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  • A better way to do concurrent programming

    - by Alex.Davies
    Programming to take advantage of multicore processors is hard. If you let multiple threads access the same memory, bad things happen. To avoid this, you use the lock keyword, but if you use that in the wrong way, your code deadlocks. It's all a nightmare. Luckily, there's a better way - Actors. They're really easy to think about. They're really safe (if you follow a couple of simple rules). And high-performance, type-safe actors are now available for .NET by using this open-source library: http://code.google.com/p/n-act/ Have a look at the site for details. I'll blog with more reasons to use actors and tips and tricks to get the best parallelism from them soon.

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  • Is it bad practice for services to share a database in SOA?

    - by Paul T Davies
    I have recently been reading Hohpe and Woolf's Enterprise Integration Patterns, some of Thomas Erl's books on SOA and watching various videos and podcasts by Udi Dahan et al. on CQRS and Event Driven systems. Systems in my place of work suffer from high coupling. Although each system theoretically has its own database, there is a lot of joining between them. In practice this means there is one huge database that all systems use. For example, there is one table of customer data. Much of what I've read seems to suggest denormalising data so that each system uses only its database, and any updates to one system are propagated to all the others using messaging. I thought this was one of the ways of enforcing the boundaries in SOA - each service should have its own database, but then I read this: http://stackoverflow.com/questions/4019902/soa-joining-data-across-multiple-services and it suggests this is the wrong thing to do. Segregating the databases does seem like a good way of decoupling systems, but now I'm a bit confused. Is this a good route to take? Is it ever recommended that you should segregate a database on, say an SOA service, an DDD Bounded context, an application, etc?

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  • What modern design pattern / software engineering books for Java SE 6 do you recommend ?

    - by Scott Davies
    Hi, I am very familiar with Java 6 SE language features and am now looking for modern books that cover design patterns in Java for beginners as well as software engineering books that discuss architectures, algorithms and best practices in Java coding (sort of like the Effective C# books). I am aware of the classic GoF design patterns book, however, I'd like a more modern reference that takes advantage of the features of Java 6 SE. What books would you recommend ? Thanks, Scott

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  • Accessing Repositories from Domain

    - by Paul T Davies
    Say we have a task logging system, when a task is logged, the user specifies a category and the task defaults to a status of 'Outstanding'. Assume in this instance that Category and Status have to be implemented as entities. Normally I would do this: Application Layer: public class TaskService { //... public void Add(Guid categoryId, string description) { var category = _categoryRepository.GetById(categoryId); var status = _statusRepository.GetById(Constants.Status.OutstandingId); var task = Task.Create(category, status, description); _taskRepository.Save(task); } } Entity: public class Task { //... public static void Create(Category category, Status status, string description) { return new Task { Category = category, Status = status, Description = descrtiption }; } } I do it like this because I am consistently told that entities should not access the repositories, but it would make much more sense to me if I did this: Entity: public class Task { //... public static void Create(Category category, string description) { return new Task { Category = category, Status = _statusRepository.GetById(Constants.Status.OutstandingId), Description = descrtiption }; } } The status repository is dependecy injected anyway, so there is no real dependency, and this feels more to me thike it is the domain that is making thedecision that a task defaults to outstanding. The previous version feels like it is the application layeer making that decision. Any why are repository contracts often in the domain if this should not be a posibility? Here is a more extreme example, here the domain decides urgency: Entity: public class Task { //... public static void Create(Category category, string description) { var task = new Task { Category = category, Status = _statusRepository.GetById(Constants.Status.OutstandingId), Description = descrtiption }; if(someCondition) { if(someValue > anotherValue) { task.Urgency = _urgencyRepository.GetById (Constants.Urgency.UrgentId); } else { task.Urgency = _urgencyRepository.GetById (Constants.Urgency.SemiUrgentId); } } else { task.Urgency = _urgencyRepository.GetById (Constants.Urgency.NotId); } return task; } } There is no way you would want to pass in all possible versions of Urgency, and no way you would want to calculate this business logic in the application layer, so surely this would be the most appropriate way? So is this a valid reason to access repositories from the domain?

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  • .NET Demon support for VS 11 dark theme

    - by Alex.Davies
    I'm pleased to announce that .NET Demon will be shipping simultaneously with Visual Studio 11, whenever it ends up being released. That means we're going to make sure that a version of .NET Demon is released very near to the Visual Studio 11 final release which supports the new version of VS fully. The interesting part of this support is going to be the new dark theme of VS, which I'm looking forward to using. I'm told dark colours reduce eye strain for developers. It's important that extensions like .NET Demon switch to a dark theme when the rest of the IDE changes, or the dark theme will look silly. Unfortunately, none of my favourite extensions look right in the dark theme yet, so even though I use Visual Studio 11 beta for my day-to-day development already, I can't use the dark theme. Luckily .NET Demon uses WPF throughout, and the team at Microsoft are helping us to use the WPF Style system to make it easy for me to implement the support without having to add colour attributes to all the controls manually. We should have dark theme support in .NET Demon in the next month or so.

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  • OSB and Ubuntu 10.04 - Too Many Open Files

    - by jeff.x.davies
    When installing the latest Oracle Service Bus (11gR1PS3) onto my Ubuntu 10.04 system, the Eclipse IDE was complaining about there being too many open files. The Oracle Service Bus and the Oracle Enterprise Pack for Eclipse (aka OEPE) do make use of ALOT of files. By default, Ubuntu will restrict each user to 1024 open files. A much more realistic number for OSB development is 4096. Changing the file limit in Ubuntu is fairly simple (if arcane). You will need to modify two different files and then restart your server. First, you need to modify the limits.conf file as the root user. Open a terminal window and enter the following command: sudo gedit /etc/security/limits.conf Add the following 2 lines to the file. The asterisk simply means that the rule will apply to all users. * soft nofile 4096 * hard nofile 4096 Save your changes and close gedit. The second file to change is the common-session file. Use the following command: sudo gedit /etc/pam.d/common-session Add the following line: session required pam_limits.so Save the file and exit gedit. Restart your machine. You shouldn't have any more problems with too many open files anymore.

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  • Would a multitouch capable PC allow me to do Android development simulating the touch UI without an Android device ?

    - by Scott Davies
    Hi, I recently purchased a Samsung Galaxy Tab as a reference implementation (phone and first gen Android tablet), of Android 2.x for app development. I have noticed a slew of Android 3.0 slates being talked about at CES 2011 (Motorola XOOM, etc.). If I had a multitouch PC with the Android SDK/Emulator on it, would this allow me to more closely approximate device simulation by allowing user input via the multitouch screen ? Would it work via touch just like Windows 7 recognizes touch as mouse style input ? Has anyone done this ? Thanks, Scott

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  • AsyncBridge? Async on .NET 4.0 using VS11

    - by Alex.Davies
    I've just found something quite cool. It's a code snippet that lets you use the real VS 11 C#5 compiler to write code that uses the async and await keywords, but to target .NET 4.0. It was published by Daniel Grunwald (from SharpDevelop).That means I can stop using the Async CTP for VS2010, which is not at all supported anymore, and a pain to install if you have windows updates turned on. Obviously I couldn't ask all my users to install .NET 4.5 beta, but .NET Demon is a VS 2010 extension, so we already have .NET 4.0. At the time of writing, VS11 is in beta still, but hopefully it's stable enough for my team to use!I would have written the code myself, but I had the wrong impression that the C# 5 beta compiler only looked in mscorlib for the helper classes it needs to implement async methods. Turns out you can provide them yourself. You can get the code here: https://gist.github.com/1961087You just add it to your project, and the compiler will apparently pick it up and use it to implement async/await. I'm at my parents' place for Easter without access to a machine with VS 11 to try it out. Let me know whether you get it to work!This reminds me of LINQBridge, which let us use C# 3 LINQ, but only require .NET 2. We should stick up a webpage to explain, with a nice easy dll, put it in nuget, and call it AsyncBridge.If you were really enthusiastic, you could re-implement the skeleton of the Task Parallel Library against .NET 2 to use async/await without even requiring .NET 4. Our usage stats suggest that practically everyone that uses Red Gate tools already has .NET 4 installed though, so I don't think I'll go to the effort.

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  • A new tool in beta: Conflict Alert

    - by Alex Davies
    You know that manual merges are a real pain? Well, I’ve just released a Visual Studio extension that makes manual merges a thing of the past. No source control system can automatically merge two edits to the same line of code. Conflict Alert solves this by warning you that you are heading down a path that will cause a manual merge later down the line. You choose whether you want to carry on, or talk to your teammate and find out what they are doing. Have you ever warned your teammates that you are doing a big refactor, and that they should ‘keep out of class X’? Conflict Alert tells them for you automatically by highlighting the sections of code that you have edited.   It doesn’t need to connect to your source control system, so it works no matter which you use. Its a first release, and I hope it is useful. Any feedback would be gratefully received. Grab a teammate and try it now.

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  • An experiment: unlimited free trial

    - by Alex.Davies
    The .NET Demon team have just implemented an experiment that is quite a break from Red Gate's normal business model. Instead of the tool expiring after the trial period, it now continues to work, but with a new message that appears after the tool has saved you a certain amount of time. The rationale is that a user that stops using .NET Demon because the trial expired isn't doing anyone any good. We'd much rather people continue using it forever, as long as everyone that finds it useful and can afford it still pays for it. Hopefully the message appearing is annoying enough to achieve that, but not for people to uninstall it. It's true that many companies have tried it before with mixed results, but we have a secret weapon. The perfect nag message? The neat thing for .NET Demon is that we can easily measure exactly how much time .NET Demon has saved you, in terms of unnecessary project builds that Visual Studio would have done. When you press F5, the message shows you the time saved, and then makes you wait a shorter time before starting your application. Confronted with the truth about how amazing .NET Demon is, who can do anything but buy it? The real secret though, is that while you wait, .NET Demon gives you entertainment, in the form of a picture of a cute kitten. I've only had time to embed one kitten so far, but the eventual aim is for a random different kitten to appear each time. The psychological health benefits of a dose of kittens in the daily life of the developer are obvious. My only concern is that people will complain after paying for .NET Demon that the kittens are gone.

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  • C# 5: At last, async without the pain

    - by Alex.Davies
    For me, the best feature in Visual Studio 11 is the async and await keywords that come with C# 5. I am a big fan of asynchronous programming: it frees up resources, in particular the thread that a piece of code needs to run in. That lets that thread run something else, while waiting for your long-running operation to complete. That's really important if that thread is the UI thread, or if it's holding a lock because it accesses some data structure. Before C# 5, I think I was about the only person in the world who really cared about asynchronous programming. The trouble was that you had to go to extreme lengths to make code asynchronous. I would forever be writing methods that, instead of returning a value, accepted an extra argument that is a "continuation". Then, when calling the method, I'd have to pass a lambda in to it, which contained all the stuff that needed to happen after the method finished. Here is a real snippet of code that is in .NET Demon: m_BuildControl.FilterEnabledForBuilding(     projects,     enabledProjects = m_OutOfDateProjectFinder.FilterNeedsBuilding(         enabledProjects,         newDirtyProjects =         {             // Mark any currently broken projects as dirty             newDirtyProjects.UnionWith(m_BrokenProjects);             // Copy what we found into the set of dirty things             m_DirtyProjects = newDirtyProjects;             RunSomeBuilds();         })); It's just obtuse. Who puts a lambda inside a lambda like that? Well, me obviously. But surely enabledProjects should just be the return value of FilterEnabledForBuilding? And newDirtyProjects should just be the return value of FilterNeedsBuilding? C# 5 async/await lets you write asynchronous code without it looking so stupid. Here's what I plan to change that code to, once we upgrade to VS 11: var enabledProjects = await m_BuildControl.FilterEnabledForBuilding(projects); var newDirtyProjects = await m_OutOfDateProjectFinder.FilterNeedsBuilding(enabledProjects); // Mark any currently broken projects as dirty newDirtyProjects.UnionWith(m_BrokenProjects); // Copy what we found into the set of dirty things m_DirtyProjects = newDirtyProjects; RunSomeBuilds(); Much easier to read! But how is this the same code? If we were on the UI thread, doesn't the UI thread have to block while FilterEnabledForBuilding runs? No, it doesn't, and that's the magic of the await keyword! It cuts your method up into its constituent pieces, much like I did manually with lambdas before. When you run it, only the piece up to the first await actually runs. The rest is passed to FilterEnabledForBuilding as a continuation, which will get called back whenever that method is finished. In the meantime, our thread returns, and can go back to making the UI responsive, or whatever else threads do in their spare time. This is actually a massive simplification, and if you're interested in all the gory details, and speed hacks that the await keyword actually does for you, I recommend Jon Skeet's blog posts about it.

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  • Object oriented wrapper around a dll

    - by Tom Davies
    So, I'm writing a C# managed wrapper around a native dll. The dll contains several hundred functions. In most cases, the first argument to each function is an opaque handle to a type internal to the dll. So, an obvious starting point for defining some classes in the wrapper would be to define classes corresponding to each of these opaque types, with each instance holding and managing the opaque handle (passed to its constructor) Things are a little awkward when dealing with callbacks from the dll. Naturally, the callback handlers in my wrapper have to be static, but the callbacks arguments invariable contain an opaque handle. In order to get from the static callback back to an object instance, I've created a static dictionary in each class, associating handles with class instances. In the constructor of each class, an entry is put into the dictionary, and this entry is then removed in the Destructors. When I receive a callback, I can then consult the dictionary to retrieve the class instance corresponding to the opaque reference. Are there any obvious flaws to this? Something that seems to be a problem is that the existence static dictionary means that the garbage collector will not act on my class instances that are otherwise unreachable. As they are never garbage collected, they never get removed from the dictionary, so the dictionary grows. It seems I might have to manually dispose of my objects, which is something absolutely would like to avoid. Can anyone suggest a good design that allows me to avoid having to do this?

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  • Latest update to Ubuntu 13.10 broke Intel graphics drivers

    - by James Davies
    I'm running a copy of Ubuntu 13.10 on an i7-4771 w/ Intel HD4600 Graphics using a Dell Ultrasharp 1440p monitor via Displayport. Up until today this configuration has been working perfectly, however the latest update appears to have broken my graphics configuration, and xorg is now refusing to go above 1280p resolution. Running xrandr it appears the driver incorrectly thinks my monitor is plugged into the HDMI port and is detecting a max resolution of 1920x1200 instead of 2560x1440. (It's actually plugged in via Displayport). Based on the apt history.log, the latest update was for the kernel. I'm presuming the issue is that the official Intel driver hasn't been updated to support this version? Is there any way to resolve this, or will I need to upgrade to 14.10 to get the latest driver from Intel? Start-Date: 2014-05-28 11:30:57 Commandline: aptdaemon role='role-commit-packages' sender=':1.473' Install: linux-image-extra-3.11.0-22-generic:amd64 (3.11.0-22.38), linux-image-3.11.0-22-generic:amd64 (3.11.0-22.38), linux-headers-3.11.0-22:amd64 (3.11.0-22.38), linux-headers-3.11.0-22-generic:amd64 (3.11.0-22.38)

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  • An experiment: unlimited free trial

    - by Alex.Davies
    The .NET Demon team have just implemented an experiment that is quite a break from Red Gate's normal business model. Instead of the tool expiring after the trial period, it now continues to work, but with a new message that appears after the tool has saved you a certain amount of time. The rationale is that a user that stops using .NET Demon because the trial expired isn't doing anyone any good. We'd much rather people continue using it forever, as long as everyone that finds it useful and can afford it still pays for it. Hopefully the message appearing is annoying enough to achieve that, but not for people to uninstall it. It's true that many companies have tried it before with mixed results, but we have a secret weapon. The perfect nag message? The neat thing for .NET Demon is that we can easily measure exactly how much time .NET Demon has saved you, in terms of unnecessary project builds that Visual Studio would have done. When you press F5, the message shows you the time saved, and then makes you wait a shorter time before starting your application. Confronted with the truth about how amazing .NET Demon is, who can do anything but buy it? The real secret though, is that while you wait, .NET Demon gives you entertainment, in the form of a picture of a cute kitten. I've only had time to embed one kitten so far, but the eventual aim is for a random different kitten to appear each time. The psychological health benefits of a dose of kittens in the daily life of the developer are obvious. My only concern is that people will complain after paying for .NET Demon that the kittens are gone.

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  • Should business services cross bounded contexts?

    - by Paul T Davies
    Firstly, I am following the convention that a bounded context is synonymous to a department, or possibly one department has 1 to many bounded contexts. We have a client consultancy department that has a Documentation Service. Documents are stored in the Document Store Service (which is where all documents in the company are stored - it is a utility service), and the Documentation Service stores information about that document (a business service). As it was designed for the client consultancy, it is information relevant to them. Now health and safety need somewhere to store information about a document. This is different information to client consultancy, but I have been instructed to extend the existing service to account for this extra information. I feel this service is now crossing a bounded context. My worry is that all departments will eventually store there information in here and the service will become bloated, trying to be all things to all departments. Each document record will only store a subset of the information because it will only belong to one department. It will get worse when different departments want to store the same information but refer to it in a diferent ways, or when two departments want to store different information that they refer to in the same way. In my understanding, this is exactly the reason for bounded contexts. I feel each department should have it's own business service for information about a document, but use the same utility service to actually store the document. What would be the correct approach?

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  • What programming language(s) could I develop this app with for an iPhone

    - by Keon Davies
    The app I'm thinking of making would be little similar to fruit ninja. The app/ game would involve different types of animals flying straight at and you have to choose the right item to catch the animal before he gets to you. For example to capture a fish you would have to select the net and then click on the fish to capture it. Also I would like to have a leader board too. Which programming language(s) could I use to develop what I just described?

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  • An experiment: unlimited free trial

    - by Alex Davies
    The .NET Demon team have just implemented an experiment that is quite a break from Red Gate’s normal business model. Instead of the tool expiring after the trial period, it now continues to work, but with a new message that appears after the tool has saved you a certain amount of time. The rationale is that a user that stops using .NET Demon because the trial expired isn’t doing anyone any good. We’d much rather people continue using it forever, as long as everyone that finds it useful and can afford it still pays for it. Hopefully the message appearing is annoying enough to achieve that, but not for people to uninstall it. It’s true that many companies have tried it before with mixed results, but we have a secret weapon. The perfect nag message? The neat thing for .NET Demon is that we can easily measure exactly how much time .NET Demon has saved you, in terms of unnecessary project builds that Visual Studio would have done. When you press F5, the message shows you the time saved, and then makes you wait a shorter time before starting your application. Confronted with the truth about how amazing .NET Demon is, who can do anything but buy it? The real secret though, is that while you wait, .NET Demon gives you entertainment, in the form of a picture of a cute kitten. I’ve only had time to embed one kitten so far, but the eventual aim is for a random different kitten to appear each time. The psychological health benefits of a dose of kittens in the daily life of the developer are obvious. My only concern is that people will complain after paying for .NET Demon that the kittens are gone.

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  • You can step over await

    - by Alex Davies
    I’ve just found the coolest feature of VS 2012 by far. I thought that being able to silence an exception from the “exception was thrown” popup was awesome, and the “reload all” button when a project file changes is amazing, but this is way beyond all of that. You can step over awaits when you debug your code!! With F10!!! Ok, so that may not sound such a big deal. You can step over ifs and whiles and no-one is celebrating. But await is different. await actually stops your method, signs up to be notified when a Task is finished,  returns, and resumes your method at some indeterminate point in the future. You could even end up continuing on a completely different thread. All that happens, and all I have to do is press F10. I used to have to painstakingly set a breakpoint on the first line of my callback before stepping over any asynchronous method. Even when we started using async, my mouse would instinctively click the margin every time I wanted to go past an await. And the times I was driven insane by my breakpoint getting hit by some other path of execution I don’t care about. I think this might have been introduced in the VS11 Beta, I’m pretty sure I tried it in the Async CTP in VS2010 and it didn’t work. Now it does! Woop!

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  • My book is released – Async in C# 5

    - by Alex Davies
    I’m pleased to announce that my book “Async in C# 5″ has been published by O’Reilly! http://oreil.ly/QQBjO3 If you want to know about how to use async, and whether it’s important for your code, I thoroughly recommend reading it. It’s the best book about the subject I’ve ever written. In fact it’s probably the best book I’ve written full stop. I may have only written one book. It also has a very fetching parrot on the cover, which would make a very good addition to your bookshelf.

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  • Is this a violation of the Liskov Substitution Principle?

    - by Paul T Davies
    Say we have a list of Task entities, and a ProjectTask sub type. Tasks can be closed at any time, except ProjectTasks which cannot be closed once they have a status of Started. The UI should ensure the option to close a started ProjectTask is never available, but some safeguards are present in the domain: public class Task { public Status Status { get; set; } public virtual void Close() { Status = Status.Closed; } } public ProjectTask : Task { public override void Close() { if (Status == Status.Started) throw new Exception("Cannot close a started Project Task"); base.Close(); } } Now when calling Close() on a Task, there is a chance the call will fail if it is a ProjectTask with the started status, when it wouldn't if it was a base Task. But this is the business requirements. It should fail. Can this be regarded as a violation?

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  • jQuery if something is more than value then hide and add a button to show whats hidden?

    - by Charlie
    Hi guys! Exactly what my title says is the problem Im having right now. Im checking a div for how many links php printed and if there is more than 10 Id like to hide them and add a button that says read more and then it show the rest of the links. $(document).ready(function() { var newsRss = $('#rssNews >li').length; var driftRss = $('#rssDrift >li').length; $(window).load(function() { if(newsRss > 10) alert(newsRss); }); }); this is how far I got with the code. Ill be happy to hear every tip and trick you guys can help me with! Best Regards, Charlie

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  • Oracle Data Mining a Star Schema: Telco Churn Case Study

    - by charlie.berger
    There is a complete and detailed Telco Churn case study "How to" Blog Series just posted by Ari Mozes, ODM Dev. Manager.  In it, Ari provides detailed guidance in how to leverage various strengths of Oracle Data Mining including the ability to: mine Star Schemas and join tables and views together to obtain a complete 360 degree view of a customer combine transactional data e.g. call record detail (CDR) data, etc. define complex data transformation, model build and model deploy analytical methodologies inside the Database  His blog is posted in a multi-part series.  Below are some opening excerpts for the first 3 blog entries.  This is an excellent resource for any novice to skilled data miner who wants to gain competitive advantage by mining their data inside the Oracle Database.  Many thanks Ari! Mining a Star Schema: Telco Churn Case Study (1 of 3) One of the strengths of Oracle Data Mining is the ability to mine star schemas with minimal effort.  Star schemas are commonly used in relational databases, and they often contain rich data with interesting patterns.  While dimension tables may contain interesting demographics, fact tables will often contain user behavior, such as phone usage or purchase patterns.  Both of these aspects - demographics and usage patterns - can provide insight into behavior.Churn is a critical problem in the telecommunications industry, and companies go to great lengths to reduce the churn of their customer base.  One case study1 describes a telecommunications scenario involving understanding, and identification of, churn, where the underlying data is present in a star schema.  That case study is a good example for demonstrating just how natural it is for Oracle Data Mining to analyze a star schema, so it will be used as the basis for this series of posts...... Mining a Star Schema: Telco Churn Case Study (2 of 3) This post will follow the transformation steps as described in the case study, but will use Oracle SQL as the means for preparing data.  Please see the previous post for background material, including links to the case study and to scripts that can be used to replicate the stages in these posts.1) Handling missing values for call data recordsThe CDR_T table records the number of phone minutes used by a customer per month and per call type (tariff).  For example, the table may contain one record corresponding to the number of peak (call type) minutes in January for a specific customer, and another record associated with international calls in March for the same customer.  This table is likely to be fairly dense (most type-month combinations for a given customer will be present) due to the coarse level of aggregation, but there may be some missing values.  Missing entries may occur for a number of reasons: the customer made no calls of a particular type in a particular month, the customer switched providers during the timeframe, or perhaps there is a data entry problem.  In the first situation, the correct interpretation of a missing entry would be to assume that the number of minutes for the type-month combination is zero.  In the other situations, it is not appropriate to assume zero, but rather derive some representative value to replace the missing entries.  The referenced case study takes the latter approach.  The data is segmented by customer and call type, and within a given customer-call type combination, an average number of minutes is computed and used as a replacement value.In SQL, we need to generate additional rows for the missing entries and populate those rows with appropriate values.  To generate the missing rows, Oracle's partition outer join feature is a perfect fit.  select cust_id, cdre.tariff, cdre.month, minsfrom cdr_t cdr partition by (cust_id) right outer join     (select distinct tariff, month from cdr_t) cdre     on (cdr.month = cdre.month and cdr.tariff = cdre.tariff);   ....... Mining a Star Schema: Telco Churn Case Study (3 of 3) Now that the "difficult" work is complete - preparing the data - we can move to building a predictive model to help identify and understand churn.The case study suggests that separate models be built for different customer segments (high, medium, low, and very low value customer groups).  To reduce the data to a single segment, a filter can be applied: create or replace view churn_data_high asselect * from churn_prep where value_band = 'HIGH'; It is simple to take a quick look at the predictive aspects of the data on a univariate basis.  While this does not capture the more complex multi-variate effects as would occur with the full-blown data mining algorithms, it can give a quick feel as to the predictive aspects of the data as well as validate the data preparation steps.  Oracle Data Mining includes a predictive analytics package which enables quick analysis. begin  dbms_predictive_analytics.explain(   'churn_data_high','churn_m6','expl_churn_tab'); end; /select * from expl_churn_tab where rank <= 5 order by rank; ATTRIBUTE_NAME       ATTRIBUTE_SUBNAME EXPLANATORY_VALUE RANK-------------------- ----------------- ----------------- ----------LOS_BAND                                      .069167052          1MINS_PER_TARIFF_MON  PEAK-5                   .034881648          2REV_PER_MON          REV-5                    .034527798          3DROPPED_CALLS                                 .028110322          4MINS_PER_TARIFF_MON  PEAK-4                   .024698149          5From the above results, it is clear that some predictors do contain information to help identify churn (explanatory value > 0).  The strongest uni-variate predictor of churn appears to be the customer's (binned) length of service.  The second strongest churn indicator appears to be the number of peak minutes used in the most recent month.  The subname column contains the interior piece of the DM_NESTED_NUMERICALS column described in the previous post.  By using the object relational approach, many related predictors are included within a single top-level column. .....   NOTE:  These are just EXCERPTS.  Click here to start reading the Oracle Data Mining a Star Schema: Telco Churn Case Study from the beginning.    

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  • So what *did* Alan Kay really mean by the term "object-oriented"?

    - by Charlie Flowers
    Reportedly, Alan Kay is the inventor of the term "object oriented". And he is often quoted as having said that what we call OO today is not what he meant. For example, I just found this on Google: "I made up the term 'object-oriented', and I can tell you I didn't have C++ in mind" - Alan Kay, OOPSLA '97 I vaguely remember hearing something pretty insightful about what he did mean. Something along the lines of "message passing". Do you know what he meant? Can you fill in more details of what he meant and how it differs from today's common OO? Please share some references if you have any. Thanks.

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  • BizTalk Cross Reference Data Management Strategy

    - by charlie.mott
    Article Source: http://geekswithblogs.net/charliemott This article describes an approach to the management of cross reference data for BizTalk.  Some articles about the BizTalk Cross Referencing features can be found here: http://home.comcast.net/~sdwoodgate/xrefseed.zip http://geekswithblogs.net/michaelstephenson/archive/2006/12/24/101995.aspx http://geekswithblogs.net/charliemott/archive/2009/04/20/value-vs.id-cross-referencing-in-biztalk.aspx Options Current options to managing this data include: Maintaining xml files in the format that can be used by the out-of-the-box BTSXRefImport.exe utility. Use of user interfaces that have been developed to manage this data: BizTalk Cross Referencing Tool XRef XML Creation Tool However, there are the following issues with the above options: The 'BizTalk Cross Referencing Tool' requires a separate database to manage.  The 'XRef XML Creation' tool has no means of persisting the data settings. The 'BizTalk Cross Referencing tool' generates integers in the common id field. I prefer to use a string (e.g. acme.country.uk). This is more readable. (see naming conventions below). Both UI tools continue to use BTSXRefImport.exe.  This utility replaces all xref data. This can be a problem in continuous integration environments that support multiple clients or BizTalk target instances.  If you upload the data for one client it would destroy the data for another client.  Yet in TFS where builds run concurrently, this would break unit tests. Alternative Approach In response to these issues, I instead use simple SQL scripts to directly populate the BizTalkMgmtDb xref tables combined with a data namepacing strategy to isolate client data. Naming Conventions All data keys use namespace prefixing.  The pattern will be <companyName>.<data Type>.  The naming conventions will be to use lower casing for all items.  The data must follow this pattern to isolate it from other company cross-reference data.  The table below shows some sample data. (Note: this data uses the 'ID' cross-reference tables.  the same principles apply for the 'value' cross-referencing tables). Table.Field Description Sample Data xref_AppType.appType Application Types acme.erp acme.portal acme.assetmanagement xref_AppInstance.appInstance Application Instances (each will have a corresponding application type). acme.dynamics.ax acme.dynamics.crm acme.sharepoint acme.maximo xref_IDXRef.idXRef Holds the cross reference data types. acme.taxcode acme.country xref_IDXRefData.CommonID Holds each cross reference type value used by the canonical schemas. acme.vatcode.exmpt acme.vatcode.std acme.country.usa acme.country.uk xref_IDXRefData.AppID This holds the value for each application instance and each xref type. GBP USD SQL Scripts The data to be stored in the BizTalkMgmtDb xref tables will be managed by SQL scripts stored in a database project in the visual studio solution. File(s) Description Build.cmd A sqlcmd script to deploy data by running the SQL scripts below.  (This can be run as part of the MSBuild process).   acme.purgexref.sql SQL script to clear acme.* data from the xref tables.  As such, this will not impact data for any other company. acme.applicationInstances.sql   SQL script to insert application type and application instance data.   acme.vatcode.sql acme.country.sql etc ...  There will be a separate SQL script to insert each cross-reference data type and application specific values for these types.

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  • New Communications Industry Data Model with "Factory Installed" Predictive Analytics using Oracle Da

    - by charlie.berger
    Oracle Introduces Oracle Communications Data Model to Provide Actionable Insight for Communications Service Providers   We've integrated pre-installed analytical methodologies with the new Oracle Communications Data Model to deliver automated, simple, yet powerful predictive analytics solutions for customers.  Churn, sentiment analysis, identifying customer segments - all things that can be anticipated and hence, preconcieved and implemented inside an applications.  Read on for more information! TM Forum Management World, Nice, France - 18 May 2010 News Facts To help communications service providers (CSPs) manage and analyze rapidly growing data volumes cost effectively, Oracle today introduced the Oracle Communications Data Model. With the Oracle Communications Data Model, CSPs can achieve rapid time to value by quickly implementing a standards-based enterprise data warehouse that features communications industry-specific reporting, analytics and data mining. The combination of the Oracle Communications Data Model, Oracle Exadata and the Oracle Business Intelligence (BI) Foundation represents the most comprehensive data warehouse and BI solution for the communications industry. Also announced today, Hong Kong Broadband Network enhanced their data warehouse system, going live on Oracle Communications Data Model in three months. The leading provider increased its subscriber base by 37 percent in six months and reduced customer churn to less than one percent. Product Details Oracle Communications Data Model provides industry-specific schema and embedded analytics that address key areas such as customer management, marketing segmentation, product development and network health. CSPs can efficiently capture and monitor critical data and transform it into actionable information to support development and delivery of next-generation services using: More than 1,300 industry-specific measurements and key performance indicators (KPIs) such as network reliability statistics, provisioning metrics and customer churn propensity. Embedded OLAP cubes for extremely fast dimensional analysis of business information. Embedded data mining models for sophisticated trending and predictive analysis. Support for multiple lines of business, such as cable, mobile, wireline and Internet, which can be easily extended to support future requirements. With Oracle Communications Data Model, CSPs can jump start the implementation of a communications data warehouse in line with communications-industry standards including the TM Forum Information Framework (SID), formerly known as the Shared Information Model. Oracle Communications Data Model is optimized for any Oracle Database 11g platform, including Oracle Exadata, which can improve call data record query performance by 10x or more. Supporting Quotes "Oracle Communications Data Model covers a wide range of business areas that are relevant to modern communications service providers and is a comprehensive solution - with its data model and pre-packaged templates including BI dashboards, KPIs, OLAP cubes and mining models. It helps us save a great deal of time in building and implementing a customized data warehouse and enables us to leverage the advanced analytics quickly and more effectively," said Yasuki Hayashi, executive manager, NTT Comware Corporation. "Data volumes will only continue to grow as communications service providers expand next-generation networks, deploy new services and adopt new business models. They will increasingly need efficient, reliable data warehouses to capture key insights on data such as customer value, network value and churn probability. With the Oracle Communications Data Model, Oracle has demonstrated its commitment to meeting these needs by delivering data warehouse tools designed to fill communications industry-specific needs," said Elisabeth Rainge, program director, Network Software, IDC. "The TM Forum Conformance Mark provides reassurance to customers seeking standards-based, and therefore, cost-effective and flexible solutions. TM Forum is extremely pleased to work with Oracle to certify its Oracle Communications Data Model solution. Upon successful completion, this certification will represent the broadest and most complete implementation of the TM Forum Information Framework to date, with more than 130 aggregate business entities," said Keith Willetts, chairman and chief executive officer, TM Forum. Supporting Resources Oracle Communications Oracle Communications Data Model Data Sheet Oracle Communications Data Model Podcast Oracle Data Warehousing Oracle Communications on YouTube Oracle Communications on Delicious Oracle Communications on Facebook Oracle Communications on Twitter Oracle Communications on LinkedIn Oracle Database on Twitter The Data Warehouse Insider Blog

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