Voice of the DBA

Category: Editorial

  • Learn to Use Filegroups

    This editorial was originally published on May 12, 2011. It is being re-run as Steve is away at SQL Relay today.

    In SQL Server, filegroups are a management technique that I don’t see many people using. It’s amazing how many people ask questions about filegroups on the discussion forums, often unsure of how they fit into a well architected SQL Server. I have tended to use filegroups mostly as a space management technique, when I need to add more disks to my server, but they can be used in many more places.

    We continue to grow our data sizes all the time. While many databases are still measured in the single digits of gigabytes (or smaller), it is fairly common to find many database servers with over a terabyte of disk space. Our disks grow larger and larger, but it seems that data grows faster than disks, requiring larger storage subsystems all the time.

    While our storage grows larger, the tolerance for delays shrinks and demands for better performance increase. That means that data professionals need to be more cognizant of not only how their code is written, but also how they design storage. Tiering storage is one idea that I think has merit, but one that requires some planning.

    In SQL Server, we can’t split a table across filegroups. Or can we? We can partition a table (Enterprise Edition and higher), which can allow us to manage performance and storage appropriately. There is also the recommended practice of only having system objects in the primary partition and using separate filegroups for user data. That allows you to bring a partial database online, again, in Enterprise Edition only, while you restore different filegroups.

    This isn’t the first thing I would recommend you learn about SQL Server, but as you advance your knowledge, you should better understand when and how filegroups can help you. You will use them at some point and being comfortable with a filegroup restore is one of the skills that separates the accidental DBA from the data professional.

    Steve Jones

  • Choosing Your Tasks

    This editorial was originally published on May 13, 2011. It is being re-run as Steve is out of town.

    I have been working for SQLServerCentral for nearly a decade. I started in 2002 and in that time I have had to define my own job most of the time. Early on Andy and Brian had a list of things they thought I should be doing, and there were certain things to get done each week, but it was a general list.

    This Friday I thought this was a topic for a good poll. Answer this question:

    What percentage of your time is self-directed?

    By self-directed I mean the tasks that you choose to do because you think they need to be done for some reason. This is opposed to the specific tasks that someone assigns you and gives you some deadline for finishing. If someone asks you to “tune the server”, I don’t consider that a specific task, and you would have to pick items to work on, and determine how much time you spend on them, that’s a self-directed task.

    Do you have a good amount of self-directed time? When I used to manage a series of production servers, I usually had at least half my time as self-directed time. I could look at poor running queries, contact groups with proactive ideas for improving performance or preventing problems. I even had time to schedule DR testing. That took a lot of investment over time. I had to understand each system, set up monitoring and standards, build in data capture and analysis routines, and of course, plenty of alerting mechanisms.

    I think that a great production DBA will have a lot of self-directed time after 6-12 months on the job. A development DBA, however, will likely be constantly responding to code requests and enhancements, which is one reason I prefer the former job.

    Steve Jones

  • Aging Software

    I wrote The Age of Software awhile back and noted that supporting previous versions of software isn’t necessarily a good use of resources for development teams. I especially think this is true of SQL Server. But does that mean we should abandon aging software platforms?

    It’s a tough question. I’ve certainly talked about the case for upgrading, and the reasons why you might not. For any particular instance, however, I think that each of you has to make the case about whether the software works, or it doesn’t.

    If it works, then it seems many of us will live with the old software and keep it running. As late as a few years ago I knew a company running SQL 6.5 with a piece of software built in 1996 and last patched in 2001. However this software ran a building key card system, and there wasn’t a good case to be made for upgrading.

    For a software developer, however, when you look at aging pieces of software, even those that customers may pay for support on, is it worth maintaining skills and support? If you don’t have staff turnover, then perhaps. If you don’t, I do think that it might be time to let the product die.

    I’m torn on the way we deal with software in our world. On one hand, I’d like to see customers given source code for end of life platforms in order to support themselves if they wish. On the other, I understand the IP concerns, and business case to let software die.

    Ultimately I’m mostly OK with the current way most vendors support software. If it works for a decade and support ends, I can continue to use it. Until it doesn’t work, and then I am glad that most vendors have an upgrade for me.

    Steve Jones

    The Voice of the DBA Podcast

    Listen to the MP3 Audio ( 2.5MB) podcast or subscribe to the feed at iTunes and LibSyn.

  • Querying Yesterday

    One of the new features coming in SQL Server 2016 is the temporal table. It’s an interesting concept, one that many businesses have wanted for years. If you’re not sure what this is, we’ve got a collection of resources on Learning about Temporal Tables (and other features). Check them out and we’ll keep adding content as we find it.

    Temporal tables give us some amazing capabilities, but at a cost. As with anything in computers, there is a cost for capability. In this case, we can look back at the view of our data as of a particular point in time. In many ways, this means that we don’t need to bolt on, or query into, auditing data.

    However there are other costs. As with any auditing system, we potentially have substantial data that we need to manage somehow. Certainly we need to choose which tables to track. Even if we don’t have to build a process, we will have to deal with the cost of storage and provisioning, as well as determining the retention periods. We also need to really depend on the system times for our various instances to be in sync.

    I think that this is a needed, and very useful feature. I’m sure there will be bugs to patch, as well as enhancements to be built. We’ll find those over time, but I think that this is one of those features that we’ll come to see as essential in a decade and wonder how we ever built systems without it.

    Steve Jones

    The Voice of the DBA Podcast

    Listen to the MP3 Audio ( 2.1MB) podcast or subscribe to the feed at iTunes and LibSyn.