Voice of the DBA

Tag: software development

  • Relying on Algorithms

    Would you trust software to drive you around?
    Would you trust software to drive you around?

    We are increasingly living in a world that is affected by software (and the data it uses). I have to admit that I’m slightly worried about this as I look at the quality of software, the bugs, the lack of effective testing. It’s not that companies don’t perform a lot of testing; many do, but it seems that many developers, and even QA people, don’t really know how to effectively test. This is especially true of testing for abnormal or unexpected situations. It there’s one area of software development that seems woefully immature, it’s testing.

    However testing isn’t the only problem. We might not like the way that software is designed, and used, to alter our world. As we become more dependent on software to accomplish tasks for us, we will run into new situations that the software may not have been designed to handle. This opinion piece on the ways in which software might alter our lives is both fascinating and scary. How do we want software to behave in unfamiliar situations? It’s not an easy question to answer, and it’s certainly not a question with a simple answer in many scenarios.

    We learn to depend on systems when they work for us. Whether in business, government, or our personal lives, when a system works, we want to use it more. However that’s not always the best long term solution. Humans adapt, and software, especially the systems using a constant stream of historical data for decisions, has flaws. More than a few of you might have encountered this type of situation with Netflix or Amazon recommendations when you have kids sharing your account.

    In some sense I think that we not only need adaptive algorithms, that we can customize over time, but we also need to understand the data that flows through the algorithms. We need ways to remove some data from consideration by the software, when we find it is removing more value than it is adding.

    Steve Jones

    The Voice of the DBA Podcasts

    We publish three versions of the podcast each day for you to enjoy.

  • How do you solve T-SQL problems?

    solvetsql

    Six scans, six logical reads. What could be the problem? There’s no problem if you’re always dealing with six rows of data. If you’re dealing with 6mm, however, this is likely to be a performance problem on your server. Many developers might write a query, check the statistics, and see something like that shown above, and think that it’s a good day’s work.

    Solving the problem is only half the job you should do. Solving things in an efficient way is the other half. When you tackle a new T-SQL challenge, what’s your methodology? Do you have one? I don’t need to know, though if you think you have a good one, post a note in the discussion, or perhaps write an article. If you aren’t sure how you begin, other than randomly trying ideas you vaguely understand or have seen others try, perhaps you want to start by reading Kathi Kellenberger’s Step by Step method.

    The image above comes from Kathi’s article, and is indeed the result of her first solution to a complex T-SQL problem. She lists out the basic steps she used to derive the solution, along with the business rules used. All too often I’ve found developers (including myself), start writing code without taking a few minutes to specifically state the business rules. Following that one step might eliminate lots of bugs in coding.

    Her solution worked, but with 6 scans occurring on her 11 rows of data, she knew this would be an issue. Moving forward she asked for help, which is perfectly acceptable way of working in your career. Try to solve it yourself, get a solution working, and then ask if it can be improved. Not only did she end up with a better performing solution, but she learned a bit more along the way. Something we all can do.

    Steve Jones

    The Voice of the DBA Podcasts

    We publish three versions of the podcast each day for you to enjoy.

  • Morphing Microsoft

     

    Microsoft has come a long way, and still has far to go. Which way will they go?
    Microsoft has come a long way, and still has far to go. Which way will they go?

    Microsoft is trying to change from a software vendor to a devices and services company? They are trying, according to this piece from Mary Jo Foley. With a Developer and Platform Evangelism group that is trying to bridge the gap between internal Microsoft developers and those external professionals in the real world, it appears this group will try to provide more code, samples, and frameworks that others can use. Perhaps they will even give us strong architectural examples that stand up to the real world.

    Personally I’d like to see them disclose code that works in real situations. Give us the code behind MSDN or the Microsoft Store. Prove to us you have code that not only works, but it written to meet your standards and needs. If you want to start with something that’s not open to the Internet because of security concerns, how about showing us how one of the internal MS systems really works? Maybe the annual employee review app?

    If the code isn’t enterprise ready, or of the quality that should be used as an example, why not? I know there are the same pressures building systems at Microsoft that many of us face, but if that’s the case, I’d hope Microsoft would tackle some of those issues in their tooling and platforms. They could then show us not only how to do things, but prove it can be done as well.

    I do think there is some truth to the fact that in many of the applications we build, the platform developers use is not just be the OS and local APIs. There is a richness gained by including data from services, data that exists outside of the organization. Whether that’s on the open web or from business partners, we need architectures that help us build applications that can survive some workload burst, tolerate individual machine failures, and do so at a reasonable cost. That doesn’t necessarily mean cloud services to me, but it does me better software patterns, practices, and models for developers.

    Steve Jones

    The Voice of the DBA Podcasts

    We publish three versions of the podcast each day for you to enjoy.

  • The Control Poll

    Source Control provides lots of benefits.
    Source Control provides lots of benefits.

    I was reading about version control systems (VCS) recently, brushing up on some skills, and saw this quote in a thread:

    “There is no excuse for not using version control, even for a small project developed by single developer. Setting up local version control is beyond trivial, benefits huge. Any developer not knowing that cannot be considered good nor experienced.”

    That’s quite a pronouncement, and one that I believe is very true. No matter what type of development you engage in, I’d expect that you’d understand the benefits of using version control, and the dangers of not using it. It’s just like never backing up your system. I’d think that any developer that cares about their craft and is a professional has used version control. The really good ones will insist upon it.

    However I know that the decision to use a VCS is not always made by a developer. The company building the software might feel differently, and while I’ve always asked for a VCS, I have ended up with a series of folders on a share, named for dates, each containing a zip file of all our code at the end of that day. It was the bare minimum of version control I could live with, and fortunately we got by with just two people coordinating work. Any more than that and I’d insist on some type of VCS.

    This week, I wanted to ask how many of you voluntarily or involuntarily might be forced to do something similar.

    How many of you skip source control for certain apps?

    Even if you have source control for those large, multi-person teams, are there apps that you avoid putting into a VCS? What about your database code? I think it’s important that you keep all your code, whether for the front end application or database objects, in some type of Version Control system. If your boss won’t buy one, then check out Git or Subversion, both of which are open source and free.

    Let us know this week how you feel about source control and whether or not you decide the effort isn’t worthwhile for your projects.

    Steve Jones

    The Voice of the DBA Podcasts

    We publish three versions of the podcast each day for you to enjoy.