Voice of the DBA

Author: way0utwest

  • VMs for Development

    Here’s the scenario: you have gotten a few consulting jobs and have a couple clients. This could be your full time employment, or a side job that you perform away from another employer. You want to watch your budget, ensure you can work efficiently, and handle whatever requirements your clients may send your way. This week’s question is:

    How do you set up your virtual environment at home?

    I think the idea of using Virtual Machines (VM) is a given these days, but do you have one VM with all your tools in it? Do you use separate VMs for each client? What about licensing? Those can be complex questions for many people, especially if your employer does not provide you with multiple license keys.

    I hope that you are using VMs as having multiple computers isn’t practical these days, especially as the cost of power rises. A relatively small, inexpensive desktop computer can run 5, or even 10, VMs to simulate a variety of environments. I’ve seen some creative uses of hypervisors and other software to simulate clusters, SANs, and even multiple domains on one host.

    Let us know this week if you have some good tricks that can help someone get started with virtual machines, building a lab, choosing hardware, or easily configuring networking for their own learning efforts. Tell us what software you use, and if you don’t mind sharing cost data, I’m sure others would appreciate the information.

    Steve Jones

    The Voice of the DBA Podcast

    Listen to the MP3 Audio ( 1.9MB) podcast or subscribe to the feed at iTunes and Mevio . 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.

  • Building a Virtual Lab with Hyper-V

    I needed to get this one on Hyper-V, so I decided to document the process. I’ve put together a series that looks at the steps I took.

    This will fill in as I go through the process, so if there’s something you don’t see, it’s coming.

  • What is Continuous Integration for Databases?

    I have a talk that I give on Automated Build and Test for databases. This was put together by one of the engineers at Red Gate Software, and I’ve presented it at a number of events. I enjoy it, and it’s one of those presentations that really gets people thinking. I enjoy getting people to think about software, and there are always good questions that come out of the session.

    The talk is essentially about how to set up continuous integration for databases. Continuous Integration is an extension of the daily build, which companies have been using for years to try and ensure some discipline in their software development practices. They want to limit the amount of code that can potentially break software.  The whole idea is to test changes developers commit to version control as quickly as possible and give feedback developers immediately so developers can fix issues while the issue is fresh in their minds.

    For databases, this can be a challenge. We have this stuff called data that has to be maintained between, during, and after builds. We can’t drop our structures and reload them as a developer does with an executable or DLL. As we work in a CI environment, we need to handle new objects, as well as alterations to existing structures. That means our scripts and code need to handle creation as well as upgrade scripts.

    This means that a CI process for databases must not only check out the DDL code from a Version Control System (VCS), but it must also handle the CREATE or ALTER code based on the state of the database. You can always build a database from scratch in your CI process, or you can restore a known version (usually the last version) and apply upgrade scripts. The way this happens depends on how you version your DDL code in a VCS and how your build process is structured.

    At Red Gate, we’ve built a number of scripts to help with this process for various CI servers. We have articles that discuss CI for Team City, Jenkins, Bamboo, and probably more by the time this piece appears. We’ve learned a lot about CI over the last few years and we are trying to share both our knowledge and code with you, as well as incorporate those ideas into our products.

    Whether you use our products or not, we do believe that you will build better software if you implement CI. We just know that we can make the process a lot smoother with our tools for developers and DBAs.

    Steve Jones

    The Voice of the DBA Podcast

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

  • Powershell in a Month Day 16 – Working with many objects

    This is part of my Powershell Challenge, to learn more about PowerShell (PoSh) using the Learn Windows Powershell 3 in a Month of Lunches book by Don Jones.

    One of the great powers of T-SQL is that we can owrk with many rows at once. We use a query to tell the server what we want done to a group of objects, and then the query executes against every row that matches the filters. It’s this power that makes SQL much more efficient than the RBAR method of moving through a cursor structure. This chapter introduces the ways in which we do that with Powershell.

    The first part of the chapter is about batch commandlets, using things like Stop-Process receiving a pipeline of objects from something like Get-Process. I like their favorite example, which I’ve yet to run. I need to do this in a VM and see what happens.
    Get-Process | Stop-Process
    That’s an easy concept for me, and I see how valuable this is. However not all of the cmdlets we call will handle batches. The next part of the chapter examines WMI and the Invoke-WmiMethod call, which can take a series of objects as well. I somewhat dread the idea of needing to use this method, or worse, having to call a series of methods in which I have to pass in all the parameters. It’s good to know that I need the $null parameter for those parameters I don’t want to deal with, but it’s an ugly syntax. It’s handy to know this is an option, but I think I’ll be doing MSDN research for those times that I need to work with these methods.
    The next part of the chapter looks at the ForEach-Object syntax. I’ve seen this in scripts, and I could guess what i does, but this starts to make sense now and I can more easily decode the scripts when I see them. Along with the $_ marker to represent an object, the whole structure of PoSh is becoming easier to read.
    The chapter isn’t long and and starts to spend time comparing the various methods of enumeration. That’s helpful. Seeing how the same end result can be achieved in different ways is very handy. The lab was easy, though I had to skip the WMi stuff as I was unwired at the time that I went through this chapter. However I had an idea of what to do, just no way to look up the WMI classes.