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  • First toe in the water with Object Databases : DB4O

    - by REA_ANDREW
    I have been wanting to have a play with Object Databases for a while now, and today I have done just that.  One of the obvious choices I had to make was which one to use.  My criteria for choosing one today was simple, I wanted one which I could literally wack in and start using, which means I wanted one which either had a .NET API or was designed/ported to .NET.  My decision was between two being: db4o MongoDb I went for db4o for the single reason that it looked like I could get it running and integrated the quickest.  I am making a Blogging application and front end as a project with which I can test and learn with these object databases.  Another requirement which I thought I would mention is that I also want to be able to use the said database in a shared hosting environment where I cannot install, run and maintain a server instance of said object database.  I can do exactly this with db4o. I have not tried to do this with MongoDb at time of writing.  There are quite a few in the industry now and you read an interesting post about different ones and how they are used with some of the heavy weights in the industry here : http://blog.marcua.net/post/442594842/notes-from-nosql-live-boston-2010 In the example which I am building I am using StructureMap as my IOC.  To inject the object for db4o I went with a Singleton instance scope as I am using a single file and I need this to be available to any thread on in the process as opposed to using the server implementation where I could open and close client connections with the server handling each one respectively.  Again I want to point out that I have chosen to stick with the non server implementation of db4o as I wanted to use this in a shared hosting environment where I cannot have such servers installed and run.     public static class Bootstrapper    {        public static void ConfigureStructureMap()        {            ObjectFactory.Initialize(x => x.AddRegistry(new MyApplicationRegistry()));        }    }    public class MyApplicationRegistry : Registry    {        public const string DB4O_FILENAME = "blog123";        public string DbPath        {            get            {                return Path.Combine(Path.GetDirectoryName(Assembly.GetAssembly(typeof(IBlogRepository)).Location), DB4O_FILENAME);            }        }        public MyApplicationRegistry()        {            For<IObjectContainer>().Singleton().Use(                () => Db4oEmbedded.OpenFile(Db4oEmbedded.NewConfiguration(), DbPath));            Scan(assemblyScanner =>            {                assemblyScanner.TheCallingAssembly();                assemblyScanner.WithDefaultConventions();            });        }    } So my code above is the structure map plumbing which I use for the application.  I am doing this simply as a quick scratch pad to play around with different things so I am simply segregating logical layers with folder structure as opposed to different assemblies.  It will be easy if I want to do this with any segment but for the purposes of example I have literally just wacked everything in the one assembly.  You can see an example file structure I have on the right.  I am planning on testing out a few implementations of the object databases out there so I can program to an interface of IBlogRepository One of the things which I was unsure about was how it performed under a multi threaded environment which it will undoubtedly be used 9 times out of 10, and for the reason that I am using the db context as a singleton, I assumed that the library was of course thread safe but I did not know as I have not read any where in the documentation, again this is probably me not reading things correctly.  In short though I threw together a simple test where I simply iterate to a limit each time kicking a common task off with a thread from a thread pool.  This task simply created and added an random Post and added it to the storage. The execution of the threads I put inside the Setup of the Test and then simply ensure the number of posts committed to the database is equal to the number of iterations I made; here is the code I used to do the multi thread jobs: [TestInitialize] public void Setup() { var sw = new System.Diagnostics.Stopwatch(); sw.Start(); var resetEvent = new ManualResetEvent(false); ThreadPool.SetMaxThreads(20, 20); for (var i = 0; i < MAX_ITERATIONS; i++) { ThreadPool.QueueUserWorkItem(delegate(object state) { var eventToReset = (ManualResetEvent)state; var post = new Post { Author = MockUser, Content = "Mock Content", Title = "Title" }; Repository.Put(post); var counter = Interlocked.Decrement(ref _threadCounter); if (counter == 0) eventToReset.Set(); }, resetEvent); } WaitHandle.WaitAll(new[] { resetEvent }); sw.Stop(); Console.WriteLine("{0:00}.{1:00} seconds", sw.Elapsed.Seconds, sw.Elapsed.Milliseconds); }   I was not doing this to test out the speed performance of db4o but while I was doing this I could not help but put in a StopWatch and see out of sheer interest how fast it would take to insert a number of Posts.  I tested it out in this case with 10000 inserts of a small, simple POCO and it resulted in an average of:  899.36 object inserts / second.  Again this is just  simple crude test which came out of my curiosity at how it performed under many threads when using the non server implementation of db4o. The spec summary of the computer I used is as follows: With regards to the actual Repository implementation itself, it really is quite straight forward and I have to say I am very surprised at how easy it was to integrate and get up and running.  One thing I have noticed in the exposure I have had so far is that the Query returns IList<T> as opposed to IQueryable<T> but again I have not looked into this in depth and this could be there already and if not they have provided everything one needs to make there own repository.  An example of a couple of methods from by db4o implementation of the BlogRepository is below: public class BlogRepository : IBlogRepository { private readonly IObjectContainer _db; public BlogRepository(IObjectContainer db) { _db = db; } public void Put(DomainObject obj) { _db.Store(obj); } public void Delete(DomainObject obj) { _db.Delete(obj); } public Post GetByKey(object key) { return _db.Query<Post>(post => post.Key == key).FirstOrDefault(); } … Anyways I hope to get a few more implementations going of the object databases and literally just get familiarized with them and the concept of no sql databases. Cheers for now, Andrew

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  • TDD and WCF behavior

    - by Frederic Hautecoeur
    Some weeks ago I wanted to develop a WCF behavior using TDD. I have lost some time trying to use mocks. After a while i decided to just use a host and a client. I don’t like this approach but so far I haven’t found a good and fast solution to use Unit Test for testing a WCF behavior. To Implement my solution I had to : Create a Dummy Service Definition; Create the Dummy Service Implementation; Create a host; Create a client in my test; Create and Add the behavior; Dummy Service Definition This is just a simple service, composed of an Interface and a simple implementation. The structure is aimed to be easily customizable for my future needs.   Using Clauses : 1: using System.Runtime.Serialization; 2: using System.ServiceModel; 3: using System.ServiceModel.Channels; The DataContract: 1: [DataContract()] 2: public class MyMessage 3: { 4: [DataMember()] 5: public string MessageString; 6: } The request MessageContract: 1: [MessageContract()] 2: public class RequestMessage 3: { 4: [MessageHeader(Name = "MyHeader", Namespace = "http://dummyservice/header", Relay = true)] 5: public string myHeader; 6:  7: [MessageBodyMember()] 8: public MyMessage myRequest; 9: } The response MessageContract: 1: [MessageContract()] 2: public class ResponseMessage 3: { 4: [MessageHeader(Name = "MyHeader", Namespace = "http://dummyservice/header", Relay = true)] 5: public string myHeader; 6:  7: [MessageBodyMember()] 8: public MyMessage myResponse; 9: } The ServiceContract: 1: [ServiceContract(Name="DummyService", Namespace="http://dummyservice",SessionMode=SessionMode.Allowed )] 2: interface IDummyService 3: { 4: [OperationContract(Action="Perform", IsOneWay=false, ProtectionLevel=System.Net.Security.ProtectionLevel.None )] 5: ResponseMessage DoThis(RequestMessage request); 6: } Dummy Service Implementation 1: public class DummyService:IDummyService 2: { 3: #region IDummyService Members 4: public ResponseMessage DoThis(RequestMessage request) 5: { 6: ResponseMessage response = new ResponseMessage(); 7: response.myHeader = "Response"; 8: response.myResponse = new MyMessage(); 9: response.myResponse.MessageString = 10: string.Format("Header:<{0}> and Request was <{1}>", 11: request.myHeader, request.myRequest.MessageString); 12: return response; 13: } 14: #endregion 15: } Host Creation The most simple host implementation using a Named Pipe binding. The GetBinding method will create a binding for the host and can be used to create the same binding for the client. 1: public static class TestHost 2: { 3: 4: internal static string hostUri = "net.pipe://localhost/dummy"; 5:  6: // Create Host method. 7: internal static ServiceHost CreateHost() 8: { 9: ServiceHost host = new ServiceHost(typeof(DummyService)); 10:  11: // Creating Endpoint 12: Uri namedPipeAddress = new Uri(hostUri); 13: host.AddServiceEndpoint(typeof(IDummyService), GetBinding(), namedPipeAddress); 14:  15: return host; 16: } 17:  18: // Binding Creation method. 19: internal static Binding GetBinding() 20: { 21: NamedPipeTransportBindingElement namedPipeTransport = new NamedPipeTransportBindingElement(); 22: TextMessageEncodingBindingElement textEncoding = new TextMessageEncodingBindingElement(); 23:  24: return new CustomBinding(textEncoding, namedPipeTransport); 25: } 26:  27: // Close Method. 28: internal static void Close(ServiceHost host) 29: { 30: if (null != host) 31: { 32: host.Close(); 33: host = null; 34: } 35: } 36: } Checking the service A simple test tool check the plumbing. 1: [TestMethod] 2: public void TestService() 3: { 4: using (ServiceHost host = TestHost.CreateHost()) 5: { 6: host.Open(); 7:  8: using (ChannelFactory<IDummyService> channel = 9: new ChannelFactory<IDummyService>(TestHost.GetBinding() 10: , new EndpointAddress(TestHost.hostUri))) 11: { 12: IDummyService svc = channel.CreateChannel(); 13: try 14: { 15: RequestMessage request = new RequestMessage(); 16: request.myHeader = Guid.NewGuid().ToString(); 17: request.myRequest = new MyMessage(); 18: request.myRequest.MessageString = "I want some beer."; 19:  20: ResponseMessage response = svc.DoThis(request); 21: } 22: catch (Exception ex) 23: { 24: Assert.Fail(ex.Message); 25: } 26: } 27: host.Close(); 28: } 29: } Running the service should show that the client and the host are running fine. So far so good. Adding the Behavior Add a reference to the Behavior project and add the using entry in the test class. We just need to add the behavior to the service host : 1: [TestMethod] 2: public void TestService() 3: { 4: using (ServiceHost host = TestHost.CreateHost()) 5: { 6: host.Description.Behaviors.Add(new MyBehavior()); 7: host.Open();¨ 8: …  If you set a breakpoint in your behavior and run the test in debug mode, you will hit the breakpoint. In this case I used a ServiceBehavior. To add an Endpoint behavior you have to add it to the endpoints. 1: host.Description.Endpoints[0].Behaviors.Add(new MyEndpointBehavior()) To add a contract or an operation behavior a custom attribute should work on the service contract definition. I haven’t tried that yet.   All the code provided in this blog and in the following files are for sample use. Improvements I don’t like to instantiate a client and a service to test my behaviors. But so far I have' not found an easy way to do it. Today I am passing a type of endpoint to the host creator and it creates the right binding type. This allows me to easily switch between bindings at will. I have used the same approach to test Mex Endpoints, another post should come later for this. Enjoy !

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  • Visual Database Design Application

    - by tshauck
    Hi, I'm getting to the point where the applications I write need a little more structure during the planning phase. So I'd like to use some sort of visual tool to design the tables and relationships. I'm on a mac and have tried mysql workbench, but I find it buggy and a bit bloated for my intended use. Is something that I could design in that has a nice interface and is primarily a tool for visual design? Thanks

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  • Web application / Domain model integration using JSON capable DTOs [on hold]

    - by g-makulik
    I'm a bit confused about architectural choices for the web-applications/java/python world. For c/c++ world the available (open source) choices to implement web applications is pretty limited to zero, involving java or python the choices explode to a,- hard to sort out -, mess of available 'frameworks' and application approaches. I want to sort out a clean MVC model, where the M stands for a fully blown (POCO, POJO driven) domain model (according M.Fowler's EAA pattern) using a mature OO language (Java,C++) for implementation. The background is: I have a system with certain hardware components (that introduce system immanent active behavior) and a configuration database for system meta and HW-components configuration data (these are even usually self contained, since the HW-components are capable to persist their configuration data anyway). For realization of the configuration/status data exchange protocol with the HW-components we have chosen the Google Protobuf format, which works well for the directly wired communication with these components. This protocol is already used successfully with a Java based GUI application via TCP/IP connection to the main system controlling HW-component. This application has some drawbacks and design flaws for historical reasons. Now we want to develop an abstract model (domain model) for configuration and monitoring those HW-components, that represents a more use case oriented view to the overall system behavior. I have the feeling that a plain Java class model would fit best for this (c++ implementation seems to have too much implementation/integration overhead with viable language-bridge interfaces). Google Protobuf message definitions could still serve well to describe DTO objects used to interact with a domain model API. But integrating Google Protobuf messages client side for e.g. data binding in the current view doesn't seem to be a good choice. I'm thinking about some extra serialization features, e.g. for JSON based data exchange with the views/controllers. Most lightweight solutions seem to involve a python based presentation layer using JSON based data transfer (I'm at least not sure to be fully informed about this). Is there some lightweight (applicable for a limited ARM Linux platform) framework available, supporting such architecture to realize a web-application? UPDATE: According to my recent research and comments of colleagues I've noticed that using Java (and some JVM) might not be the preferable choice for integration with python on a limited linux system as we have (running on ARM9 with hard to discuss memory and MCU costs), but C/C++ modules would do well for this (since this forms the native interface to python extensions, doesn't it?). I can imagine to provide a domain model from an appropriate C/C++ API (though I still think it's more efforts and higher skill requirements for the involved developers to do with these languages). Still I'm searching for a good approach that supports such architecture. I'll appreciate any pointers!

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  • Sending Big Files with WCF

    - by Sean Feldman
    I had to look into a project that submits large files to WCF service. Implementation is based on data chunking. This is a good approach when your client and server are not both based on WCF, bud different technologies. The problem with something like this is that chunking (either you wish it or not) complicates the overall solution. Alternative would be streaming. In WCF to WCF scenario, this is a piece of cake. When client is Java, it becomes a bit more challenging (has anyone implemented Java client streaming data to WCF service?). What I really liked about .NET implementation with WCF, is that sending header info along with stream was dead simple, and from the developer point of view looked like it’s all a part of the DTO passed into the service. [ServiceContract] public interface IFileUpload { [OperationContract] void UploadFile(SendFileMessage message); } Where SendFileMessage is [MessageContract] public class SendFileMessage { [MessageBodyMember(Order = 1)] public Stream FileData; [MessageHeader(MustUnderstand = true)] public FileTransferInfo FileTransferInfo; }

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  • Absent Code attribute in method that is not native or abstract

    - by kerry
    I got the following, quite puzzling error today when running a unit test: java.lang.ClassFormatError: Absent Code attribute in method that is not native or abstract in class file javax/servlet/http/Cookie A google search found this post, which explains that it is caused by having an interface in the classpath, and not an actual implementation. In this case it’s the java-ee interface. To fix this I added the jetty servlet api implementation to my pom: jetty javax.servlet test Piece of cake. I have run in to this before, so I figured I would capture the fix here in case I run in to it again.

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  • SSAS Native v .net Provider

    - by ACALVETT
    Recently I was investigating why a new server which is in its parallel running phase was taking significantly longer to process the daily data than the server its due to replace. The server has SQL & SSAS installed so the problem was not likely to be in the network transfer as its using shared memory. As i dug around the SQL dmv’s i noticed in sys.dm_exec_connections that the SSAS connection had a packet size of 8000 bytes instead of the usual 4096 bytes and from there i found that the datasource...(read more)

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  • Wrong perspective is showing in Eclipse plugin project [closed]

    - by Arun Kumar Choudhary
    I am working in Eclipse Modeling Framework (Eclipse plugin development) in my project the tool(project i am working) provides three perspectives. 1.Accelerator Analyst perspective 2.Contract Validation and 3.Underwriter rules Editor... By default it starts with Contract validation perspective (As we define it within the plugin_customization.ini). However after switching to other perspective does not change the perspective shown... As all perspective (Class, Id and Name) is define only inside Plugin.XML as it is the task of org.eclipse.ui.perspective that that perspective name should be come forefront. Out of 10 7 times it is working fine but I am not getting why this is not working in that 3 cases. I am pasting my plugin.XML file <?xml version="1.0" encoding="UTF-8"?> <?eclipse version="3.0"?> <plugin> <extension id="RuleEditor.application" name="Accelerator Tooling" point="org.eclipse.core.runtime.applications"> <application> <run class="com.csc.fs.underwriting.product.UnderWritingApplication"> </run> </application> </extension> <extension point="org.eclipse.ui.perspectives"> <perspective class="com.csc.fs.underwriting.product.ContractValidationPerspective" icon="icons/javadevhov_obj.gif" id="com.csc.fs.underwriting.product.ContractValidationPerspective" name="Contract Validation"> </perspective> </extension> <extension point="org.eclipse.ui.perspectives"> <perspective class="com.csc.fs.underwriting.product.UnderwritingPerspective" icon="icons/javadevhov_obj.gif" id="com.csc.fs.underwriting.product.UnderwritingPerspective" name="Underwriting"> </perspective> </extension> <extension id="product" point="org.eclipse.core.runtime.products"> <product application="com.csc.fs.nba.underwriting.application.RuleEditor.application" name="Rule Configurator Workbench" description="%AppName"> <property name="introTitle" value="Welcome to Accelerator Tooling"/> <property name="introVer" value="%version"/> <property name="introBrandingImage" value="product:csclogo.png"/> <property name="introBrandingImageText" value="CSC FSG"/> <property name="preferenceCustomization" value="plugin_customization.ini"/> <property name="appName" value="Rule Configurator Workbench"> </property> </product> </extension> <extension point="org.eclipse.ui.intro"> <intro class="org.eclipse.ui.intro.config.CustomizableIntroPart" icon="icons/Welcome.gif" id="com.csc.fs.nba.underwriting.intro"/> <introProductBinding introId="com.csc.fs.nba.underwriting.intro" productId="com.csc.fs.nba.underwriting.application.product"/> <intro class="org.eclipse.ui.intro.config.CustomizableIntroPart" id="com.csc.fs.nba.underwriting.application.intro"> </intro> <introProductBinding introId="com.csc.fs.nba.underwriting.application.intro" productId="com.csc.fs.nba.underwriting.application.product"> </introProductBinding> </extension> <extension name="Accelerator Tooling" point="org.eclipse.ui.intro.config"> <config content="$nl$/intro/introContent.xml" id="org.eclipse.platform.introConfig.mytest" introId="com.csc.fs.nba.underwriting.intro"> <presentation home-page-id="news"> <implementation kind="html" os="win32,linux,macosx" style="$nl$/intro/css/shared.css"/> </presentation> </config> <config content="introContent.xml" id="com.csc.fs.nba.underwriting.application.introConfigId" introId="com.csc.fs.nba.underwriting.application.intro"> <presentation home-page-id="root"> <implementation kind="html" os="win32,linux,macosx" style="content/shared.css"> </implementation> </presentation> </config> </extension> <extension point="org.eclipse.ui.intro.configExtension"> <theme default="true" id="org.eclipse.ui.intro.universal.circles" name="%theme.name.circles" path="$nl$/themes/circles" previewImage="themes/circles/preview.png"> <property name="introTitle" value="Accelerator Tooling"/> <property name="introVer" value="%version"/> </theme> </extension> <extension point="org.eclipse.ui.ide.resourceFilters"> <filter pattern="*.dependency" selected="true"/> <filter pattern="*.producteditor" selected="true"/> <filter pattern="*.av" selected="true"/> <filter pattern=".*" selected="true"/> </extension> <extension point="org.eclipse.ui.splashHandlers"> <splashHandler class="com.csc.fs.nba.underwriting.application.splashHandlers.InteractiveSplashHandler" id="com.csc.fs.nba.underwriting.application.splashHandlers.interactive"> </splashHandler> <splashHandler class="com.csc.fs.underwriting.application.splashHandlers.InteractiveSplashHandler" id="com.csc.fs.underwriting.application.splashHandlers.interactive"> </splashHandler> <splashHandlerProductBinding productId="com.csc.fs.nba.underwriting.application" splashId="com.csc.fs.underwriting.application.splashHandlers.interactive"> </splashHandlerProductBinding> </extension> <extension id="com.csc.fs.pa.security" point="com.csc.fs.pa.security.implementation.secure"> <securityImplementation class="com.csc.fs.pa.security.PASecurityImpl"> </securityImplementation> </extension> <extension id="productApplication.security.pep" name="com.csc.fs.pa.producteditor.application.security.pep" point="com.csc.fs.pa.security.implementation.authorize"> <authorizationManager class="com.csc.fs.pa.security.authorization.PAAuthorizationManager"> </authorizationManager> </extension> <extension point="org.eclipse.ui.editors"> <editor class="com.csc.fs.underwriting.product.editors.PDFViewer" extensions="pdf" icon="icons/pdficon_small.gif" id="com.csc.fs.pa.producteditor.application.editors.PDFViewer" name="PDF Viewer"> </editor> </extension> <extension point="org.eclipse.ui.views"> <category id="com.csc.fs.pa.application.viewCategory" name="%category"> </category> </extension> <extension point="org.eclipse.ui.newWizards"> <category id="com.csc.fs.pa.application.newWizardCategory" name="%category"> </category> <category id="com.csc.fs.pa.application.newWizardInitialize" name="%initialize" parentCategory="com.csc.fs.pa.application.newWizardCategory"> </category> </extension> <extension point="com.csc.fs.pa.common.usability.addNewCategory"> <addNewCategoryId id="com.csc.fs.pa.application.newWizardCategory"> </addNewCategoryId> </extension> <!--extension point="org.eclipse.ui.activities"> <activity description="View Code Generation Option" id="com.csc.fs.pa.producteditor.application.viewCodeGen" name="ViewCodeGen"> </activity> <activityPatternBinding activityId="com.csc.fs.pa.producteditor.application.viewCodeGen" pattern="com.csc.fs.pa.bpd.vpms.codegen/com.csc.fs.pa.bpd.vpms.codegen.bpdCodeGenActionId"> </activityPatternBinding> Add New Product Definition Extension </extension--> </plugin> class="com.csc.fs.underwriting.product.editors.PDFViewer" extensions="pdf" icon="icons/pdficon_small.gif" id="com.csc.fs.pa.producteditor.application.editors.PDFViewer" name="PDF Viewer"> </editor> </extension> <extension point="org.eclipse.ui.views"> <category id="com.csc.fs.pa.application.viewCategory" name="%category"> </category> </extension> <extension point="org.eclipse.ui.newWizards"> <category id="com.csc.fs.pa.application.newWizardCategory" name="%category"> </category> <category id="com.csc.fs.pa.application.newWizardInitialize" name="%initialize" parentCategory="com.csc.fs.pa.application.newWizardCategory"> </category> </extension> <extension point="com.csc.fs.pa.common.usability.addNewCategory"> <addNewCategoryId id="com.csc.fs.pa.application.newWizardCategory"> </addNewCategoryId> </extension> <!--extension point="org.eclipse.ui.activities"> <activity description="View Code Generation Option" id="com.csc.fs.pa.producteditor.application.viewCodeGen" name="ViewCodeGen"> </activity> <activityPatternBinding activityId="com.csc.fs.pa.producteditor.application.viewCodeGen" pattern="com.csc.fs.pa.bpd.vpms.codegen/com.csc.fs.pa.bpd.vpms.codegen.bpdCodeGenActionId"> </activityPatternBinding> Add New Product Definition Extension </extension--> </plugin> Inside each class(the qualified classes in above xml) i did only hide and show the view according to perspective and that is working very fine.. Please provide any method that Eclipse provide so that I can override it in each classed so that it can work accordingly.

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  • Data Modeling Resources

    - by Dejan Sarka
    You can find many different data modeling resources. It is impossible to list all of them. I selected only the most valuable ones for me, and, of course, the ones I contributed to. Books Chris J. Date: An Introduction to Database Systems – IMO a “must” to understand the relational model correctly. Terry Halpin, Tony Morgan: Information Modeling and Relational Databases – meet the object-role modeling leaders. Chris J. Date, Nikos Lorentzos and Hugh Darwen: Time and Relational Theory, Second Edition: Temporal Databases in the Relational Model and SQL – all theory needed to manage temporal data. Louis Davidson, Jessica M. Moss: Pro SQL Server 2012 Relational Database Design and Implementation – the best SQL Server focused data modeling book I know by two of my friends. Dejan Sarka, et al.: MCITP Self-Paced Training Kit (Exam 70-441): Designing Database Solutions by Using Microsoft® SQL Server™ 2005 – SQL Server 2005 data modeling training kit. Most of the text is still valid for SQL Server 2008, 2008 R2, 2012 and 2014. Itzik Ben-Gan, Lubor Kollar, Dejan Sarka, Steve Kass: Inside Microsoft SQL Server 2008 T-SQL Querying – Steve wrote a chapter with mathematical background, and I added a chapter with theoretical introduction to the relational model. Itzik Ben-Gan, Dejan Sarka, Roger Wolter, Greg Low, Ed Katibah, Isaac Kunen: Inside Microsoft SQL Server 2008 T-SQL Programming – I added three chapters with theoretical introduction and practical solutions for the user-defined data types, dynamic schema and temporal data. Dejan Sarka, Matija Lah, Grega Jerkic: Training Kit (Exam 70-463): Implementing a Data Warehouse with Microsoft SQL Server 2012 – my first two chapters are about data warehouse design and implementation. Courses Data Modeling Essentials – I wrote a 3-day course for SolidQ. If you are interested in this course, which I could also deliver in a shorter seminar way, you can contact your closes SolidQ subsidiary, or, of course, me directly on addresses [email protected] or [email protected]. This course could also complement the existing courseware portfolio of training providers, which are welcome to contact me as well. Logical and Physical Modeling for Analytical Applications – online course I wrote for Pluralsight. Working with Temporal data in SQL Server – my latest Pluralsight course, where besides theory and implementation I introduce many original ways how to optimize temporal queries. Forthcoming presentations SQL Bits 12, July 17th – 19th, Telford, UK – I have a full-day pre-conference seminar Advanced Data Modeling Topics there.

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  • Getting Started with Prism (aka Composite Application Guidance for WPF and Silverlight)

    - by dotneteer
    Overview Prism is a framework from the Microsoft Patterns and Practice team that allow you to create WPF and Silverlight in a modular way. It is especially valuable for larger projects in which a large number of developers can develop in parallel. Prism achieves its goal by supplying several services: · Dependency Injection (DI) and Inversion of control (IoC): By using DI, Prism takes away the responsibility of instantiating and managing the life time of dependency objects from individual components to a container. Prism relies on containers to discover, manage and compose large number of objects. By varying the configuration, the container can also inject mock objects for unit testing. Out of the box, Prism supports Unity and MEF as container although it is possible to use other containers by subclassing the Bootstrapper class. · Modularity and Region: Prism supplies the framework to split application into modules from the application shell. Each module is a library project that contains both UI and code and is responsible to initialize itself when loaded by the shell. Each window can be further divided into regions. A region is a user control with associated model. · Model, view and view-model (MVVM) pattern: Prism promotes the user MVVM. The use of DI container makes it much easier to inject model into view. WPF already has excellent data binding and commanding mechanism. To be productive with Prism, it is important to understand WPF data binding and commanding well. · Event-aggregation: Prism promotes loosely coupled components. Prism discourages for components from different modules to communicate each other, thus leading to dependency. Instead, Prism supplies an event-aggregation mechanism that allows components to publish and subscribe events without knowing each other. Architecture In the following, I will go into a little more detail on the services provided by Prism. Bootstrapper In a typical WPF application, application start-up is controls by App.xaml and its code behind. The main window of the application is typically specified in the App.xaml file. In a Prism application, we start a bootstrapper in the App class and delegate the duty of main window to the bootstrapper. The bootstrapper will start a dependency-injection container so all future object instantiations are managed by the container. Out of box, Prism provides the UnityBootstrapper and MefUnityBootstrapper abstract classes. All application needs to either provide a concrete implementation of one of these bootstrappers, or alternatively, subclass the Bootstrapper class with another DI container. A concrete bootstrapper class must implement the CreateShell method. Its responsibility is to resolve and create the Shell object through the DI container to serve as the main window for the application. The other important method to override is ConfigureModuleCatalog. The bootstrapper can register modules for the application. In a more advance scenario, an application does not have to know all its modules at compile time. Modules can be discovered at run time. Readers to refer to one of the Open Modularity Quick Starts for more information. Modules Once modules are registered with or discovered by Prism, they are instantiated by the DI container and their Initialize method is called. The DI container can inject into a module a region registry that implements IRegionViewRegistry interface. The module, in its Initialize method, can then call RegisterViewWithRegion method of the registry to register its regions. Regions Regions, once registered, are managed by the RegionManager. The shell can then load regions either through the RegionManager.RegionName attached property or dynamically through code. When a view is created by the region manager, the DI container can inject view model and other services into the view. The view then has a reference to the view model through which it can interact with backend services. Service locator Although it is possible to inject services into dependent classes through a DI container, an alternative way is to use the ServiceLocator to retrieve a service on demard. Prism supplies a service locator implementation and it is possible to get an instance of the service by calling: ServiceLocator.Current.GetInstance<IServiceType>() Event aggregator Prism supplies an IEventAggregator interface and implementation that can be injected into any class that needs to communicate with each other in a loosely-coupled fashion. The event aggregator uses a publisher/subscriber model. A class can publishes an event by calling eventAggregator.GetEvent<EventType>().Publish(parameter) to raise an event. Other classes can subscribe the event by calling eventAggregator.GetEvent<EventType>().Subscribe(EventHandler, other options). Getting started The easiest way to get started with Prism is to go through the Prism Hands-On labs and look at the Hello World QuickStart. The Hello World QuickStart shows how bootstrapper, modules and region works. Next, I would recommend you to look at the Stock Trader Reference Implementation. It is a more in depth example that resemble we want to set up an application. Several other QuickStarts cover individual Prism services. Some scenarios, such as dynamic module discovery, are more advanced. Apart from the official prism document, you can get an overview by reading Glen Block’s MSDN Magazine article. I have found the best free training material is from the Boise Code Camp. To be effective with Prism, it is important to understands key concepts of WPF well first, such as the DependencyProperty system, data binding, resource, theme and ICommand. It is also important to know your DI container of choice well. I will try to explorer these subjects in depth in the future. Testimony Recently, I worked on a desktop WPF application using Prism. I had a wonderful experience with Prism. The Prism is flexible enough even in the presence of third party controls such as Telerik WPF controls. We have never encountered any significant obstacle.

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  • cannot connect with huawei e173 after upgrade to 12.10 using network manager

    - by user104195
    Since upgrade from 12.04 to 12.10 I can't connect to internet using mobile broadband modem Huawei e173. It worked earlier without problems and now it seems to be properly recognized (at least its connections appear in network manager applet), and after selecting connection manually it starts connection procedure. After about 20 seconds it returns to state disconnected. After browsing internet I've found that running network manager with: NM_PPP_DEBUG=1 /usr/sbin/NetworkManager --no-daemon After inserting modem I get: NetworkManager[507]: <warn> (ttyUSB2): failed to look up interface index NetworkManager[507]: <info> (ttyUSB2): new GSM/UMTS device (driver: 'option1' ifindex: 0) NetworkManager[507]: <info> (ttyUSB2): exported as /org/freedesktop/NetworkManager/Devices/2 NetworkManager[507]: <info> (ttyUSB2): now managed NetworkManager[507]: <info> (ttyUSB2): device state change: unmanaged -> unavailable (reason 'managed') [10 20 2] NetworkManager[507]: <info> (ttyUSB2): deactivating device (reason 'managed') [2] NetworkManager[507]: <info> (ttyUSB2): device state change: unavailable -> disconnected (reason 'none') [20 30 0] where 'failed to look up interface index' seems to be suspicious. After starting connecting: NetworkManager[507]: <info> Activation (ttyUSB2) starting connection 'Plus - Dostep standardowy' NetworkManager[507]: <info> (ttyUSB2): device state change: disconnected -> prepare (reason 'none') [30 40 0] NetworkManager[507]: <info> Activation (ttyUSB2) Stage 1 of 5 (Device Prepare) scheduled... NetworkManager[507]: <info> Activation (ttyUSB2) Stage 1 of 5 (Device Prepare) started... NetworkManager[507]: <info> (ttyUSB2): device state change: prepare -> need-auth (reason 'none') [40 60 0] NetworkManager[507]: <info> Activation (ttyUSB2) Stage 1 of 5 (Device Prepare) complete. NetworkManager[507]: <info> Activation (ttyUSB2) Stage 1 of 5 (Device Prepare) scheduled... NetworkManager[507]: <info> Activation (ttyUSB2) Stage 1 of 5 (Device Prepare) started... NetworkManager[507]: <info> (ttyUSB2): device state change: need-auth -> prepare (reason 'none') [60 40 0] NetworkManager[507]: <info> Activation (ttyUSB2) Stage 1 of 5 (Device Prepare) complete. NetworkManager[507]: <info> WWAN now enabled by management service NetworkManager[507]: <info> Activation (ttyUSB2) Stage 2 of 5 (Device Configure) scheduled... NetworkManager[507]: <info> Activation (ttyUSB2) Stage 2 of 5 (Device Configure) starting... NetworkManager[507]: <info> (ttyUSB2): device state change: prepare -> config (reason 'none') [40 50 0] NetworkManager[507]: <info> Activation (ttyUSB2) Stage 2 of 5 (Device Configure) successful. NetworkManager[507]: <info> Activation (ttyUSB2) Stage 3 of 5 (IP Configure Start) scheduled. NetworkManager[507]: <info> Activation (ttyUSB2) Stage 2 of 5 (Device Configure) complete. NetworkManager[507]: <info> Activation (ttyUSB2) Stage 3 of 5 (IP Configure Start) started... NetworkManager[507]: <info> (ttyUSB2): device state change: config -> ip-config (reason 'none') [50 70 0] NetworkManager[507]: <info> starting PPP connection NetworkManager[507]: <info> pppd started with pid 663 NetworkManager[507]: <info> Activation (ttyUSB2) Stage 4 of 5 (IPv6 Configure Timeout) scheduled... NetworkManager[507]: <info> Activation (ttyUSB2) Stage 3 of 5 (IP Configure Start) complete. NetworkManager[507]: <info> Activation (ttyUSB2) Stage 4 of 5 (IPv6 Configure Timeout) started... NetworkManager[507]: <info> Activation (ttyUSB2) Stage 4 of 5 (IPv6 Configure Timeout) complete. Plugin /usr/lib/pppd/2.4.5/nm-pppd-plugin.so loaded. ** Message: nm-ppp-plugin: (plugin_init): initializing ** Message: nm-ppp-plugin: (nm_phasechange): status 3 / phase 'serial connection' Removed stale lock on ttyUSB2 (pid 32146) using channel 23 NetworkManager[507]: SCPlugin-Ifupdown: devices added (path: /sys/devices/virtual/net/ppp0, iface: ppp0) NetworkManager[507]: SCPlugin-Ifupdown: device added (path: /sys/devices/virtual/net/ppp0, iface: ppp0): no ifupdown configuration found. NetworkManager[507]: <warn> /sys/devices/virtual/net/ppp0: couldn't determine device driver; ignoring... Using interface ppp0 Connect: ppp0 <--> /dev/ttyUSB2 ** Message: nm-ppp-plugin: (nm_phasechange): status 5 / phase 'establish' sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x64b4024a> <pcomp> <accomp>] sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x64b4024a> <pcomp> <accomp>] sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x64b4024a> <pcomp> <accomp>] sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x64b4024a> <pcomp> <accomp>] sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x64b4024a> <pcomp> <accomp>] sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x64b4024a> <pcomp> <accomp>] sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x64b4024a> <pcomp> <accomp>] NetworkManager[507]: <warn> pppd timed out or didn't initialize our dbus module NetworkManager[507]: <info> Activation (ttyUSB2) Stage 4 of 5 (IPv4 Configure Timeout) scheduled... NetworkManager[507]: <info> Activation (ttyUSB2) Stage 4 of 5 (IPv4 Configure Timeout) started... NetworkManager[507]: <info> (ttyUSB2): device state change: ip-config -> failed (reason 'ip-config-unavailable') [70 120 5] NetworkManager[507]: <warn> Activation (ttyUSB2) failed for connection 'Plus - Dostep standardowy' NetworkManager[507]: <info> Activation (ttyUSB2) Stage 4 of 5 (IPv4 Configure Timeout) complete. NetworkManager[507]: <info> (ttyUSB2): device state change: failed -> disconnected (reason 'none') [120 30 0] NetworkManager[507]: <info> (ttyUSB2): deactivating device (reason 'none') [0] Terminating on signal 15 ** Message: nm-ppp-plugin: (nm_phasechange): status 10 / phase 'terminate' sent [LCP TermReq id=0x2 "User request"] NetworkManager[507]: SCPlugin-Ifupdown: devices removed (path: /sys/devices/virtual/net/ppp0, iface: ppp0) where repeated: sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x64b4024a> <pcomp> <accomp>] last for about 20 seconds. I've tried to downgrade network manager but failed due to many dependencies. Can anyone point me to solution or tell what should I do to further investigate the problem?

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  • Calling All Agile Customers-Share Your Stories at the Upcoming PLM Summit

    - by Terri Hiskey
    Now that we've closed the door on another Oracle OpenWorld, planning is in full swing for the next PLM Summit, taking place February 4-6, 2013 in San Francisco, in conjunction with the Oracle Value Chain Summit. This event is a must-attend for all Agile PLM customers. We will be holding five tracks with over forty Agile PLM-focused sessions covering a range of topics and industries. If you'd like to be notified once registration is live for this event, be sure to sign up at www.oracle.com/goto/vcs. CALL FOR PRESENTATIONS: We are looking for some fresh, new customer stories to share with attendees. Read below for descriptions of the five tracks, and the suggested topics that we'd like to hear from customers. If you are interested in presenting at the PLM Summit (and getting a FREE pass to attend if your presentation is accepted!) send me an email at terri.hiskey-AT-oracle.com with: Your proposed session title and the track your session fits into 3-5 bullets of takeaways that attendees will get from your presentation Your complete contact information including name, title, company, telephone number and email The deadline for this call for presentations is Thursday, November 15, so get your submission in soon! PLM Track #1:  Product Insights and Best Practices This track will provide executive attendees and line of business managers with an overview of how Agile PLM has been deployed and used at customers to enable and manage critical product-related business processes including enterprise quality and supplier management, compliance, product cost management, portfolio management, commercialization and software lifecycle management. These sessions will also provide details around how to manage the development and rollout of the solutions and how to achieve and track value. Possible session topics: Software Lifecycle Management Enterprise Quality Management New Product Development Integrated Business Planning ECO effectivity planning Rapid Commercialization             Manage the Design to Release Process for Complex Configured Products PLM for Life Sciences Companies I (Compliant Data Set) PLM for Life Sciences Companies II (eMDR, UDI) Discrete CPG – Private Label Mgmt Cost Management and Strategic Sourcing IP Mgmt in the Semiconductor Industry Implementing the Enterprise Training Record using Agile PLM PLM Track #2: Product Deep Dives & Demos This track is aimed at line of business  and IT managers who would like to understand the benefits of expanding their PLM footprint. The sessions in this track will provide attendees with an up-close and in-depth look Agile PLM’s newer and exciting applications, including analytics and innovation management, and will detail features and functionality that are available in the latest version of Agile PLM Possible session topics: Oracle Product Lifecycle Analytics Integrating PLM with Engineering and Supply Chain Systems Streamline PLM Design to Manufacturing Processes with AutoVue Visualization Solutions         Achieve Environmental Compliance (REACH and ROHS) with Agile Product Governance & Compliance PIM Deep Dive Achieving Integrated Change Control with Agile PLM and E-Business Suite Deploying PLM at Small and Midsize Enterprises Enhancing Oracle PQM w/APQP and 8D functionality Advanced Roles and Privileges – Enabling ITAR Model Unit Effectivity Implementing REACH with 9.3.2 Deploying Job Functions, Functional Teams in 9.3.2 to Improve Your Approval Matrix PLM Track #3: Administration & Integrations This track will provide sessions for Agile administrators, managers and daily Agile PLM users who are preparing to upgrade or looking to extend the use of their current PLM implementation through AIA and process extensions. It will include deeper conversation about Agile PLM features and best practices on managing an Agile PLM infrastructure. Possible session topics: Expand the Value of your Agile Investment with Innovative Process Extension Ideas Ensuring Implementation & Upgrade Success Ensure the Integrity and Accuracy of Product Data Across the Enterprise              Maximize the Benefits of an Integrated Architecture with AIA Integrating your PLM Implementation with ERP               Infrastructure Optimization Expanding Your PLM Implementation PLM Administrator Open Forum Q&A/Discussion FDA Validation Best Practices Best Practices for Managing a large Agile Deployment: Clustering, Load Balancing and Firewalls PLM Track #4: Agile PLM for Process This track is aimed at attendees interested in or currently using Agile PLM for Process. The sessions in this track will go over new features and functionality available in the newest version of PLM for Process and will give attendees an overview on how PLM for Process is being used to manage critical business processes such as formulation, recipe and specification management Possible session topics: PLM for Process Strategy, Roadmap and Update New Product Development and Introduction Effective Product Supplier Collaboration             Leverage Agile Formulation and Compliance to Manage Cost, Compliance, Quality, Labeling and Nutrition Menu Management Innovation Data Management Food Safety/ Introduction of P4P Quality Mgmt PLM Track #5: Agile PLM and Innovation Management This track consists of five sessions, and is for attendees interested in learning more about Oracle’s Agile Innovation Management, an exciting new addition to the Agile PLM application family that redefines the industry’s scope of product lifecycle management. Oracle’s innovation solutions enable companies to collaborate in a focused way among various functional groups (marketing, sales, operations, engineering/R&D and sourcing), combining insights of customer needs/requirements, competition, available technologies, alternate design scenarios and portfolio constraints to deliver what customers truly value. The results are better products, higher margins, greater efficiencies, more satisfied customers and the increased ability to continuously innovate. Possible session topics: Product Innovation Management Solution Overview Product Requirements & Ideation Management Concept Design Management Product Lifecycle Portfolio Management Innovation as a Competitive Differentiator

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  • WebLogic 12c hands-on bootcamps for partners – free of charge

    - by JuergenKress
    For all WebLogic Partner Community members we offer our WebLogic 12c hands-on Bootcamps – free of charge! If you want to become an Application Grid Specialized: Register Here! Country Date Location Registration Germany 3-5 April 2012 Oracle Düsseldorf Click here France 24-26 April 2012 Oracle Colombes Click here Spain 08-10 May 2012 Oracle Madrid Click here Netherlands 22-24 May 2012 Oracle Amsterdam Click here United Kingdom 06-08 June 2012 Oracle Reading Click here Italy 19-21 June 2012 Oracle Cinisello Balsamo Click here Portugal 10-12 July 2012 Oracle Lisbon Click here Skill requirements Attendees need to have the following skills as this is required by the product-set and to make sure they get the most out of the training: Basic knowledge in Java and JavaEE Understanding the Application Server concept Basic knowledge in older releases of WebLogic Server would be beneficial Member of WebLogic Partner Community for registration please vist http://www.oracle.com/partners/goto/wls-emea Hardware requirements Every participant works on his own notebook. The minimal hardware requirements are: 4Gb physical RAM (we will boot the image with 2Gb RAM) dual core CPU 15 GB HD Software requirements Please install Oracle VM VirtualBox 4.1.8 Follow-up and certification With the workshop registration you agree to the following next steps Follow-up training attend and pass the Oracle Application Grid Certified Implementation Specialist Registration For details and registration please visit Register Here Free WebLogic Certification (Free assessment voucher to become certified) For all WebLogic experts, we offer free vouchers worth $195 for the Oracle Application Grid Certified Implementation Specialist assessment. To demonstrate your WebLogic knowledge you first have to pass the free online assessment Oracle Application Grid PreSales Specialist. For free vouchers, please send an e-mail with the screenshot of your Oracle Application Grid PreSales certirficate to [email protected] including your Name, Company, E-mail and Country. Note: This offer is limited to partners from Europe Middle East and Africa. Partners from other countries please contact your Oracle partner manager. WebLogic Specialization To become specialized in Application Grid, please make sure that you access the: Application Grid Specialization Guide Application Grid Specialization Checklist If you have any questions please contact the Oracle Partner Business Center. WebLogic Partner Community For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Mix Forum Wiki Technorati Tags: WebLogic training,Java training,WebLogic 12c,WebLogic Community,OPN,WebLogic,Oracle,WebLogic Certification,Apps Grid Certification,Implementation Specialist,Apps Grid Specialist,Oracle education

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  • Tutorial: Getting Started with the NoSQL JavaScript / Node.js API for MySQL Cluster

    - by Mat Keep
    Tutorial authored by Craig Russell and JD Duncan  The MySQL Cluster team are working on a new NoSQL JavaScript connector for MySQL. The objectives are simplicity and high performance for JavaScript users: - allows end-to-end JavaScript development, from the browser to the server and now to the world's most popular open source database - native "NoSQL" access to the storage layer without going first through SQL transformations and parsing. Node.js is a complete web platform built around JavaScript designed to deliver millions of client connections on commodity hardware. With the MySQL NoSQL Connector for JavaScript, Node.js users can easily add data access and persistence to their web, cloud, social and mobile applications. While the initial implementation is designed to plug and play with Node.js, the actual implementation doesn't depend heavily on Node, potentially enabling wider platform support in the future. Implementation The architecture and user interface of this connector are very different from other MySQL connectors in a major way: it is an asynchronous interface that follows the event model built into Node.js. To make it as easy as possible, we decided to use a domain object model to store the data. This allows for users to query data from the database and have a fully-instantiated object to work with, instead of having to deal with rows and columns of the database. The domain object model can have any user behavior that is desired, with the NoSQL connector providing the data from the database. To make it as fast as possible, we use a direct connection from the user's address space to the database. This approach means that no SQL (pun intended) is needed to get to the data, and no SQL server is between the user and the data. The connector is being developed to be extensible to multiple underlying database technologies, including direct, native access to both the MySQL Cluster "ndb" and InnoDB storage engines. The connector integrates the MySQL Cluster native API library directly within the Node.js platform itself, enabling developers to seamlessly couple their high performance, distributed applications with a high performance, distributed, persistence layer delivering 99.999% availability. The following sections take you through how to connect to MySQL, query the data and how to get started. Connecting to the database A Session is the main user access path to the database. You can get a Session object directly from the connector using the openSession function: var nosql = require("mysql-js"); var dbProperties = {     "implementation" : "ndb",     "database" : "test" }; nosql.openSession(dbProperties, null, onSession); The openSession function calls back into the application upon creating a Session. The Session is then used to create, delete, update, and read objects. Reading data The Session can read data from the database in a number of ways. If you simply want the data from the database, you provide a table name and the key of the row that you want. For example, consider this schema: create table employee (   id int not null primary key,   name varchar(32),   salary float ) ENGINE=ndbcluster; Since the primary key is a number, you can provide the key as a number to the find function. function onSession = function(err, session) {   if (err) {     console.log(err);     ... error handling   }   session.find('employee', 0, onData); }; function onData = function(err, data) {   if (err) {     console.log(err);     ... error handling   }   console.log('Found: ', JSON.stringify(data));   ... use data in application }; If you want to have the data stored in your own domain model, you tell the connector which table your domain model uses, by specifying an annotation, and pass your domain model to the find function. var annotations = new nosql.Annotations(); function Employee = function(id, name, salary) {   this.id = id;   this.name = name;   this.salary = salary;   this.giveRaise = function(percent) {     this.salary *= percent;   } }; annotations.mapClass(Employee, {'table' : 'employee'}); function onSession = function(err, session) {   if (err) {     console.log(err);     ... error handling   }   session.find(Employee, 0, onData); }; Updating data You can update the emp instance in memory, but to make the raise persistent, you need to write it back to the database, using the update function. function onData = function(err, emp) {   if (err) {     console.log(err);     ... error handling   }   console.log('Found: ', JSON.stringify(emp));   emp.giveRaise(0.12); // gee, thanks!   session.update(emp); // oops, session is out of scope here }; Using JavaScript can be tricky because it does not have the concept of block scope for variables. You can create a closure to handle these variables, or use a feature of the connector to remember your variables. The connector api takes a fixed number of parameters and returns a fixed number of result parameters to the callback function. But the connector will keep track of variables for you and return them to the callback. So in the above example, change the onSession function to remember the session variable, and you can refer to it in the onData function: function onSession = function(err, session) {   if (err) {     console.log(err);     ... error handling   }   session.find(Employee, 0, onData, session); }; function onData = function(err, emp, session) {   if (err) {     console.log(err);     ... error handling   }   console.log('Found: ', JSON.stringify(emp));   emp.giveRaise(0.12); // gee, thanks!   session.update(emp, onUpdate); // session is now in scope }; function onUpdate = function(err, emp) {   if (err) {     console.log(err);     ... error handling   } Inserting data Inserting data requires a mapped JavaScript user function (constructor) and a session. Create a variable and persist it: function onSession = function(err, session) {   var data = new Employee(999, 'Mat Keep', 20000000);   session.persist(data, onInsert);   } }; Deleting data To remove data from the database, use the session remove function. You use an instance of the domain object to identify the row you want to remove. Only the key field is relevant. function onSession = function(err, session) {   var key = new Employee(999);   session.remove(Employee, onDelete);   } }; More extensive queries We are working on the implementation of more extensive queries along the lines of the criteria query api. Stay tuned. How to evaluate The MySQL Connector for JavaScript is available for download from labs.mysql.com. Select the build: MySQL-Cluster-NoSQL-Connector-for-Node-js You can also clone the project on GitHub Since it is still early in development, feedback is especially valuable (so don't hesitate to leave comments on this blog, or head to the MySQL Cluster forum). Try it out and see how easy (and fast) it is to integrate MySQL Cluster into your Node.js platforms. You can learn more about other previewed functionality of MySQL Cluster 7.3 here

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  • Dynamically switching the theme in Orchard

    - by Bertrand Le Roy
    It may sound a little puzzling at first, but in Orchard CMS, more than one theme can be active at any given time. The reason for that is that we have an extensibility point that allows a module (or a theme) to participate in the choice of the theme to use, for each request. The motivation for building the theme engine this way was to enable developers to switch themes based on arbitrary criteria, such as user preferences or the user agent (if you want to serve a mobile theme for phones for example). The choice is made between the active themes, which is why there is a difference between the default theme and the active themes. In order to have a say in the choice of the theme, all you have to do is implement IThemeSelector. That interface is quite simple as it only has one method, GetTheme, that takes the current RequestContext and returns a ThemeSelectorResult or null if the implementation of the interface does not want to participate in the current request (we'll see an example in a moment). ThemeSelectorResult itself is just a ThemeName string property and an integer Priority. We're using a priority so that an arbitrary number of implementations of IThemeSelector can contribute to the choice of a theme. If you look for existing implementations of the interface in Orchard, you'll find four: AdminThemeSelector: selects the TheAdmin theme with a very high priority (100) if the current request is for a page that is part of the admin. Otherwise, null is returned, which enables other implementations to choose the theme. PreviewThemeSelector: selects the preview theme if there is one, with a high priority (90), and null otherwise. This enables administrators to view the site under a different theme while everybody else continues to see the current default theme. SiteThemeSelector: this is the implementation that is doing what you expect most of the time, which is to get the current theme from site settings and set it with a priority of –5. SafeModeThemeSelector: this is the fallback implementation, which should almost never win. It sets the theme as the safe mode theme, which has no style and just uses the default templates for everything. The priority is very low (-100). While this extensibility mechanism is great to have, I wanted to bring that level of choice into the hands of the site administrator rather than just developers. In order to achieve that, I built the Vandelay Theme Picker module. The module provides administration UI to create rules for theme selection. It provides its own extensibility point (the IThemeSelectionRule interface) and one implementation of a rule: UserAgentThemeSelectorRule. This rule gets the current user agent from the context and tries to match it with a regular expression that the administrator can configure in the admin UI. You can for example configure a rule with a regular expression that matches IE6 and serve a different subtheme where the stylesheet has been tweaked for such an antique browser. Another possible configuration is to detect mobile devices from their agent string and serve the mobile theme. All those operations can be done with this module entirely from the admin UI, without writing a line of code. The module also offers the administrator the opportunity to inject a link into the front-end in a specific zone and with a specific position that enables the user to switch to the default theme if he wishes to. This is especially useful for sites that use a mobile theme but still want to allow users to use the full desktop site. While the module is nice and flexible, it may be overkill. On my own personal blog, I have only two active themes: the desktop theme and the mobile theme. I'm fine with going into code to change the criteria on which to switch the theme, so I'm not using my own Theme Picker module. Instead, I made the mobile theme a theme with code (in other words there is a csproj file in the theme). The project includes a single C# file, my MobileThemeSelector for which the code is the following: public class MobileThemeSelector : IThemeSelector { private static readonly Regex _Msie678 = new Regex(@"^Mozilla\/4\.0 \(compatible; MSIE [678]" + @"\.0; Windows NT \d\.\d(.*)\)$", RegexOptions.IgnoreCase); private ThemeSelectorResult _requestCache; private bool _requestCached; public ThemeSelectorResult GetTheme(RequestContext context) { if (_requestCached) return _requestCache; _requestCached = true; var userAgent = context.HttpContext.Request.UserAgent; if (userAgent.IndexOf("phone", StringComparison.OrdinalIgnoreCase) != -1 || _Msie678.IsMatch(userAgent) || userAgent.IndexOf("windows live writer", StringComparison.OrdinalIgnoreCase) != -1) { _requestCache = new ThemeSelectorResult { Priority = 10, ThemeName = "VuLuMobile" }; } return _requestCache; } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } The theme selector selects the current theme for Internet Explorer versions 6 to 8, for phones, and for Windows Live Writer (so that the theme that is used when I write posts is as simple as possible). What's interesting here is that it's the theme that selects itself here, based on its own criteria. This should give you a good panorama of what's possible in terms of dynamic theme selection in Orchard. I hope you find some fun uses for it. As usual, I can't wait to see what you're going to come up with…

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  • Oracle Services for Oracle Engineered Systems

    - by Bandari Huang
    ACS(Advanced Customer Support) for Engineered Systems Oracle Solution Support Center Oracle Advanced Monitoring and Resolution ACS for Exadata Oracle Exadata Start-Up Pack Exadata Disk Swap Service Exadata Re-rack Service ACS for Exalogic Oracle Exalogic Start-Up Pack ACS for SuperCluster Oracle SPARC SuperCluster Start-Up Pack ACS for Exalytics Oracle Exalytics Start-Up Pack ACS for BDA(Big Data Appliance) ACS for ODA(Oracle Database Appliance) ACS for ZSA(ZFS Storage Appliance) ACS for ZBA(ZFS Backup Appliance) OCS(Oracle Consulting Services) for Engineered Systems Oracle Expert Services for Oracle Engineered Systems Oracle Consulting Virtualization Services  OCS for Exadata Oracle Exadata Architecture Service Oracle Exadata Architecture Transition Service Oracle Exadata Implementation Service Oracle Expert Services for SAP on Oracle Exadata Oracle Exadata Roadmap Service OCS for Exalogic Oracle Exalogic Architecture Service Oracle Exalogic Implementation Service  

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  • Grant Showplan : MS SQL Server 2005

    SQL version applied to: 2005 Grant Showplan The SHOWPLAN permission only governs who can run the various SET SHOWPLAN statements. There is no impact on performance of this. And with some of the SHOWPLAN statement in effect, the statement(s) is not executed and goes through compilation phase only.  read moreBy Sachin DiwakerDid you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • PTLQueue : a scalable bounded-capacity MPMC queue

    - by Dave
    Title: Fast concurrent MPMC queue -- I've used the following concurrent queue algorithm enough that it warrants a blog entry. I'll sketch out the design of a fast and scalable multiple-producer multiple-consumer (MPSC) concurrent queue called PTLQueue. The queue has bounded capacity and is implemented via a circular array. Bounded capacity can be a useful property if there's a mismatch between producer rates and consumer rates where an unbounded queue might otherwise result in excessive memory consumption by virtue of the container nodes that -- in some queue implementations -- are used to hold values. A bounded-capacity queue can provide flow control between components. Beware, however, that bounded collections can also result in resource deadlock if abused. The put() and take() operators are partial and wait for the collection to become non-full or non-empty, respectively. Put() and take() do not allocate memory, and are not vulnerable to the ABA pathologies. The PTLQueue algorithm can be implemented equally well in C/C++ and Java. Partial operators are often more convenient than total methods. In many use cases if the preconditions aren't met, there's nothing else useful the thread can do, so it may as well wait via a partial method. An exception is in the case of work-stealing queues where a thief might scan a set of queues from which it could potentially steal. Total methods return ASAP with a success-failure indication. (It's tempting to describe a queue or API as blocking or non-blocking instead of partial or total, but non-blocking is already an overloaded concurrency term. Perhaps waiting/non-waiting or patient/impatient might be better terms). It's also trivial to construct partial operators by busy-waiting via total operators, but such constructs may be less efficient than an operator explicitly and intentionally designed to wait. A PTLQueue instance contains an array of slots, where each slot has volatile Turn and MailBox fields. The array has power-of-two length allowing mod/div operations to be replaced by masking. We assume sensible padding and alignment to reduce the impact of false sharing. (On x86 I recommend 128-byte alignment and padding because of the adjacent-sector prefetch facility). Each queue also has PutCursor and TakeCursor cursor variables, each of which should be sequestered as the sole occupant of a cache line or sector. You can opt to use 64-bit integers if concerned about wrap-around aliasing in the cursor variables. Put(null) is considered illegal, but the caller or implementation can easily check for and convert null to a distinguished non-null proxy value if null happens to be a value you'd like to pass. Take() will accordingly convert the proxy value back to null. An advantage of PTLQueue is that you can use atomic fetch-and-increment for the partial methods. We initialize each slot at index I with (Turn=I, MailBox=null). Both cursors are initially 0. All shared variables are considered "volatile" and atomics such as CAS and AtomicFetchAndIncrement are presumed to have bidirectional fence semantics. Finally T is the templated type. I've sketched out a total tryTake() method below that allows the caller to poll the queue. tryPut() has an analogous construction. Zebra stripping : alternating row colors for nice-looking code listings. See also google code "prettify" : https://code.google.com/p/google-code-prettify/ Prettify is a javascript module that yields the HTML/CSS/JS equivalent of pretty-print. -- pre:nth-child(odd) { background-color:#ff0000; } pre:nth-child(even) { background-color:#0000ff; } border-left: 11px solid #ccc; margin: 1.7em 0 1.7em 0.3em; background-color:#BFB; font-size:12px; line-height:65%; " // PTLQueue : Put(v) : // producer : partial method - waits as necessary assert v != null assert Mask = 1 && (Mask & (Mask+1)) == 0 // Document invariants // doorway step // Obtain a sequence number -- ticket // As a practical concern the ticket value is temporally unique // The ticket also identifies and selects a slot auto tkt = AtomicFetchIncrement (&PutCursor, 1) slot * s = &Slots[tkt & Mask] // waiting phase : // wait for slot's generation to match the tkt value assigned to this put() invocation. // The "generation" is implicitly encoded as the upper bits in the cursor // above those used to specify the index : tkt div (Mask+1) // The generation serves as an epoch number to identify a cohort of threads // accessing disjoint slots while s-Turn != tkt : Pause assert s-MailBox == null s-MailBox = v // deposit and pass message Take() : // consumer : partial method - waits as necessary auto tkt = AtomicFetchIncrement (&TakeCursor,1) slot * s = &Slots[tkt & Mask] // 2-stage waiting : // First wait for turn for our generation // Acquire exclusive "take" access to slot's MailBox field // Then wait for the slot to become occupied while s-Turn != tkt : Pause // Concurrency in this section of code is now reduced to just 1 producer thread // vs 1 consumer thread. // For a given queue and slot, there will be most one Take() operation running // in this section. // Consumer waits for producer to arrive and make slot non-empty // Extract message; clear mailbox; advance Turn indicator // We have an obvious happens-before relation : // Put(m) happens-before corresponding Take() that returns that same "m" for T v = s-MailBox if v != null : s-MailBox = null ST-ST barrier s-Turn = tkt + Mask + 1 // unlock slot to admit next producer and consumer return v Pause tryTake() : // total method - returns ASAP with failure indication for auto tkt = TakeCursor slot * s = &Slots[tkt & Mask] if s-Turn != tkt : return null T v = s-MailBox // presumptive return value if v == null : return null // ratify tkt and v values and commit by advancing cursor if CAS (&TakeCursor, tkt, tkt+1) != tkt : continue s-MailBox = null ST-ST barrier s-Turn = tkt + Mask + 1 return v The basic idea derives from the Partitioned Ticket Lock "PTL" (US20120240126-A1) and the MultiLane Concurrent Bag (US8689237). The latter is essentially a circular ring-buffer where the elements themselves are queues or concurrent collections. You can think of the PTLQueue as a partitioned ticket lock "PTL" augmented to pass values from lock to unlock via the slots. Alternatively, you could conceptualize of PTLQueue as a degenerate MultiLane bag where each slot or "lane" consists of a simple single-word MailBox instead of a general queue. Each lane in PTLQueue also has a private Turn field which acts like the Turn (Grant) variables found in PTL. Turn enforces strict FIFO ordering and restricts concurrency on the slot mailbox field to at most one simultaneous put() and take() operation. PTL uses a single "ticket" variable and per-slot Turn (grant) fields while MultiLane has distinct PutCursor and TakeCursor cursors and abstract per-slot sub-queues. Both PTL and MultiLane advance their cursor and ticket variables with atomic fetch-and-increment. PTLQueue borrows from both PTL and MultiLane and has distinct put and take cursors and per-slot Turn fields. Instead of a per-slot queues, PTLQueue uses a simple single-word MailBox field. PutCursor and TakeCursor act like a pair of ticket locks, conferring "put" and "take" access to a given slot. PutCursor, for instance, assigns an incoming put() request to a slot and serves as a PTL "Ticket" to acquire "put" permission to that slot's MailBox field. To better explain the operation of PTLQueue we deconstruct the operation of put() and take() as follows. Put() first increments PutCursor obtaining a new unique ticket. That ticket value also identifies a slot. Put() next waits for that slot's Turn field to match that ticket value. This is tantamount to using a PTL to acquire "put" permission on the slot's MailBox field. Finally, having obtained exclusive "put" permission on the slot, put() stores the message value into the slot's MailBox. Take() similarly advances TakeCursor, identifying a slot, and then acquires and secures "take" permission on a slot by waiting for Turn. Take() then waits for the slot's MailBox to become non-empty, extracts the message, and clears MailBox. Finally, take() advances the slot's Turn field, which releases both "put" and "take" access to the slot's MailBox. Note the asymmetry : put() acquires "put" access to the slot, but take() releases that lock. At any given time, for a given slot in a PTLQueue, at most one thread has "put" access and at most one thread has "take" access. This restricts concurrency from general MPMC to 1-vs-1. We have 2 ticket locks -- one for put() and one for take() -- each with its own "ticket" variable in the form of the corresponding cursor, but they share a single "Grant" egress variable in the form of the slot's Turn variable. Advancing the PutCursor, for instance, serves two purposes. First, we obtain a unique ticket which identifies a slot. Second, incrementing the cursor is the doorway protocol step to acquire the per-slot mutual exclusion "put" lock. The cursors and operations to increment those cursors serve double-duty : slot-selection and ticket assignment for locking the slot's MailBox field. At any given time a slot MailBox field can be in one of the following states: empty with no pending operations -- neutral state; empty with one or more waiting take() operations pending -- deficit; occupied with no pending operations; occupied with one or more waiting put() operations -- surplus; empty with a pending put() or pending put() and take() operations -- transitional; or occupied with a pending take() or pending put() and take() operations -- transitional. The partial put() and take() operators can be implemented with an atomic fetch-and-increment operation, which may confer a performance advantage over a CAS-based loop. In addition we have independent PutCursor and TakeCursor cursors. Critically, a put() operation modifies PutCursor but does not access the TakeCursor and a take() operation modifies the TakeCursor cursor but does not access the PutCursor. This acts to reduce coherence traffic relative to some other queue designs. It's worth noting that slow threads or obstruction in one slot (or "lane") does not impede or obstruct operations in other slots -- this gives us some degree of obstruction isolation. PTLQueue is not lock-free, however. The implementation above is expressed with polite busy-waiting (Pause) but it's trivial to implement per-slot parking and unparking to deschedule waiting threads. It's also easy to convert the queue to a more general deque by replacing the PutCursor and TakeCursor cursors with Left/Front and Right/Back cursors that can move either direction. Specifically, to push and pop from the "left" side of the deque we would decrement and increment the Left cursor, respectively, and to push and pop from the "right" side of the deque we would increment and decrement the Right cursor, respectively. We used a variation of PTLQueue for message passing in our recent OPODIS 2013 paper. ul { list-style:none; padding-left:0; padding:0; margin:0; margin-left:0; } ul#myTagID { padding: 0px; margin: 0px; list-style:none; margin-left:0;} -- -- There's quite a bit of related literature in this area. I'll call out a few relevant references: Wilson's NYU Courant Institute UltraComputer dissertation from 1988 is classic and the canonical starting point : Operating System Data Structures for Shared-Memory MIMD Machines with Fetch-and-Add. Regarding provenance and priority, I think PTLQueue or queues effectively equivalent to PTLQueue have been independently rediscovered a number of times. See CB-Queue and BNPBV, below, for instance. But Wilson's dissertation anticipates the basic idea and seems to predate all the others. Gottlieb et al : Basic Techniques for the Efficient Coordination of Very Large Numbers of Cooperating Sequential Processors Orozco et al : CB-Queue in Toward high-throughput algorithms on many-core architectures which appeared in TACO 2012. Meneghin et al : BNPVB family in Performance evaluation of inter-thread communication mechanisms on multicore/multithreaded architecture Dmitry Vyukov : bounded MPMC queue (highly recommended) Alex Otenko : US8607249 (highly related). John Mellor-Crummey : Concurrent queues: Practical fetch-and-phi algorithms. Technical Report 229, Department of Computer Science, University of Rochester Thomasson : FIFO Distributed Bakery Algorithm (very similar to PTLQueue). Scott and Scherer : Dual Data Structures I'll propose an optimization left as an exercise for the reader. Say we wanted to reduce memory usage by eliminating inter-slot padding. Such padding is usually "dark" memory and otherwise unused and wasted. But eliminating the padding leaves us at risk of increased false sharing. Furthermore lets say it was usually the case that the PutCursor and TakeCursor were numerically close to each other. (That's true in some use cases). We might still reduce false sharing by incrementing the cursors by some value other than 1 that is not trivially small and is coprime with the number of slots. Alternatively, we might increment the cursor by one and mask as usual, resulting in a logical index. We then use that logical index value to index into a permutation table, yielding an effective index for use in the slot array. The permutation table would be constructed so that nearby logical indices would map to more distant effective indices. (Open question: what should that permutation look like? Possibly some perversion of a Gray code or De Bruijn sequence might be suitable). As an aside, say we need to busy-wait for some condition as follows : "while C == 0 : Pause". Lets say that C is usually non-zero, so we typically don't wait. But when C happens to be 0 we'll have to spin for some period, possibly brief. We can arrange for the code to be more machine-friendly with respect to the branch predictors by transforming the loop into : "if C == 0 : for { Pause; if C != 0 : break; }". Critically, we want to restructure the loop so there's one branch that controls entry and another that controls loop exit. A concern is that your compiler or JIT might be clever enough to transform this back to "while C == 0 : Pause". You can sometimes avoid this by inserting a call to a some type of very cheap "opaque" method that the compiler can't elide or reorder. On Solaris, for instance, you could use :"if C == 0 : { gethrtime(); for { Pause; if C != 0 : break; }}". It's worth noting the obvious duality between locks and queues. If you have strict FIFO lock implementation with local spinning and succession by direct handoff such as MCS or CLH,then you can usually transform that lock into a queue. Hidden commentary and annotations - invisible : * And of course there's a well-known duality between queues and locks, but I'll leave that topic for another blog post. * Compare and contrast : PTLQ vs PTL and MultiLane * Equivalent : Turn; seq; sequence; pos; position; ticket * Put = Lock; Deposit Take = identify and reserve slot; wait; extract & clear; unlock * conceptualize : Distinct PutLock and TakeLock implemented as ticket lock or PTL Distinct arrival cursors but share per-slot "Turn" variable provides exclusive role-based access to slot's mailbox field put() acquires exclusive access to a slot for purposes of "deposit" assigns slot round-robin and then acquires deposit access rights/perms to that slot take() acquires exclusive access to slot for purposes of "withdrawal" assigns slot round-robin and then acquires withdrawal access rights/perms to that slot At any given time, only one thread can have withdrawal access to a slot at any given time, only one thread can have deposit access to a slot Permissible for T1 to have deposit access and T2 to simultaneously have withdrawal access * round-robin for the purposes of; role-based; access mode; access role mailslot; mailbox; allocate/assign/identify slot rights; permission; license; access permission; * PTL/Ticket hybrid Asymmetric usage ; owner oblivious lock-unlock pairing K-exclusion add Grant cursor pass message m from lock to unlock via Slots[] array Cursor performs 2 functions : + PTL ticket + Assigns request to slot in round-robin fashion Deconstruct protocol : explication put() : allocate slot in round-robin fashion acquire PTL for "put" access store message into slot associated with PTL index take() : Acquire PTL for "take" access // doorway step seq = fetchAdd (&Grant, 1) s = &Slots[seq & Mask] // waiting phase while s-Turn != seq : pause Extract : wait for s-mailbox to be full v = s-mailbox s-mailbox = null Release PTL for both "put" and "take" access s-Turn = seq + Mask + 1 * Slot round-robin assignment and lock "doorway" protocol leverage the same cursor and FetchAdd operation on that cursor FetchAdd (&Cursor,1) + round-robin slot assignment and dispersal + PTL/ticket lock "doorway" step waiting phase is via "Turn" field in slot * PTLQueue uses 2 cursors -- put and take. Acquire "put" access to slot via PTL-like lock Acquire "take" access to slot via PTL-like lock 2 locks : put and take -- at most one thread can access slot's mailbox Both locks use same "turn" field Like multilane : 2 cursors : put and take slot is simple 1-capacity mailbox instead of queue Borrow per-slot turn/grant from PTL Provides strict FIFO Lock slot : put-vs-put take-vs-take at most one put accesses slot at any one time at most one put accesses take at any one time reduction to 1-vs-1 instead of N-vs-M concurrency Per slot locks for put/take Release put/take by advancing turn * is instrumental in ... * P-V Semaphore vs lock vs K-exclusion * See also : FastQueues-excerpt.java dice-etc/queue-mpmc-bounded-blocking-circular-xadd/ * PTLQueue is the same as PTLQB - identical * Expedient return; ASAP; prompt; immediately * Lamport's Bakery algorithm : doorway step then waiting phase Threads arriving at doorway obtain a unique ticket number Threads enter in ticket order * In the terminology of Reed and Kanodia a ticket lock corresponds to the busy-wait implementation of a semaphore using an eventcount and a sequencer It can also be thought of as an optimization of Lamport's bakery lock was designed for fault-tolerance rather than performance Instead of spinning on the release counter, processors using a bakery lock repeatedly examine the tickets of their peers --

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  • Unlock the full potential of Oracle Retail with Oracle Retail Consulting

    - by user801960
    In this video, Maria Porretta, Engagement Director, introduces Oracle Retail Consulting which supports Oracle Retail customers by unlocking the potential of the software solutions they are utilising. Oracle Retail Consulting comprises of a global team of over 300 consultants, 70 of which are EMEA based. 90% of the team have a retail background in either IT or business, ensuring true industry expertise and maximum business benefit. Oracle Retail Consulting offers two primary streams of service; design authority which looks at analysis and design to ensure a guided process through to implementation, and delivery ownership which runs throughout the implementation process. Further information is available on our website regarding Oracle Retail Consulting.

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  • Microsoft Introduces WebMatrix

    - by Rick Strahl
    originally published in CoDe Magazine Editorial Microsoft recently released the first CTP of a new development environment called WebMatrix, which along with some of its supporting technologies are squarely aimed at making the Microsoft Web Platform more approachable for first-time developers and hobbyists. But in the process, it also provides some updated technologies that can make life easier for existing .NET developers. Let’s face it: ASP.NET development isn’t exactly trivial unless you already have a fair bit of familiarity with sophisticated development practices. Stick a non-developer in front of Visual Studio .NET or even the Visual Web Developer Express edition and it’s not likely that the person in front of the screen will be very productive or feel inspired. Yet other technologies like PHP and even classic ASP did provide the ability for non-developers and hobbyists to become reasonably proficient in creating basic web content quickly and efficiently. WebMatrix appears to be Microsoft’s attempt to bring back some of that simplicity with a number of technologies and tools. The key is to provide a friendly and fully self-contained development environment that provides all the tools needed to build an application in one place, as well as tools that allow publishing of content and databases easily to the web server. WebMatrix is made up of several components and technologies: IIS Developer Express IIS Developer Express is a new, self-contained development web server that is fully compatible with IIS 7.5 and based on the same codebase that IIS 7.5 uses. This new development server replaces the much less compatible Cassini web server that’s been used in Visual Studio and the Express editions. IIS Express addresses a few shortcomings of the Cassini server such as the inability to serve custom ISAPI extensions (i.e., things like PHP or ASP classic for example), as well as not supporting advanced authentication. IIS Developer Express provides most of the IIS 7.5 feature set providing much better compatibility between development and live deployment scenarios. SQL Server Compact 4.0 Database access is a key component for most web-driven applications, but on the Microsoft stack this has mostly meant you have to use SQL Server or SQL Server Express. SQL Server Compact is not new-it’s been around for a few years, but it’s been severely hobbled in the past by terrible tool support and the inability to support more than a single connection in Microsoft’s attempt to avoid losing SQL Server licensing. The new release of SQL Server Compact 4.0 supports multiple connections and you can run it in ASP.NET web applications simply by installing an assembly into the bin folder of the web application. In effect, you don’t have to install a special system configuration to run SQL Compact as it is a drop-in database engine: Copy the small assembly into your BIN folder (or from the GAC if installed fully), create a connection string against a local file-based database file, and then start firing SQL requests. Additionally WebMatrix includes nice tools to edit the database tables and files, along with tools to easily upsize (and hopefully downsize in the future) to full SQL Server. This is a big win, pending compatibility and performance limits. In my simple testing the data engine performed well enough for small data sets. This is not only useful for web applications, but also for desktop applications for which a fully installed SQL engine like SQL Server would be overkill. Having a local data store in those applications that can potentially be accessed by multiple users is a welcome feature. ASP.NET Razor View Engine What? Yet another native ASP.NET view engine? We already have Web Forms and various different flavors of using that view engine with Web Forms and MVC. Do we really need another? Microsoft thinks so, and Razor is an implementation of a lightweight, script-only view engine. Unlike the Web Forms view engine, Razor works only with inline code, snippets, and markup; therefore, it is more in line with current thinking of what a view engine should represent. There’s no support for a “page model” or any of the other Web Forms features of the full-page framework, but just a lightweight scripting engine that works with plain markup plus embedded expressions and code. The markup syntax for Razor is geared for minimal typing, plus some progressive detection of where a script block/expression starts and ends. This results in a much leaner syntax than the typical ASP.NET Web Forms alligator (<% %>) tags. Razor uses the @ sign plus standard C# (or Visual Basic) block syntax to delineate code snippets and expressions. Here’s a very simple example of what Razor markup looks like along with some comment annotations: <!DOCTYPE html> <html>     <head>         <title></title>     </head>     <body>     <h1>Razor Test</h1>          <!-- simple expressions -->     @DateTime.Now     <hr />     <!-- method expressions -->     @DateTime.Now.ToString("T")          <!-- code blocks -->     @{         List<string> names = new List<string>();         names.Add("Rick");         names.Add("Markus");         names.Add("Claudio");         names.Add("Kevin");     }          <!-- structured block statements -->     <ul>     @foreach(string name in names){             <li>@name</li>     }     </ul>           <!-- Conditional code -->        @if(true) {                        <!-- Literal Text embedding in code -->        <text>         true        </text>;    }    else    {        <!-- Literal Text embedding in code -->       <text>       false       </text>;    }    </body> </html> Like the Web Forms view engine, Razor parses pages into code, and then executes that run-time compiled code. Effectively a “page” becomes a code file with markup becoming literal text written into the Response stream, code snippets becoming raw code, and expressions being written out with Response.Write(). The code generated from Razor doesn’t look much different from similar Web Forms code that only uses script tags; so although the syntax may look different, the operational model is fairly similar to the Web Forms engine minus the overhead of the large Page object model. However, there are differences: -Razor pages are based on a new base class, Microsoft.WebPages.WebPage, which is hosted in the Microsoft.WebPages assembly that houses all the Razor engine parsing and processing logic. Browsing through the assembly (in the generated ASP.NET Temporary Files folder or GAC) will give you a good idea of the functionality that Razor provides. If you look closely, a lot of the feature set matches ASP.NET MVC’s view implementation as well as many of the helper classes found in MVC. It’s not hard to guess the motivation for this sort of view engine: For beginning developers the simple markup syntax is easier to work with, although you obviously still need to have some understanding of the .NET Framework in order to create dynamic content. The syntax is easier to read and grok and much shorter to type than ASP.NET alligator tags (<% %>) and also easier to understand aesthetically what’s happening in the markup code. Razor also is a better fit for Microsoft’s vision of ASP.NET MVC: It’s a new view engine without the baggage of Web Forms attached to it. The engine is more lightweight since it doesn’t carry all the features and object model of Web Forms with it and it can be instantiated directly outside of the HTTP environment, which has been rather tricky to do for the Web Forms view engine. Having a standalone script parser is a huge win for other applications as well – it makes it much easier to create script or meta driven output generators for many types of applications from code/screen generators, to simple form letters to data merging applications with user customizability. For me personally this is very useful side effect and who knows maybe Microsoft will actually standardize they’re scripting engines (die T4 die!) on this engine. Razor also better fits the “view-based” approach where the view is supposed to be mostly a visual representation that doesn’t hold much, if any, code. While you can still use code, the code you do write has to be self-contained. Overall I wouldn’t be surprised if Razor will become the new standard view engine for MVC in the future – and in fact there have been announcements recently that Razor will become the default script engine in ASP.NET MVC 3.0. Razor can also be used in existing Web Forms and MVC applications, although that’s not working currently unless you manually configure the script mappings and add the appropriate assemblies. It’s possible to do it, but it’s probably better to wait until Microsoft releases official support for Razor scripts in Visual Studio. Once that happens, you can simply drop .cshtml and .vbhtml pages into an existing ASP.NET project and they will work side by side with classic ASP.NET pages. WebMatrix Development Environment To tie all of these three technologies together, Microsoft is shipping WebMatrix with an integrated development environment. An integrated gallery manager makes it easy to download and load existing projects, and then extend them with custom functionality. It seems to be a prominent goal to provide community-oriented content that can act as a starting point, be it via a custom templates or a complete standard application. The IDE includes a project manager that works with a single project and provides an integrated IDE/editor for editing the .cshtml and .vbhtml pages. A run button allows you to quickly run pages in the project manager in a variety of browsers. There’s no debugging support for code at this time. Note that Razor pages don’t require explicit compilation, so making a change, saving, and then refreshing your page in the browser is all that’s needed to see changes while testing an application locally. It’s essentially using the auto-compiling Web Project that was introduced with .NET 2.0. All code is compiled during run time into dynamically created assemblies in the ASP.NET temp folder. WebMatrix also has PHP Editing support with syntax highlighting. You can load various PHP-based applications from the WebMatrix Web Gallery directly into the IDE. Most of the Web Gallery applications are ready to install and run without further configuration, with Wizards taking you through installation of tools, dependencies, and configuration of the database as needed. WebMatrix leverages the Web Platform installer to pull the pieces down from websites in a tight integration of tools that worked nicely for the four or five applications I tried this out on. Click a couple of check boxes and fill in a few simple configuration options and you end up with a running application that’s ready to be customized. Nice! You can easily deploy completed applications via WebDeploy (to an IIS server) or FTP directly from within the development environment. The deploy tool also can handle automatically uploading and installing the database and all related assemblies required, making deployment a simple one-click install step. Simplified Database Access The IDE contains a database editor that can edit SQL Compact and SQL Server databases. There is also a Database helper class that facilitates database access by providing easy-to-use, high-level query execution and iteration methods: @{       var db = Database.OpenFile("FirstApp.sdf");     string sql = "select * from customers where Id > @0"; } <ul> @foreach(var row in db.Query(sql,1)){         <li>@row.FirstName @row.LastName</li> } </ul> The query function takes a SQL statement plus any number of positional (@0,@1 etc.) SQL parameters by simple values. The result is returned as a collection of rows which in turn have a row object with dynamic properties for each of the columns giving easy (though untyped) access to each of the fields. Likewise Execute and ExecuteNonQuery allow execution of more complex queries using similar parameter passing schemes. Note these queries use string-based queries rather than LINQ or Entity Framework’s strongly typed LINQ queries. While this may seem like a step back, it’s also in line with the expectations of non .NET script developers who are quite used to writing and using SQL strings in code rather than using OR/M frameworks. The only question is why was something not included from the beginning in .NET and Microsoft made developers build custom implementations of these basic building blocks. The implementation looks a lot like a DataTable-style data access mechanism, but to be fair, this is a common approach in scripting languages. This type of syntax that uses simple, static, data object methods to perform simple data tasks with one line of code are common in scripting languages and are a good match for folks working in PHP/Python, etc. Seems like Microsoft has taken great advantage of .NET 4.0’s dynamic typing to provide this sort of interface for row iteration where each row has properties for each field. FWIW, all the examples demonstrate using local SQL Compact files - I was unable to get a SQL Server connection string to work with the Database class (the connection string wasn’t accepted). However, since the code in the page is still plain old .NET, you can easily use standard ADO.NET code or even LINQ or Entity Framework models that are created outside of WebMatrix in separate assemblies as required. The good the bad the obnoxious - It’s still .NET The beauty (or curse depending on how you look at it :)) of Razor and the compilation model is that, behind it all, it’s still .NET. Although the syntax may look foreign, it’s still all .NET behind the scenes. You can easily access existing tools, helpers, and utilities simply by adding them to the project as references or to the bin folder. Razor automatically recognizes any assembly reference from assemblies in the bin folder. In the default configuration, Microsoft provides a host of helper functions in a Microsoft.WebPages assembly (check it out in the ASP.NET temp folder for your application), which includes a host of HTML Helpers. If you’ve used ASP.NET MVC before, a lot of the helpers should look familiar. Documentation at the moment is sketchy-there’s a very rough API reference you can check out here: http://www.asp.net/webmatrix/tutorials/asp-net-web-pages-api-reference Who needs WebMatrix? Uhm… good Question Clearly Microsoft is trying hard to create an environment with WebMatrix that is easy to use for newbie developers. The goal seems to be simplicity in providing a minimal development environment and an easy-to-use script engine/language that makes it easy to get started with. There’s also some focus on community features that can be used as starting points, such as Web Gallery applications and templates. The community features in particular are very nice and something that would be nice to eventually see in Visual Studio as well. The question is whether this is too little too late. Developers who have been clamoring for a simpler development environment on the .NET stack have mostly left for other simpler platforms like PHP or Python which are catering to the down and dirty developer. Microsoft will be hard pressed to win those folks-and other hardcore PHP developers-back. Regardless of how much you dress up a script engine fronted by the .NET Framework, it’s still the .NET Framework and all the complexity that drives it. While .NET is a fine solution in its breadth and features once you get a basic handle on the core features, the bar of entry to being productive with the .NET Framework is still pretty high. The MVC style helpers Microsoft provides are a good step in the right direction, but I suspect it’s not enough to shield new developers from having to delve much deeper into the Framework to get even basic applications built. Razor and its helpers is trying to make .NET more accessible but the reality is that in order to do useful stuff that goes beyond the handful of simple helpers you still are going to have to write some C# or VB or other .NET code. If the target is a hobby/amateur/non-programmer the learning curve isn’t made any easier by WebMatrix it’s just been shifted a tad bit further along in your development endeavor when you run out of canned components that are supplied either by Microsoft or the community. The database helpers are interesting and actually I’ve heard a lot of discussion from various developers who’ve been resisting .NET for a really long time perking up at the prospect of easier data access in .NET than the ridiculous amount of code it takes to do even simple data access with raw ADO.NET. It seems sad that such a simple concept and implementation should trigger this sort of response (especially since it’s practically trivial to create helpers like these or pick them up from countless libraries available), but there it is. It also shows that there are plenty of developers out there who are more interested in ‘getting stuff done’ easily than necessarily following the latest and greatest practices which are overkill for many development scenarios. Sometimes it seems that all of .NET is focused on the big life changing issues of development, rather than the bread and butter scenarios that many developers are interested in to get their work accomplished. And that in the end may be WebMatrix’s main raison d'être: To bring some focus back at Microsoft that simpler and more high level solutions are actually needed to appeal to the non-high end developers as well as providing the necessary tools for the high end developers who want to follow the latest and greatest trends. The current version of WebMatrix hits many sweet spots, but it also feels like it has a long way to go before it really can be a tool that a beginning developer or an accomplished developer can feel comfortable with. Although there are some really good ideas in the environment (like the gallery for downloading apps and components) which would be a great addition for Visual Studio as well, the rest of the development environment just feels like crippleware with required functionality missing especially debugging and Intellisense, but also general editor support. It’s not clear whether these are because the product is still in an early alpha release or whether it’s simply designed that way to be a really limited development environment. While simple can be good, nobody wants to feel left out when it comes to necessary tool support and WebMatrix just has that left out feeling to it. If anything WebMatrix’s technology pieces (which are really independent of the WebMatrix product) are what are interesting to developers in general. The compact IIS implementation is a nice improvement for development scenarios and SQL Compact 4.0 seems to address a lot of concerns that people have had and have complained about for some time with previous SQL Compact implementations. By far the most interesting and useful technology though seems to be the Razor view engine for its light weight implementation and it’s decoupling from the ASP.NET/HTTP pipeline to provide a standalone scripting/view engine that is pluggable. The first winner of this is going to be ASP.NET MVC which can now have a cleaner view model that isn’t inconsistent due to the baggage of non-implemented WebForms features that don’t work in MVC. But I expect that Razor will end up in many other applications as a scripting and code generation engine eventually. Visual Studio integration for Razor is currently missing, but is promised for a later release. The ASP.NET MVC team has already mentioned that Razor will eventually become the default MVC view engine, which will guarantee continued growth and development of this tool along those lines. And the Razor engine and support tools actually inherit many of the features that MVC pioneered, so there’s some synergy flowing both ways between Razor and MVC. As an existing ASP.NET developer who’s already familiar with Visual Studio and ASP.NET development, the WebMatrix IDE doesn’t give you anything that you want. The tools provided are minimal and provide nothing that you can’t get in Visual Studio today, except the minimal Razor syntax highlighting, so there’s little need to take a step back. With Visual Studio integration coming later there’s little reason to look at WebMatrix for tooling. It’s good to see that Microsoft is giving some thought about the ease of use of .NET as a platform For so many years, we’ve been piling on more and more new features without trying to take a step back and see how complicated the development/configuration/deployment process has become. Sometimes it’s good to take a step - or several steps - back and take another look and realize just how far we’ve come. WebMatrix is one of those reminders and one that likely will result in some positive changes on the platform as a whole. © Rick Strahl, West Wind Technologies, 2005-2010Posted in ASP.NET   IIS7  

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  • Best practice to propagate preferences of application

    - by Shebuka
    What is your approach with propagation to all classes/windows of preferences/settings of your application? Do you share the preference_manager class to all classes/windows who need it or you make variables in each classes/windows and update them manually each time setting are changed? Currently I have a PreferencesInterface class that hold all preferences and is responsible to default all values with a dedicated method called on create and when needed, all values are public, so non getters/setters, also it have virtual SavePreferences/LoadPreferences methods. Then I have PreferencesManager that extends from PreferencesInterface and is responsible for actually implementation of SavePreferences/LoadPreferences. I've made this basically for cross-platform so that every platform can have a different implementation of actual storage (registry, ini, plist, xml, whatever).

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