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  • Hear about Oracle Supply Chain at Pella, Apr 27-29 '10

    - by [email protected]
    Oracle Customer Showcase - Apr 27-29'10 Featuring Pella Corp. Delivering Greater Customer Value "Discovering the Lean Value Chain" Pella is once again hosting Oracle customers at a mega-reference event in Pella, Iowa, on April 27-29. The agenda features a cross-stack set of topics and issues, including strategies for delivering customer value, improving the customer experience, Value Chain Planning / Manufacturing / Enterprise Performance Management, and Lean practices. Several executives will keynote, including Pella CIO Steve Printz. The event includes a demo grounds, round-table discussion groups, plant tours, and networking opportunities. !  

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  • Agile Executives

    - by Robert May
    Over the years, I have experienced many different styles of software development. In the early days, most of the development was Waterfall development. In the last few years, I’ve become an advocate of Scrum. As I talked about last month, many people have misconceptions about what Scrum really is. The reason why we do Scrum at Veracity is because of the difference it makes in the life of the team doing Scrum. Software is for people, and happy motivated people will build better software. However, not all executives understand Scrum and how to get the information from development teams that use Scrum. I think that these executives need a support system for managing Agile teams. Historical Software Management When Henry Ford pioneered the assembly line, I doubt he realized the impact he’d have on Management through the ages. Historically, management was about managing the process of building things. The people were just cogs in that process. Like all cogs, they were replaceable. Unfortunately, most of the software industry followed this same style of management. Many of today’s senior managers learned how to manage companies before software was a significant influence on how the company did business. Software development is a very creative process, but too many managers have treated it like an assembly line. Idea’s go in, working software comes out, and we just have to figure out how to make sure that the ideas going in are perfect, then the software will be perfect. Lean Manufacturing In the manufacturing industry, Lean manufacturing has revolutionized Henry Ford’s assembly line. Derived from the Toyota process, Lean places emphasis on always providing value for the customer. Anything the customer wouldn’t be willing to pay for is wasteful. Agile is based on similar principles. We’re building software for people, and anything that isn’t useful to them doesn’t add value. Waterfall development would have teams build reams and reams of documentation about how the software should work. Agile development dispenses with this work because excessive documentation doesn’t add value. Instead, teams focus on building documentation only when it truly adds value to the customer. Many other Agile principals are similar. Playing Catch-up Just like in the manufacturing industry, many managers in the software industry have yet to understand the value of the principles of Lean and Agile. They think they can wrap the uncertainties of software development up in a nice little package and then just execute, usually followed by failure. They spend a great deal of time and money trying to exactly predict the future. That expenditure of time and money doesn’t add value to the customer. Managers that understand that Agile know that there is a better way. They will instead focus on the priorities of the near term in detail, and leave the future to take care of itself. They have very detailed two week plans with less detailed quarterly plans. These plans are guided by a general corporate strategy that doesn’t focus on the exact implementation details. These managers also think in smaller features rather than large functionality. This adds a great deal of value to customers, since the features that matter most are the ones that the team focuses on in the near term and then are able to deliver to the customers that are paying for them. Agile managers also realize that stale software is very costly. They know that keeping the technology in their software current is much less expensive and risky than large rewrites that occur infrequently and schedule time in each release for refactoring of the existing software. Agile Executives Even though Agile is a better way, I’ve still seen failures using the Agile process. While some of these failures can be attributed to the team, most of them are caused by managers, not the team. Managers fail to understand what Agile is, how it works, and how to get the information that they need to make good business decisions. I think this is a shame. I’m very pleased that Veracity understands this problem and is trying to do something about it. Veracity is a key sponsor of Agile Executives. In fact, Galen is this year’s acting president for Agile Executives. The purpose of Agile Executives is to help managers better manage Agile teams and see better success. Agile Executives is trying to build a community of executives that range from managers interested in Agile to managers that have successfully adopted Agile. Together, these managers can form a community of support and ideas that will help make Agile teams more successful. Helping Your Team You can help too! Talk with your manager and get them involved in Agile Executives. Help Veracity build the community. If your manager understands Agile better, he’ll understand how to help his teams, which will result in software that adds more value for customers. If you have any questions about how you can be involved, please let me know. Technorati Tags: Agile,Agile Executives

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  • Inside Red Gate - Exercises in Leanness

    - by simonc
    There's a new movement rumbling around Red Gate Towers - the Lean Startup. At its core is the idea that you don't have to be in a company with single-digit employees to be an entrepreneur; you simply have to (being blunt) not know what you should be doing. Specifically, you accept that you don't know everything you need to know in order to create a useful, successful & profitable product. This is something that Red Gate has had problems with in the past; we've created products that weren't aimed at the correct market, or didn't solve the problem the user had (although they solved the problem we thought the users had, or the problem the users thought they had). As a result, these products weren't as successful as they could have been. The ideas at the core of the Lean Startup help to combat this tendency to build large, well-engineered products that solve the wrong problem. You need to actually test your hypotheses about what the users and the market needs, rather than just running a project based on those untested assumptions. Furthermore, these tests need to be done as fast as possible (on the order of a week) so that, if necessary, you can change the direction of the project without wasting effort going down a dead end. Over time, as more tests are done and more hypotheses are confirmed or refuted, the project moves towards something that solves users' actual problems. However, re-aligning the development teams that operate within Red Gate along these lines does itself have some issues; we've got very good at doing large, monolithic releases, with a feature set decided well in advance. Currently it takes about 2 weeks to do install & release testing before a release; this is clearly not practicable for a team doing weekly, or even daily releases. There's also many infrastructure issues to be solved; in our source control, build system, release mechanism, support pages & documentation, licensing system, update system, and download pages. All these need modifications to allow the fast releases necessary for each experiment. Not only do we have to change our infrastructure, we have to change our mindset. Doing daily releases means each release won't get nearly as much testing as 'standard' releases. As a team, we have to be prepared that there will be releases that have bugs and issues with them; not only do we have to be prepared to change direction with every experiment we do, but we have to be ready to fix any bugs that are reported very quickly as well. The SmartAssembly team is spearheading this move towards leanness within the company, using Feature Usage Reporting (FUR). We think this is a cracking feature that will really help developers learn how people use their products, but we need to confirm this hypothesis. So, over the next few weeks, we'll be running a variety of experiments on SmartAssembly to either confirm or refute our hypotheses concerning how people use SmartAssembly and apply FUR to their own products. In the rest of this series, I'll be documenting how the experiments we perform get on, and our experiences with applying the Lean Startup model to a mature product like SmartAssembly. Cross posted from Simple Talk.

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  • Inside Red Gate - Exercises in Leanness

    - by Simon Cooper
    There's a new movement rumbling around Red Gate Towers - the Lean Startup. At its core is the idea that you don't have to be in a company with single-digit employees to be an entrepreneur; you simply have to (being blunt) not know what you should be doing. Specifically, you accept that you don't know everything you need to know in order to create a useful, successful & profitable product. This is something that Red Gate has had problems with in the past; we've created products that weren't aimed at the correct market, or didn't solve the problem the user had (although they solved the problem we thought the users had, or the problem the users thought they had). As a result, these products weren't as successful as they could have been. The ideas at the core of the Lean Startup help to combat this tendency to build large, well-engineered products that solve the wrong problem. You need to actually test your hypotheses about what the users and the market needs, rather than just running a project based on those untested assumptions. Furthermore, these tests need to be done as fast as possible (on the order of a week) so that, if necessary, you can change the direction of the project without wasting effort going down a dead end. Over time, as more tests are done and more hypotheses are confirmed or refuted, the project moves towards something that solves users' actual problems. However, re-aligning the development teams that operate within Red Gate along these lines does itself have some issues; we've got very good at doing large, monolithic releases, with a feature set decided well in advance. Currently it takes about 2 weeks to do install & release testing before a release; this is clearly not practicable for a team doing weekly, or even daily releases. There's also many infrastructure issues to be solved; in our source control, build system, release mechanism, support pages & documentation, licensing system, update system, and download pages. All these need modifications to allow the fast releases necessary for each experiment. Not only do we have to change our infrastructure, we have to change our mindset. Doing daily releases means each release won't get nearly as much testing as 'standard' releases. As a team, we have to be prepared that there will be releases that have bugs and issues with them; not only do we have to be prepared to change direction with every experiment we do, but we have to be ready to fix any bugs that are reported very quickly as well. The SmartAssembly team is spearheading this move towards leanness within the company, using Feature Usage Reporting (FUR). We think this is a cracking feature that will really help developers learn how people use their products, but we need to confirm this hypothesis. So, over the next few weeks, we'll be running a variety of experiments on SmartAssembly to either confirm or refute our hypotheses concerning how people use SmartAssembly and apply FUR to their own products. In the rest of this series, I'll be documenting how the experiments we perform get on, and our experiences with applying the Lean Startup model to a mature product like SmartAssembly.

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  • Inside Red Gate - Experimenting In Public

    - by Simon Cooper
    Over the next few weeks, we'll be performing experiments on SmartAssembly to confirm or refute various hypotheses we have about how people use the product, what is stopping them from using it to its full extent, and what we can change to make it more useful and easier to use. Some of these experiments can be done within the team, some within Red Gate, and some need to be done on external users. External testing Some external testing can be done by standard usability tests and surveys, however, there are some hypotheses that can only be tested by building a version of SmartAssembly with some things in the UI or implementation changed. We'll then be able to look at how the experimental build is used compared to the 'mainline' build, which forms our baseline or control group, and use this data to confirm or refute the relevant hypotheses. However, there are several issues we need to consider before running experiments using separate builds: Ideally, the user wouldn't know they're running an experimental SmartAssembly. We don't want users to use the experimental build like it's an experimental build, we want them to use it like it's the real mainline build. Only then will we get valid, useful, and informative data concerning our hypotheses. There's no point running the experiments if we can't find out what happens after the download. To confirm or refute some of our hypotheses, we need to find out how the tool is used once it is installed. Fortunately, we've applied feature usage reporting to the SmartAssembly codebase itself to provide us with that information. Of course, this then makes the experimental data conditional on the user agreeing to send that data back to us in the first place. Unfortunately, even though this does limit the amount of useful data we'll be getting back, and possibly skew the data, there's not much we can do about this; we don't collect feature usage data without the user's consent. Looks like we'll simply have to live with this. What if the user tries to buy the experiment? This is something that isn't really covered by the Lean Startup book; how do you support users who give you money for an experiment? If the experiment is a new feature, and the user buys a license for SmartAssembly based on that feature, then what do we do if we later decide to pivot & scrap that feature? We've either got to spend time and money bringing that feature up to production quality and into the mainline anyway, or we've got disgruntled customers. Either way is bad. Again, there's not really any good solution to this. Similarly, what if we've removed some features for an experiment and a potential new user downloads the experimental build? (As I said above, there's no indication the build is an experimental build, as we want to see what users really do with it). The crucial feature they need is missing, causing a bad trial experience, a lost potential customer, and a lost chance to help the customer with their problem. Again, this is something not really covered by the Lean Startup book, and something that doesn't have a good solution. So, some tricky issues there, not all of them with nice easy answers. Turns out the practicalities of running Lean Startup experiments are more complicated than they first seem!

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  • Inside Red Gate - Exercising Externally

    - by simonc
    Over the next few weeks, we'll be performing experiments on SmartAssembly to confirm or refute various hypotheses we have about how people use the product, what is stopping them from using it to its full extent, and what we can change to make it more useful and easier to use. Some of these experiments can be done within the team, some within Red Gate, and some need to be done on external users. External testing Some external testing can be done by standard usability tests and surveys, however, there are some hypotheses that can only be tested by building a version of SmartAssembly with some things in the UI or implementation changed. We'll then be able to look at how the experimental build is used compared to the 'mainline' build, which forms our baseline or control group, and use this data to confirm or refute the relevant hypotheses. However, there are several issues we need to consider before running experiments using separate builds: Ideally, the user wouldn't know they're running an experimental SmartAssembly. We don't want users to use the experimental build like it's an experimental build, we want them to use it like it's the real mainline build. Only then will we get valid, useful, and informative data concerning our hypotheses. There's no point running the experiments if we can't find out what happens after the download. To confirm or refute some of our hypotheses, we need to find out how the tool is used once it is installed. Fortunately, we've applied feature usage reporting to the SmartAssembly codebase itself to provide us with that information. Of course, this then makes the experimental data conditional on the user agreeing to send that data back to us in the first place. Unfortunately, even though this does limit the amount of useful data we'll be getting back, and possibly skew the data, there's not much we can do about this; we don't collect feature usage data without the user's consent. Looks like we'll simply have to live with this. What if the user tries to buy the experiment? This is something that isn't really covered by the Lean Startup book; how do you support users who give you money for an experiment? If the experiment is a new feature, and the user buys a license for SmartAssembly based on that feature, then what do we do if we later decide to pivot & scrap that feature? We've either got to spend time and money bringing that feature up to production quality and into the mainline anyway, or we've got disgruntled customers. Either way is bad. Again, there's not really any good solution to this. Similarly, what if we've removed some features for an experiment and a potential new user downloads the experimental build? (As I said above, there's no indication the build is an experimental build, as we want to see what users really do with it). The crucial feature they need is missing, causing a bad trial experience, a lost potential customer, and a lost chance to help the customer with their problem. Again, this is something not really covered by the Lean Startup book, and something that doesn't have a good solution. So, some tricky issues there, not all of them with nice easy answers. Turns out the practicalities of running Lean Startup experiments are more complicated than they first seem! Cross posted from Simple Talk.

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  • Agile Testing Days 2012 – Day 2 – Learn through disagreement

    - by Chris George
    I think I was in the right place! During Day 1 I kept on reading tweets about Lean Coffee that has happened earlier that morning. It intrigued me and I figured in for a penny in for a pound, and set my alarm for 6:45am. Following the award night the night before, it was _really_ hard getting up when it went off, but I did and after a very early breakfast, set off for the 10 min walk to the Dorint. With Lean Coffee due to start at 07:30, I arrived at the hotel and made my way to one of the hotel bars. I soon realised I was in the right place as although the bar was empty, there was a table with post-it’s and pens! This MUST be the place! The premise of Lean Coffee is to have several small timeboxed discussions. Everyone writes down what they would like to discuss on post-its that are then briefly explained and submitted to the pile. Once everyone is done, the group dot-votes on the topics. The topics are then sorted by the dot vote counts and the discussions begin. Each discussion had 8 mins to start with, which meant it prevented the discussions getting off topic too much. After the time elapsed, the group had a vote whether to extend the discussion by a further 4 mins or move on. Several discussion were had around training, soft skills etc. The conversations were really interesting and there were quite a few good ideas. Overall it was a very enjoyable experience, certainly worth the early start! Make Melly Happy Following Lean Coffee was real coffee, and much needed that was! The first keynote of the day was “Let’s help Melly (Changing Work into Life)”by Jurgen Appelo. Draw lines to track happiness This was a very interesting presentation, and set the day nicely. The theme to the keynote was projects are about the people, more-so than the actual tasks. So he started by showing a photo of an employee ‘Melly’ who looked happy enough. He then stated that she looked happy but actually hated her job. In fact 50% of Americans hate their jobs. He went on to say that the world over 50% of people hate Americans their jobs. Jurgen talked about many ways to reduce the feedback cycle, not only of the project, but of the people management. Ideas such as Happiness doors, happiness tracking (drawing lines on a wall indicating your happiness for that day), kudo boxes (to compliment a colleague for good work). All of these (and more) ideas stimulate conversation amongst the team, lead to early detection of issues and investigation of solutions. I’ve massively simplified Jurgen’s keynote and have certainly not done it justice, so I will post a link to the video once it’s available. Following more coffee, the next talk was “How releasing faster changes testing” by Alexander Schwartz. This is a topic very close to our hearts at the moment, so I was eager to find out any juicy morsels that could help us achieve more frequent releases, and Alex did not disappoint. He started off by confirming something that I have been a firm believer in for a number of years now; adding more people can do more harm than good when trying to release. This is for a number of reasons, but just adding new people to a team at such a critical time can be more of a drain on resources than they add. The alternative is to have the whole team have shared responsibility for faster delivery. So the whole team is responsible for quality and testing. Obviously you will have the test engineers on the project who have the specialist skills, but there is no reason that the entire team cannot do exploratory testing on the product. This links nicely with the Developer Exploratory testing presented by Sigge on Day 1, and certainly something that my team are really striving towards. Focus on cycle time, so what can be done to reduce the time between dev cycles, release cycles. What’s stops a release, what delays a release? all good solid questions that can be answered. Alex suggested that perhaps the product doesn’t need to be fully tested. Doing less testing will reduce the cycle time therefore get the release out faster. He suggested a risk-based approach to planning what testing needs to happen. Reducing testing could have an impact on revenue if it causes harm to customers, so test the ‘right stuff’! Determine a set of tests that are ‘face saving’ or ‘smoke’ tests. These tests cover the core functionality of the product and aim to prevent major embarrassment if these areas were to fail! Amongst many other very good points, Alex suggested that a good approach would be to release after every new feature is added. So do a bit of work -> release, do some more work -> release. By releasing small increments of work, the impact on the customer of bugs being introduced is reduced. Red Pill, Blue Pill The second keynote of the day was “Adaptation and improvisation – but your weakness is not your technique” by Markus Gartner and proved to be another very good presentation. It started off quoting lines from the Matrix which relate to adapting, improvising, realisation and mastery. It has alot of nerds in the room smiling! Markus went on to explain how through deliberate practice ( and a lot of it!) you can achieve mastery, but then you never stop learning. Through methods such as code retreats, testing dojos, workshops you can continually improve and learn. The code retreat idea was one that interested me. It involved pairing to write an automated test for, say, 45 mins, they deleting all the code, finding a different partner and writing the same test again! This is another keynote where the video will speak louder than anything I can write here! Markus did elaborate on something that Lisa and Janet had touched on yesterday whilst busting the myth that “Testers Must Code”. Whilst it is true that to be a tester, you don’t need to code, it is becoming more common that there is this crossover happening where more testers are coding and more programmers are testing. Markus made a special distinction between programmers and developers as testers develop tests code so this helped to make that clear. “Extending Continuous Integration and TDD with Continuous Testing” by Jason Ayers was my next talk after lunch. We already do CI and a bit of TDD on my project team so I was interested to see what this continuous testing thing was all about and whether it would actually work for us. At the start of the presentation I was of the opinion that it just would not work for us because our tests are too slow, and that would be the case for many people. Jason started off by setting the scene and saying that those doing TDD spend between 10-15% of their time waiting for tests to run. This can be reduced by testing less often, reducing the test time but this then increases the risk of introduced bugs not being spotted quickly. Therefore, in comes Continuous Testing (CT). CT systems run your unit tests whenever you save some code and runs them in the background so you can continue working. This is a really nice idea, but to do this, your tests must be fast, independent and reliable. The latter two should be the case anyway, and the first is ideal, but hard! Jason makes several suggestions to make tests fast. Firstly keep the scope of the test small, secondly spin off any expensive tests into a suite which is run, perhaps, overnight or outside of the CT system at any rate. So this started to change my mind, perhaps we could re-engineer our tests, and continuously run the quick ones to give an element of coverage. This talk was very interesting and I’ve already tried a couple of the tools mentioned on our product (Mighty Moose and NCrunch). Sadly due to the way our solution is built, it currently doesn’t work, but we will look at whether we can make this work because this has the potential to be a mini-game-changer for us. Using the wrong data Gojko’s Hierarchy of Quality The final keynote of the day was “Reinventing software quality” by Gojko Adzic. He opened the talk with the statement “We’ve got quality wrong because we are using the wrong data”! Gojko then went on to explain that we should judge a bug by whether the customer cares about it, not by whether we think it’s important. Why spend time fixing issues that the customer just wouldn’t care about and releasing months later because of this? Surely it’s better to release now and get customer feedback? This was another reference to the idea of how it’s better to build the right thing wrong than the wrong thing right. Get feedback early to make sure you’re making the right thing. Gojko then showed something which was very analogous to Maslow’s heirachy of needs. Successful – does it contribute to the business? Useful – does it do what the user wants Usable – does it do what it’s supposed to without breaking Performant/Secure – is it secure/is the performance acceptable Deployable Functionally ok – can it be deployed without breaking? He then explained that User Stories should focus on change. In other words they should focus on the users needs, not the users process. Describe what the change will be, how that change will happen then measure it! Networking and Beer Following the day’s closing keynote, there were drinks and nibble for the ‘Networking’ evening. This was a great opportunity to talk to people. I find approaching strangers very uncomfortable but once again, when in Rome! Pete Walen and I had a long conversation about only fixing issues that the customer cares about versus fixing issues that make you proud of your software! Without saying much, and asking the right questions, Pete made me re-evaluate my thoughts on the matter. Clever, very clever!  Oh and he ‘bought’ me a beer! My Takeaway Triple from Day 2: release small and release often to minimize issues creeping in and get faster feedback from ‘the real world’ Focus on issues that the customers care about, not what we think is important It’s okay to disagree with someone, even if they are well respected agile testing gurus, that’s how discussion and learning happens!  

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  • I am looking to make a spaceship tilt as it corners but I cant get it to return

    - by bobthemac
    I am using the TL game engine I am not allowed to use a physics engine but I need to make the spaceship lean as it corners, I can make it lean but cannot make it return to its starting position. I have looked at implementing some kind of spring physics but I don't understand it. Here is my code so far if(myEngine->KeyHeld(Key_A)) { car->RotateY(carSteer * frameTime); if(carSteer >= -carMaxSteer) { carSteer -= carSteerIncrement; car->RotateLocalZ(-(carSteer * frameTime)); } } if(!myEngine->KeyHeld(Key_A)) { if(carSteer < 0) { carSteer = 0; } } if(myEngine->KeyHeld(Key_D)) { car->RotateY(carSteer * frameTime); if(carSteer <= carMaxSteer) { carSteer += carSteerIncrement; car->RotateLocalZ(-(carSteer * frameTime)); } } if(!myEngine->KeyHeld(Key_D)) { if(carSteer > 0) { carSteer = 0; } } All the functions I am calling are built into the engine and I did not write them. Any Help Would Be Appreciated Thanks.

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  • On Turning 30&hellip;

    - by MOSSLover
    I know I am not a wise old sage like some people in the community.  I just turned 30 however I feel like all my years looking back have changed me.  My collective experiences and thoughts have given me a different perspective on life recently.  Seven months ago my head was in a gutter and since then a lot of things have happened.  I was always the weird kid in the corner reading Star Trek books.  When I was in elementary school I thought that kids would throw me birthday parties out of pity because I was the poor kid who everyone hated.  I am no longer that person.  I realized that during the worst possible period between my 29th and 30th year when I hit rock bottom.  You all know the insane story as I’ve told it two billion times over.  Honestly it was the best thing that ever happened to me in my life time, because many things would not have happened.  My friends came through for me at every given moment people from all over were checking up on me all over the world.  I fell and I landed on a bunch of people it was awesome.  I landed on family and friends who I thought I was never close enough to talk about these things.  They helped me realize I had a ton of unfulfilled dreams.  I got to move to New York City one of the greatest cities in the universe.  I got to do whatever I wanted without judgment from anyone.  I got to meet some great people at a few meetup groups in the past few months.  I got to meet an awesome person that I have been dating for 3 months.  I am trying to run for the 8 billionth time and keep up with it.  I got to go to Europe and next week for the first time New Orleans.  I got renewed for MVP for 2012.  I am grateful for all the people and things in my life.  I understand that sometimes when things seem bad you can always seek friends and family.  They will always help me.  I have to learn to lean on people sometimes just how they occasionally lean on me.  That is the biggest thing I have learned from the decade of 20 to 30.  I hope that 30 to 40 will be the best decade.  I hope that I can continue to grow.  I will catch you all later. Technorati Tags: Turning 30,Wisdom

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  • Talking JavaOne with Rock Star Adam Bien

    - by Janice J. Heiss
    Among the most celebrated developers in recent years, especially in the domain of Java EE and JavaFX, is consultant Adam Bien, who, in addition to being a JavaOne Rock Star for Java EE sessions given in 2009 and 20011, is a Java Champion, the winner of Oracle Magazine’s 2011 Top Java Developer of the Year Award, and recently won a 2012 JAX Innovation Award as a top Java Ambassador. Bien will be presenting the following sessions: TUT3907 - Java EE 6/7: The Lean Parts CON3906 - Stress-Testing Java EE 6 Applications Without Stress CON3908 - Building Serious JavaFX 2 Applications CON3896 - Interactive Onstage Java EE Overengineering I spoke with Bien to get his take on Java today. He expressed excitement that the smallest companies and startups are showing increasing interest in Java EE. “This is a very good sign,” said Bien. “Only a few years ago J2EE was mostly used by larger companies -- now it becomes interesting even for one-person shows. Enterprise Java events are also extremely popular. On the Java SE side, I'm really excited about Project Nashorn.” Nashorn is an upcoming JavaScript engine, developed fully in Java by Oracle, and based on the Da Vinci Machine (JSR 292) which is expected to be available for Java 8.   Bien expressed concern about a common misconception regarding Java's mediocre productivity. “The problem is not Java,” explained Bien, “but rather systems built with ancient patterns and approaches. Sometimes it really is ‘Cargo Cult Programming.’ Java SE/EE can be incredibly productive and lean without the unnecessary and hard-to-maintain bloat. The real problems are ‘Ivory Towers’ and not Java’s lack of productivity.” Bien remarked that if there is one thing he wanted Java developers to understand it is that, "Premature optimization is the root of all evil. Or at least of some evil. Modern JVMs and application servers are hard to optimize upfront. It is far easier to write simple code and measure the results continuously. Identify the hotspots first, then optimize.” He advised Java EE developers to, “Rethink everything you know about Enterprise Java. Before you implement anything, ask the question: ‘Why?’ If there is no clear answer -- just don't do it. Most well known best practices are outdated. Focus your efforts on the domain problem and not the technology.” Looking ahead, Bien said, “I would like to see open source application servers running directly on a hypervisor. Packaging the whole runtime in a single file would significantly simplify the deployment and operations.”Check out a recent Java Magazine interview with Bien about his Java EE 6 stress monitoring tool here. Originally published on blogs.oracle.com/javaone.

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  • JavaOne Rock Star – Adam Bien

    - by Janice J. Heiss
    Among the most celebrated developers in recent years, especially in the domain of Java EE and JavaFX, is consultant Adam Bien, who, in addition to being a JavaOne Rock Star for Java EE sessions given in 2009 and 2011, is a Java Champion, the winner of Oracle Magazine’s 2011 Top Java Developer of the Year Award, and recently won a 2012 JAX Innovation Award as a top Java Ambassador. Bien will be presenting the following sessions: TUT3907 - Java EE 6/7: The Lean Parts CON3906 - Stress-Testing Java EE 6 Applications Without Stress CON3908 - Building Serious JavaFX 2 Applications CON3896 - Interactive Onstage Java EE Overengineering I spoke with Bien to get his take on Java today. He expressed excitement that the smallest companies and startups are showing increasing interest in Java EE. “This is a very good sign,” said Bien. “Only a few years ago J2EE was mostly used by larger companies -- now it becomes interesting even for one-person shows. Enterprise Java events are also extremely popular. On the Java SE side, I'm really excited about Project Nashorn.” Nashorn is an upcoming JavaScript engine, developed fully in Java by Oracle, and based on the Da Vinci Machine (JSR 292) which is expected to be available for Java 8.    Bien expressed concern about a common misconception regarding Java's mediocre productivity. “The problem is not Java,” explained Bien, “but rather systems built with ancient patterns and approaches. Sometimes it really is ‘Cargo Cult Programming.’ Java SE/EE can be incredibly productive and lean without the unnecessary and hard-to-maintain bloat. The real problems are ‘Ivory Towers’ and not Java’s lack of productivity.” Bien remarked that if there is one thing he wanted Java developers to understand it is that, "Premature optimization is the root of all evil. Or at least of some evil. Modern JVMs and application servers are hard to optimize upfront. It is far easier to write simple code and measure the results continuously. Identify the hotspots first, then optimize.”   He advised Java EE developers to, “Rethink everything you know about Enterprise Java. Before you implement anything, ask the question: ‘Why?’ If there is no clear answer -- just don't do it. Most well known best practices are outdated. Focus your efforts on the domain problem and not the technology.” Looking ahead, Bien remarked, “I would like to see open source application servers running directly on a hypervisor. Packaging the whole runtime in a single file would significantly simplify the deployment and operations.” Check out a recent Java Magazine interview with Bien about his Java EE 6 stress monitoring tool here.

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  • The Google TV Story

    Vincent Dureau, who’s in charge of Google TV , is a lean, bony-faced man with a strong French accent; not too far off my own age, I’d say...

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  • ArchBeat Link-o-Rama for 11/17/2011

    - by Bob Rhubart
    Building an Infrastructure Cloud with Oracle VM for x86 + Enterprise Manager 12c | Richard Rotter Richard Rotter demonstrates "how easy it could be to build a cloud infrastructure with Oracle's solution for cloud computing." Article: Social + Lean = Agile | Dave Duggal In today’s increasingly dynamic business environment, organizations must continuously adapt to survive. Change management has become a major bottleneck. Organizations’ need a practical mechanism for managing controlled variance and change in-flight to break the logjam. This paper provides a foundation for applying lean and agile principles to achieve Enterprise Agility through social collaboration. Stress Testing Java EE 6 Applications - Free Article In Free Java Magazine : Adam Bien "It is strange," says Adam Bien, "everyone is obsessed about green bars and code coverage, but testing of multi threaded behavior is widely ignored - until the applications run into massive problems." Using Access Manager to Secure Applications Deployed on WebLogic | Rene van Wijk Another great how-to post from Oracle ACE Rene van Wijk, this time involving JBoss RichFaces, Facelets, Oracle Coherence, and Oracle WebLogic Server. DOAG 2011 vs. Devoxx - Value and Attraction | Markus Eisele Oracle ACE Director Markus Eisele compares and contrasts these popular conferences with the aim of helping others decide which to attend. SOA All the Time; Architects in AZ; Clearing Info Integration hurdles SOA all the Time; Architects in AZ; Clearing Info Integration Hurdles This week on the Architect Home Page on OTN. Webcast: Oracle Business Intelligence Mobile Event Date: Wednesday, December 7, 2011 Time: 10 a.m. PT/1 p.m. ET Featuring Manan Goel (Director BI Product Marketing, Oracle) and Shailesh Shedge (Director BI and Analytics Practice, Ascentt). Webcast: Maximum Availability on Private Clouds A discussion of Oracle’s Maximum Availability Architecture, Oracle Database 11g, Oracle Exadata Database Machine, and Oracle Database appliance, featuring Margaret Hamburger (Director, Product Marketing, Oracle) and Joe Meeks (Director, Product Management, Oracle). November 30, 2011 at 10:00am PT / 1:00pm ET. Oracle Technology Network Architect Day - Phoenix, AZ Wednesday December 14, 2011, 8:30am - 5:00pm. The Ritz-Carlton, Phoenix, 2401 East Camelback Road, Phoenix, AZ 85016. Registration is free, but seating is limited.

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  • Thou shalt not put code on a piedestal - Code is a tool, no more, no less

    - by Ralf Westphal
    “Write great code and everything else becomes easier” is what Paul Pagel believes in. That´s his version of an adage by Brian Marick he cites: “treat code as an end, not just a means.” And he concludes: “My post-Agile world is software craftsmanship.” I wonder, if that´s really the way to go. Will “simply” writing great code lead the software industry into the light? He´s alluding to the philosopher Kant who proposed, a human beings should never be treated as a means, but always as an end. But should we transfer this ethical statement into the world of software? I doubt it.   Reason #1: Human beings are categorially different from code. They are autonomous entities who need to find a way of living happily together. To Kant it seemed this goal could only be reached if nobody (ab)used a human being for his/her purposes. Because using a human being, i.e. treating it as a means, would contradict the fundamental autonomy and freedom of human beings. People should hold up a symmetric view of their relationships: Since nobody wants to be (ab)used, nobody should (ab)use anybody else. If you want to be treated decently, with respect, in accordance with your own free will - which means as an end - then do the same to other people. Code is dead, it´s a product, it´s a tool for people to reach their goals. No company spends any money on code other than to save money or earn money in the long run. Code is not a puppy. Enterprises do not commission software development to just feel good in its company. Code is not a buddy. Code is a slave, if you will. A mechanical slave, a non-tangible robot. Code is a tool, is a tool. And if we start to treat it differently, if we elevate its status unduely… I guess that will contort our relationship in a contraproductive way. Please get me right: Just because something is “just a tool”, “just a product” does not mean we should not be careful while designing, building, using it. Right to the contrary. We should be very careful when writing code – but not for the code´s sake! We should be careful because we respect our customers who are fellow human beings who should be treated as an end. If we are careless, neglectful, ignorant when producing code on their behalf, then we´re using them. Being sloppy means you´re caring more for yourself that for your customer. You´re then treating the customer as a means to fulfill some of your own needs. That´s plain unethical behavior.   Reason #2: The focus should always be on your purpose, not on any tool. But if code is treated as an end, then the focus is on the code. That might sound right, because where else should be your focus as a software developer? But, well, I´d say, your focus should be on delivering value to your customer. Because in the end your customer does not care if you write a single line of code. She just wants her problem to be solved. Solving problems is the purpose of any contractor. Code must be treated just as a means, a tool we know how to handle very well. But if we´re really trying to be craftsmen then we should be conscious about exactly that and act ethically. That means we must never be so focused on our tool as to be unable to suggest better solutions to the problems of our customers than code.   I´m all with Paul when he urges us to “Write great code”. Sure, if you need to write code, then by all means do so. Write the best code you can think of – and then try to improve it. Paul has all the best intentions when he signs Brians “treat code as an end” - but as we all know: “The road to hell is paved with best intentions” ;-) Yes, I can imagine a “hell of code focus”. In fact, I don´t need to imagine it, I´m seeing it quite often. Because code hell is whereever two developers stand together and are so immersed in talking about all sorts of coding tricks, design patterns, code smells, technologies, platforms, tools that they lose sight of the big picture. Talking about TDD or SOLID or refactoring is a sign of consciousness – relative to the “cowboy coders” view of the world. But from yet another point of view TDD, SOLID, and refactoring are just cures for ailments within a system. And I fear, if “Writing great code” is the only focus or the main focus of software development, then we as an industry lose the ability to see that. Focus draws a line around something, it defines a horizon for perceptions and thinking. So if we focus on code our horizon ends where “the land of code” ends. I don´t think that should be our professional attitude.   So what about Software Craftsmanship as the next big thing after Agility? I think Software Craftsmanship has an important message for all software developers and beyond. But to make it the successor of the Agility movement seems to miss a point. Agility never claimed to solve all software development problems, I´d say. So to blame it for having missed out on certain aspects of it is wrong. If I had to summarize Agility in one word I´d say “Value”. Agility put value for the customer back in software development. Focus on delivering value early and often – that´s Agility´s mantra. All else follows from that. And I ask you: Is that obsolete? Is delivering value not hip anymore? No, sure not. That´s our very purpose as software developers. So how can Agility become obsolete and need to be replaced? We need to do away with this “either/or”-thinking. It´s either Agility or Lean or Software Craftsmanship or whatnot. Instead we should start integrating concepts and movements. Think “both/and”. Think Agility plus Software Craftsmanship plus Lean plus whatnot. We don´t neet to tear down anything from a piedestal and replace it with a new idol. Instead we should do away with piedestals and arrange whatever is helpful is a circle. Then we can turn to concepts, movements for whatever they are best. After 10 years of Agility we should be able to identify what it was good at – and keep that. Keep Agility around and add whatever Agility was lacking or never concerned with. Add whatever is at the core of Software Craftsmanship. Add whatever is at the core of Lean etc. But don´t call out the age of Post-Agility. Because it better never will end. Because once we start to lose Agility´s core we´re losing focus of the customer.

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  • Industrial Manufacturing Industry Trends and Challenges

    Mr. Lorne Jones, Senior Director of Oracle's Global Manufacturing Strategy and Marketing practice, talks with Fred about the challenges industrial manufacturing companies face, and Oracle's expertise in supporting their Lean enterprise initiatives with Oracle enterprise solutions.

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  • Tools of the Trade

    - by Ajarn Mark Caldwell
    I got pretty excited a couple of days ago when my new laptop arrived. “The new phone books are here!  The new phone books are here!  I’m a somebody!” - Steve Martin in The Jerk It is a Dell Precision M4500 with an Intel i7 Core 2.8 GHZ running 64-bit Windows 7 with a 15.6” widescreen, 8 GB RAM, 256 GB SSD.  For some of you high fliers, this may be nothing to write home about, but compared to the 32–bit Windows XP laptop with 2 GB of RAM and a regular hard disk that I’m coming from, it’s a really nice step forward.  I won’t even bore you with the details of the desktop PC I was first given when I started here 5 1/2 years ago.  Let’s just say that things have improved.  One really nice thing is that while we are definitely running a lean and mean department in terms of staffing, my boss believes in supporting that lean staff with good tools in order to stay lean instead of having to spend even more money on additional employees.  Of course, that only goes so far, and at some point you have to add more people in order to get more work done, which is why we are bringing on-board a new employee and a new contract developer next week.  But that’s a different story for a different time. But the main topic for this post is to highlight the variety of tools that I use in my job and that you might find useful, too.  This is easy to do right now because the process of building up my new laptop from scratch has forced me to assemble a list of software that had to be installed and configured.  Keep in mind as you look through this list that I play many roles in our company.  My official title is Software Engineering Manager, but in addition to managing the team, I am also an active ASP.NET and SQL developer, the Database Administrator, and 50% of the SAN Administrator team.  So, without further ado, here are the tools and some comments about why I use them: Tool Purpose Virtual Clone Drive Easily mount an ISO image as a DVD Drive.  This is particularly handy when you are downloading disk images from Microsoft for your tools. SQL Server 2008 R2 Developer Edition We are migrating all of our active systems to SQL 2008 R2.  Developer Edition has all the features of Enterprise Edition, but intended for development use. SQL Server 2005 Developer Edition (BIDS ONLY) The migration to SSRS 2008 R2 is just getting started, and in the meantime, maintenance work still has to be done on the reports on our SQL 2005 server.  For some reason, you can’t use BIDS from 2008 to write reports for a 2005 server.  There is some different format and when you open 2005 reports in 2008 BIDS, it forces you to upgrade, and they can no longer be uploaded to a 2005 server.  Hopefully Microsoft will fix this soon in some manner similar to Visual Studio now allows you to pick which version of the .NET Framework you are coding against. Visual Studio 2010 Premium All of our application development is in ASP.NET, and we might as well use the tool designed for it. I’ve used a version of Visual Studio going all the way back to VB 6.0 and Visual Interdev. Vault Professional Client Several years ago we replaced Visual Source Safe with SourceGear Vault (then Fortress, and now Vault Pro), and I love it.  It is very reliable with low overhead - perfect for a small to medium size development team.  And being a small ISV, their support is exceptional. Red-Gate Developer Bundle with the SQL Source Control update for Vault I first used, and fell in love with, SQL Prompt shortly before Red-Gate bought it, and then Red-Gate’s first release made me love it even more.  SQL Refactor (which has since been rolled into the latest version of SQL Prompt) has saved me many hours and migraine’s trying to understand somebody else’s code when their indenting was nonexistant, or worse, irrational.  SQL Compare has been awesome for troubleshooting potential schema issues between different instances of system databases.  SQL Data Compare helped us identify the cause behind a bug which appeared in PROD but could not be reproduced in a nearly (but not quite exactly) identical copy in UAT.  And the newest tool we are embracing: SQL Source Control.  I blogged about it here (and here, and here) last December.  This is really going to help us keep each developer’s copy of the database in sync with one another. Fiddler Helps you watch the whole traffic stream on web visits.  Haven’t used it a lot, but it did help me track down some odd 404 errors we were finding in our own application logs.  Has some other JavaScript troubleshooting capabilities, but some of its usefulness has been supplanted by the Developer Tools option in IE8. Funduc Search & Replace Find any string anywhere in a mound of source code really, really fast.  Does RegEx searches, if you understand that foreign language.  Has really helped with some refactoring work to pinpoint, for example, everywhere a particular stored procedure is referenced, whether in .NET code or other SQL procedures (which we have in script files).  Provides in-context preview of the search results.  Fantastic tool, and a bargain price. SciTE SciTE is a Scintilla based Text Editor and it is a fantastic, light-weight tool for quickly reviewing (or writing) program code, SQL scripts, and extract files.  It has language-specific syntax highlighting.  I used it to write several batch and CMD programs a year ago, and to examine data extract files for exchanging information with other systems.  Extremely handy are the options to View End of Line and View Whitespace.  Ever receive a file that is supposed to use CRLF as an end-of-line marker, but really only has CRs?  SciTE will quickly make that visible. Infragistics Controls We do a lot of ASP.NET development, and frequently use the WebGrid, WebTab, and date picker controls.  We will likely be implementing the Hierarchical Data Grid soon.  Infragistics has control suites for WebForms, WinForms, Silverlight, and coming soon MVC/JQuery. WinZip - WITH Command-Line add-in The classic compression program with a great command-line interface that allows me to build those CMD (and soon PowerShell) programs for automated compression jobs.  Our versioned Build packages are zip files. XML Notepad Haven’t used this a lot myself, but one of my team really likes it for examining large XML files. LINQPad Again, haven’t used this one a lot, but it was recommended to me for learning and practicing my LINQ skills which will come in handy as we implement Entity Framework. SQL Sentry Plan Explorer SQL Server Show Plan on steroids.  Great for helping you focus on the parts of a large query that are of most importance.  Also great for just compressing the graphical plan into more readable layout. Araxis Merge A great DIFF and Merge tool.  SourceGear provides a great tool called DiffMerge that we use all the time, but occasionally, I like the cross-edit capabilities of Araxis Merge.  For a while, we also produced DIFF reports in HTML that showed all the changes that occurred between two releases.  This was most important when we were putting out very small, but very important hot fixes on a very politically hot system.  The reports produced by Araxis Merge gave the Director of IS assurance that we were not accidentally introducing ripples throughout the system with our releases. Idera SQL Admin Toolset A great collection of tools including a password checker to help analyze your SQL Server for weak user passwords, a Backup Status tool to quickly scan a large list of servers and databases to identify any that are overdue for backups.  Particularly helpful for highlighting new databases that have been deployed without getting included in your backup processing.  I also like Space Analyzer to keep an eye on disk space consumed by database files. Idera SQL Job Manager This free tool provides a nice calendar view of SQL Server Job Schedules, but to a degree, you also get what you pay for.  We will be purchasing SQL Sentry Event Manager later this year as an even better job schedule reviewer/manager.  But in the meantime, this at least gives me a good view on potential resource conflicts across multiple instances of SQL Server. DBFViewer 2000 I inherited a couple of FoxPro databases that I have to keep an eye on occasionally and have not yet been able to migrate them to SQL Server. Balsamiq Mockups We are still in evaluation-mode on this tool, but I really like it as a quick UI mockup tool that does not require Visual Studio, so someone other than a programmer can do UI design.  The interface looks hand-drawn which definitely has some psychological benefits when communicating to users, too. FeedDemon I have to stay on top of my WAY TOO MANY blog subscriptions somehow.  I may read blogs on a couple of different computers, and FeedDemon’s integration with Google Reader allows me to keep them all in sync.  I don’t particularly like the Google Reader interface, or the fact that it always wanted to mark articles as read just because I scrolled past them.  FeedDemon solves this problem for me, and provides a multi-tabbed interface which is good because fairly frequently one blog will link to something else I want to read, and I can end up with a half-dozen open tabs all from one article. Synergy+ In my office, I run four monitors across two computers all with one mouse and keyboard.  Synergy is the magic software that makes this work. TweetDeck I’m not the most active Tweeter in the world, but when I want to check-in with the Twitterverse, this really helps.  I have found the #sqlhelp and #PoshHelp hash tags particularly useful, and I also have columns setup to make it easy to monitor #sqlpass, #PASSProfDev, and short term events like #sqlsat68.   Whew!  That’s a lot.  No wonder it took me a couple of days to get everything setup the way I wanted it.  Oh, that and actually getting some work accomplished at the same time.  Anyway, I know that is a huge dump of info, and most people never make it here to the end, so for those who did, let me say, CONGRATULATIONS, you made it! I hope you’ll find a new tool or two to make your work life a little easier.

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  • Community License Agreement for Commercial (SaaS) software?

    - by indomitablehef
    I've got a commercial SaaS application, an online collaboration/lean project mgmt tool. I want to offer a "Community Edition", with specific limitations on how the software can be used, for free. For example free for groups using it to manage open source projects free to K-12 teachers to use in the classroom free for authors collaborating on Lean/Kanban/AgileSoftwareDevelopment books and research papers. free for community conference organizers, user group organizers, etc. The license would grant use of the software with limitations. The software itself can enforce limitations on the number of users/projects. I'm looking for a license agreement / EULA that I can use to specify what uses the software can be used for (see above). It would restrict the users from using it in different ways, such as for commercial use, managing consulting projects, client work, etc. I've been combing the web for good examples of such agreements, and so far coming up short. Any ideas? To be clear, this would not be an open source license of any kind. It would cover the use of commercial software, for specific "community" uses, as we define them.

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  • Inheritance Mapping Strategies with Entity Framework Code First CTP5: Part 3 – Table per Concrete Type (TPC) and Choosing Strategy Guidelines

    - by mortezam
    This is the third (and last) post in a series that explains different approaches to map an inheritance hierarchy with EF Code First. I've described these strategies in previous posts: Part 1 – Table per Hierarchy (TPH) Part 2 – Table per Type (TPT)In today’s blog post I am going to discuss Table per Concrete Type (TPC) which completes the inheritance mapping strategies supported by EF Code First. At the end of this post I will provide some guidelines to choose an inheritance strategy mainly based on what we've learned in this series. TPC and Entity Framework in the Past Table per Concrete type is somehow the simplest approach suggested, yet using TPC with EF is one of those concepts that has not been covered very well so far and I've seen in some resources that it was even discouraged. The reason for that is just because Entity Data Model Designer in VS2010 doesn't support TPC (even though the EF runtime does). That basically means if you are following EF's Database-First or Model-First approaches then configuring TPC requires manually writing XML in the EDMX file which is not considered to be a fun practice. Well, no more. You'll see that with Code First, creating TPC is perfectly possible with fluent API just like other strategies and you don't need to avoid TPC due to the lack of designer support as you would probably do in other EF approaches. Table per Concrete Type (TPC)In Table per Concrete type (aka Table per Concrete class) we use exactly one table for each (nonabstract) class. All properties of a class, including inherited properties, can be mapped to columns of this table, as shown in the following figure: As you can see, the SQL schema is not aware of the inheritance; effectively, we’ve mapped two unrelated tables to a more expressive class structure. If the base class was concrete, then an additional table would be needed to hold instances of that class. I have to emphasize that there is no relationship between the database tables, except for the fact that they share some similar columns. TPC Implementation in Code First Just like the TPT implementation, we need to specify a separate table for each of the subclasses. We also need to tell Code First that we want all of the inherited properties to be mapped as part of this table. In CTP5, there is a new helper method on EntityMappingConfiguration class called MapInheritedProperties that exactly does this for us. Here is the complete object model as well as the fluent API to create a TPC mapping: public abstract class BillingDetail {     public int BillingDetailId { get; set; }     public string Owner { get; set; }     public string Number { get; set; } }          public class BankAccount : BillingDetail {     public string BankName { get; set; }     public string Swift { get; set; } }          public class CreditCard : BillingDetail {     public int CardType { get; set; }     public string ExpiryMonth { get; set; }     public string ExpiryYear { get; set; } }      public class InheritanceMappingContext : DbContext {     public DbSet<BillingDetail> BillingDetails { get; set; }              protected override void OnModelCreating(ModelBuilder modelBuilder)     {         modelBuilder.Entity<BankAccount>().Map(m =>         {             m.MapInheritedProperties();             m.ToTable("BankAccounts");         });         modelBuilder.Entity<CreditCard>().Map(m =>         {             m.MapInheritedProperties();             m.ToTable("CreditCards");         });                 } } The Importance of EntityMappingConfiguration ClassAs a side note, it worth mentioning that EntityMappingConfiguration class turns out to be a key type for inheritance mapping in Code First. Here is an snapshot of this class: namespace System.Data.Entity.ModelConfiguration.Configuration.Mapping {     public class EntityMappingConfiguration<TEntityType> where TEntityType : class     {         public ValueConditionConfiguration Requires(string discriminator);         public void ToTable(string tableName);         public void MapInheritedProperties();     } } As you have seen so far, we used its Requires method to customize TPH. We also used its ToTable method to create a TPT and now we are using its MapInheritedProperties along with ToTable method to create our TPC mapping. TPC Configuration is Not Done Yet!We are not quite done with our TPC configuration and there is more into this story even though the fluent API we saw perfectly created a TPC mapping for us in the database. To see why, let's start working with our object model. For example, the following code creates two new objects of BankAccount and CreditCard types and tries to add them to the database: using (var context = new InheritanceMappingContext()) {     BankAccount bankAccount = new BankAccount();     CreditCard creditCard = new CreditCard() { CardType = 1 };                      context.BillingDetails.Add(bankAccount);     context.BillingDetails.Add(creditCard);     context.SaveChanges(); } Running this code throws an InvalidOperationException with this message: The changes to the database were committed successfully, but an error occurred while updating the object context. The ObjectContext might be in an inconsistent state. Inner exception message: AcceptChanges cannot continue because the object's key values conflict with another object in the ObjectStateManager. Make sure that the key values are unique before calling AcceptChanges. The reason we got this exception is because DbContext.SaveChanges() internally invokes SaveChanges method of its internal ObjectContext. ObjectContext's SaveChanges method on its turn by default calls AcceptAllChanges after it has performed the database modifications. AcceptAllChanges method merely iterates over all entries in ObjectStateManager and invokes AcceptChanges on each of them. Since the entities are in Added state, AcceptChanges method replaces their temporary EntityKey with a regular EntityKey based on the primary key values (i.e. BillingDetailId) that come back from the database and that's where the problem occurs since both the entities have been assigned the same value for their primary key by the database (i.e. on both BillingDetailId = 1) and the problem is that ObjectStateManager cannot track objects of the same type (i.e. BillingDetail) with the same EntityKey value hence it throws. If you take a closer look at the TPC's SQL schema above, you'll see why the database generated the same values for the primary keys: the BillingDetailId column in both BankAccounts and CreditCards table has been marked as identity. How to Solve The Identity Problem in TPC As you saw, using SQL Server’s int identity columns doesn't work very well together with TPC since there will be duplicate entity keys when inserting in subclasses tables with all having the same identity seed. Therefore, to solve this, either a spread seed (where each table has its own initial seed value) will be needed, or a mechanism other than SQL Server’s int identity should be used. Some other RDBMSes have other mechanisms allowing a sequence (identity) to be shared by multiple tables, and something similar can be achieved with GUID keys in SQL Server. While using GUID keys, or int identity keys with different starting seeds will solve the problem but yet another solution would be to completely switch off identity on the primary key property. As a result, we need to take the responsibility of providing unique keys when inserting records to the database. We will go with this solution since it works regardless of which database engine is used. Switching Off Identity in Code First We can switch off identity simply by placing DatabaseGenerated attribute on the primary key property and pass DatabaseGenerationOption.None to its constructor. DatabaseGenerated attribute is a new data annotation which has been added to System.ComponentModel.DataAnnotations namespace in CTP5: public abstract class BillingDetail {     [DatabaseGenerated(DatabaseGenerationOption.None)]     public int BillingDetailId { get; set; }     public string Owner { get; set; }     public string Number { get; set; } } As always, we can achieve the same result by using fluent API, if you prefer that: modelBuilder.Entity<BillingDetail>()             .Property(p => p.BillingDetailId)             .HasDatabaseGenerationOption(DatabaseGenerationOption.None); Working With The Object Model Our TPC mapping is ready and we can try adding new records to the database. But, like I said, now we need to take care of providing unique keys when creating new objects: using (var context = new InheritanceMappingContext()) {     BankAccount bankAccount = new BankAccount()      {          BillingDetailId = 1                          };     CreditCard creditCard = new CreditCard()      {          BillingDetailId = 2,         CardType = 1     };                      context.BillingDetails.Add(bankAccount);     context.BillingDetails.Add(creditCard);     context.SaveChanges(); } Polymorphic Associations with TPC is Problematic The main problem with this approach is that it doesn’t support Polymorphic Associations very well. After all, in the database, associations are represented as foreign key relationships and in TPC, the subclasses are all mapped to different tables so a polymorphic association to their base class (abstract BillingDetail in our example) cannot be represented as a simple foreign key relationship. For example, consider the the domain model we introduced here where User has a polymorphic association with BillingDetail. This would be problematic in our TPC Schema, because if User has a many-to-one relationship with BillingDetail, the Users table would need a single foreign key column, which would have to refer both concrete subclass tables. This isn’t possible with regular foreign key constraints. Schema Evolution with TPC is Complex A further conceptual problem with this mapping strategy is that several different columns, of different tables, share exactly the same semantics. This makes schema evolution more complex. For example, a change to a base class property results in changes to multiple columns. It also makes it much more difficult to implement database integrity constraints that apply to all subclasses. Generated SQLLet's examine SQL output for polymorphic queries in TPC mapping. For example, consider this polymorphic query for all BillingDetails and the resulting SQL statements that being executed in the database: var query = from b in context.BillingDetails select b; Just like the SQL query generated by TPT mapping, the CASE statements that you see in the beginning of the query is merely to ensure columns that are irrelevant for a particular row have NULL values in the returning flattened table. (e.g. BankName for a row that represents a CreditCard type). TPC's SQL Queries are Union Based As you can see in the above screenshot, the first SELECT uses a FROM-clause subquery (which is selected with a red rectangle) to retrieve all instances of BillingDetails from all concrete class tables. The tables are combined with a UNION operator, and a literal (in this case, 0 and 1) is inserted into the intermediate result; (look at the lines highlighted in yellow.) EF reads this to instantiate the correct class given the data from a particular row. A union requires that the queries that are combined, project over the same columns; hence, EF has to pad and fill up nonexistent columns with NULL. This query will really perform well since here we can let the database optimizer find the best execution plan to combine rows from several tables. There is also no Joins involved so it has a better performance than the SQL queries generated by TPT where a Join is required between the base and subclasses tables. Choosing Strategy GuidelinesBefore we get into this discussion, I want to emphasize that there is no one single "best strategy fits all scenarios" exists. As you saw, each of the approaches have their own advantages and drawbacks. Here are some rules of thumb to identify the best strategy in a particular scenario: If you don’t require polymorphic associations or queries, lean toward TPC—in other words, if you never or rarely query for BillingDetails and you have no class that has an association to BillingDetail base class. I recommend TPC (only) for the top level of your class hierarchy, where polymorphism isn’t usually required, and when modification of the base class in the future is unlikely. If you do require polymorphic associations or queries, and subclasses declare relatively few properties (particularly if the main difference between subclasses is in their behavior), lean toward TPH. Your goal is to minimize the number of nullable columns and to convince yourself (and your DBA) that a denormalized schema won’t create problems in the long run. If you do require polymorphic associations or queries, and subclasses declare many properties (subclasses differ mainly by the data they hold), lean toward TPT. Or, depending on the width and depth of your inheritance hierarchy and the possible cost of joins versus unions, use TPC. By default, choose TPH only for simple problems. For more complex cases (or when you’re overruled by a data modeler insisting on the importance of nullability constraints and normalization), you should consider the TPT strategy. But at that point, ask yourself whether it may not be better to remodel inheritance as delegation in the object model (delegation is a way of making composition as powerful for reuse as inheritance). Complex inheritance is often best avoided for all sorts of reasons unrelated to persistence or ORM. EF acts as a buffer between the domain and relational models, but that doesn’t mean you can ignore persistence concerns when designing your classes. SummaryIn this series, we focused on one of the main structural aspect of the object/relational paradigm mismatch which is inheritance and discussed how EF solve this problem as an ORM solution. We learned about the three well-known inheritance mapping strategies and their implementations in EF Code First. Hopefully it gives you a better insight about the mapping of inheritance hierarchies as well as choosing the best strategy for your particular scenario. Happy New Year and Happy Code-Firsting! References ADO.NET team blog Java Persistence with Hibernate book a { color: #5A99FF; } a:visited { color: #5A99FF; } .title { padding-bottom: 5px; font-family: Segoe UI; font-size: 11pt; font-weight: bold; padding-top: 15px; } .code, .typeName { font-family: consolas; } .typeName { color: #2b91af; } .padTop5 { padding-top: 5px; } .padTop10 { padding-top: 10px; } .exception { background-color: #f0f0f0; font-style: italic; padding-bottom: 5px; padding-left: 5px; padding-top: 5px; padding-right: 5px; }

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  • Server Density or Scout-like Services for Windows?

    - by Michael Gorsuch
    Hi all. I've been very impressed with agent-based / SaaS-like monitoring services such as Scout and Server Density. They both provide very nice trending, alerting, and reporting capabilities for my *nix boxes, and I need to find something similar for Windows. Can anyone out there recommend such a tool? It is important that this tool is a centralized service in line with the aforementioned products, as the deployment environment is owned by a lean team with limited resources. Thanks!

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