Voice of the DBA

Tag: software development

  • Testing is Your Best Investment

    I signed up for the FlowCon 2014 conference in San Francisco this September. It’s a two day event about software development and how we can do better. My job is starting to encompass more work in this area, and I’m excited to go see some of the ThoughtWorks developers talk about what they do well. Part of the reason I wanted to go came after watching a few videos from last year, including this one from Randy Shoup.

    There are some interesting things in the talk, but one thing really caught my eye at the 9:52 mark. Mr. Shoup made a statement that “tests help you go faster” and “the best investment you can make in your own code …[are] tests for your code.” Those statements are a short part of the talk, but they make a lot of sense to me.

    It’s easy to ignore testing, after all, it’s hard to test for everything that can possibly happen, and writing tests can be extremely tedious. However building tests JIT, when you find bugs or problems, can give you good code coverage, especially in the areas where you find developers are likely to make mistakes.

    And like with all other software development skills, the more you work on writing tests, the easier, and faster you become at building them.

    Steve Jones

    The Voice of the DBA Podcast

    Listen to the MP3 Audio ( 1.6MB) podcast or subscribe to the feed at iTunes and LibSyn. feed

    The Voice of the DBA 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.

  • Production Subsets

    Continuous delivery recommends developers never use production data. It’s too big, too cumbersome, and slows the process too much. Developers should have enough data to determine if their solutions work as they build them. Testing should have enough to do some tuning, but unless you plan on full performance/load tests (which you should), then you don’t need the full set of production data.

    It’s an interesting idea, and overall I agree. A subset of data, hundreds of rows, can usually tell you if you’re writing code that works if you profile the code and look for inefficiencies. Note that profiling code doesn’t mean use Profiler. It means examining the resource used by your code in terms of CPU, I/O, memory, etc. There are tools to help you, and at some point in your development process, you should be using them.

    However it can be time consuming and cumbersome to build small development data sets. There are lots of choices in how you might do this, and I thought this would make an interesting poll. For those of you that deal with development, whether that’s T-SQL, .NET, or something else, what do you think?

    Should we have a subset of production data, a custom data set, or perhaps deal with complete production data?

    Some of this depends on the size of your production data, and I hope, it’s contents. I would not want any PII, PCI, medical, etc. in any development area. However if that’s not the case, then what do you prefer?

    Whether you have  custom data set or a subset of production, it can be cumbersome to keep this up to date. Your data may evolve over time and there’s overhead in maintaining some scripts that would produce the data you need. Perhaps that’s the cost of writing good software, but I’m curious how many of you feel.

    Steve Jones

    The Voice of the DBA Podcast

    Listen to the MP3 Audio ( 2.2MB) podcast or subscribe to the feed at iTunes and LibSyn. feed

    The Voice of the DBA 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.

  • Bronze Age Development

    I was watching a presentation on testing recently where the speaker noted that on one project he’d spent twice as much time testing as coding. That sounds like an outrageous amount of time, but my concern was tempered when he said the release to production produced no bugs. I’m sure some bugs surfaced later, but I have often seen that most of the bugs, especially the incredibly annoying ones, are typically discovered quickly.

    I was reminded of that presentation when I saw this quote: “…the result was a two-year development process in which only about four months would be spent writing new code. Twice as long would be spent fixing that code.”

    That’s a quote on the development of Visual Studio a few years back. I wonder if the “twice as long fixing” time would have been reduced with better testing efforts earlier in development. It’s hard to know since all evidence on the value of testing is based on disparate projects with different teams working at different levels of experience, but I’ve run into a few people that think more testing reduces overall development time.

    The consultant who gave the presentation believes strongly in testing, not only at the application level, but also at the database level. This person has tried different levels of testing on different projects, and found that building and writing tests throughout development results in many fewer issues at release. Perhaps more telling is that when the person has performed less testing in later projects (because the clients declined to pay for it), there were more bugs in production.

    I don’t know if the total time spent on building software is less with testing occurring early than with allowing clients and customers to test and report bugs. Certainly some of that might depend on how many bugs you fix and how many bugs people must cope with, but I do know that the fewer issues people find with your software, the more excited they are to ask you to write more code in the future.

    Steve Jones

    The Voice of the DBA Podcast

    Listen to the MP3 Audio ( 2.2MB) podcast or subscribe to the feed at iTunes and LibSyn. feed

    The Voice of the DBA 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.

  • Updating tsqlt

    I was looking to write a new test with the tsqlt framework recently. I wanted to isolate a stored procedure’s logic and planned on using the FakeFunction procedure available in tsqlt.

    I wrote my test, using a template from the Pluralsight course on tsqlt and the documentation. I tried to execute the test and get a “tsqlt.fakefunction does not exist” error.

    I was slightly confused at first, but checking my list of functions and stored procedures showed that I didn’t have the FakeFunction procedure available. It’s a relatively recent addition to tsqlt, so I needed and update.

    After downloading the framework (a zip file), I opened it up to find this:

    tsqlt_a

    A number of files there, but the tsqlt.class.sql is the important one. I double clicked it from the zip and it opened in SSMS.

    tsqlt_b

    It’s a standard T-SQL script, albeit a long one. I executed it and it ran fine. My framework was updated to the latest version and I now had the function I needed.

    tsqlt_c

    Of course, I used my test to ensure this worked as expected and I was pleased to see it work well.