Voice of the DBA

Category: Editorial

  • It Starts with Version Control

    As a software developer, I learned about the value of version control over time. My first forays into development were as a child, where I made a single backup of my code on a separate floppy disk in the event I had an issue. This was my one-man-wolf-pack version control system, and it served me well, although it wasn’t efficient. In a few of my early development positions, we zipped up all our code each night to a separate folder, giving us the pentagram-version-control system. This worked as long as we didn’t need to go back over a week, but it still wasn’t very efficient. I think that because we worked on fairly small projects and could hold most of the code in our minds, we muddled through issues.

    Later I was introduced to a real version control system (VCS), Visual SourceSafe. Some of you cringe, but that system worked well. We could see the differences in code, and over time I learned to cut loose with my development, just trying new things, knowing that I could easily revert code backwards without much effort. Since then I’ve worked a bit with Subversion and Git, both of which seem to be very capable, mature systems. I still plan on getting some work done with Mercurial and TFS at some point, just to compare the features and functions.

    I started source controlling my databases after reading an article by Bill Wunder. This was over a decade ago, and it seemed to make sense to me. All of the things I had learned about VCS worked with databases as well, and I learned that having a database under VCS provided me with some stability in development, including the ability to roll back to previous versions of code when we found bugs. Trust me, checking out a previous version of a stored procedure is much, much less stressful than restoring an old backup just to look at stored procedure code.

    These days I see more and more people putting their databases under version control, which is comforting. It makes me think that we, as data professionals, are maturing in our industry. However there are still lots of people out there that don’t use a VCS for their database (DDL) code. Some don’t even use a VCS for their application code.

    There’s no excuse these days. Subversion and Git are free and open source. Download them, spend a few days, and get control of your code. All of the ways in which you can improve the efficiency and quality of your software start with more knowledge, and a bit of version control on which to apply your craft.

    Steve Jones

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  • Testing Skills

    This editorial was originally published on May 11, 2009. It is being re-run as Steve is on vacation.

    How can you measure someone’s skills? Is there a good way to actually assess how well a DBA or developer will do in your company? If you have one, there is some money to be made by passing the information along.

    Traditional interviews where you ask lots of questions typically haven’t necessarily proven to be a great way to do this.  Some people give tests, but they often are thrown together, and might contain multiple choice answers to make them easy to grade. However the other day someone posted a technique they used that I liked.

    This person suggested that a VM be configured with Windows and SQL Server and then with a certain number of things wrong with the install. Or at least things that would be seen as wrong in that particular  environment. You then give it to a candidate and ask them to tell you what’s wrong. You could let them work through it in a stream of consciousness way, telling you what was wrong as they found it. You could also give them some time, say an hour, and then come back and let them explain what is wrong.

    Actually I’d recommend you give the candidate the choice since some people work better alone.

    I’ve thought about asking them to accomplish certain tasks before, but after considering this technique, I like it a bit more. Just asking them “what’s wrong?” or “what would you change?” is a good way to see how people think. Interacting with them, getting them to dig into a real system, is a great way to assess not only technical skills, but also some interaction. See how they debate, argue, or question a co-worker is important, at least it’s important to me.

    Is this is a better way to interview people and assess skills? Would you like to be interviewed like this? Maybe this would even be a fun competition at somewhere like the PASS Summit.

    Steve Jones

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  • Time for Learning

    Working in technology means that we are constantly challenged to learn new skills and improve our existing ability to get work done. When I started as a DBA, I could work within SQL Server, writing T-SQL, making backups, and managing security. As the product has evolved, I’ve needed to learn more about Active Directory to troubleshoot security, I’ve been called upon to cluster machines and implement replication. There are all sorts of areas in which I’ve found it important to develop some expertise.

    However time is short. With family, with work, with commitments in the rest of my life, how do I find time to work on improving my career skills? Most of the time has been spent at work, slipping in learning time during a project, but I’ve also had to spend some time at night, practicing skills or reading about the intricacies of some feature.

    Andy Warren has estimated that it really takes around 100 hours to develop some level of competence with a new skill. That’s 100 hours in a year, which doesn’t sound like a lot, but dedicating two hours a week to your career can be challenging. It’s much less than the 10,000 estimate for expertise, which is good since most of us can’t spare that much time to become an expert.

    However is 100 hours too many? There was a TED talk that noted you could learn a new skill, at an acceptable level in 20 hours. I’m skeptical that this is true, and I’d certainly point out that there is prep time to analyze a skill, learn something about it, and then build the plan to learn. Those items alone could take much more than 20 hours.

    I’m not sure what a good level is, but I’m thinking to try this in my life in some area and see what 20 hours gets me. I’m also on a Powershell Challenge, which will probably end up being close to 30 hours, but I’ll see how comfortable I am with the skill after that time. However, do you think you could learn something like Powershell in 20 hours?

    Steve Jones

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    Today’s podcast features music by Everyday Jones. No relation, but I stumbled on to them and really like the music. Support this great duo at www.everydayjones.com.

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  • Runtime Code

    I was talking with someone recently who was building a dynamic process that generated its own code at runtime to process ETL files based on a set of rules. It was an impressive system, and reminded me of how BIML can dynamically produce code and build packages.

    However then I started to wonder. If you produce code at runtime that then runs, how well is that code tested? I suspect most people would test the code generation process. Is this producing the code I expect, but how many would then write additional tests for the generated code as it executes? I suppose people might also just test the generated code, but if that’s the case, are they really testing the generation process extensively?

    I’m not sure there’s an easy answer, and not sure if there’s actually a strong testing framework that exists to help here. As BIML becomes more popular and even ETL frameworks are used more and more in our software processes, I hope that we develop new testing methods to better ensure we are building quality code. I know some SSIS test frameworks exist, and there has been some writing on the topic, but I wonder how many SSIS developers bother to perform anything more than cursory tests? My suspicion is very, very few.

    Ultimately I think we as an industry need to learn to build better software by improving our techniques, samples, skills, and testing.

    Steve Jones

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    Today’s podcast features music by Everyday Jones. No relation, but I stumbled on to them and really like the music. Support this great duo at www.everydayjones.com.

    Follow Steve Jones on Twitter to find links and database related items and announcements.
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