Voice of the DBA

Category: Editorial

  • Who’s a Good Developer?

    I hear people in all industries and careers say that all of us should hire the best person for the job. We should pick the most qualified person and engage their services. However what’s left out of most of this advice is the most important question: how do you measure the best?

    We talked about this recently in a DLM Workshop led by Ike Ellis. He asked the question: how do you tell who’s a good developer? Think about it for a few minutes. I’m sure you (think you) know who the best developer or DBA is in your company, but how do you know? What’s the measure?

    I suspect you’ll find it to be a very abstract idea. Perhaps it’s like pornography, where you know a good developer when you see them, but if so, then have you always been able to tell a good developer right away? In an interview?

    Embedded in the idea of determining who’s good and who’s not is the idea of ranking. Is there any way to rank one developer over another? I think you might be able to do so, but only in broad ranges. We (as a group) might feel Developer A is better than Developer B, but not necessarily better or worse than Developer C. However, do we have any way of ranking these two that would stand up to outside analysis?

    I don’t have any great ways of measuring one developer v another. A best I think you can trust a developer to get a particular project done, and to the satisfaction of the client. However the trust would be based on previous experience and not any objective measures.

    This isn’t likely to be a problem that we will solve anytime soon, in any industry. I think the best way to gain confidence in someone is to examine their body of work. See how it matches up with the work expected from an individual and then cross your fingers, trusting they continue to perform as expected.

    Steve Jones

    The Voice of the DBA Podcast

    Listen to the MP3 Audio ( 2.4MB) podcast or subscribe to the feed at iTunes and LibSyn. feed

  • The History of the VCS

    I’ve been looking for ways to convince more DBAs to use a version control system for their code. I realize that many of you have gotten along without them for years, but that doesn’t mean it’s a good idea. A VCS is like a safety net, and someday you’ll be glad you have one.

    Recently I was reading about the history of VCS, and ran across some interesting posts. One on some amazing things, and another that has a timeline, showing us to be in a Renaissance period. If this is the Renaissance, then what comes next? I can’t even imagine, but I suspect someone will improve the process.

    It’s incredible to think about the ways in which we’ve managed versioning code in the past. I’m sure most of us have used comments to both document as well as preserve old code. Some of us have worked with simple backups of files, one per day (for a week or month), or dealt with a first generation system where only one person could work with a particular file.

    The move to CVCS systems, like TFS or Subversion, was a major improvement, allowing everyone to work on all the code, and merge their code with others when they needed to commit. That’s a system many of us inherently understand. It’s what we would do in an offline system. However the DVCS systems (Git, Mercurial), are much more complex, and they can be confusing. However separating the ability from committing changes to performing the merge can be valuable, especially in distributed development.

    More and more tools are integrating version control, including for database code. Whether you like or hate TFS, it includes lots of additional functionality to allow bugs, features, and other workflow items to link to the VCS items that solve them.

    The choice of which system works well in your environment will probably be driven by arguments from your development staff. Some will prefer one interface over another or feel the need to work offline, but I’m not sure it really matters which system you choose. I’d pick one of the modern CVCS or DVCS systems and use it.

    That’s what’s really important; you need to use the system and track your code. It’s frees you as a developer, allowing you to clean up your code, remove excess comments, and easily find out what worked (or didn’t) in previous code.

    Steve Jones

    The Voice of the DBA Podcast

    Listen to the MP3 Audio ( 2.9MB) podcast or subscribe to the feed at iTunes and LibSyn.

  • ER Modeling

    I saw someone recently note that an Entity-Relationship model is important for your database development project. That UML is important, and the model should be actively maintained. I agree.

    However, I’ve usually not seen this done. Typically when I’ve seen an ER diagram in a shop, it resides on a wall, printed out on multiple sheets of paper. Often there are as many handwritten additions on the pages as there are marks from a printer. The diagram is also usually out of date, even allowing for handwritten notes.

    Maintaining a diagram is hard. Deciding to actually spend time working on one instead of just talking about a few entities and building them, may be harder. This week, I wanted to ask you if you’re up to the challenge in your organization.

    How many of you maintain an ER model for your database?

    Do you have an ER diagram you’ve built? Whether it’s in ErWin, Visio, or Paint. Is there a diagram that’s actively maintained and that everyone can use for designing changes to the database(s) in use? Do people actually consult this and use it in design meetings? Let us know this week.

    Steve Jones

    The Voice of the DBA Podcast

    Listen to the MP3 Audio ( 1.5MB) podcast or subscribe to the feed at iTunes and LibSyn.

  • Big Data Problems

    Nate Silver is a “data guy.” He has made a career of analyzing data, and doing it well. His site, FiveThirtyEight, has become very popular in the last few years after some of their political predictions were surprisingly accurate. Now the site publishes analyses of sports, politics, economics, and more.

    Mr. Silver works with a lot of data, as does the rest of his company, and arguably, he’s one of the people that understands just what “big data” is and isn’t. We could argue about what the term means, but no matter what “big” is to you, Mr. Silver has some thoughts about the challenges we all face with larger data sets.

    In an interview, he noted that storage and access are always issues. Many of are us know this because we are charged with managing data. However he also talks about bias, false positives, and complexity being problems with an analysis that isn’t performed well. It’s a short piece, and I wish there were more depth since many of these topics could be the subject of a book all by themselves.

    While many of us aren’t in charge of performing the analysis, we do often work with those that do. We assist others in writing the queries or assembling the data. Our skill in helping perform analysis, understanding the meaning of data stored in our systems, and learning how to separate the signal from the noise will be talents that your employer will appreciate.

    Steve Jones

    The Voice of the DBA Podcast

    Listen to the MP3 Audio ( 2.0MB) podcast or subscribe to the feed at iTunes and LibSyn.