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• MVVM Light V4 preview 2 (BL0015) #mvvmlight

  - by Laurent Bugnion

  Over the past few weeks, I have worked hard on a few new features for MVVM Light V4. Here is a second early preview (consider this pre-alpha if you wish). The features are unit-tested, but I am now looking for feedback and there might be bugs! Bug correction: Messenger.CleanupList is now thread safe This was an annoying bug that is now corrected: In some circumstances, an exception could be thrown when the Messenger’s recipients list was cleaned up (i.e. the “dead” instances were removed). The method is called now and then and the exception was thrown apparently at random. In fact it was really a multi-threading issue, which is now corrected. Bug correction: AllowPartiallyTrustedCallers prevents EventToCommand to work This is a particularly annoying regression bug that was introduced in BL0014. In order to allow MVVM Light to work in XBAPs too, I added the AllowPartiallyTrustedCallers attribute to the assemblies. However, we just found out that this causes issues when using EventToCommand. In order to allow EventToCommand to continue working, I reverted to the previous state by removing the AllowPartiallyTrustedCallers attribute for now. I will work with my friends at Microsoft to try and find a solution. Stay tuned. Bug correction: XML documentation file is now generated in Release configuration The XML documentation file was not generated for the Release configuration. This was a simple flag in the project file that I had forgotten to set. This is corrected now. Applying EventToCommand to non-FrameworkElements This feature has been requested in order to be able to execute a command when a Storyboard is completed. I implemented this, but unfortunately found out that EventToCommand can only be added to Storyboards in Silverlight 3 and Silverlight 4, but not in WPF or in Windows Phone 7. This obviously limits the usefulness of this change, but I decided to publish it anyway, because it is pretty damn useful in Silverlight… Why not in WPF? In WPF, Storyboards added to a resource dictionary are frozen. This is a feature of WPF which allows to optimize certain objects for performance: By freezing them, it is a contract where we say “this object will not be modified anymore, so do your perf optimization on them without worrying too much”. Unfortunately, adding a Trigger (such as EventTrigger) to an object in resources does not work if this object is frozen… and unfortunately, there is no way to tell WPF not to freeze the Storyboard in the resources… so there is no way around that (at least none I can see. In Silverlight, objects are not frozen, so an EventTrigger can be added without problems. Why not in WP7? In Windows Phone 7, there is a totally different issue: Adding a Trigger can only be done to a FrameworkElement, which Storyboard is not. Here I think that we might see a change in a future version of the framework, so maybe this small trick will work in the future. Workaround? Since you cannot use the EventToCommand on a Storyboard in WPF and in WP7, the workaround is pretty obvious: Handle the Completed event in the code behind, and call the Command from there on the ViewModel. This object can be obtained by casting the DataContext to the ViewModel type. This means that the View needs to know about the ViewModel, but I never had issues with that anyway. New class: NotifyPropertyChanged Sometimes when you implement a model object (for example Customer), you would like to have it implement INotifyPropertyChanged, but without having all the frills of a ViewModelBase. A new class named NotifyPropertyChanged allows you to do that. This class is a simple implementation of INotifyPropertyChaned (with all the overloads of RaisePropertyChanged that were implemented in BL0014). In fact, ViewModelBase inherits NotifyPropertyChanged. ViewModelBase does not implement IDisposable anymore The IDisposable interface and the Dispose method had been marked obsolete in the ViewModelBase class already in V3. Now they have been removed. Note: By this, I do not mean that IDisposable is a bad interface, or that it shouldn’t be used on viewmodels. In the contrary, I know that this interface is very useful in certain circumstances. However, I think that having it by default on every instance of ViewModelBase was sending a wrong message. This interface has a strong meaning in .NET: After Dispose has been executed, the instance should not be used anymore, and should be ready for garbage collection. What I really wanted to have on ViewModelBase was rather a simple cleanup method, something that can be executed now and then during runtime. This is fulfilled by the ICleanup interface and its Cleanup method. If your ViewModels need IDisposable, you can still use it! You will just have to implement the interface on the class itself, because it is not available on ViewModelBase anymore. What’s next? I have a couple exciting new features implemented already but that need more testing before they go live… Just stay tuned and by MIX11 (12-14 April 2011), we should see at least a major addition to MVVM Light Toolkit, as well as another smaller feature which is pretty cool nonetheless More about this later! Happy Coding Laurent   Laurent Bugnion (GalaSoft) Subscribe | Twitter | Facebook | Flickr | LinkedIn

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• Liskov Substitution Principle and the Oft Forgot Third Wheel

  - by Stacy Vicknair

  Liskov Substitution Principle (LSP) is a principle of object oriented programming that many might be familiar with from the SOLID principles mnemonic from Uncle Bob Martin. The principle highlights the relationship between a type and its subtypes, and, according to Wikipedia, is defined by Barbara Liskov and Jeanette Wing as the following principle:   Let be a property provable about objects of type . Then should be provable for objects of type where is a subtype of .   Rectangles gonna rectangulate The iconic example of this principle is illustrated with the relationship between a rectangle and a square. Let’s say we have a class named Rectangle that had a property to set width and a property to set its height. 1: Public Class Rectangle 2: Overridable Property Width As Integer 3: Overridable Property Height As Integer 4: End Class   We all at some point here that inheritance mocks an “IS A” relationship, and by gosh we all know square IS A rectangle. So let’s make a square class that inherits from rectangle. However, squares do maintain the same length on every side, so let’s override and add that behavior. 1: Public Class Square 2: Inherits Rectangle 3:  4: Private _sideLength As Integer 5:  6: Public Overrides Property Width As Integer 7: Get 8: Return _sideLength 9: End Get 10: Set(value As Integer) 11: _sideLength = value 12: End Set 13: End Property 14:  15: Public Overrides Property Height As Integer 16: Get 17: Return _sideLength 18: End Get 19: Set(value As Integer) 20: _sideLength = value 21: End Set 22: End Property 23: End Class   Now, say we had the following test: 1: Public Sub SetHeight_DoesNotAffectWidth(rectangle As Rectangle) 2: 'arrange 3: Dim expectedWidth = 4 4: rectangle.Width = 4 5:  6: 'act 7: rectangle.Height = 7 8:  9: 'assert 10: Assert.AreEqual(expectedWidth, rectangle.Width) 11: End Sub   If we pass in a rectangle, this test passes just fine. What if we pass in a square?   This is where we see the violation of Liskov’s Principle! A square might "IS A” to a rectangle, but we have differing expectations on how a rectangle should function than how a square should! Great expectations Here’s where we pat ourselves on the back and take a victory lap around the office and tell everyone about how we understand LSP like a boss. And all is good… until we start trying to apply it to our work. If I can’t even change functionality on a simple setter without breaking the expectations on a parent class, what can I do with subtyping? Did Liskov just tell me to never touch subtyping again? The short answer: NO, SHE DIDN’T. When I first learned LSP, and from those I’ve talked with as well, I overlooked a very important but not appropriately stressed quality of the principle: our expectations. Our inclination is to want a logical catch-all, where we can easily apply this principle and wipe our hands, drop the mic and exit stage left. That’s not the case because in every different programming scenario, our expectations of the parent class or type will be different. We have to set reasonable expectations on the behaviors that we expect out of the parent, then make sure that those expectations are met by the child. Any expectations not explicitly expected of the parent aren’t expected of the child either, and don’t register as a violation of LSP that prevents implementation. You can see the flexibility mentioned in the Wikipedia article itself: A typical example that violates LSP is a Square class that derives from a Rectangle class, assuming getter and setter methods exist for both width and height. The Square class always assumes that the width is equal with the height. If a Square object is used in a context where a Rectangle is expected, unexpected behavior may occur because the dimensions of a Square cannot (or rather should not) be modified independently. This problem cannot be easily fixed: if we can modify the setter methods in the Square class so that they preserve the Square invariant (i.e., keep the dimensions equal), then these methods will weaken (violate) the postconditions for the Rectangle setters, which state that dimensions can be modified independently. Violations of LSP, like this one, may or may not be a problem in practice, depending on the postconditions or invariants that are actually expected by the code that uses classes violating LSP. Mutability is a key issue here. If Square and Rectangle had only getter methods (i.e., they were immutable objects), then no violation of LSP could occur. What this means is that the above situation with a rectangle and a square can be acceptable if we do not have the expectation for width to leave height unaffected, or vice-versa, in our application. Conclusion – the oft forgot third wheel Liskov Substitution Principle is meant to act as a guidance and warn us against unexpected behaviors. Objects can be stateful and as a result we can end up with unexpected situations if we don’t code carefully. Specifically when subclassing, make sure that the subclass meets the expectations held to its parent. Don’t let LSP think you cannot deviate from the behaviors of the parent, but understand that LSP is meant to highlight the importance of not only the parent and the child class, but also of the expectations WE set for the parent class and the necessity of meeting those expectations in order to help prevent sticky situations.   Code examples, in both VB and C# Technorati Tags: LSV,Liskov Substitution Principle,Uncle Bob,Robert Martin,Barbara Liskov,Liskov

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• Advice on learning programming languages and math.

  - by Joris Ooms

  I feel like I'm getting stuck lately when it comes to learning about programming-related things; I thought I'd ask a question here and write it all down in the hope to get some pointers/advice from people. Perhaps writing it down helps me put things in perspective for myself aswell. I study Interactive Multimedia Design. This course is based on two things: graphic design on one hand, and web development on the other hand. I have quite a decent knowledge of web-related languages (the usual HTML/JS/PHP) and I'll be getting a course on ASP.NET next year. In my free time, I have learnt how to work with CodeIgniter, aswell as some diving into Ruby (and Rails) and basic iOS programming. In my first year of college I also did a class on Java (19/20 on the end result). This grade doesn't really mean anything though; I have the basics of OOP down but Java-wise, we learnt next to nothing. Considering the time I have been programming in, for example, PHP.. I can't say I'm bad at it. I'm definitely not good or great at it, but I'm decent. My teachers tell me I have the programming thing down. They just tell me I should keep on learning. So that's what I do, and I try to take in as much as possible; however, sometimes I'm unsure where to start and I have this tendency to always doubt myself. Now, for the 'question'. I want to get into iOS programming. I know iOS programming boils down to programming in Cocoa Touch and Objective-C. I also know Obj-C is a superset of C. I have done a class on C a couple of years ago, but I failed miserably. I got stuck at pointers and never really understood them.. Until like a month ago. I suddenly 'got' it. I have been working through a book on Objective-C for a week or so now, and I understand the basics (I'm at like.. chapter 6 or so). However, I keep running into similar problems as the ones I had when I did the C class: I suck at math. No, really. I come from a Latin-Modern Languages background in high school and I had nearly no math classes back then. I wanted to study Computer Science, but I failed there because of the miserable state of my mathematics knowledge. I can't explain why I'm suddenly talking about math here though, because it isn't directly related to programming.. yet it is. For example, the examples in the book I'm reading now are about programming a fraction-calculator. All good, I can do the programming when I get the formulas down.. but it takes me a full day or more to actually get to that point. I also find it hard to come up with ideas for myself. I made one small iOS app the other day and it's just a button / label kind of thing. When I press the button, it generates a random number. That's really all I could come up with. Can you 'learn' that? It probably comes down to creativity, but evidently, I'm not too great at being creative. Are there any sites or resources out there that provide something like a basic list of things you can program when you're just starting out? Maybe I'm focusing on too many things at once. I want to keep my HTML/CSS at a decent level, while learning PHP and CodeIgniter, while diving into Ruby on Rails and learning Objective-C and the iOS SDK at the same time. I just want to be good at something, I guess. The problem is that I can't seem to be happy with my PHP stuff. I want more, something 'harder'; that's why I decided to pick up the iOS thing. Like I said, I have the basics down of a lot of different languages. I can program something simple in Java, in C, in Objective-C as of this week.. but it ends there. Mostly because I can't come up with ideas for more complex applications, and also because I just doubt myself: 'Oh, that's too complex, I can never do that'. And then it ends there. To conclude my rant, let me basically rephrase my questions into a 'tl;dr' part. A. I want to get into iOS programming and I have basic knowledge of C/Objective-C. However, I struggle to come up with ideas of my own and implement them and I also suck at math which is something that isn't directly related to, yet often needed while programming. What can I do? B. I have an interest in a lot of different programming languages and I can't stop reading/learning. However, I don't feel like I'm good in anything. Should I perhaps focus on just one language for a year or longer, or keep taking it all in at the same time and hope I'll finally get them all down? C. Are there any resources out there that provide basic ideas of things I can program? I'm thinking about 'simple' command-line applications here to help me while studying C/Obj-C away from the whole iPhone SDK. Like I said, the examples in my book are mainly math-based (fraction calculator) and it's kinda hard. :( Thanks a lot for reading my post. I didn't plan it to be this long but oh well. Thanks in advance for any answers.

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• Implementing an Interceptor Using NHibernate’s Built In Dynamic Proxy Generator

  - by Ricardo Peres

  NHibernate 3.2 came with an included proxy generator, which means there is no longer the need – or the possibility, for that matter – to choose Castle DynamicProxy, LinFu or Spring. This is actually a good thing, because it means one less assembly to deploy. Apparently, this generator was based, at least partially, on LinFu. As there are not many tutorials out there demonstrating it’s usage, here’s one, for demonstrating one of the most requested features: implementing INotifyPropertyChanged. This interceptor, of course, will still feature all of NHibernate’s functionalities that you are used to, such as lazy loading, and such. We will start by implementing an NHibernate interceptor, by inheriting from the base class NHibernate.EmptyInterceptor. This class does not do anything by itself, but it allows us to plug in behavior by overriding some of its methods, in this case, Instantiate: 1: public class NotifyPropertyChangedInterceptor : EmptyInterceptor 2: { 3: private ISession session = null; 4:  5: private static readonly ProxyFactory factory = new ProxyFactory(); 6:  7: public override void SetSession(ISession session) 8: { 9: this.session = session; 10: base.SetSession(session); 11: } 12:  13: public override Object Instantiate(String clazz, EntityMode entityMode, Object id) 14: { 15: Type entityType = Type.GetType(clazz); 16: IProxy proxy = factory.CreateProxy(entityType, new _NotifyPropertyChangedInterceptor(), typeof(INotifyPropertyChanged)) as IProxy; 17: 18: _NotifyPropertyChangedInterceptor interceptor = proxy.Interceptor as _NotifyPropertyChangedInterceptor; 19: interceptor.Proxy = this.session.SessionFactory.GetClassMetadata(entityType).Instantiate(id, entityMode); 20:  21: this.session.SessionFactory.GetClassMetadata(entityType).SetIdentifier(proxy, id, entityMode); 22:  23: return (proxy); 24: } 25: } Then we need a class that implements the NHibernate dynamic proxy behavior, let’s place it inside our interceptor, because it will only need to be used there: 1: class _NotifyPropertyChangedInterceptor : NHibernate.Proxy.DynamicProxy.IInterceptor 2: { 3: private PropertyChangedEventHandler changed = delegate { }; 4:  5: public Object Proxy 6: { 7: get; 8: set;} 9:  10: #region IInterceptor Members 11:  12: public Object Intercept(InvocationInfo info) 13: { 14: Boolean isSetter = info.TargetMethod.Name.StartsWith("set_") == true; 15: Object result = null; 16:  17: if (info.TargetMethod.Name == "add_PropertyChanged") 18: { 19: PropertyChangedEventHandler propertyChangedEventHandler = info.Arguments[0] as PropertyChangedEventHandler; 20: this.changed += propertyChangedEventHandler; 21: } 22: else if (info.TargetMethod.Name == "remove_PropertyChanged") 23: { 24: PropertyChangedEventHandler propertyChangedEventHandler = info.Arguments[0] as PropertyChangedEventHandler; 25: this.changed -= propertyChangedEventHandler; 26: } 27: else 28: { 29: result = info.TargetMethod.Invoke(this.Proxy, info.Arguments); 30: } 31:  32: if (isSetter == true) 33: { 34: String propertyName = info.TargetMethod.Name.Substring("set_".Length); 35: this.changed(this.Proxy, new PropertyChangedEventArgs(propertyName)); 36: } 37:  38: return (result); 39: } 40:  41: #endregion 42: } What this does for every interceptable method (those who are either virtual or from the INotifyPropertyChanged) is: For methods that came from the INotifyPropertyChanged interface, add_PropertyChanged and remove_PropertyChanged (yes, events are methods ), we add an implementation that adds or removes the event handlers to the delegate which we declared as changed; For all the others, we direct them to the place where they are actually implemented, which is the Proxy field; If the call is setting a property, it fires afterwards the PropertyChanged event. In order to use this, we need to add the interceptor to the Configuration before building the ISessionFactory: 1: using (ISessionFactory factory = cfg.SetInterceptor(new NotifyPropertyChangedInterceptor()).BuildSessionFactory()) 2: { 3: using (ISession session = factory.OpenSession()) 4: using (ITransaction tx = session.BeginTransaction()) 5: { 6: Customer customer = session.Get<Customer>(100); //some id 7: INotifyPropertyChanged inpc = customer as INotifyPropertyChanged; 8: inpc.PropertyChanged += delegate(Object sender, PropertyChangedEventArgs e) 9: { 10: //fired when a property changes 11: }; 12: customer.Address = "some other address"; //will raise PropertyChanged 13: customer.RecentOrders.ToList(); //will trigger the lazy loading 14: } 15: } Any problems, questions, do drop me a line!

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• Use Drive Mirroring for Instant Backup in Windows 7

  - by Trevor Bekolay

  Even with the best backup solution, a hard drive crash means you’ll lose a few hours of work. By enabling drive mirroring in Windows 7, you’ll always have an up-to-date copy of your data. Windows 7’s mirroring – which is only available in Professional, Enterprise, and Ultimate editions – is a software implementation of RAID 1, which means that two or more disks are holding the exact same data. The files are constantly kept in sync, so that if one of the disks fails, you won’t lose any data. Note that mirroring is not technically a backup solution, because if you accidentally delete a file, it’s gone from both hard disks (though you may be able to recover the file). As an additional caveat, having mirrored disks requires changing them to “dynamic disks,” which can only be read within modern versions of Windows (you may have problems working with a dynamic disk in other operating systems or in older versions of Windows). See this Wikipedia page for more information. You will need at least one empty disk to set up disk mirroring. We’ll show you how to mirror an existing disk (of equal or lesser size) without losing any data on the mirrored drive, and how to set up two empty disks as mirrored copies from the get-go. Mirroring an Existing Drive Click on the start button and type partitions in the search box. Click on the Create and format hard disk partitions entry that shows up. Alternatively, if you’ve disabled the search box, press Win+R to open the Run window and type in: diskmgmt.msc The Disk Management window will appear. We’ve got a small disk, labeled OldData, that we want to mirror in a second disk of the same size. Note: The disk that you will use to mirror the existing disk must be unallocated. If it is not, then right-click on it and select Delete Volume… to mark it as unallocated. This will destroy any data on that drive. Right-click on the existing disk that you want to mirror. Select Add Mirror…. Select the disk that you want to use to mirror the existing disk’s data and press Add Mirror. You will be warned that this process will change the existing disk from basic to dynamic. Note that this process will not delete any data on the disk! The new disk will be marked as a mirror, and it will starting copying data from the existing drive to the new one. Eventually the drives will be synced up (it can take a while), and any data added to the E: drive will exist on both physical hard drives. Setting Up Two New Drives as Mirrored If you have two new equal-sized drives, you can format them to be mirrored copies of each other from the get-go. Open the Disk Management window as described above. Make sure that the drives are unallocated. If they’re not, and you don’t need the data on either of them, right-click and select Delete volume…. Right-click on one of the unallocated drives and select New Mirrored Volume…. A wizard will pop up. Click Next. Click on the drives you want to hold the mirrored data and click Add. Note that you can add any number of drives. Click Next. Assign it a drive letter that makes sense, and then click Next. You’re limited to using the NTFS file system for mirrored drives, so enter a volume label, enable compression if you want, and then click Next. Click Finish to start formatting the drives. You will be warned that the new drives will be converted to dynamic disks. And that’s it! You now have two mirrored drives. Any files added to E: will reside on both physical disks, in case something happens to one of them. Conclusion While the switch from basic to dynamic disks can be a problem for people who dual-boot into another operating system, setting up drive mirroring is an easy way to make sure that your data can be recovered in case of a hard drive crash. Of course, even with drive mirroring, we advocate regular backups to external drives or online backup services. Similar Articles Productive Geek Tips Rebit Backup Software [Review]Disabling Instant Search in Outlook 2007Restore Files from Backups on Windows Home ServerSecond Copy 7 [Review]Backup Windows Home Server Folders to an External Hard Drive TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips CloudBerry Online Backup 1.5 for Windows Home Server Snagit 10 VMware Workstation 7 Acronis Online Backup Windows Firewall with Advanced Security – How To Guides Sculptris 1.0, 3D Drawing app AceStock, a Tiny Desktop Quote Monitor Gmail Button Addon (Firefox) Hyperwords addon (Firefox) Backup Outlook 2010

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• FairScheduling Conventions in Hadoop

  - by dan.mcclary

  While scheduling and resource allocation control has been present in Hadoop since 0.20, a lot of people haven't discovered or utilized it in their initial investigations of the Hadoop ecosystem. We could chalk this up to many things: Organizations are still determining what their dataflow and analysis workloads will comprise Small deployments under tests aren't likely to show the signs of strains that would send someone looking for resource allocation options The default scheduling options -- the FairScheduler and the CapacityScheduler -- are not placed in the most prominent position within the Hadoop documentation. However, for production deployments, it's wise to start with at least the foundations of scheduling in place so that you can tune the cluster as workloads emerge. To do that, we have to ask ourselves something about what the off-the-rack scheduling options are. We have some choices: The FairScheduler, which will work to ensure resource allocations are enforced on a per-job basis. The CapacityScheduler, which will ensure resource allocations are enforced on a per-queue basis. Writing your own implementation of the abstract class org.apache.hadoop.mapred.job.TaskScheduler is an option, but usually overkill. If you're going to have several concurrent users and leverage the more interactive aspects of the Hadoop environment (e.g. Pig and Hive scripting), the FairScheduler is definitely the way to go. In particular, we can do user-specific pools so that default users get their fair share, and specific users are given the resources their workloads require. To enable fair scheduling, we're going to need to do a couple of things. First, we need to tell the JobTracker that we want to use scheduling and where we're going to be defining our allocations. We do this by adding the following to the mapred-site.xml file in HADOOP_HOME/conf: <property> <name>mapred.jobtracker.taskScheduler</name> <value>org.apache.hadoop.mapred.FairScheduler</value> </property> <property> <name>mapred.fairscheduler.allocation.file</name> <value>/path/to/allocations.xml</value> </property> <property> <name>mapred.fairscheduler.poolnameproperty</name> <value>pool.name</value> </property> <property> <name>pool.name</name> <value>${user.name}</name> </property> What we've done here is simply tell the JobTracker that we'd like to task scheduling to use the FairScheduler class rather than a single FIFO queue. Moreover, we're going to be defining our resource pools and allocations in a file called allocations.xml For reference, the allocation file is read every 15s or so, which allows for tuning allocations without having to take down the JobTracker. Our allocation file is now going to look a little like this <?xml version="1.0"?> <allocations> <pool name="dan"> <minMaps>5</minMaps> <minReduces>5</minReduces> <maxMaps>25</maxMaps> <maxReduces>25</maxReduces> <minSharePreemptionTimeout>300</minSharePreemptionTimeout> </pool> <mapreduce.job.user.name="dan"> <maxRunningJobs>6</maxRunningJobs> </user> <userMaxJobsDefault>3</userMaxJobsDefault> <fairSharePreemptionTimeout>600</fairSharePreemptionTimeout> </allocations> In this case, I've explicitly set my username to have upper and lower bounds on the maps and reduces, and allotted myself double the number of running jobs. Now, if I run hive or pig jobs from either the console or via the Hue web interface, I'll be treated "fairly" by the JobTracker. There's a lot more tweaking that can be done to the allocations file, so it's best to dig down into the description and start trying out allocations that might fit your workload.

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• SQL SERVER – SQL in Sixty Seconds – 5 Videos from Joes 2 Pros Series – SQL Exam Prep Series 70-433

  - by pinaldave

  Joes 2 Pros SQL Server Learning series is indeed fun. Joes 2 Pros series is written for beginners and who wants to build expertise for SQL Server programming and development from fundamental. In the beginning of the series author Rick Morelan is not shy to explain the simplest concept of how to open SQL Server Management Studio. Honestly the book starts with that much basic but as it progresses further Rick discussing about various advanced concepts from query tuning to Core Architecture. This five part series is written with keeping SQL Server Exam 70-433. Instead of just focusing on what will be there in exam, this series is focusing on learning the important concepts thoroughly. This book no way take short cut to explain any concepts and at times, will go beyond the topic at length. The best part is that all the books has many companion videos explaining the concepts and videos. Every Wednesday I like to post a video which explains something in quick few seconds. Today we will go over five videos which I posted in my earlier posts related to Joes 2 Pros series. Introduction to XML Data Type Methods – SQL in Sixty Seconds #015 The XML data type was first introduced with SQL Server 2005. This data type continues with SQL Server 2008 where expanded XML features are available, most notably is the power of the XQuery language to analyze and query the values contained in your XML instance. There are five XML data type methods available in SQL Server 2008: query() – Used to extract XML fragments from an XML data type. value() – Used to extract a single value from an XML document. exist() – Used to determine if a specified node exists. Returns 1 if yes and 0 if no. modify() – Updates XML data in an XML data type. node() – Shreds XML data into multiple rows (not covered in this blog post). [Detailed Blog Post] | [Quiz with Answer] Introduction to SQL Error Actions – SQL in Sixty Seconds #014 Most people believe that when SQL Server encounters an error severity level 11 or higher the remaining SQL statements will not get executed. In addition, people also believe that if any error severity level of 11 or higher is hit inside an explicit transaction, then the whole statement will fail as a unit. While both of these beliefs are true 99% of the time, they are not true in all cases. It is these outlying cases that frequently cause unexpected results in your SQL code. To understand how to achieve consistent results you need to know the four ways SQL Error Actions can react to error severity levels 11-16: Statement Termination – The statement with the procedure fails but the code keeps on running to the next statement. Transactions are not affected. Scope Abortion – The current procedure, function or batch is aborted and the next calling scope keeps running. That is, if Stored Procedure A calls B and C, and B fails, then nothing in B runs but A continues to call C. @@Error is set but the procedure does not have a return value. Batch Termination – The entire client call is terminated. XACT_ABORT – (ON = The entire client call is terminated.) or (OFF = SQL Server will choose how to handle all errors.) [Detailed Blog Post] | [Quiz with Answer] Introduction to Basics of a Query Hint – SQL in Sixty Seconds #013 Query hints specify that the indicated hints should be used throughout the query. Query hints affect all operators in the statement and are implemented using the OPTION clause. Cautionary Note: Because the SQL Server Query Optimizer typically selects the best execution plan for a query, it is highly recommended that hints be used as a last resort for experienced developers and database administrators to achieve the desired results. [Detailed Blog Post] | [Quiz with Answer] Introduction to Hierarchical Query – SQL in Sixty Seconds #012 A CTE can be thought of as a temporary result set and are similar to a derived table in that it is not stored as an object and lasts only for the duration of the query. A CTE is generally considered to be more readable than a derived table and does not require the extra effort of declaring a Temp Table while providing the same benefits to the user. However; a CTE is more powerful than a derived table as it can also be self-referencing, or even referenced multiple times in the same query. A recursive CTE requires four elements in order to work properly: Anchor query (runs once and the results ‘seed’ the Recursive query) Recursive query (runs multiple times and is the criteria for the remaining results) UNION ALL statement to bind the Anchor and Recursive queries together. INNER JOIN statement to bind the Recursive query to the results of the CTE. [Detailed Blog Post] | [Quiz with Answer] Introduction to SQL Server Security – SQL in Sixty Seconds #011 Let’s get some basic definitions down first. Take the workplace example where “Tom” needs “Read” access to the “Financial Folder”. What are the Securable, Principal, and Permissions from that last sentence? A Securable is a resource that someone might want to access (like the Financial Folder). A Principal is anything that might want to gain access to the securable (like Tom). A Permission is the level of access a principal has to a securable (like Read). [Detailed Blog Post] | [Quiz with Answer] Please leave a comment explain which one was your favorite video as that will help me understand what works and what needs improvement. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology, Video

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• Profit's COLLABORATE 10 Session Selections

  - by Aaron Lazenby

  COLLABORATE 2010 is a mere 11 days away (thanks for the reminder @ocp_advisor). Every year I publish my a list of the sessions I think reflect some of the more interesting people/trends in enterprise IT. I should be at all of these sessions, so drop by for a chat--I'll be the guy tapping out emails on my iPad... Monday, April 19 9:15 a.m. - Keynote: Transforming Customer Value, Delivering Highest Customer Service Location: Keynote Hall I never miss Charles Phillips when he speaks--it's one of the best opportunities to get an update on Oracle product developments and strategy. And there's certainly occasion for an update: this will be Phillips' first big presentation since the Oracle + Sun Strategy Update in late January. Phillips is appearing with Oracle Executive Vice President of Development Thomas Kurian which means there should be some excellent information about how customers are using Oracle's complete software and hardware stack to address enterprise IT challenges. The session should provide some excellent context for the rest of the week's session...don't miss it. 10:45 a.m. - Oracle Fusion Applications: Functional Overview Location: South Seas FI met Basheer Khan at COLLABORATE 08 in Denver and have followed his work ever since. He's a former member of the OAUG Board of Directors, an Oracle ACE, and a charismatic enterprise IT expert. Having worked with the Oracle Usability Advisory Board, Basheer should have some fascinating insights to share about the features and interface of Oracle's Fusine Applications. This session, along with Nadia Bendjedou's "10 Things You Can Do Today to Prepare for the Next Generation Applications" (on Tuesday, April 20 8:00 a.m. in room 3662) should give attendees the update they need about Oracle's next-generation applications.   1:15p.m. - E-Business Suite in the Amazon Cloud Location: South Seas HI did my first full-fledged cloud computing coverage at last year's COLLABORATE show (check out my interview with Oracle's Bill Hodak), where I first learned about Amazon's EC2 offering. I've since talked with several people who have provisioned server space on Amazon's cloud with great results. So I'm looking forward to watching the audience configure an instance of the Oracle E-Business Suite release 12 on the cloud while Chuck Edwards from Blue Gecko drives. This session should take some of the mist and vapor out of the cloud conversation.2:30 p.m. - "Zero Sign-on" to EBS - Enabling 96000 Users to Login to EBS Without User Maintenance Location: South Seas HI'll be sitting tight in South Seas H for the next session on Monday where Doug Pepka, a ten-year veteran of communications giant Comcast, will be walking attendees through a massive single sign-on (SSO) project across the enterprise. I'm working on a story about SSO for the August issue of Profit, so this session has real practical value to me. Plus the proliferation of user account logins--both personal and professional--makes this a critical usability/change management issue for IT leaders planning for successful long-term IT implementations.   Tuesday 8:00 am  - Information Architecture for Men in Kilts Location: SURF AGetting to a 8:00 a.m. presentation is a tall order in Las Vegas, but presenter Billy Cripe will make it worth your effort. Not only is the title of this session great, but the content should appeal to any IT strategist looking to push the limits of Web 2.0 technologies in the enterprise. Cripe is a product management director of Enterprise 2.0 and Enterprise Content Management at Oracle, author of Reshaping Your Business with Web 2.0, and a prolific blogger--he knows how information architecture is critical to and enterprise 2.0 implementation.    10:30a.m. - Oracle Virtualization: From Desktop to Data Center Location: REEF FData center virtualization is still one of the best ways to reduce the cost of running enterprise IT. With the addition of Sun products, Oracle has the industry's most comprehensive virtualization portfolio. I must admit, I'm no expert in this subject. So I'm looking forward to Monica Kumar's presentation so I can get up to speed.   Wednesday 8:00 a.m. - The Art of the Steal Location: Mandalay Bay Ballroom JMany will know Frank Abagnale from Steven Spielberg's 2002 film "Catch Me if You Can." The one-time con man and international fugitive who swindled $2.5 million in forged checks went on to help U.S. federal officials investigate fraud cases. Now the CEO of Abagnale and Associates, he has become an invaluable source to the business world on the subject of fraud and fraud protection. With identity theft and digital fraud still on the rise, this session should be an entertaining, and sobering, education on the threats facing businesses and customers around the world. A great way to start Wednesday.1:00 p.m. - Google Wave: Will it replace e-mail as we know it today? Location: SURF EBy many assessments (my own included), Google Wave is a bit of an open collaboration failure. It may seem like an odd reason for me to be excited about this session, but I'm looking forward to the chance to revisit the technology. Also, this is a great case study in connecting free, available Internet tools to existing enterprise computing environments--an issue that IT strategists must contend with as workers spreads out and choose their own productivity tools.  

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• Five Reasons to Attend PLM Summit 2013: The Conference Formerly Known as AGILITY

  - by Terri Hiskey

  As we approach the end of 2012, we are also closing in on the last couple of weeks that Agile customers and prospects can register for the upcoming PLM Summit 2013 for the bargain early bird rate of $195. Register now to secure your spot! The Conference Formerly Known as AGILITY... Long-time Agile customers may remember AGILITY, which was Agile's PLM customer conference that was held on an annual basis prior to Oracle's acquisiton of Agile in 2007. In February 2012, due to feedback we received from our Agile PLM community, we successfully resurrected the AGILITY conference and renamed it the PLM Summit. The PLM Summit was so well received and well-attended, that we are doing it again in 2013. This upcoming PLM Summit is being co-located in San Francisco under the overarching banner of the Oracle Value Chain Summit, and will be held alongside several other Oracle customer conferences that cover a range of value chain solutions, including Value Chain Planning, Value Chain Execution, Procurement, Maintenance and Manufacturing. This setup offers PLM attendees the best of all worlds--the opportunity to participate and learn about PLM in smaller, focused sessions by product and by industry, while also giving attendees the chance to see how PLM works together with other critical enterprise applications that address other important aspects of the value chain. Top Five Reasons to Attend the PLM Summit 2013 In the spirit of all of the end-of-the-year lists that are currently popping up, here is a list of the top five reasons to attend the PLM Summit for anyone out there needs a little extra encouragement to register: 1. The Best Opportunities for Customer Networking   The PLM Summit offers attendees numerous opportunities to learn and network with fellow Agile users. Customer stories are featured in keynote and breakout presentations and the schedule allows for plenty of networking time during breakfasts, lunches, breaks and dinners. Customer networking is the number one reason that Agile users attend the PLM Summit. Read what attendees thought of the most recent PLM Summit: "Hearing about the implementation of Agile products from a customers’ perspective is invaluable." - Director of Quality Assurance & Regulatory Affairs, leading medical device manufacturer "Understanding the scope of other companies’ projects and the lessons learned made attending this event well worth my time." - Director of Test Engineering, global industrial manufacturer "The most beneficial thing about attending this event is the opportunity to network with other customers with similar experiences." - Director of Business Process Improvement, leading high technology company Come to the PLM Summit and play an active role within the PLM community: swap war stories and business cards, connect on LinkedIn and Facebook, share your stories and discuss the sessions from each day. Register now! 2. It's Educational! The PLM Summit is the premier educational event for anyone in the Agile PLM community. There are nearly 40 PLM-focused in-depth educational sessions led by Agile PLM experts, customers and partners that will cover a range of specific product and industry-focused topics. Keynotes will give attendees a broad overview of the entire Agile PLM footprint, while sessions will delve deeply into specific product functionality and customer case studies. There is truly something for everyone. Check out the latest agenda for view of all the sessions. 3. Visit with the PLM Partner Community Our partners play a significant and important role within the Agile PLM community. At the PLM Summit, attendees will be able to meet and mingle with several of the top Oracle Agile PLM partners including: Deloitte, Domain, GoEngineer, Hitachi Consulting, IBM, Kalypso, KPIT Cummins (CPG Solutions), Perception Software, Verdant, Xavor and ZeroWaitState. Go here for a complete list of all the Value Chain Summit sponsors. 4. See Agile PLM in Action at our Dedicated PLM Demo Pods At the PLM Summit, attendees will have the chance to see Agile PLM in action at dedicated PLM demo pods, manned by expert members of our Agile PLM team. If you would like to see up close specific Agile PLM functionality, or if you have a question on how to extend the scope of your current implemention or if you want a better understanding of how to leverage Agile PLM to address specific use-cases, stop by one of the Agile PLM demo pods and engage the Agile PLM experts on hand at the PLM Summit. 5. Spend Some Time in Lovely San Francisco Still on the fence about the upcoming PLM Summit? Remember that it is being held in San Francisco, which is a fantastic city for a getaway. After spending time learning and networking about PLM, take an extra day or two to escape the dreary winter and enjoy the beautiful scenery and the unique actitivies offered only by the City by the Bay. You will walk away from the conference not only with renewed excitement about Agile PLM, but feeling rejuvenated in general.

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• Persisting settings without using Options dialog in Visual Studio

  - by Utkarsh Shigihalli

  Originally posted on: http://geekswithblogs.net/onlyutkarsh/archive/2013/11/02/persisting-settings-without-using-options-dialog-in-visual-studio.aspxIn one of my previous blog post we have seen persisting settings using Visual Studio's options dialog. Visual Studio options has many advantages in automatically persisting user options for you. However, during our latest Team Rooms extension development, we decided to provide our users; ability to use our preferences directly from Team Explorer. The main reason was that we had only one simple option for user and we thought it is cumbersome for user to go to Tools –> Options dialog to change this. Another reason was, we wanted to highlight this setting to user as soon as he is using our extension.   So if you are in such a scenario where you do not want to use VS options window, but still would like to persist the settings, this post will guide you through. Visual Studio SDK provides two ways to persist settings in your extensions. One is using DialogPage as shown in my previous post. Another way is to use by implementing IProfileManager interface which I will explain in this post. Please note that the class implementing IProfileManager should be independent class. This is because, VS instantiates this class during Tools –> Import and Export Settings. IProfileManager provides 2 different sets of methods (total 4 methods) to persist the settings. They are LoadSettingsFromXml and SaveSettingsToXml – Implement these methods to persist settings to disk from VS settings storage. The VS will persist your settings along with other options to disk. LoadSettingsFromStorage and SaveSettingsToStorage – Implement these methods to persist settings to local storage, usually it be registry. VS calls LoadSettingsFromStorage method when it is initializing the package too. We are going to use the 2nd set of methods for this example. First, we are creating a separate class file called UserOptions.cs. Please note that, we also need to implement IComponent, which can be done by inheriting Component along with IProfileManager. [ComVisible(true)] [Guid("XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX")] public class UserOptions : Component, IProfileManager { private const string SUBKEY_NAME = "TForVS2013"; private const string TRAY_NOTIFICATIONS_STRING = "TrayNotifications"; ... } Define the property so that it can be used to set and get from other classes. public bool TrayNotifications { get; set; } Implement the members of IProfileManager. public void LoadSettingsFromStorage() { RegistryKey reg = null; try { using (reg = Package.UserRegistryRoot.OpenSubKey(SUBKEY_NAME)) { if (reg != null) { // Key already exists, so just update this setting. TrayNotifications = Convert.ToBoolean(reg.GetValue(TRAY_NOTIFICATIONS_STRING, true)); } } } catch (TeamRoomException exception) { TrayNotifications = true; ExceptionReporting.Report(exception); } finally { if (reg != null) { reg.Close(); } } } public void LoadSettingsFromXml(IVsSettingsReader reader) { reader.ReadSettingBoolean(TRAY_NOTIFICATIONS_STRING, out _isTrayNotificationsEnabled); TrayNotifications = (_isTrayNotificationsEnabled == 1); } public void ResetSettings() { } public void SaveSettingsToStorage() { RegistryKey reg = null; try { using (reg = Package.UserRegistryRoot.OpenSubKey(SUBKEY_NAME, true)) { if (reg != null) { // Key already exists, so just update this setting. reg.SetValue(TRAY_NOTIFICATIONS_STRING, TrayNotifications); } else { reg = Package.UserRegistryRoot.CreateSubKey(SUBKEY_NAME); reg.SetValue(TRAY_NOTIFICATIONS_STRING, TrayNotifications); } } } catch (TeamRoomException exception) { ExceptionReporting.Report(exception); } finally { if (reg != null) { reg.Close(); } } } public void SaveSettingsToXml(IVsSettingsWriter writer) { writer.WriteSettingBoolean(TRAY_NOTIFICATIONS_STRING, TrayNotifications ? 1 : 0); } Let me elaborate on the method implementation. The Package class provides UserRegistryRoot (which is HKCU\Microsoft\VisualStudio\12.0 for VS2013) property which can be used to create and read the registry keys. So basically, in the methods above, I am checking if the registry key exists already and if not, I simply create it. Also, in case there is an exception I return the default values. If the key already exists, I update the value. Also, note that you need to make sure that you close the key while exiting from the method. Very simple right? Accessing and settings is simple too. We just need to use the exposed property. UserOptions.TrayNotifications = true; UserOptions.SaveSettingsToStorage(); Reading settings is as simple as reading a property. UserOptions.LoadSettingsFromStorage(); var trayNotifications = UserOptions.TrayNotifications; Lastly, the most important step. We need to tell Visual Studio shell that our package exposes options using the UserOptions class. For this we need to decorate our package class with ProvideProfile attribute as below. [ProvideProfile(typeof(UserOptions), "TForVS2013", "TeamRooms", 110, 110, false, DescriptionResourceID = 401)] public sealed class TeamRooms : Microsoft.VisualStudio.Shell.Package { ... } That's it. If everything is alright, once you run the package you will also see your options appearing in "Import Export settings" window, which allows you to export your options.

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• Aggregating cache data from OCEP in CQL

  - by Manju James

  There are several use cases where OCEP applications need to join stream data with external data, such as data available in a Coherence cache. OCEP’s streaming language, CQL, supports simple cache-key based joins of stream data with data in Coherence (more complex queries will be supported in a future release). However, there are instances where you may need to aggregate the data in Coherence based on input data from a stream. This blog describes a sample that does just that. For our sample, we will use a simplified credit card fraud detection use case. The input to this sample application is a stream of credit card transaction data. The input stream contains information like the credit card ID, transaction time and transaction amount. The purpose of this application is to detect suspicious transactions and send out a warning event. For the sake of simplicity, we will assume that all transactions with amounts greater than $1000 are suspicious. The transaction history is available in a Coherence distributed cache. For every suspicious transaction detected, a warning event must be sent with maximum amount, total amount and total number of transactions over the past 30 days, as shown in the diagram below. Application Input Stream input to the EPN contains events of type CCTransactionEvent. This input has to be joined with the cache with all credit card transactions. The cache is configured in the EPN as shown below: <wlevs:caching-system id="CohCacheSystem" provider="coherence"/> <wlevs:cache id="CCTransactionsCache" value-type="CCTransactionEvent" key-properties="cardID, transactionTime" caching-system="CohCacheSystem"> </wlevs:cache> Application Output The output that must be produced by the application is a fraud warning event. This event is configured in the spring file as shown below. Source for cardHistory property can be seen here. <wlevs:event-type type-name="FraudWarningEvent"> <wlevs:properties type="tuple"> <wlevs:property name="cardID" type="CHAR"/> <wlevs:property name="transactionTime" type="BIGINT"/> <wlevs:property name="transactionAmount" type="DOUBLE"/> <wlevs:property name="cardHistory" type="OBJECT"/> </wlevs:properties </wlevs:event-type> Cache Data Aggregation using Java Cartridge In the output warning event, cardHistory property contains data from the cache aggregated over the past 30 days. To get this information, we use a java cartridge method. This method uses Coherence’s query API on credit card transactions cache to get the required information. Therefore, the java cartridge method requires a reference to the cache. This may be set up by configuring it in the spring context file as shown below: <bean class="com.oracle.cep.ccfraud.CCTransactionsAggregator"> <property name="cache" ref="CCTransactionsCache"/> </bean> This is used by the java class to set a static property: public void setCache(Map cache) { s_cache = (NamedCache) cache; } The code snippet below shows how the total of all the transaction amounts in the past 30 days is computed. Rest of the information required by CardHistory object is calculated in a similar manner. Complete source of this class can be found here. To find out more information about using Coherence's API to query a cache, please refer Coherence Developer’s Guide. public static CreditHistoryData(String cardID) { … Filter filter = QueryHelper.createFilter("cardID = :cardID and transactionTime :transactionTime", map); CardHistoryData history = new CardHistoryData(); Double sum = (Double) s_cache.aggregate(filter, new DoubleSum("getTransactionAmount")); history.setTotalAmount(sum); … return history; } The java cartridge method is used from CQL as seen below: select cardID, transactionTime, transactionAmount, CCTransactionsAggregator.execute(cardID) as cardHistory from inputChannel where transactionAmount1000 This produces a warning event, with history data, for every credit card transaction over $1000. That is all there is to it. The complete source for the sample application, along with the configuration files, is available here. In the sample, I use a simple java bean to load the cache with initial transaction history data. An input adapter is used to create and send transaction events for the input stream.

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• LINQ und ArcObjects

  - by Marko Apfel

  LINQ und ArcObjects Motivation LINQ1 (language integrated query) ist eine Komponente des Microsoft .NET Frameworks seit der Version 3.5. Es erlaubt eine SQL-ähnliche Abfrage zu verschiedenen Datenquellen wie SQL, XML u.v.m. Wie SQL auch, bietet LINQ dazu eine deklarative Notation der Problemlösung - d.h. man muss nicht im Detail beschreiben wie eine Aufgabe, sondern was überhaupt zu lösen ist. Das befreit den Entwickler abfrageseitig von fehleranfälligen Iterator-Konstrukten. Ideal wäre es natürlich auf diese Möglichkeiten auch in der ArcObjects-Programmierung mit Features zugreifen zu können. Denkbar wäre dann folgendes Konstrukt: var largeFeatures = from feature in features where (feature.GetValue("SHAPE_Area").ToDouble() > 3000) select feature; bzw. dessen Äquivalent als Lambda-Expression: var largeFeatures = features.Where(feature => (feature.GetValue("SHAPE_Area").ToDouble() > 3000)); Dazu muss ein entsprechender Provider zu Verfügung stehen, der die entsprechende Iterator-Logik managt. Dies ist leichter als man auf den ersten Blick denkt - man muss nur die gewünschten Entitäten als IEnumerable<IFeature> liefern. (Anm.: nicht wundern - die Methoden GetValue() und ToDouble() habe ich nebenbei als Erweiterungsmethoden deklariert.) Im Hintergrund baut LINQ selbständig eine Zustandsmaschine (state machine)2 auf deren Ausführung verzögert ist (deferred execution)3 - d.h. dass erst beim tatsächlichen Anfordern von Entitäten (foreach, Count(), ToList(), ..) eine Instanziierung und Verarbeitung stattfindet, obwohl die Zuweisung schon an ganz anderer Stelle erfolgte. Insbesondere bei mehrfacher Iteration durch die Entitäten reibt man sich bei den ersten Debuggings verwundert die Augen wenn der Ausführungszeiger wie von Geisterhand wieder in die Iterator-Logik springt. Realisierung Eine ganz knappe Logik zum Konstruieren von IEnumerable<IFeature> lässt sich mittels Durchlaufen eines IFeatureCursor realisieren. Dazu werden die einzelnen Feature mit yield ausgegeben. Der einfachen Verwendung wegen, habe ich die Logik in eine Erweiterungsmethode GetFeatures() für IFeatureClass aufgenommen: public static IEnumerable GetFeatures(this IFeatureClass featureClass, IQueryFilter queryFilter, RecyclingPolicy policy) { IFeatureCursor featureCursor = featureClass.Search(queryFilter, RecyclingPolicy.Recycle == policy); IFeature feature; while (null != (feature = featureCursor.NextFeature())) { yield return feature; } //this is skipped in unit tests with cursor-mock if (Marshal.IsComObject(featureCursor)) { Marshal.ReleaseComObject(featureCursor); } } Damit kann man sich nun ganz einfach die IEnumerable<IFeature> erzeugen lassen: IEnumerable features = _featureClass.GetFeatures(RecyclingPolicy.DoNotRecycle); Etwas aufpassen muss man bei der Verwendung des "Recycling-Cursors". Nach einer verzögerten Ausführung darf im selben Kontext nicht erneut über die Features iteriert werden. In diesem Fall wird nämlich nur noch der Inhalt des letzten (recycelten) Features geliefert und alle Features sind innerhalb der Menge gleich. Kritisch würde daher das Konstrukt largeFeatures.ToList(). ForEach(feature => Debug.WriteLine(feature.OID)); weil ToList() schon einmal durch die Liste iteriert und der Cursor somit einmal durch die Features bewegt wurde. Die Erweiterungsmethode ForEach liefert dann immer dasselbe Feature. In derartigen Situationen darf also kein Cursor mit Recycling verwendet werden. Ein mehrfaches Ausführen von foreach ist hingegen kein Problem weil dafür jedes Mal die Zustandsmaschine neu instanziiert wird und somit der Cursor neu durchlaufen wird – das ist die oben schon erwähnte Magie. Ausblick Nun kann man auch einen Schritt weiter gehen und ganz eigene Implementierungen für die Schnittstelle IEnumerable<IFeature> in Angriff nehmen. Dazu müssen nur die Methode und das Property zum Zugriff auf den Enumerator ausprogrammiert werden. Im Enumerator selbst veranlasst man in der Reset()-Methode das erneute Ausführen der Suche – dazu übergibt man beispielsweise ein entsprechendes Delegate in den Konstruktur: new FeatureEnumerator( _featureClass, featureClass => featureClass.Search(_filter, isRecyclingCursor)); und ruft dieses beim Reset auf: public void Reset() {     _featureCursor = _resetCursor(_t); } Auf diese Art und Weise können Enumeratoren für völlig verschiedene Szenarien implementiert werden, die clientseitig restlos identisch nach obigen Schema verwendet werden. Damit verschmelzen Cursors, SelectionSets u.s.w. zu einer einzigen Materie und die Wiederverwendbarkeit von Code steigt immens. Obendrein lässt sich ein IEnumerable in automatisierten Unit-Tests sehr einfach mocken - ein großer Schritt in Richtung höherer Software-Qualität.4 Fazit Nichtsdestotrotz ist Vorsicht mit diesen Konstrukten in performance-relevante Abfragen geboten. Dadurch dass im Hintergrund eine Zustandsmaschine verwalten wird, entsteht einiges an Overhead dessen Verarbeitung zusätzliche Zeit kostet - ca. 20 bis 100 Prozent. Darüber hinaus ist auch das Arbeiten ohne Recycling schnell ein Performance-Gap. Allerdings ist deklarativer LINQ-Code viel eleganter, fehlerfreier und wartungsfreundlicher als das manuelle Iterieren, Vergleichen und Aufbauen einer Ergebnisliste. Der Code-Umfang verringert sich erfahrungsgemäß im Schnitt um 75 bis 90 Prozent! Dafür warte ich gerne ein paar Millisekunden länger. Wie so oft muss abgewogen werden zwischen Wartbarkeit und Performance - wobei für mich Wartbarkeit zunehmend an Priorität gewinnt. Zumeist ist sowieso nicht der Code sondern der Anwender die Bremse im Prozess. Demo-Quellcode support.esri.de   [1] Wikipedia: LINQ http://de.wikipedia.org/wiki/LINQ [2] Wikipedia: Zustandsmaschine http://de.wikipedia.org/wiki/Endlicher_Automat [3] Charlie Calverts Blog: LINQ and Deferred Execution http://blogs.msdn.com/b/charlie/archive/2007/12/09/deferred-execution.aspx [4] Clean Code Developer - gelber Grad/Automatisierte Unit Tests http://www.clean-code-developer.de/Gelber-Grad.ashx#Automatisierte_Unit_Tests_8

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• Big Data – Various Learning Resources – How to Start with Big Data? – Day 20 of 21

  - by Pinal Dave

  In yesterday’s blog post we learned how to become a Data Scientist for Big Data. In this article we will go over various learning resources related to Big Data. In this series we have covered many of the most essential details about Big Data. At the beginning of this series, I have encouraged readers to send me questions. One of the most popular questions is - “I want to learn more about Big Data. Where can I learn it?” This is indeed a great question as there are plenty of resources out to learn about Big Data and it is indeed difficult to select on one resource to learn Big Data. Hence I decided to write here a few of the very important resources which are related to Big Data. Learn from Pluralsight Pluralsight is a global leader in high-quality online training for hardcore developers.  It has fantastic Big Data Courses and I started to learn about Big Data with the help of Pluralsight. Here are few of the courses which are directly related to Big Data. Big Data: The Big Picture Big Data Analytics with Tableau NoSQL: The Big Picture Understanding NoSQL Data Analysis Fundamentals with Tableau I encourage all of you start with this video course as they are fantastic fundamentals to learn Big Data. Learn from Apache Resources at Apache are single point the most authentic learning resources. If you want to learn fundamentals and go deep about every aspect of the Big Data, I believe you must understand various concepts in Apache’s library. I am pretty impressed with the documentation and I am personally referencing it every single day when I work with Big Data. I strongly encourage all of you to bookmark following all the links for authentic big data learning. Haddop - The Apache Hadoop® project develops open-source software for reliable, scalable, distributed computing. Ambari: A web-based tool for provisioning, managing, and monitoring Apache Hadoop clusters which include support for Hadoop HDFS, Hadoop MapReduce, Hive, HCatalog, HBase, ZooKeeper, Oozie, Pig and Sqoop. Ambari also provides a dashboard for viewing cluster health such as heat maps and ability to view MapReduce, Pig and Hive applications visually along with features to diagnose their performance characteristics in a user-friendly manner. Avro: A data serialization system. Cassandra: A scalable multi-master database with no single points of failure. Chukwa: A data collection system for managing large distributed systems. HBase: A scalable, distributed database that supports structured data storage for large tables. Hive: A data warehouse infrastructure that provides data summarization and ad hoc querying. Mahout: A Scalable machine learning and data mining library. Pig: A high-level data-flow language and execution framework for parallel computation. ZooKeeper: A high-performance coordination service for distributed applications. Learn from Vendors One of the biggest issues with about learning Big Data is setting up the environment. Every Big Data vendor has different environment request and there are lots of things require to set up Big Data framework. Many of the users do not start with Big Data as they are afraid about the resources required to set up framework as well as a time commitment. Here Hortonworks have created fantastic learning environment. They have created Sandbox with everything one person needs to learn Big Data and also have provided excellent tutoring along with it. Sandbox comes with a dozen hands-on tutorial that will guide you through the basics of Hadoop as well it contains the Hortonworks Data Platform. I think Hortonworks did a fantastic job building this Sandbox and Tutorial. Though there are plenty of different Big Data Vendors I have decided to list only Hortonworks due to their unique setup. Please leave a comment if there are any other such platform to learn Big Data. I will include them over here as well. Learn from Books There are indeed few good books out there which one can refer to learn Big Data. Here are few good books which I have read. I will update the list as I will learn more. Ethics of Big Data Balancing Risk and Innovation Big Data for Dummies Head First Data Analysis: A Learner’s Guide to Big Numbers, Statistics, and Good Decisions If you search on Amazon there are millions of the books but I think above three books are a great set of books and it will give you great ideas about Big Data. Once you go through above books, you will have a clear idea about what is the next step you should follow in this series. You will be capable enough to make the right decision for yourself. Tomorrow In tomorrow’s blog post we will wrap up this series of Big Data. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Big Data, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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• Responsible BI for Excel, Even for Older Versions

  - by andrewbrust

  On Wednesday, I will have the honor of co-presenting, for both The Data Warehouse Institute (TDWI) and the New York Technology Council. on the subject of Excel and BI. My co-presenter will be none other than Bill Baker, who was a Microsoft Distinguished Engineer and, essentially, the father of BI at that company.  Details on the events are here and here. We'll be talking about PowerPivot, of course, but that's not all. Probably even more important than any one product, will be our discussion of whether the usual characterization of Excel as the nemesis of IT, the guilty pleasure of business users and the antithesis of formal BI is really valid and/or hopelessly intractable. Without giving away our punchline, I'll tell you that we are much more optimistic than that. There are huge upsides to Excel and while there are real dangers to using it in the BI space, there are standards and practices you can employ to ensure Excel is used responsibly. And when those practices are followed, Excel becomes quite powerful indeed. One of the keys to this is using Excel as a data consumer rather than data storage mechanism. Caching data in Excel is OK, but only if that data is (a) not modified and (b) configured for automated periodic refresh. PowerPivot meets both criteria -- it stores a read-only copy of your data in the form of a model, and once workbook containing a PowerPivot model is published to SharePoint, it can be configured for scheduled data refresh, on the server, requiring no user intervention whatsoever. Data refresh is a bit like hard drive backup: it will only happen reliably if it's automated, and super-easy to configure. PowerPivot hits a real home run here (as does Windows Home Server for PC backup, but I digress). The thing about PowerPivot is that it's an add-in for Excel 2010. What if you're not planning to go to that new version for quite a while? What if you’ve just deployed Office 2007 in your organization? What if you're still on Office 2003, or an even earlier version? What can you do immediately to share data responsibly and easily? As it turns out, there's a feature in Excel that's been around for quite a while, that can help: Web Queries.  The Web Query feature was introduced, ostensibly, to allow Excel to pull data in from Internet Web pages…for example, data in a stock quote history table will come in nicely, as will any data in a Web page that is displayed in an HTML table.  To use the feature In Excel 2007 or 2010, click the Data Tab or the ribbon and click the “From Web” button towards the left; in older versions use the corresponding option in  the menu or  toolbars.  Next, paste a URL into the resulting dialog box and tap Enter or click the Go button.  A preview of the Web page will come up, and the dialog will allow you to select the specific table within the page whose data you’d like to import.  Here’s an example: Now just click the table, click the Import button, and the Import Data dialog appears.  You can simply click OK to bring in your data or you can first click the Properties… button and configure the data import to be refreshed at an interval in minutes that you select.  Now your data’s in the spreadsheet and ready to worked with: Your data may be vulnerable to modification, but if you’ve set up the data refresh, any accidental or malicious changes will be corrected in time anyway. The thing about this feature is that it’s most useful not for public Web pages, but for pages behind the firewall.  In effect, the Web Query feature provides an incredibly easy way to consume data in Excel that’s “published” from an application.  Users just need a URL.  They don’t need to know server and database names and since the data is read-only, providing credentials may be unnecessary, or can be handled using integrated security.  If that’s not good enough, the Web Query can be saved to a special .iqy file, which can be edited to provide POST parameter data. The only requirement is that the data must be provided in an HTML table, with the first row providing the column names.  From an ASP.NET project, it couldn’t be easier: a simple bound GridView control is totally compatible.  Use a data source control with it, and you don’t even have to write any code.  Users can link to pages that are part of an application’s UI, or developers can create pages that are specially designed for the purpose of providing an interface to the Web Query import feature.  And none of this is Microsoft- or .NET-specific.  You can create pages in any language you want (PHP comes to mind) that output the result set of a query in HTML table format, and then consume that data in a Web Query.  Then build PivotTables and charts on the data, and in Excel 2007 or 2010 you can use conditional formatting to create scorecards and dashboards. This strategy allows you to create pages that function quite similarly to the OData XML feeds rendered when .NET developers create an “Astoria” WCF Data Service.  And while it’s cool that PowerPivot and Excel 2010 can import such OData feeds, it’s good to know that older versions of Excel can function in a similar fashion, and can consume data produced by virtually any Web development platform. As a final matter, instead of just telling you that “older versions” of Excel support this feature, I’ll be more specific.  To discover what the first version of Excel was to support Web queries, go to http://bit.ly/OldSchoolXL.

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• Simple Preferred time control using silverlight 3.

  - by mohanbrij

  Here I am going to show you a simple preferred time control, where you can select the day of the week and the time of the day. This can be used in lots of place where you may need to display the users preferred times. Sample screenshot is attached below. This control is developed using Silverlight 3 and VS2008, I am also attaching the source code with this post. This is a very basic example. You can download and customize if further for your requirement if you want. I am trying to explain in few words how this control works and what are the different ways in which you can customize it further. File: PreferredTimeControl.xaml, in this file I have just hardcoded the controls and their positions which you can see in the screenshot above. In this example, to change the start day of the week and time, you will have to go and change the design in XAML file, its not controlled by your properties or implementation classes. You can also customize it to change the start day of the week, Language, Display format, styles, etc, etc. File: PreferredTimeControl.xaml.cs, In this control using the code below, first I am taking all the checkbox from my form and store it in the Global Variable, which I can use across my page. List<CheckBox> checkBoxList; #region Constructor public PreferredTimeControl() { InitializeComponent(); GetCheckboxes();//Keep all the checkbox in List in the Load itself } #endregion #region Helper Methods private List<CheckBox> GetCheckboxes() { //Get all the CheckBoxes in the Form checkBoxList = new List<CheckBox>(); foreach (UIElement element in LayoutRoot.Children) { if (element.GetType().ToString() == "System.Windows.Controls.CheckBox") { checkBoxList.Add(element as CheckBox); } } return checkBoxList; } Then I am exposing the two methods which you can use in the container form to get and set the values in this controls. /// <summary> /// Set the Availability on the Form, with the Provided Timings /// </summary> /// <param name="selectedTimings">Provided timings comes from the DB in the form 11,12,13....37 /// Where 11 refers to Monday Morning, 12 Tuesday Morning, etc /// Here 1, 2, 3 is for Morning, Afternoon and Evening respectively, and for weekdays /// 1,2,3,4,5,6,7 where 1 is for Monday, Tuesday, Wednesday, Thrusday, Friday, Saturday and Sunday respectively /// So if we want Monday Morning, we can can denote it as 11, similarly for Saturday Evening we can write 36, etc /// </param> public void SetAvailibility(string selectedTimings) { foreach (CheckBox chk in checkBoxList) { chk.IsChecked = false; } if (!String.IsNullOrEmpty(selectedTimings)) { string[] selectedString = selectedTimings.Split(','); foreach (string selected in selectedString) { foreach (CheckBox chk in checkBoxList) { if (chk.Tag.ToString() == selected) { chk.IsChecked = true; } } } } } /// <summary> /// Gets the Availibility from the selected checkboxes /// </summary> /// <returns>String in the format of 11,12,13...41,42...31,32...37</returns> public string GetAvailibility() { string selectedText = string.Empty; foreach (CheckBox chk in GetCheckboxes()) { if (chk.IsChecked == true) { selectedText = chk.Tag.ToString() + "," + selectedText; } } return selectedText; }   In my example I am using the matrix format for Day and Time, for example Monday=1, Tuesday=2, Wednesday=3, Thursday = 4, Friday = 5, Saturday = 6, Sunday=7. And Morning = 1, Afternoon =2, Evening = 3. So if I want to represent Morning-Monday I will have to represent it as 11, Afternoon-Tuesday as 22, Morning-Wednesday as 13, etc. And in the other way to set the values in the control I am passing the values in the control in the same format as preferredTimeControl.SetAvailibility("11,12,13,16,23,22"); So this will set the checkbox value for Morning-Monday, Morning-Tuesday, Morning-Wednesday, Morning-Saturday, Afternoon of Tuesday and Afternoon of Wednesday. To implement this control, first I have to import this control in xmlns namespace as xmlns:controls="clr-namespace:PreferredTimeControlApp" and finally put in your page wherever you want, <Grid x:Name="LayoutRoot" Style="{StaticResource LayoutRootGridStyle}"> <Border x:Name="ContentBorder" Style="{StaticResource ContentBorderStyle}"> <controls:PreferredTimeControl x:Name="preferredTimeControl"></controls:PreferredTimeControl> </Border> </Grid> And in the code behind you can just include this code: private void InitializeControl() { preferredTimeControl.SetAvailibility("11,12,13,16,23,22"); } And you are ready to go. For more details you can refer to my code attached. I know there can be even simpler and better way to do this. Let me know if any other ideas. Sorry, Guys Still I have used Silverlight 3 and VS2008, as from the system I am uploading this is still not upgraded, but still you can use the same code with Silverlight 4 and VS2010 without any changes. May be just it will ask you to upgrade your project which will take care of rest. Download Source Code.   Thanks ~Brij

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• BizTalk 2009 - Installing BizTalk Server 2009 on XP for Development

  - by StuartBrierley

  At my previous employer, when developing for BizTalk Server 2004 using Visual Studio 2003, we made use of separate development and deployment environments; developing in Visual Studio on our client PCs and then deploying to a seperate shared BizTalk 2004 Server from there.  This server was part of a multi-server Standard BizTalk environment comprising of separate BizTalk Server 2004 and SQL Server 2000 servers.  This environment was implemented a number of years ago by an outside consulting company, and while it worked it did occasionally cause contention issues with three developers deploying to the same server to carry out unit testing! Now that I am making the design and implementation decisions about the environment that BizTalk will be developed in and deployed to, I have chosen to create a single "server" installation on my development PC, installling SQL Server 2008, Visual Studio 2008 and BizTalk Server 2009 on a single system.  The client PC in use is actually a MacBook Pro running Windows XP; not the most powerful of systems for high volume processing but it should be powerful enough to allow development and initial unit testing to take place. I did not need to, and so chose not to, install all of the components detailed in the Microsoft guide for installing BizTalk 2009 on Windows XP but I did follow the basics of the procedures detailed within.  Outlined below are the highlights of this process and any details of what choices I made.   Install IIS I had previsouly installed Windows XP, including all current service packs and critical updates.  At the time of installation this included Service Pack 3, the .Net Framework 3.5 and MS Windows Installer 3.1.  Having a running XP system, my first step was to install IIS - this is quite straightforward and posed no difficulties. Install Visual Studio 2008 The next step for me was to install Visual Studio 2008.  Making sure to select a custom installation is crucial at this point, as you need to make sure that you deselect SQL Server 2005 Express Edition as it can cause the BizTalk installation to fail.  The installation guide suggests that you only select Visual C# when selecting features to install, but  I decided that due to some legacy systems I have code for that I would also select the VB and ASP options. Visual Studio 2008 Service Pack 1 Following the completion of the installation of Visual Studio itself you should then install the Visual Studio 2008 Service Pack 1. SQL Server 2008 Standard Edition The next step before intalling BizTalk Server 2009 itself is to install SQL Server 2008 Standard Edition. On the feature selection screen make sure that you select the follwoing options: Database Engine Services SQL Server Replication Full-Text Search Analysis Services Reporting Services Business Intelligence Development Studio Client Tools Connectivity Integration Services Management Tools Basic and Complete Use the default instance and the same accounts for all SQL server instances - in my case I used the Network Service and Local Service accounts for the two sets of accounts. On the database engine configuration screen I selected windows authentication and added the current user, adding the same user again on the Analysis services Configuration screen.  All other screens were left on the default settings. The SQL Server 2008 installation also included the installation of hotfix for XP KB942288-v3, the Windows Installer 4.5 Redistributable. System Configuration At this stage I took a moment to disable the SQL Server shared memory protocol and enable the Named Pipes and TCP/IP protocols.  These can be found in the SQL Server Configuration Manager > SQL Server Network Configuration > Protocols for MSSQLServer.  I also made sure that the DTC settings were configured correctley.   BizTalk Server 2009 The penultimate step is to install BizTalk Server 2009 Standard Edition. I had previsouly downloaded the redistributable prerequisites as a CAB file so was able to make use of this when carrying out the installation. When selecting which components to install I selected: Server Runtime BizTalk EDI/AS2 Runtime WCF Adapter Runtime Portal Components Administrative Tools WFC Administartion Tools Developer Tools and SDK, Enterprise SSO Administration Module Enterprise SSO Master Secret Server Business Rules Components BAM Alert Provider BAM Client BAM Eventing Once installation has completed clear the launch BizTalk Server Configuration check box and select finish. Verify the Installation Before configuring BizTalk Server it is a good idea to check that BizTalk Server 2009 is installed and that SQL Server 2008 has started correctly.  The easiest way to verify the BizTalk installation is check the Programs and Features in Control panel.  Check that SQL is started by looking in the SQL Server Configuration Manager. Configure BizTalk Server 2009 Finally we are ready to configure BizTalk Server 2009.  To start this I opted for a custom configuration that allowed me to choose in more detail the settings to be used. For all databases I selected the local server and default database names. For all Accounts I used a local account that had been created specifically for the BizTalk Services. For all windows groups I allowed the configuration wizard to create the default local groups. The configuration wizard then ran:   Upon completion you will be presented with a screen detailing the success or failure of the configuration.  If your configuration failed you will need to sort out the issues and try again (it is possible to save the configuration settings for later use if you want too - except passwords of course!).  If you see lots of nice green ticks - congratulations BizTalk Server 2009 on XP is now installed and configured ready for development.

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• Find odd and even rows using $.inArray() function when using jQuery Templates

  - by hajan

  In the past period I made series of blogs on ‘jQuery Templates in ASP.NET’ topic. In one of these blogs dealing with jQuery Templates supported tags, I’ve got a question how to create alternating row background. When rendering the template, there is no direct access to the item index. One way is if there is an incremental index in the JSON string, we can use it to solve this. If there is not, then one of the ways to do this is by using the jQuery’s $.inArray() function. - $.inArray(value, array) – similar to JavaScript indexOf() Here is an complete example how to use this in context of jQuery Templates: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" > <head runat="server">     <style type="text/css">         #myList { cursor:pointer; }                  .speakerOdd { background-color:Gray; color:White;}         .speaker { background-color:#443344; color:White;}                  .speaker:hover { background-color:White; color:Black;}         .speakerOdd:hover { background-color:White; color:Black;}     </style>     <title>jQuery ASP.NET</title>     <script src="http://ajax.aspnetcdn.com/ajax/jQuery/jquery-1.4.4.min.js" type="text/javascript"></script>     <script src="http://ajax.aspnetcdn.com/ajax/jquery.templates/beta1/jquery.tmpl.min.js" type="text/javascript"></script>     <script language="javascript" type="text/javascript">         var speakers = [             { Name: "Hajan1" },             { Name: "Hajan2" },             { Name: "Hajan3" },             { Name: "Hajan4" },             { Name: "Hajan5" }         ];         $(function () {             $("#myTemplate").tmpl(speakers).appendTo("#myList");         });         function oddOrEven() {             return ($.inArray(this.data, speakers) % 2) ? "speaker" : "speakerOdd";         }     </script>     <script id="myTemplate" type="text/x-jquery-tmpl">         <tr class="${oddOrEven()}">             <td> ${Name}</td>         </tr>     </script> </head> <body>     <table id="myList"></table> </body> </html> So, I have defined stylesheet classes speakerOdd and speaker as well as corresponding :hover styles. Then, you have speakers JSON string containing five items. And what is most important in our case is the oddOrEven function where $.inArray(value, data) is implemented. function oddOrEven() {     return ($.inArray(this.data, speakers) % 2) ? "speaker" : "speakerOdd"; } Remark: The $.inArray() method is similar to JavaScript's native .indexOf() method in that it returns -1 when it doesn't find a match. If the first element within the array matches value, $.inArray() returns 0. From http://api.jquery.com/jQuery.inArray/ So, now we can call oddOrEven function from inside our jQuery Template in the following way: <script id="myTemplate" type="text/x-jquery-tmpl">     <tr class="${oddOrEven()}">         <td> ${Name}</td>     </tr> </script> And the result is I hope you like it. Regards, Hajan

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• How to restore your production database without needing additional storage

  - by David Atkinson

  Production databases can get very large. This in itself is to be expected, but when a copy of the database is needed the database must be restored, requiring additional and costly storage.  For example, if you want to give each developer a full copy of your production server, you'll need n times the storage cost for your n-developer team. The same is true for any test databases that are created during the course of your project lifecycle. If you've read my previous blog posts, you'll be aware that I've been focusing on the database continuous integration theme. In my CI setup I create a "production"-equivalent database directly from its source control representation, and use this to test my upgrade scripts. Despite this being a perfectly valid and practical thing to do as part of a CI setup, it's not the exact equivalent to running the upgrade script on a copy of the actual production database. So why shouldn't I instead simply restore the most recent production backup as part of my CI process? There are two reasons why this would be impractical. 1. My CI environment isn't an exact copy of my production environment. Indeed, this would be the case in a perfect world, and it is strongly recommended as a good practice if you follow Jez Humble and David Farley's "Continuous Delivery" teachings, but in practical terms this might not always be possible, especially where storage is concerned. It may just not be possible to restore a huge production database on the environment you've been allotted. 2. It's not just about the storage requirements, it's also the time it takes to do the restore. The whole point of continuous integration is that you are alerted as early as possible whether the build (yes, the database upgrade script counts!) is broken. If I have to run an hour-long restore each time I commit a change to source control I'm just not going to get the feedback quickly enough to react. So what's the solution? Red Gate has a technology, SQL Virtual Restore, that is able to restore a database without using up additional storage. Although this sounds too good to be true, the explanation is quite simple (although I'm sure the technical implementation details under the hood are quite complex!) Instead of restoring the backup in the conventional sense, SQL Virtual Restore will effectively mount the backup using its HyperBac technology. It creates a data and log file, .vmdf, and .vldf, that becomes the delta between the .bak file and the virtual database. This means that both read and write operations are permitted on a virtual database as from SQL Server's point of view it is no different from a conventional database. Instead of doubling the storage requirements upon a restore, there is no 'duplicate' storage requirements, other than the trivially small virtual log and data files (see illustration below). The benefit is magnified the more databases you mount to the same backup file. This technique could be used to provide a large development team a full development instance of a large production database. It is also incredibly easy to set up. Once SQL Virtual Restore is installed, you simply run a conventional RESTORE command to create the virtual database. This is what I have running as part of a nightly "release test" process triggered by my CI tool. RESTORE DATABASE WidgetProduction_virtual FROM DISK=N'C:\WidgetWF\ProdBackup\WidgetProduction.bak' WITH MOVE N'WidgetProduction' TO N'C:\WidgetWF\ProdBackup\WidgetProduction_WidgetProduction_Virtual.vmdf', MOVE N'WidgetProduction_log' TO N'C:\WidgetWF\ProdBackup\WidgetProduction_log_WidgetProduction_Virtual.vldf', NORECOVERY, STATS=1, REPLACE GO RESTORE DATABASE mydatabase WITH RECOVERY   Note the only change from what you would do normally is the naming of the .vmdf and .vldf files. SQL Virtual Restore intercepts this by monitoring the extension and applies its magic, ensuring the 'virtual' restore happens rather than the conventional storage-heavy restore. My automated release test then applies the upgrade scripts to the virtual production database and runs some validation tests, giving me confidence that were I to run this on production for real, all would go smoothly. For illustration, here is my 8Gb production database: And its corresponding backup file: Here are the .vldf and .vmdf files, which represent the only additional used storage for the new database following the virtual restore.   The beauty of this product is its simplicity. Once it is installed, the interaction with the backup and virtual database is exactly the same as before, as the clever stuff is being done at a lower level. SQL Virtual Restore can be downloaded as a fully functional 14-day trial. Technorati Tags: SQL Server

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• Identity R2 - Experts Podcast Series

  - by Tanu Sood

  To follow up on the Identity Management R2 launch, a series of podcasts were recorded with subject matter experts from customer organizations, our partners and Oracle’s PM team to discuss key trends, R2 capabilities, implementation best practices and more. Below is a roll-up of the podcast series that is available on Fusion Middleware radio. R2 Podcasts:   ·         Designing the Next-Generation Identity Platform Vadim Lander, Oracle Highlights: Common architecture model, integration, interoperability and the driving factors behind R2 innovation IT Departments are shifting their Identity Management strategy to be able to support mobile, cloud and social applications. Oracle has anticipated this shift and has built a product roadmap to take advantage of this focus. Join Vadim as he discusses the design strategy behind the latest 11gR2 release and talks about how IDM services have to evolve to meet this new challenge.   ·         BETA Customer Perspective on R2 Ravi Meduri, Kaiser Permanente Highlights: R2 scalability and high availability In this podcast Ravi discusses the new features in 11gR2 that he is most interested in, including High Availability options for Access Management, multi-datacenter architecture, and what it was like working with the Oracle product team during the BETA program.   ·         Partner Perspective on R2 Rex Thexton, PricewaterhouseCoopers Highlights: Usability Enhancements for Users and Administrators A lot of new usability features went into the 11gR2 release making this the most business friendly IDM release to date. In this podcast Rex Thexton, Managing Director from PwC, talks about some of the new UI changes for both end users and administrators, and also about the new connector creation framework.   Access Request Updates in R2 Marc Boroditsky, Oracle Highlights: Access request User Interface innovations A lot of changes have been made to the Access Request user interface in the latest version of Oracle Identity Manager 11gR2. A real focus has been put on making the request process more business user friendly, and a lot of new customization capability has been added for the IT administrators. Hear Marc discuss the updated UI, and explain how administrators will be able to customize OIM to meet their company's requirements   ·         Oracle Optimized System for Oracle Unified Directory (OOS4OUD) Nick Kloski, Oracle Highlights: New Optimized System configuration for Unified Directory One of the new features in 11gR2 is the availability of an Optimized System configuration for Oracle Unified Directory. Oracle engineers installed the OUD software onto off the shelf hardware and then created a performance tuned configuration. Join us as we talk to Nick Kloski, Infrastructure Solutions Manager, all about the testing process and the resulting performance metrics.   Privileged Account Management Mark Wilcox, Oracle Highlights: Oracle Privileged Account Manager key capabilities, use cases The new release of Oracle Identity Management 11g R2 includes the capability to manage privileged accounts. Privileged accounts, if compromised, create a risk for fraud in the enterprise and as a result controlling access to privileged accounts is critical. Hear what Mark Wilcox, Principal Product Manager of Oracle Privileged Account Manager has to say about the capabilities of the offering in this podcast.   ·         Browser-based User Interface (UI) Customization Clayton Donley, Oracle Highlights: Benefits of Durable UI Configuration framework Business users need user interfaces that are not only friendly but also easily customizable. However the downside of any customization project is the cost and complexity involved in developing, testing, deploying and managing custom code. In this podcast, we examine how a new capability in Oracle Identity Management around browser based UI customization can reduce costs and complexity of customization while simplifying self service integration with corporate portal strategies.   ·         Simplifying Mobile and Social Sign-On Dan Killmer, Oracle Highlights: Secure mobile sign-on and consumption of social identities with Oracle Access Management The proliferation of mobile devices has spurred a new trend where employees tend to bring their own mobile devices to work and access corporate applications the same way they would access from a desktop or laptop. In this podcast, we examine how Oracle's latest innovation in Identity Management around Mobile and Social Sign On can simplify security and access management challenges posed by the widespread adoption of mobile devices in the enterprise. ·         Enabling Your Business with IDM R2 Scott Bonnell, Oracle Highlights: Self service, mobile access, personalization Gone are the days when Identity Management was just about stopping unauthorized users in their tracks. Identity Management if done right, can also enable your business. Join Scott Bonnell as he discusses how the IDM 11gR2 release enables the enterprise by providing self service, personalization and mobile access to corporate resources.

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• How to write a generic service in WCF

  - by rezaxp

  In one of my recent projects I needed a generic service as a facade to handle General activities such as CRUD.Therefor I searched as Many as I could but there was no Idea on generic services so I tried to figure it out by my self.Finally,I found a way :Create a generic contract as below :[ServiceContract] public interface IEntityReadService<TEntity>         where TEntity : EntityBase, new()     {         [OperationContract(Name = "Get")]         TEntity Get(Int64 Id);         [OperationContract(Name = "GetAll")]         List<TEntity> GetAll();         [OperationContract(Name = "GetAllPaged")]         List<TEntity> GetAll(int pageSize, int currentPageIndex, ref int totalRecords);         List<TEntity> GetAll(string whereClause, string orderBy, int pageSize, int currentPageIndex, ref int totalRecords);            }then create your service class :  public class GenericService<TEntity> :IEntityReadService<TEntity> where TEntity : EntityBase, new() {#region Implementation of IEntityReadService<TEntity>         public TEntity Get(long Id)         {             return BusinessController.Get(Id);         }         public List<TEntity> GetAll()         {             try             {                 return BusinessController.GetAll().ToList();             }             catch (Exception ex)             {                                  throw;             }                      }         public List<TEntity> GetAll(int pageSize, int currentPageIndex, ref int totalRecords)         {             return                 BusinessController.GetAll(pageSize, currentPageIndex, ref totalRecords).ToList();         }         public List<TEntity> GetAll(string whereClause, string orderBy, int pageSize, int currentPageIndex, ref int totalRecords)         {             return                 BusinessController.GetAll(pageSize, currentPageIndex, ref totalRecords, whereClause, orderBy).ToList();         }         #endregion} Then, set your EndPoint configuration in this way :<endpoint address="myAddress" binding="basicHttpBinding" bindingConfiguration="myBindingConfiguration1" contract="Contracts.IEntityReadService`1[[Entities.mySampleEntity, Entities]], Service.Contracts" />

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• Calculated Columns in Entity Framework Code First Migrations

  - by David Paquette

  I had a couple people ask me about calculated properties / columns in Entity Framework this week.  The question was, is there a way to specify a property in my C# class that is the result of some calculation involving 2 properties of the same class.  For example, in my database, I store a FirstName and a LastName column and I would like a FullName property that is computed from the FirstName and LastName columns.  My initial answer was: 1: public string FullName 2: { 3: get { return string.Format("{0} {1}", FirstName, LastName); } 4: } Of course, this works fine, but this does not give us the ability to write queries using the FullName property.  For example, this query: 1: var users = context.Users.Where(u => u.FullName.Contains("anan")); Would result in the following NotSupportedException: The specified type member 'FullName' is not supported in LINQ to Entities. Only initializers, entity members, and entity navigation properties are supported. It turns out there is a way to support this type of behavior with Entity Framework Code First Migrations by making use of Computed Columns in SQL Server.  While there is no native support for computed columns in Code First Migrations, we can manually configure our migration to use computed columns. Let’s start by defining our C# classes and DbContext: 1: public class UserProfile 2: { 3: public int Id { get; set; } 4: 5: public string FirstName { get; set; } 6: public string LastName { get; set; } 7: 8: [DatabaseGenerated(DatabaseGeneratedOption.Computed)] 9: public string FullName { get; private set; } 10: } 11: 12: public class UserContext : DbContext 13: { 14: public DbSet<UserProfile> Users { get; set; } 15: } The DatabaseGenerated attribute is needed on our FullName property.  This is a hint to let Entity Framework Code First know that the database will be computing this property for us. Next, we need to run 2 commands in the Package Manager Console.  First, run Enable-Migrations to enable Code First Migrations for the UserContext.  Next, run Add-Migration Initial to create an initial migration.  This will create a migration that creates the UserProfile table with 3 columns: FirstName, LastName, and FullName.  This is where we need to make a small change.  Instead of allowing Code First Migrations to create the FullName property, we will manually add that column as a computed column. 1: public partial class Initial : DbMigration 2: { 3: public override void Up() 4: { 5: CreateTable( 6: "dbo.UserProfiles", 7: c => new 8: { 9: Id = c.Int(nullable: false, identity: true), 10: FirstName = c.String(), 11: LastName = c.String(), 12: //FullName = c.String(), 13: }) 14: .PrimaryKey(t => t.Id); 15: Sql("ALTER TABLE dbo.UserProfiles ADD FullName AS FirstName + ' ' + LastName"); 16: } 17: 18: 19: public override void Down() 20: { 21: DropTable("dbo.UserProfiles"); 22: } 23: } Finally, run the Update-Database command.  Now we can query for Users using the FullName property and that query will be executed on the database server.  However, we encounter another potential problem. Since the FullName property is calculated by the database, it will get out of sync on the object side as soon as we make a change to the FirstName or LastName property.  Luckily, we can have the best of both worlds here by also adding the calculation back to the getter on the FullName property: 1: [DatabaseGenerated(DatabaseGeneratedOption.Computed)] 2: public string FullName 3: { 4: get { return FirstName + " " + LastName; } 5: private set 6: { 7: //Just need this here to trick EF 8: } 9: } Now we can both query for Users using the FullName property and we also won’t need to worry about the FullName property being out of sync with the FirstName and LastName properties.  When we run this code: 1: using(UserContext context = new UserContext()) 2: { 3: UserProfile userProfile = new UserProfile {FirstName = "Chanandler", LastName = "Bong"}; 4: 5: Console.WriteLine("Before saving: " + userProfile.FullName); 6: 7: context.Users.Add(userProfile); 8: context.SaveChanges(); 9:  10: Console.WriteLine("After saving: " + userProfile.FullName); 11:  12: UserProfile chanandler = context.Users.First(u => u.FullName == "Chanandler Bong"); 13: Console.WriteLine("After reading: " + chanandler.FullName); 14:  15: chanandler.FirstName = "Chandler"; 16: chanandler.LastName = "Bing"; 17:  18: Console.WriteLine("After changing: " + chanandler.FullName); 19:  20: } We get this output: It took a bit of work, but finally Chandler’s TV Guide can be delivered to the right person. The obvious downside to this implementation is that the FullName calculation is duplicated in the database and in the UserProfile class. This sample was written using Visual Studio 2012 and Entity Framework 5. Download the source code here.

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• EU Digital Agenda scores 85/100

  - by trond-arne.undheim

  If the Digital Agenda was a bottle of wine and I were wine critic Robert Parker, I would say the Digital Agenda has "a great bouquet, many good elements, with astringent, dry and puckering mouth feel that will not please everyone, but still displaying some finesse. A somewhat controlled effort with no surprises and a few noticeable flaws in the delivery. Noticeably shorter aftertaste than advertised by the producers. Score: 85/100. Enjoy now". The EU Digital Agenda states that "standards are vital for interoperability" and has a whole chapter on interoperability and standards. With this strong emphasis, there is hope the EU's outdated standardization system finally is headed for reform. It has been 23 years since the legal framework of standardisation was completed by Council Decision 87/95/EEC8 in the Information and Communications Technology (ICT) sector. Standardization is market driven. For several decades the IT industry has been developing standards and specifications in global open standards development organisations (fora/consortia), many of which have transparency procedures and practices far superior to the European Standards Organizations. The Digital Agenda rightly states: "reflecting the rise and growing importance of ICT standards developed by certain global fora and consortia". Some fora/consortia, of course, are distorted, influenced by single vendors, have poor track record, and need constant vigilance, but they are the minority. Therefore, the recognition needs to be accompanied by eligibility criteria focused on openness. Will the EU reform its ICT standardization by the end of 2010? Possibly, and only if DG Enterprise takes on board that Information and Communications Technologies (ICTs) have driven half of the productivity growth in Europe over the past 15 years, a prominent fact in the EU's excellent Digital Competitiveness report 2010 published on Monday 17 May. It is ok to single out the ICT sector. It simply is the most important sector right now as it fuels growth in all other sectors. Let's not wait for the entire standardization package which may take another few years. Europe does not have time. The Digital Agenda is an umbrella strategy with deliveries from a host of actors across the Commission. For instance, the EU promises to issue "guidance on transparent ex-ante disclosure rules for essential intellectual property rights and licensing terms and conditions in the context of standard setting", by 2011 in the Horisontal Guidelines now out for public consultation by DG COMP and to some extent by DG ENTR's standardization policy reform. This is important. The EU will issue procurement guidance as interoperability frameworks are put into practice. This is a joint responsibility of several DGs, and is likely to suffer coordination problems, controversy and delays. We have seen plenty of the latter already and I have commented on the Commission's own interoperability elsewhere, with mixed luck. :( Yesterday, I watched the cartoonesque Korean western film The Good, the Bad and the Weird. In the movie (and I meant in the movie only), a bandit, a thief, and a bounty hunter, all excellent at whatever they do, fight for a treasure map. Whether that is a good analogy for the situation within the Commission, others are better judges of than I. However, as a movie fanatic, I still await the final shoot-out, and, as in the film, the only certainty is that "life is about chasing and being chased". The missed opportunity (in this case not following up the push from Member States to better define open standards based interoperability) is a casualty of the chaos ensued in the European Wild West (and I mean that in the most endearing sense, and my excuses beforehand to actors who possibly justifiably cannot bear being compared to fictional movie characters). Instead of exposing the ongoing fight, the EU opted for the legalistic use of the term "standards" throughout the document. This is a term that--to the EU-- excludes most standards used by the IT industry world wide. So, while it, for a moment, meant "weapon down", it will not lead to lasting peace. The Digital Agenda calls for the Member States to "Implement commitments on interoperability and standards in the Malmö and Granada Declarations by 2013". This is a far cry from the actual Ministerial Declarations which called upon the Commission to help them with this implementation by recognizing and further defining open standards based interoperability. Unless there is more forthcoming from the Commission, the market's judgement will be: you simply fall short. Generally, I think the EU focus now should be "from policy to practice" and the Digital Agenda does indeed stop short of tackling some highly practical issues. There is need for progress beyond the Digital Agenda. Here are some suggestions that would help Europe re-take global leadership on openness, public sector reform, and economic growth: A strong European software strategy centred around open standards based interoperability by 2011. An ambitious new eCommission strategy for 2011-15 focused on migration to open standards by 2015. Aligning the IT portfolio across the Commission into one Digital Agenda DG by 2012. Focusing all best practice exchange in eGovernment on one social networking site, epractice.eu (full disclosure: I had a role in getting that site up and running) Prioritizing public sector needs in global standardization over European standardization by 2014.

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• MySQL Connect Only 10 Days Away - Focus on InnoDB Sessions

  - by Bertrand Matthelié

  Time flies and MySQL Connect is only 10 days away! You can check out the full program here as well as in the September edition of the MySQL newsletter. Mat recently blogged about the MySQL Cluster sessions you’ll have the opportunity to attend, and below are those focused on InnoDB. Remember you can plan your schedule with Schedule Builder. Saturday, 1.00 pm, Room Golden Gate 3: 10 Things You Should Know About InnoDB—Calvin Sun, Oracle InnoDB is the default storage engine for Oracle’s MySQL as of MySQL Release 5.5. It provides the standard ACID-compliant transactions, row-level locking, multiversion concurrency control, and referential integrity. InnoDB also implements several innovative technologies to improve its performance and reliability. This presentation gives a brief history of InnoDB; its main features; and some recent enhancements for better performance, scalability, and availability. Saturday, 5.30 pm, Room Golden Gate 4: Demystified MySQL/InnoDB Performance Tuning—Dimitri Kravtchuk, Oracle This session covers performance tuning with MySQL and the InnoDB storage engine for MySQL and explains the main improvements made in MySQL Release 5.5 and Release 5.6. Which setting for which workload? Which value will be better for my system? How can I avoid potential bottlenecks from the beginning? Do I need a purge thread? Is it true that InnoDB doesn't need thread concurrency anymore? These and many other questions are asked by DBAs and developers. Things are changing quickly and constantly, and there is no “silver bullet.” But understanding the configuration setting’s impact is already a huge step in performance improvement. Bring your ideas and problems to share them with others—the discussion is open, just moderated by a speaker. Sunday, 10.15 am, Room Golden Gate 4: Better Availability with InnoDB Online Operations—Calvin Sun, Oracle Many top Web properties rely on Oracle’s MySQL as a critical piece of infrastructure for serving millions of users. Database availability has become increasingly important. One way to enhance availability is to give users full access to the database during data definition language (DDL) operations. The online DDL operations in recent MySQL releases offer users the flexibility to perform schema changes while having full access to the database—that is, with minimal delay of operations on a table and without rebuilding the entire table. These enhancements provide better responsiveness and availability in busy production environments. This session covers these improvements in the InnoDB storage engine for MySQL for online DDL operations such as add index, drop foreign key, and rename column. Sunday, 11.45 am, Room Golden Gate 7: Developing High-Throughput Services with NoSQL APIs to InnoDB and MySQL Cluster—Andrew Morgan and John Duncan, Oracle Ever-increasing performance demands of Web-based services have generated significant interest in providing NoSQL access methods to MySQL (MySQL Cluster and the InnoDB storage engine of MySQL), enabling users to maintain all the advantages of their existing relational databases while providing blazing-fast performance for simple queries. Get the best of both worlds: persistence; consistency; rich SQL queries; high availability; scalability; and simple, flexible APIs and schemas for agile development. This session describes the memcached connectors and examines some use cases for how MySQL and memcached fit together in application architectures. It does the same for the newest MySQL Cluster native connector, an easy-to-use, fully asynchronous connector for Node.js. Sunday, 1.15 pm, Room Golden Gate 4: InnoDB Performance Tuning—Inaam Rana, Oracle The InnoDB storage engine has always been highly efficient and includes many unique architectural elements to ensure high performance and scalability. In MySQL 5.5 and MySQL 5.6, InnoDB includes many new features that take better advantage of recent advances in operating systems and hardware platforms than previous releases did. This session describes unique InnoDB architectural elements for performance, new features, and how to tune InnoDB to achieve better performance. Sunday, 4.15 pm, Room Golden Gate 3: InnoDB Compression for OLTP—Nizameddin Ordulu, Facebook and Inaam Rana, Oracle Data compression is an important capability of the InnoDB storage engine for Oracle’s MySQL. Compressed tables reduce the size of the database on disk, resulting in fewer reads and writes and better throughput by reducing the I/O workload. Facebook pushes the limit of InnoDB compression and has made several enhancements to InnoDB, making this technology ready for online transaction processing (OLTP). In this session, you will learn the fundamentals of InnoDB compression. You will also learn the enhancements the Facebook team has made to improve InnoDB compression, such as reducing compression failures, not logging compressed page images, and allowing changes of compression level. Not registered yet? You can still save US$ 300 over the on-site fee – Register Now!

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• The illusion of Competence

  - by tony_lombardo

  Working as a contractor opened my eyes to the developer food chain.  Even though I had similar experiences earlier in my career, the challenges seemed much more vivid this time through.  I thought I’d share a couple of experiences with you, and the lessons that can be taken from them. Lesson 1: Beware of the “funnel” guy.  The funnel guy is the one who wants you to funnel all thoughts, ideas and code changes through him.  He may say it’s because he wants to avoid conflicts in source control, but the real reason is likely that he wants to hide your contributions.  Here’s an example.  When I finally got access to the code on one of my projects, I was told by the developer that I had to funnel all of my changes through him.  There were 4 of us coding on the project, but only 2 of us working on the UI.  The other 2 were working on a separate application, but part of the overall project.  So I figured, I’ll check it into SVN, he reviews and accepts then merges in.  Not even close.  I didn’t even have checkin rights to SVN, I had to email my changes to the developer so he could check those changes in.  Lesson 2: If you point out flaws in code to someone supposedly ‘higher’ than you in the developer chain, they’re going to get defensive.  My first task on this project was to review the code, familiarize myself with it.  So of course, that’s what I did.  And in familiarizing myself with it, I saw so many bad practices and code smells that I immediately started coming up with solutions to fix it.  Of course, when I reviewed these changes with the developer (guy who originally wrote the code), he smiled and nodded and said, we can’t make those changes now, it’s too destabilizing.  I recommended we create a new branch and start working on refactoring, but branching was a new concept for this guy and he was worried we would somehow break SVN. How about some concrete examples? I started out by recommending we remove NUnit dependency and tests from the application project, and create a separate Unit testing project.  This was met with a little bit of resistance because - “How do I access the private methods?”  As it turned out there weren’t really any private methods that weren’t exposed by public methods, so I quickly calmed this fear. Win 1 Loss 0 Next, I recommended that all of the File IO access be wrapped in Using clauses, or at least properly wrapped in try catch finally.  This recommendation was accepted.. but never implemented. Win 2  Loss 1 Next recommendation was to refactor the command pattern implementation.  The command pattern was implemented, but it wasn’t really necessary for the application.  More over, the fact that we had 100 different command classes, each with it’s own specific command parameters class, made maintenance a huge hassle.  The same code repeated over and over and over.  This recommendation was declined, the code was too fragile and this change would destabilize it.  I couldn’t disagree, though it was the commands themselves in many cases that were fragile. Win 2 Loss 2 Next recommendation was to aid performance (and responsiveness) of the application by using asynchronous service calls.  This on was accepted. Win 2 Loss 3 If you’re paying any attention, you’re wondering why the async service calls was scored as a loss.. Let me explain.  The service call was made using the async pattern.  Followed by a thread.sleep  <facepalm>. Now it’s easy to be harsh on this kind of code, especially if you’re an experienced developer.  But I understood how most of this happened.  One junior guy, working as hard as he can to build his first real world application, with little or no guidance from anyone else.  He had his pattern book and theory of programming to help him, but no real world experience.  He didn’t know how difficult it would be to trace the crashes to the coding issues above, but he will one day.  The part that amazed me was the management position that “this guy should be a team lead, because he’s worked so hard”.  I’m all for rewarding hard work, but when you reward someone by promoting them past the point of their competence, you’re setting yourself and them up for failure.  And that’s lesson 3.  Just because you’ve got a hard worker, doesn’t mean he should be leading a development project.  If you’re a junior guy busting your ass, keep at it.  I encourage you to try new things, but most importantly to learn from your mistakes.  And correct your mistakes.  And if someone else looks at your code and shows you a laundry list of things that should be done differently, don’t take it personally – they’re really trying to help you.  And if you’re a senior guy, working with a junior guy, it’s your duty to point out the flaws in the code.  Even if it does make you the bad guy.  And while I’ve used “guy” above, I mean both men and women.  And in some cases mutant dinosaurs. 

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• Shadow mapping with deffered shading for directional lights - shadow map projection problem

  - by Harry

  I'm trying to implement shadow mapping to my engine. I started with directional lights because they seemed to be the easiest one, but I was wrong :) I have implemented deferred shading and I retrieve position from depth. I think that there is the biggest problem but code looks ok for me. Now more about problem: Shadow map projected onto meshes looks bad scaled and translated and also some informations from shadow map texture aren't visible. You can see it on this screen: http://img5.imageshack.us/img5/2254/93dn.png Yelow frustum is light frustum and I have mixed shadow map preview and actual scene. As you can see shadows are in wrong place and shadow of cone and sphere aren't visible. Could you look at my codes and tell me where I have a mistake? // create shadow map if(!_shd)glGenTextures(1, &_shd); glBindTexture(GL_TEXTURE_2D, _shd); glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, 1024, 1024, 0, GL_DEPTH_COMPONENT, GL_FLOAT,NULL); // shadow map size glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, _shd, 0); glDrawBuffer(GL_NONE); // setting camera Vector dire=Vector(0,0,1); ACamera.setLookAt(dire,Vector(0)); ACamera.setPerspectiveView(60.0f,1,0.1f,10.0f); // currently needed for proper frustum corners calculation Vector min(ACamera._point[0]),max(ACamera._point[0]); for(int i=0;i<8;i++){ max=Max(max,ACamera._point[i]); min=Min(min,ACamera._point[i]); } ACamera.setOrthogonalView(min.x,max.x,min.y,max.y,-max.z,-min.z); glBindFramebuffer(GL_DRAW_FRAMEBUFFER, _s_buffer); // framebuffer for shadow map // rendering to depth buffer glBindFramebuffer(GL_DRAW_FRAMEBUFFER, _g_buffer); Shaders["DirLight"].set(true); Matrix4 bias; bias.x.set(0.5,0.0,0.0,0.0); bias.y.set(0.0,0.5,0.0,0.0); bias.z.set(0.0,0.0,0.5,0.0); bias.w.set(0.5,0.5,0.5,1.0); Shaders["DirLight"].set("textureMatrix",ACamera.matrix*Projection3D*bias); // order of multiplications are 100% correct, everything gives mi the same result as using glm glActiveTexture(GL_TEXTURE5); glBindTexture(GL_TEXTURE_2D,_shd); lightDir(dir); // light calculations Vertex Shader makes nothing related to shadow calculatons Pixel shader function which calculates if pixel is in shadow or not: float readShadowMap(vec3 eyeDir) { // retrieve depth of pixel float z = texture2D(depth, gl_FragCoord.xy/screen).z; vec3 pos = vec3(gl_FragCoord.xy/screen, z); // transform by the projection and view inverse vec4 worldSpace = inverse(View)*inverse(ProjectionMatrix)*vec4(pos*2-1,1); worldSpace /= worldSpace.w; vec4 coord=textureMatrix*worldSpace; float vis=1.0f; if(texture2D(shadow, coord.xy).z < coord.z-0.001)vis=0.2f; return vis; } I also have question about shadows specifically for directional light. Currently I always look at 0,0,0 position and in further implementation I have to move light frustum along to camera frustum. I've found how to do this here: http://www.gamedev.net/topic/505893-orthographic-projection-for-shadow-mapping/ but it doesn't give me what I want. Maybe because of problems mentioned above, but I want know your opinion. EDIT: vec4 worldSpace is position read from depht of the scene (not shadow map). Maybe I wasn't precise so I'll try quick explain what is what: View is camera view matrix, ProjectionMatrix is camera projection,. First I try to get world space position from depth map and then multiply it by textureMatrix which is light view *light projection*bias. Rest of code is the same as in many tutorials. I can't use vertex shader to make something like gl_Position=textureMatrix*gl_Vertex and get it interpolated in fragment shader because of deffered rendering use so I want get it from depht buffer. EDIT2: I also tried make it as in Coding Labs tutorial about Shadow Mapping with Deferred Rendering but unfortunately this either works wrong.

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