Tuesday, July 14, 2009

Book review: SQL Server 2008 Internals

One of the topics I'm interested in is performance of a database. Based on this topic I read the book SQL Server 2008 Internals. I enjoyed to read this book. It is easy to read and usefull for people with and without knowledge of previous versions of SQL Server. After reading this book it will help you to better understand the performance of your SQL Server configuration and databases. I can imagine that everybody has it's own favorite topics when reading this book. This is the list of my  favorite topics:

  • SQL Server Resource Governor
  • Indexes: Internals and Management
    • Tools for analyzing indexes.
    • Data modification Internals
    • Managing index structures
  • Special Storage
    • Sparse columns
    • Data compression
  • The query optimizer
    • Optimizer architecture
    • Statistics, Cardinality Estimation and Costing
    • Index selection
    • Plan Hinting
  • Plan Caching and Recompilation
    • Cache mechanisme
    • Plan cache internals.
  • DBCC Internals.
I think it is a usefull investment of only 52 Euro (60 US Dollar). It is a must to have for every DBA'er who wants to deliver the best performance of his SQL server environment to his users. This also applies to software engineers who want to build well performing applications on SQL Server.

Happy reading.

Tuesday, July 7, 2009

Performance improvement: Disk Partition alignment Best Practices for SQL Server

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.

Microsoft has published a usefull best practices document about this topic. Take your time to read and understand it. It can improve your performance of your disks up to 30% depending on your storage configuration. 
Within my company Exact we have seen a performance improvement of 10% with aligned partitions on a HP EVA 5000 storage system.

The good news is that partition alignment is simple to perform; The bad news is that partition alignment must be done at partition creation time, prior to partitions being formatted. This is great if you have a new SAN, but it might be painful to convert large amounts of existing data on misaligned partitions. Correct disk partition alignment is done by default on Windows Server 2008. On prior versions of Windows Server partitions are misaligned by default.

More details and test results about EVA Partition alignment can be found here

Friday, July 3, 2009

My visit to the first tweetup of Dutch Minister Verhagen of Foreign Affairs.

Today, I was invited by our Dutch Minister of Foreign Affairs Maxime Verhagen to join his first tweetup. He organized this tweetup to celebrate the fact that he has more than 10.000 followers. It was a nice event. Maxime told about his experience with Twitter.
  1. In the Dutch House of Representatives it is not allowed to Twitter because representatives should listen. However it is allowed to write 140 characters on paper. A messenger will bring this paper to his spokesman. His spokesman is now able to tweet the message. I think the chairmain of the Dutch House of Representatives should allow tweets. Accept this new way of communication. People will always find their way to be able to tweet. Maxime reaction on this: 'I do not listen with my fingers.'
  2. People do not understand that Maxime has time to tweet. As Minister of Foreign Affairs Maxime travels a lot. During travelling by car, plane, ..... you always have some time to tweet.
  3. It is nice way to get feedback on what you are doing. Postive feedback is nice, but you can learn from negative feedback and take action on it.
  4. He told about his twitpic from the Treves zaal. This was not allowed. He was suprised because a lot of pictures are available on the internet of the Treves zaal. Only official pictures of the Treves zaal are allowed. The end result of this discussion resulted in a lot more followers for Maxime.

My observations during this event:
  1. Average age of the attendees was around 35. This was higher as what I expected. Maybe because the generation Y is not interested in politics and there for not following politicans like Maxime. I saw a womam which could be my mother. Nice to see that people from that generation can make the shift to the new way of communication.
  2. The spokesman of Maxime is not twittering.
  3. Most guests are twittering since the last 6 months.
  4. Most guests are twittering from a personal perspective, not from a business perspective.
  5. Some guests are following Maxime to understand what he is doing as Minister of Foreign Affairs others are following Maxime to understand his political point of view and a group who are interested in the way Maxime uses social media.
  6. Mixture of Nokia Smartphone, Blackberries, IPhones to tweet live. But also a group of people which only make their tweets via a PC.
  7. Everybody is looking forward to the next tweetup. For instance a BBQ on the Binnenhof

The Twitters: @rotjong, @kruithoph @tonyjansen @jacokoster @zorg20 made a nice certificate for Maxime: Minister Tweep. The first minister which is using Twitter in a formal way.

Thanks Maxime for organizing this tweetup. I have enjoyed it. More politicans should follow your way of using social media.

Wednesday, July 1, 2009

Exact Synergy Enterprise supports SQL Server 2008 as of product update 241

As of 30 June 2009, Exact Synergy Enterprise product update 241 is general available. In this product update SQL Server 2008 is supported. Exact is selling this new version of SQL Server. Please contact your local Exact office or reseller. If you want to have a look at the unique selling points of SQL Server 2008, please have a look at the overview on the Microsoft website. For an overview of technical documentation for SQL Server 2008, please refer to the Books Online.

SQL Server 2008 licenses grant customers the right to downgrade, which means that customers wanting to use SQL Server 2005 can still do so when purchasing SQL Server 2008 licenses. The upgrade to SQL Server 2008 can then take place at their own convenience. So if you are currently using SQL 2000, you can buy SQL 2008 instead of SQL 2005. If one of your applications does not support SQL 2008 at this moment, you are allowed to install SQL 2005.
More information about the product update 241 of Exact Synergy Enterprise can be found on the Exact Product Blog.