Louis Davidson

Louis is the editor of this Simple-Talk website. Prior to that, has was a corporate database developer and data architect for a non-profit organization for 25 years! Louis has been a Microsoft MVP since 2004, and is the author of a series of SQL Server Database Design books, most recently Pro SQL Server Relational Database Design and Implementation.

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30 June 2009
30 June 2009

Best Thing I Learned at PASS Summit

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I have learned many things at every PASS Summit I have attended. First off, all of the people who are speakers are just human beings like you and me (including everyone’s favorite Kalen Delaney). I learned that it is really expensive to put on a conference like PASS, and I have especially learned to enjoy … Read more
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20 June 2009
20 June 2009

Read/Write Ratio versus Read/Write Ratio?

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So, Jason Massie (http://twitter.com/statisticsio) had a blog post (http://statisticsio.com/Home/tabid/36/articleType/ArticleView/articleId/324/Is-8020-a-90rsquos-Estimate.aspx) that Kendal Van Dyke (http://twitter.com/sqldba) alerted me to at SQL Saturday in Atlanta .  It does this by taking the number times an index was used for a read operation versus update operations using sys.dm_db_index_usage_stats.  Coincidentally, I was working on a chapter in a book about … Read more
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17 June 2009
17 June 2009

SQL Quiz: Gilligan’s Island

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Tagged, I was by the Rambling SQLSarg, Jonathan Kehayias, to answer the following question: So You’re On A Deserted Island With WiFi and you’re still on the clock at work. Okay, so not a very good situational exercise here, but let’s roll with it; we’ll call it a virtual deserted island. Perhaps what I should … Read more
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11 June 2009
11 June 2009

What is a physical database?

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A bit of terminology that gets beaten to death is that of the “physical” database.  I would think most every DBA uses this term (I do), but…to mean what?  I think there are two common utilizations: The layer of tables, constraints, indexes, etc used to store data The actual on-disk structures. Frankly, until 3 years … Read more
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06 June 2009
06 June 2009

disallow results from triggers

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A setting that I noticed a while back when looking at sys.configurations was disallow results from triggers.  Triggers are one of my favorite subjects, and you will find a lot of good uses of them in my book (triggers are also well named, as poor usage of them will allow you to shoot your foot … Read more
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14 May 2009
14 May 2009

Checkpoint – Four pillars down, Three to Go

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With the previous post on the fourth pillar, I have reached the “end” of the design posts.  To review, these were: Coherent – cohesive, comprehendible, standards based, names/datatypes all make sense, needs little documentation Normal – normalized as much as possible without harming usability/performance (based on testing) Fundamentally Sound – fundamental rules enforced such that … Read more
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29 April 2009
29 April 2009

Do you care where an idea comes from?

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Ok, so you are the lead ______________ for your company.  The big cheese, the super duper guy who knows everything…right?  So then some newbie comes up with an idea that might solve a problem you have been dealing with for a few days/weeks/months/whatever.  What do you do? A. Ignore his idea and use your own, … Read more
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20 April 2009
20 April 2009

Book Reviews – Again

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I have gotten a few more reviews in, and interestingly I appreciate the negative ones almost as much as the positive ones. I prefer the negative ones that have decent star ratings better… but what are you going to do. The most recent review was critical of the book for not having mentioned testing. I … Read more
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15 April 2009
15 April 2009

The fourth pillar – Documented

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This blog probably won’t stir up a hornet’s nest or anything, but I would also expect that it would be the least popular in practice. The person who feels they can disagree with the need for a reasonable amount of documentation is probably nuts. In the first post, I defined documented as “Anything that cannot … Read more
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12 April 2009
12 April 2009

Requirements vs Architecture

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Okay, so on the first look this sounds like the most boring Japanese action movie ever. Requirements is tearing through the village, and Architecture is in the city.  Developers by the horde are trying to code both of these into oblivion…Maybe not.  Clearly I am talking about something a little more exciting…the battle between the … Read more
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20 March 2009
20 March 2009

Heading to SQL Connections!

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You know how when you go to a session and there is always this person who is heckling the presenter?  Well, it isn’t that often that this person is authorized to be annoying people/answering questions at the request of the main presenter.  Well, that is about to change.  By a nice coincidence, I was going … Read more
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01 March 2009
01 March 2009

The second pillar – Normal

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The first pillar was easy, since no reasonable person is going to argue that having a design that is not coherent is desirable. No matter what the type of system, any design that isn’t easy to understand is likely to be a bad design (obvious caveats are that it must be understandable to other people … Read more
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16 February 2009
16 February 2009

Business Rule Enforcement

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I know this is a topic that could cause a few heads to spin around uncontrollably if taken the wrong way, but I preserve.  Today I was having a conversation with an end user, an influential one at that, about a business rule that was needed for the time entry system we are putting together … Read more
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