[2008/08/25] This post has been modified significantly to correct some inaccurate statements because I mis-read Joe Chang's post. Joe Chang posted some interesting results using the TPC-H queries with the scale factor set to 10. I happened to have done something similar, and naturally noticed a rather significant difference between his results ...

Microsoft quietly released CU #9 (build 9.00.3282) yesterday; it contains a few dozen fixes, including a nasty AV involving UNION queries, documented in KB #956006.  You can read about / obtain the cumulative update at the following KB: http://support.microsoft.com/kb/953752 So, now you can start hitting F5 all day, every day on the article ...

“I sense you skipped SQL Server 2005 in you...  Skipping SQL Server 2005 leads to a bigger learning curve...  A bigger learning curve leads to not knowing the product as well...Not knowing the product as well leads to suffering..Running in compatibility mode 8.0 is the path to the darkside.. SQL Server 2008 (mode 10.0) is the force...May ...

It’s well known that bookmark lookup (aka key lookup in case of a clustered index) is not cheap, especially when it comes to retrieving a lot of data. So I’m not going to rehash the pros and cons of bookmark lookup or why bookmark lookup is expensive. But I’ve noticed that when it comes to discussing bookmark lookup, all the literature seems ...

In the next series of posts, I'll focus on SQL Server I/O, revisiting some common issues and taking a closer look at some others. In each post and as always, I'll make the case with specific data points from my tests. For the first two posts in this series, let me check out the read-ahead technique used by SQL server. Read-ahead is an important ...

Dedicated Admin Connection (DAC) is one of the highly touted features introduced in SQL Server 2005. Now that it has been around for a few years, I wonder how it is actually being used or whether it's being used at all in the real world. I have not run into any real production scenarios where I'm forced to use DAC. But that may just be due to my ...

A frequently asked question that surfaced again today is, ''how do I see when my data has been accessed last?''  SQL Server does not track this information for you.  SELECT triggers still do not exist.  Third party tools are expensive and can incur unexpected overhead.  And people continue to be reluctant or unable to constrain ...

Bob Ward posted a blog entry today where he explains the process of getting a cumulative update for SQL Server 2005 without having to call Microsoft's support team (they are called CSS now but you may remember them as PSS).  This is a great evolution in the process, which used to be very difficult (you had to open a support case and be deemed ...

Another recycled post from days gone by...   One of my favorite blogs on SQL Server Integration Services (SSIS) is by Jamie Thompson.  He does a tremendous job sharing tips, tricks, and lessons learned from working with SSIS.  Recently he posted a blog on three of the destination adapters and the performance implications of ...

I have just learned that my old blog will be disabled, so I will be recycling some of the more meaningful blogs to SQLBlog.  This was written last year during an engagement where I was troubleshooting an issue with procedure cache growth.  The good news appears to be that some relief is on the way (SQL Server Procedure Cache: More ...