SQL University: Introduction to Indexes, Part the First

PowerShell, Spatial Data, SQL Server, T-SQL
Right, all eldritch tomes are to be closed and Elder Signs are to be put away during this course. Welcome to the History department here at the Miskatonic branch of SQL University. Why the History department? Well, first, because I like history and have frequently thought I would enjoy teaching it. Second, because I needed a hook upon which to hang part of the story I want to tell. What story is that you ask? Why, the story of the Dewey Decimal System. We are interested in studying history and historians must classify our subjects carefully. For advanced students we'll be covering the Library of Congress Classification System and the... Right, I give, this is the introductory class on indexes. If you thought we were covering something exciting and sexy like PowerShell,…
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Maps in Reports!

Spatial Data
I've been playing with SQL Server 2008 R2 for quite a while in the CTP's and what not. But, I hadn't made a concerted effort to look at the new version of Reporting Services... HUGE mistake. There are a number of, not insubstantial, updates to Reporting Services that, probably, are the primary selling points of 2008 R2. The big one, for me, was the incorporation of mapping directly into reports. Did I say big? I'm sorry, I meant, enormous, gigantic, galactic, really, really important... Why you ask? I work for an insurance company. We insure factories, warehouses, that sort of thing. Funny bit of information about a factory, when floods, high wind or earthquakes come calling, they just don't seem to be able to get out of the way adequately. Weird, huh?…
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Learning Spatial Data in SQL Server 2008

PASS, Spatial Data
PASS just published a new Top 10 list of mine over at the their web site. This one is the Top 10 Articles on the web if you're trying to learn about spatial data. I'm not trying to say that I know what I'm doing with spatial data. I'm still feeling my way forward. These articles have proved to be the most useful in the learning I've done so far. I wanted to publish a little more information than we put into our Top 10 lists over at PASS. Having the list is good, but I thought it needed a bit of commentary to be complete. All these articles are good and all the web sites hosting the articles have good stuff on them. A few of the web sites stand out. Paul Randal's…
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More Spatial Headaches

Spatial Data, T-SQL
I keep thinking I've got a handle on spatial data and I keep finding out I'm wrong. I rewrote the cursor that my co-worker used into a query that joined the list of test criteria onto our list of locations. I used an OUTER APPLY to more or less run a check for each of the test criteria since, except for the proximity to the locations, there's no actual relationship between the test criteria and the location data for me to join on. The query looked something like this: [crayon-5b57814be8570443393665/] The cursor was taking almost a full minute to return just under 400 rows worth of data. This query took about 25 seconds. SCORE! Unfortunately when I looked at the execution plan, the optimizer was not able to recognize that…
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Spatial Indexes and a Lack of Data

Spatial Data, T-SQL
I was feeling quite confident about my new-found abilities with spatial indexes so I did a presentation for my team, to share what I had learned. I had also been sharing with one co-worker as I developed the knowledge of spatial indexes. While I was preparing my presentation, he was preparing his. I had focused on finding a set of data that showed it's proximity to a test location and then showing how retrieving that set of data was faster because of the spatial index. He took a different approach. He took the idea of saying, here's a list of different test locations, let's see which one of our internal locations meet the proximity test. At the same time, he tried three different spatial indexes, one with high granularity, one with medium and a final…
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Spatial Index & Performance & Brain Pain

Spatial Data, T-SQL
In my previous post, Spatial Data Hurts My Brain, I showed how a query used the spatial index, but hurt performance. Several people jumped in to try to help out. Thanks to Bob Beauchamin, Isaac Kunin, Gail Shaw, and Valerie Yakich (via Twitter). I've definately learned a bit more than I knew previously about spatial data and spatial indexes. I've posted about it before, but it bears repeating, if you're just starting out, I can't recommend Alistair Aitchison's book, Beginning Spatial with SQL Server 2008, enough. Here's where I'm at. I think I was confusing/confused/confounded/something about what to expect from a spatial index. I'm going to present two queries and two indexes and try to explain why each works well, or not together, mainly as a means for enabling my…
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Spatial Data Hurts My Brain

Spatial Data, T-SQL
I'm still barely scratching the surface working with spatial data in SQL Server 2008. We've ported some of the data into a table where we built a geography spatial data column and we're begginning to work with point data. The requirements from the developers are, so far, very simple. They'll feed me a point and I find all the locations "close" to it. We had to go round & round on what defines "close" but finally settled on, I think, 15km. The query to answer a question like this is ridiculously simple (a few object names have been changed): [crayon-5b57814bea4b0492510986/] I'm not even hard-coding the "close" value so it can change when they change their minds. It retrieves exactly what's needed. But... Well, look at the STATISTICS IO & TIME:…
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Spatial Data

Spatial Data, T-SQL
I work for an insurance company. If you think that maybe, we might be interested in the physical location of the things we insure, you'd be right. Actually, we're an insurance company predicated on the idea that risk can be managed. That means that not only do we know where your factory is located. We know the wind zone, earthquake zone, flood zone, rain zone and temperature zone it's in. We send engineers out to the site to inspect it and recommend upgrades. We track the upgrades and the condition of your facility. With all that location specific information, just how important do you think it is that with SQL Server 2008 we're finally getting a spatial data type? Yeah, exactly. We're in the process of launching our first full implementation…
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Reading to Learn

Spatial Data
I just finished chapter 1 of Alastair Aitchison'snew book on SQL Server spatial data, "Beginning Spatial with SQL Server 2008." If this is the beginners book... oh boy. The advanced book must be insane. Seriously though, Mr. Aitchison seems to have written a fantastic book. I'm going to tear through it as fast as I can because I've got two projects that are looking to start using spatial data and quite frankly, I'm a bit lost. There's a great discussiongoing on over at SSC as to the worth of technical books for DBA's. It's based on this editorialby Tony Davis. I'm surprised by the number of people who say they don't use books. It seems that a lot more people use blogs and articles and discussion groups to learn. Maybe…
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