommendation seem a bit controversial:

- 2005 BOL: http://technet.microsoft.com/en-us/library/ms190730(SQL.90).aspx

"Although not required, we recommend locking pages in memory when using 64-bit operating systems"

- 2008 BOL: http://technet.microsoft.com/en-us/library/ms190730.aspx

"Locking pages in memory is not required on 64-bit operating systems"

What's the solution then?

Well, as in most cases, there are not simple and easy solutions.

You can hit serious issues with Lock Pages in Memory Option enabled as it can cause freezing, timeouts and application failures. Especially if your memory (Max and Min) is not sized properly.

You can therefore wait to see paging messages logged on your system, as for example

"A significant part of sql server process memory has been paged out. This may result in a performance degradation"

and then opt to turn on Lock Pages in Memory Option,

You can set it up from the beginning, but make sure to size properly max and min memory setting by capturing a Performance Monitor log to determine the memory requirements of various applications and services that are installed on the system.

More information:

Do I have to assign the Lock Pages in Memory privilege for Local System?

http://blogs.msdn.com/psssql/archive/2007/10/18/do-i-have-to-assign-the-lock-privilege-for-local-system.aspx

How to reduce paging of buffer pool memory in the 64-bit version of SQL Server 2005

http://support.microsoft.com/kb/918483

- Beatrice Nicolini -

The Hidden Database in SQL Server 2005 and 2008

beatrice — Wed, 19 Nov 2008 12:22:00 GMT

Have you ever had to move your master database? Or have you ever opened the folder which contains your master database? Both cases - if that ever happened to you, you should already know about the Resource Database - a hidden, read-only database introduced with SQL 2005 which contains all the system objects that are included with SQL Server.

The purpose of this database it to speed up the upgrading process. In earlier versions of SQL Server, upgrading required dropping and creating system objects. Because the Resource database file contains all system objects, an upgrade is now accomplished simply by copying the single Resource database file to the local server. Similarly, rolling back system object changes in a service pack only requires overwriting the current version of the Resource database with the older version.

What you need to know about it:

The Resource Database must be placed in the same location as the master database. Therefore - in SQL 2005 and 2008 - if you move the master database you need to move the resource database as well otherwise your SQL Server installation won't start.

More info: http://msdn.microsoft.com/en-us/library/ms345408(SQL.90).aspx

You should back it up at each upgrade of your installation (SP, CU or hotfix). Unfortunately, as it's not a standard database, you cannot back it up in the traditional way, but you have to perform your own file-based or a disk-based backup by treating the mssqlsystemresource.mdf file as if it were a binary (.EXE) file.

Note that - After restoring a backup of the Resource Database you must reapply any subsequent updates. Say that you took your RD backup when you upgraded to CU1, now you are on CU10 and have lost the RD - you can re-apply the old backup but then you will have to re-apply all the update steps you're performed since CU1.

To determine the version number of the Resource database, use:

SELECT SERVERPROPERTY('ResourceVersion');
GO

More info:

Resource Database

http://msdn.microsoft.com/en-us/library/ms190940(SQL.90).aspx

Reserved Resource Database in SQL Server 2005

http://www.extremeexperts.com/sql/Yukon/ResourceDatabase.aspx

SQL Server backup and restore of the Resource database

http://www.mssqltips.com/tip.asp?tip=1544

Geek City: The Resource Database

http://sqlblog.com/blogs/kalen_delaney/archive/2007/09/13/geek-city-the-resource-database.aspx

- Beatrice Nicolini -