February 2008 Blog Posts
A very astute SQL Server professional and reader of this blog posed the following question in a comment to a prior posting entitled "Does the order of criteria the WHERE clause matter?" The comment, submitted through Plaxo Pulse, is not available outside the Pulse community so I've included it below since it's the genesis of today's post.
"What if you were using join statements? Does it matter what order your columns are used in the ON statement? ~ Ariel M."
There are several derivatives of the original question:
Does the order of tables referenced in the ON clause of...
Recently, I demonstrated that the order of columns in a composite index greatly determines its usefulness. Microsoft SQL Server can efficiently resolve queries using a composite index if the search criteria includes the first column in the index. If the search criteria omits the first column and includes only subsequent columns, the index is of no use to SQL Server for resolving that query. To see the proof, refer to this post.
The example I used in the prior post included the following query as a basis for the discussion.
After blogging yesterday that you can try the latest Microsoft SQL Server 2008 CTP online for free on the SqlServerBeta site, Microsoft has announced the release of a new CTP.
The February CTP available! And it's feature complete. If you have the bandwidth, head on over to the download site and get it while it's hot.
Note: at the time of this posting, the download page indicates that it was last updated in November, but it will take you to the February CTP download.
Had a chance to play with Microsoft SQL Server 2008 yet? If so, you've probably downloaded the most recent Community Technology Preview (CTP). It's not small either. The DVD's can take almost an hour to download at T1 speeds. And the virtual machine version is over 2 gigabytes!
For many, that's not an issue. But for the rest of us, downloads of that magnitude are a bit overwhelming. So what can we do?
Well, three organizations (Dell, MaximumASP, and PASS) have gotten together to create an online, virtualized way for us to test-drive the next version of the RDMS. You can...
The old adage "An ounce of prevention is worth a pound of cure" can be applied to many topics and areas of life. And while it has its origins in personal health care, nowhere is it more true than in an IT shop. Whether you're talking about high availability solutions or starting with a good database design, planning ahead is well worth the effort. Anyone who has been through an IT crisis can testify to that!
But alas, we live in a dynamic world and we can only make calculated guesses at what the the ounce of prevention should be....
A single column index is fairly straightforward to understand. You may have heard it compared to the index in the back of a technical book. When you want to find some information in the book, say DBCC INPUTBUFFER, you turn to the index in the back of the book and look up DBCC INPUTBUFFER. The index doesn't actually contain the information on DBCC INPUTBUFFER, it has a pointer to the page in the book where the command is described. So, what do you do? You turn to that page and read all about how DBCC INPUTBUFFER may be used. This...
That's right! After a bit of a break, the Nashville SQL Server User Group is getting back together again. Our first meeting back will be this Friday, February 15th at 11:30am. Our own Kevin Kline is presenting a rather timely topic - "SQL Server 2008, Worth the Wait".
Check out our new web site for further details, http://nashville.sqlpass.org.
If you're in the Nashville area, come on by for a free lunch with friends from the SQL Server community.
To prepare for an upcoming technical presentation, I need to create some test data to use in a demo. I'm planning to show how different T-SQL programming techniques directly affect SQL Server's efficiency in resolving the query. So, 10 - 20 million rows of data will likely suffice for this demo.
The question is: how to create all of that data? Obviously, a simple INSERT...VALUES statement is good for creating up to a few dozen rows of data, but 10 - 20 million rows of data is out of the question for such a simple technique.
Fortunately, SQL Server has...