Search Results

Search found 14031 results on 562 pages for 'language concepts'.

Page 514/562 | < Previous Page | 510 511 512 513 514 515 516 517 518 519 520 521  | Next Page >

  • Day 2 - Game Design Documentation

    - by dapostolov
    So yesterday I didn't cut any code for my game but I was able to do a tiny bit of research on the XNA Game Development Technology and the communities out there and do you know what? I feel I'm a bit closer to my goal. The bad news is today I didn't cut code either. However, not all is lost because I wanted to get my ideas on paper and today I just did that.  Today, I began to jot down notes about the game and how I felt the visual elements would interact with each other. Unlike my workplace, my personal level of documentation is nothing more than a task list or a mind map of my ideas; it helps me streamline my solutions quiet effectively and circumvent the long process of articulating each thought to the n-th degree. I truly dislike documentation (because I have an extremely hard time articulating my thought and solutions); however, because I tend to do a really good job with documentation I tend to get stuck writing the buggers. But as a generalist remark: 'No Developer likes documentation.' For now let's stick with my basic notes and call this post a living document. Here are my notes, fresh, from after watching the new first episode of Merlin second season! Actually, a quick recommendation to anyone who is reading this (if anyone is): I truly recommend you envelope yourself in the medium or task you're trying to tackle. Be one with moment and feel it! For instance: Are you writing a fantasy script / game? What would the music of the genre sound like? For me the Conan the Barbarian soundtrack by Basil Poledouris is frackin awesome. There are many other good CD's out there, which I listen to (some who even use medival instruments, but Conan I keep returning to. It's a creative trigger for me. Ask yourself what would the imagery look like? Time to surf google for artist renditions of fantasy! What would the game feel like? Start playing some of your favorite games that inspire you, be wary though, have some self control and don't let it absorb your time. Anyhow, onto the documentation... Screens, Scenes, and Sprites. Oh My! (groan...) The first thing that came to mind were the screens, I thought the following would suffice: Menu Screen Character Customisation Screen Loading Screen? Battle Ground The Menu Screen Ok. So, the thought here is when the game loads a huge title is displayed: Wizard Wars. The player is prompted with 3 menu items: 1 Player Game, 2 Player Game, and Exit. Since I'm targetting the PC platform, as a non-networked game to start, I picture myself running my mouse over each menu option and the visual element of the menu item changes, along with a sound to indicate that I am over a curent menu item. And as I move my mouse away, it changes back, and possibly an exit mouse sound. Maybe on the screen somewhere is a brazier alit with a magical tome open right beside it, OR, maybe the tome is the menu! I hear the menu music as mellow, not obtrusive or piercing. On a menu item select, a confirmation sound bellows to indicate the players selection. The Esc key will always return me to the previous screens or desktop. The menu screen must feel...dark, like a really important ritual is about to happen and thus the music should build up. 1 Player Game - > Customize Character(s) 2 Player Game - > Customize Character(s) Exit - > Back to Windows Notes: So the first thing I pick up here are a couple things: First and foremost, my artistic abilities suck crap, so I may have to hire an artist (now that i've said that, lets get techy) graphical objects will be positioned within a scene on each screen / window. Menu items will be represented grapically, possibly animated, and have sound / animation effects triggered by user input or a time line. I have an animated scene involving a brazier or fire on a stick IF I was to move this game to the xbox, I'd have to track which menu item is currently selected (unless I do a mouse pointer type thing.) WindowObject has a scene A Scene has many GameObjects GameObject has a position graphic or animation MenuObject is a GameObject which has a mouse in, mouse out, and click event which either does something graphically (animation), does something with sound, or moves to another screen.  Character Customisation Screen With either the 1 or 2 player option selected, both selections will come to this screen; a wizard requires a name, powers, and vestements of course! Player one will configure his character first and then player two. I considered a split screen for PC but to have two people fighting over a keyboard would probably suck. For XBox, a split screen could work; maybe when I get into the networking portion (phase 2 blog?) of this game I will remove the 2 player option for PC and provide only multiplayer and I will leave 2 player for xbox...hmm... Anyhow...I picture the creation process as follows: Name: (textbox / keyboard entry) - for xbox, this would have to be different. Robe Color: (color box, or something) Stats: Speed, Oomph, and Health. (as sliders) 1 as minimum and 10 as maximum. Ok, Back, and Cancel buttons / options. Each stat has a benefit which are listed below. The idea is the player decides if he wants his wizard to run fast, be a tank and ... hit with a purse.Regardless, the player will have a pool of 12 points to use. Ideally, A balanced wizard will have 5 in each attribute. Spells? The only spell of choice is a ball of fire which comes without question. The music and screen should still feel like a ritual. The Character Speed Basically, how fast your character moves and casts. Oomph (Best Monster Truck Voice): PURE POWAH!!! The damage output of your fireball. Health How much damage you can take. Notes: I realise the game dynamics may sound uninteresting at the moment; but I think after a couple releases, we could have some other grand ideas such as: saved profiles, gold to upgrade arsenal of spells, talents, etc...but for now...a vanilla fireball thrower mage will suffice for this experiment. OK. So... a MenuObject  may need to be loosely coupled to allow future items such as networking? may be a button? a CharacterObject has a name speed oomph health and a funky robe color. cap on the three stats (1-10) an arsenal of 1 spell (possibly could expand this) The Loading Screen As is. The Battleground Screen For now, I'm keeping the screen as max resolution for the PC. The screen isn't going to move or even be a split screen. I'm not aiming high here because I want to see what level of change is involved when new features / concepts are added to game content. I'm interested to find out if we could apply techniques such as MVC or MVVM to this type of development or is it too tightly coupled? This reminds me when when my best friend and I were brainstorming our game idea (this is going back a while...1994, 6?) and he cringed at the thought of bringing business technology into games, especially when I suggested a database to store character information and COM / DCOM as the medium, but it seems I wasn't far off (reflecting); just like his implementation of a xml "config file" for dynamic direct-x menus back before .net in 1999...anyhow...i digress... The Battle One screen, two characters lobing balls of fire at each other...It doesn't get better than that. Every so often a scroll appears...and the fireballs bounce off walls, or the wizard has rapid fire, or even scrolls of healing! The scroll options are endless. Two bars at the top, each the color of the wizard (with their name beside the bar) indicate how much health they have. Possibly the appearance of the scrolls means the battle is taking too long? I'm thinking 1 player controls: up, down, left, right and space to fire the button. Or even possibly, mouse click and shift - mouse button to fire a spell in the direction they are facing. Two player controls: a, s, d, f and space AND arrows (up, down, left, right) and Del key or Crtl. The game ends when a player has 0 health and a dialog box appears asking for a rematch / reconfigure / exit. Health goes down when a fireball (friendly or not), connects with a wizard. When a wizard connects with a scroll, a countdown clock / icon appears near the health bar and the wizard begins to glow. For the most part, a wizard can have only scroll 1 effect on him at a time. Notes: Ok, there's alot to cover here. a CharacterObject is a GameObject it travels at a set velocity it travels in a direction it has sounds (walking, running, casting, impact, dying, laughing, whistling, other?) it has animations (walking, running, casting, impact, dying, laughing, idle, other?) it has a lifespan (determined by health) it is alive or dead it has a position a ScrollObject is a GameObject it carries a transferance of points "damage" (or healing, bad scroll effect?) (determinde by caster) it carries a transferance of "other" it is stationary it has a sound on impact it has a stationary animation it has an impact animation / or transfers an impact animation it has a fade animation? it has a lifespan (determined by game) it is alive or dead it has a position a WallObject is a GameObject it has a sound on fireball impact? it is a still image / stationary it has an impact animation / or transfers an impact animation it is dead it has a position A FireBall is a GameObject it carries a transferance of poinst "damage" (or healing, bad scroll effect?) (determinde by caster) it travels at a set velocity it travels in a direction it has a sound it has a travel animation it has an impact animation / or transfers an impact animation it has a fade animation? it has a lifespan (determined by caster) it is alive or dead it has a position As I look at this, I can see some common attributes in each object that I can carry up to the GameObject. I think I'm going to end the documentation here, it's taken me a bit of time to type this all out, tomorrow. I'll load up my IDE and my paint studio to get some good old fashioned cowboy hacking going!   D.

    Read the article

  • CodePlex Daily Summary for Thursday, February 18, 2010

    CodePlex Daily Summary for Thursday, February 18, 2010New ProjectsASP .NET MVC CMS (Content Management System): Open source Content management system based on ASP.NET MVC platform.AutoFolders: AutoFolders package for Umbraco CMS This package auto creates folder structures for new and existing pages. The folders structures can be date bas...AutoPex: This project combines CCI with Pex by allowing the developer to run Pex on methods based on differences between two assemblies. Canvas VSDOC Intellisense: JavaScript VSDOC documentation for HTML5 Canvas element and 2d Context interface.CSUDH: California State University, Domguiez Hills Game projectsD-AMPS: System for Analysis of Microelectronic and Photonic StructuresDispX: Disease PredictorEmployee Info Starter Kit: This is a starter kit, which includes very simple user requirements, where we can create, read, update and delete (crud) the employee info of a com...Enhanced Discussion Board for SharePoint: Provide later... publishing project to share with Malaysians firstFlowPad: Flowpad is a light, fast and easy to use flow diagram editor. It helps you quickly pour your algorithms from your mind to 'paper'. It is written us...Henge3D Physics Library for XNA: Henge3D is a 3D physics library written in C# for XNA. It is implemented entirely in managed code and is compatible with the XBOX 360.Hybrid Windows Service: Abstracted design pattern for running a windows service interactively. Implemented as a base class to replace ServiceBase it will automatically pro...Image Cropper datatype for Umbraco: Stand alone version of the Image Cropper datatype in Umbraco. Listinator: A social wishlist application done in asp.net MVCMicrosoft Dynamics Ax User Group (AXUG) Code Repository: The goal of this project is to make it easier for customers of Microsoft Dynamics Ax to be able to share relevant source code. Code base should inc...Mobil Trials: Sebuah game sederhana yang dibuat di atas Silverlight 3.0 dengan bantuan Physics Helper 3.0 Demo : http://gameagam.co.cc/default.html Mirror link...NavigateTo Providers: This project is a collection of NavigateTo providers for Visual Studio 2010. NExtLib: NExtLib is a general-purpose extension library for .NET, which adds some useful features and addresses some alleged omissions.Nom - .NET object-mapper: Nom is a light-weight, storage-type agnostic persistence framework which is intended to provide an abstraction over both relational and non-relatio...Numerical Methods on Silverlight: Numerical Methods, Silverlight, Math Parser, Simple, EulerOpenGLViewController for Visual Basic .NET 2008: A single class in pure VB.NET code to create and control an OpenGL window by calling opengl32.dll directly without use of additional wrapper librar...RestaurantMIS: RestaurantMIS is a simple Restaurant management system developed in Visual C# 2008 with Chinese language.SmartKonnect: <project name>A WPF application for windows with shoutcast, twitter, facebook and etc.SSRS Excel file Sheet rename: SSRS wont support renaming excel reports sheet rename. This program support to generate the report and change the excel sheet nameSWENTRIZ.NET: SWENTRIZ.NET allows to build graphics of implicit functions via .NET functionality.TFT: Tropical forecast tracker is a web application. It will measure the error of the National Hurricane Center's forecast as compared to the actual tr...WCF Dynamic Client Proxy: A WCF Dynamic Client Proxy so you don't have to inherit from ClientBase all the time. The proxy also has fault tolerance so you don't have to dispo...Web.Config Role Provider: Stores ASP.NET Roles in web.config. Easy to set up and deploy. Works great for simple websites with authentication. The projects includes support ...WPF Line of Business App: Example WPF patterns for line of business applications. Includes navigation, animation, and visualization.YuBiS Framework: Silverlight and WF based a workflow RAD framework. New ReleasesASP .NET MVC CMS (Content Management System): AtomicCms 1.0: This is the first public release of AtomicCms. To get more information about this content management system, visit website http://atomiccms.com/Blogsprajeesh.Blogspot samples: Designing Modular Smart Clients using CAL: This whitepaper provides architectural guidance for designing and implementing enterprise WPF/ silverlight client applications based on the Composi...DB Ghost Build Tools: 1.0.2: Made a change to the datetime format per dewee.DotNetNuke® Community Edition: 05.02.03: Major HighlightsFixed the issue where LinkClick.aspx links were incorrect for child portals Fixed the issue with the PayPal URL settings. Fixed...Employee Directory webpart for sharepoint 2007 user profiles: Employee Directory Source V2.0: Features: 1. Displays a complete list of all Active Directory profiles imported by the SSP into SharePoint 2007. 2. Displays the following fields ...Enhanced Discussion Board for SharePoint: Alpha Release: Meant for those who attended my presentation. Not cleaned upESPEHA: Espeha 9 PFR: Some small issues fixedFlowPad: FlowPad 0.1: FlowPad 0.1 build. Run it to get fammiliar with major concepts of easy diagramming :)Fluent Ribbon Control Suite: Fluent Ribbon Control Suite BETA2: Fluent Ribbon Control Suite BETA2 Includes: - Fluent.dll (with .pdb and .xml) - Demo Application - Samples - Foundation (Tabs, Groups, Contextu...Henge3D Physics Library for XNA: Henge3D Source (2010-02): This is the initial 2010-02 release.Highlight: Highlight 2.5: This release is primarily a maintenance release of the library and is functionally equivalent to version 2.3 that was released in 2004.Magiq: Magiq 0.3.0: Magiq 0.3.0 contains: Magiq-to-objects: Full support to Linq-to-objects Magiq-to-sql: Full support to Linq-to-sql New features: Plugin model Bu...Microsoft Points Converter: Pre-Alpha ClickOnce Installer v0.03: This release builds on the 0.02 release by adding more thorough validation checks for the amount to convert from as well as adding several currency...Mobil Trials: Mobil Trials Source Code: Sebuah game sederhana yang dibuat di atas Silverlight 3.0 dengan bantuan Physics Helper 3.0 Game ini masih perlu dikembangkan lebih jauh lagi! Si...Numerical Methods on Silverlight: Numerical Methods on Silverlight 1.00: This a new version of Numerical Methods on Silverlight.OAuthLib: OAuthLib (1.5.0.0): Changed point is as next. 7037 Fix spell miss of RequestFactoryMedthodSharePoint Outlook Connector: Version 1.0.1.0: Now it supports simply attaching SharePoint documents feature.Sharpy: Sharpy 1.1 Alpha: This is the second Sharpy release. Only a single change has been made - the foreach function now uses IEnumerable as a source instead of IList. Th...SkinDroidCreator: SkinDroidCreator ALPHA 1: Primera releaseTan solo carga mapas, ya sea de un zip o de un directorio. Para probarlo se pueden cargar temas Metamorph o temas flasheables, ya se...SkyDrive .Net API Client: SkyDrive .Net API Client 0.8.9: SkyDrive .Net API Client assembly version 0.8.9. Changes/improvements: - Added Web Proxy support - Introduced WebDriveInfo - Introduced DownloadUrl...spikes: Salient.Web.Administration 1.0: WebAdmin is simply the built in ASP.NetWebAdministrationFiles application cleaned up with codebehinds to make customization and refactoring possibl...SSRS Excel file Sheet rename: Change SSRS excel file sheet name: Create stored procedure from the attached file in sql server 2005/2008SWENTRIZ.NET: Approach 1: First approachTortoiseSVN Addin for Visual Studio: TortoiseSVN Addin 1.0.4: Visual Studio 2005 support Custom working root bug fixingTotal Commander SkyDrive File System Plugin (.wfx): Total Commander SkyDrive File System Plugin 0.8.4: Total Commander SkyDrive File System Plugin version 0.8.4. Bug fixes: - Upgraded SkyDriveWebClient to version 0.8.9 Please do not forget to expres...UnOfficial AW Wrapper dot Net: UAWW.Net 0.1.5.85 Béta 2: Fixed and Added SomethingVr30 OS: Space Brick Break 1.1: A brick breaker. ADD Level 3, 4, 5Web.Config Role Provider: First release: Three downloads are available: A compiled dll ready to use. The schema to enable intellisense The complete source (zipped)WI Assistant: WI Assistant 2.1: This release improves the work item selection functionality. These selection methods are now supported (some require at least one item selected): ...WI Assistant: WI Assistant 2.2: Improved error handling and fix for linking several times in a row. DISCLAIMER: While I have tested this app on my TFS Server, by downloading and...ZipStorer - A Pure C# Class to Store Files in Zip: ZipStorer 2.30: Added stream-oriented methods Improved support for ePUB & Open Container Format specification (OCF) Automatic switch from Deflate to Store algo...Most Popular ProjectsRawrDotNetNuke® Community EditionASP.NET Ajax LibraryFacebook Developer ToolkitWindows 7 USB/DVD Download ToolWSPBuilder (SharePoint WSP tool)Virtual Router - Wifi Hot Spot for Windows 7 / 2008 R2Json.NETPerformance Analysis of Logs (PAL) ToolQuickGraph, Graph Data Structures And Algorithms for .NetMost Active ProjectsDinnerNow.netRawrSharpyBlogEngine.NETSimple SavantjQuery Library for SharePoint Web ServicesNB_Store - Free DotNetNuke Ecommerce Catalog Modulepatterns & practices – Enterprise LibraryPHPExcelFacebook Developer Toolkit

    Read the article

  • SQLAuthority Book Review – DBA Survivor: Become a Rock Star DBA

    - by pinaldave
    DBA Survivor: Become a Rock Star DBA – Thomas LaRock Link to Amazon Link to Flipkart First of all, I thank all my readers when I wrote that I could not get this book in any local book stores, because they offered me to send a copy of this good book. A very special mention goes to Sripada and Jayesh for they gave so much effort in finding my home address and sending me the hard copy. Before, I did not have the copy of the book, but now I have two of it already! It surprises me how my readers were able to find my home address, which I have not publicly shared. Quick Review: This is indeed a one easy-to-read and fun book. We all work day and night with technology yet we should not forget to show our love and care for our family at home. For our souls that starve for peace and guidance, this one book is the “it” book for all the technology enthusiasts. Though this book was specifically written for DBAs, the reach is not limited to DBAs only because the lessons incorporated in it actually applies to all. This is one of the most motivating technical books I have read. Detailed Review: Let us go over a few questions first: Who wants to be as famous as rockstars in the field of Database Administration? How can one learn what it takes to become a top notch software developer? If you are a beginner in your field, how will you go to next level? Your boss may be very kind or like Dilbert’s Boss, what will you do? How do you keep growing when Eco-system around you does not support you? You are almost at top but there is someone else at the TOP, what do you do and how do you avoid office politics? As a database developer what should be your basic responsibility? and many more… I was able to completely read book in one sitting and I loved it. Before I continue with my opinion, I want to echo the opinion of Kevin Kline who has written the Forward of the book. He has truly suggested that “You hold in your hands a collection of insights and wisdom on the topic of database administration gained through many years of hard-won experience, long nights of study, and direct mentorship under some of the industry’s most talented database professionals and information technology (IT) experts.” Today, IT field is getting bigger and better, while talking about terabytes of the database becomes “more” normal every single day. The gods and demigods of database professionals are taking care of these large scale databases and are carefully maintaining them. In this world, there are only a few beginnings on the first step. There are many experts in different technology fields who are asked to address the issues with databases. There is YOU and ME, who is just new to this work. So we ask ourselves WHERE to begin and HOW to begin. We adore and follow the religion of our rockstars, but oftentimes we really have no idea about their background and their struggles. Every rockstar has his success story which needs to be digested before learning his tricks and tips. This book starts with the same note and teaches the two most important lessons for anybody who wants to be a DBA Rockstar –  to focus on their single goal of learning and to excel the technology. The story starts with three simple guidelines – Get Prepared, Get Trained, Get Certified. Once a person learns the skills, and then, it would be about time that he needs to enrich or to improve those skills you have learned. I am sure that the right opportunity will come finding themselves and they will not have to go run behind it. However, the real challenge for any person is the first day or first week. A new employee, no matter how much experienced he is, sometimes has no clue about what should one do at new job. Chapter 2 and chapter 3 precisely talk about what one should do as soon as the new job begins. It is also written with keeping the fact in focus that each job can be very much different but there are few infrastructure setups and programming concepts are the same. Learning basics of database was really interesting. I like to focus on the roots of any technology. It is important to understand the structure of the database before suggesting what indexes needs to be created, the same way this book covers the most essential knowledge one must learn by most database developers. I think the title of the fourth chapter is my favorite sentence in this book. I can see that I will be saying this again and again in the future – “A Development Server Is a Production Server to a Developer“. I have worked in the software industry for almost 8 years now and I have seen so many developers sitting on their chairs and waiting for instructions from their lead about how to improve the code or what to do the next. When I talk to them, I suggest that the experiment with their server and try various techniques. I think they all should understand that for them, a development server is their production server and needs to pay proper attention to the code from the beginning. There should be NO any inappropriate code from the beginning. One has to fully focus and give their best, if they are not sure they should ask but should do something and stay active. Chapter 5 and 6 talks about two essential skills for any developer and database administration – what are the ethics of developers when they are working with production server and how to support software which is running on the production server. I have met many people who know the theory by heart but when put in front of keyboard they do not know where to start. The first thing they do opening the browser and searching online, instead of opening SQL Server Management Studio. This can very well happen to anybody who is experienced as well. Chapter 5 and 6 addresses that situation as well includes the handy scripts which can solve almost all the basic trouble shooting issues. “Where’s the Buffet?” By far, this is the best chapter in this book. If you have ever met me, you would know that I love food. I think after reading this chapter, I felt Thomas has written this just keeping me in mind. I think there will be many other people who feel the same way, too. Even my wife who read this chapter thought this was specifically written for me. I will not talk any more about this chapter as this is one must read chapter. And of course this is about real ‘FOOD‘. I am an SQL Server Trainer and Consultant and I totally agree with the point made in the chapter 8 of this book. Yes, it says here that what is necessary to train employees and people. Millions of dollars worth the labor is continuously done in the world which has faults and incorrect. Once something goes wrong, very expensive consultant comes in and fixes the problem. This whole cycle which can be stopped and improved if proper training is done. There is plenty of free trainings available as well, if one cannot afford paid training. “Connect. Learn. Share” – I think this is a great summary and bird’s eye view of this book. Networking is the key. Everything which is discussed in this book can be taken to next level if one properly uses this tips and continuously grow with it. Connecting with others, helping learn each other and building the good knowledge sharing environment should be the goal of everyone. Before I end the review I want to share a real experience. I have personally met one DBA who has worked in a single department in a company for so long that when he was put in a different department in his company due to closing that department, he could not adjust and quit the job despite the same people and company around him. Adjusting in the new environment gets much tougher as one person gets more and more experienced. This book precisely addresses the same issue along with their solutions. I just cannot stop comparing the book with my personal journey. I found so many things which are coincidently in the book is written as how we developer and DBA think. I must express special thanks to Thomas for taking time in his personal life and write this book for us. This book is indeed a book for everybody who wants to grow healthy in the tough and competitive environment. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority Book Review, SQLAuthority News, SQLServer, T SQL, Technology

    Read the article

  • Adventures in MVVM &ndash; My ViewModel Base

    - by Brian Genisio's House Of Bilz
    More Adventures in MVVM First, I’d like to say: THIS IS NOT A NEW MVVM FRAMEWORK. I tend to believe that MVVM support code should be specific to the system you are building and the developers working on it.  I have yet to find an MVVM framework that does everything I want it to without doing too much.  Don’t get me wrong… there are some good frameworks out there.  I just like to pick and choose things that make sense for me.  I’d also like to add that some of these features only work in WPF.  As of Silveright 4, they don’t support binding to dynamic properties, so some of the capabilities are lost. That being said, I want to share my ViewModel base class with the world.  I have had several conversations with people about the problems I have solved using this ViewModel base.  A while back, I posted an article about some experiments with a “Rails Inspired ViewModel”.  What followed from those ideas was a ViewModel base class that I take with me and use in my projects.  It has a lot of features, all designed to reduce the friction in writing view models. I have put the code out on Codeplex under the project: ViewModelSupport. Finally, this article focuses on the ViewModel and only glosses over the View and the Model.  Without all three, you don’t have MVVM.  But this base class is for the ViewModel, so that is what I am focusing on. Features: Automatic Command Plumbing Property Change Notification Strongly Typed Property Getter/Setters Dynamic Properties Default Property values Derived Properties Automatic Method Execution Command CanExecute Change Notification Design-Time Detection What about Silverlight? Automatic Command Plumbing This feature takes the plumbing out of creating commands.  The common pattern for commands in a ViewModel is to have an Execute method as well as an optional CanExecute method.  To plumb that together, you create an ICommand Property, and set it in the constructor like so: Before public class AutomaticCommandViewModel { public AutomaticCommandViewModel() { MyCommand = new DelegateCommand(Execute_MyCommand, CanExecute_MyCommand); } public void Execute_MyCommand() { // Do something } public bool CanExecute_MyCommand() { // Are we in a state to do something? return true; } public DelegateCommand MyCommand { get; private set; } } With the base class, this plumbing is automatic and the property (MyCommand of type ICommand) is created for you.  The base class uses the convention that methods be prefixed with Execute_ and CanExecute_ in order to be plumbed into commands with the property name after the prefix.  You are left to be expressive with your behavior without the plumbing.  If you are wondering how CanExecuteChanged is raised, see the later section “Command CanExecute Change Notification”. After public class AutomaticCommandViewModel : ViewModelBase { public void Execute_MyCommand() { // Do something } public bool CanExecute_MyCommand() { // Are we in a state to do something? return true; } }   Property Change Notification One thing that always kills me when implementing ViewModels is how to make properties that notify when they change (via the INotifyPropertyChanged interface).  There have been many attempts to make this more automatic.  My base class includes one option.  There are others, but I feel like this works best for me. The common pattern (without my base class) is to create a private backing store for the variable and specify a getter that returns the private field.  The setter will set the private field and fire an event that notifies the change, only if the value has changed. Before public class PropertyHelpersViewModel : INotifyPropertyChanged { private string text; public string Text { get { return text; } set { if(text != value) { text = value; RaisePropertyChanged("Text"); } } } protected void RaisePropertyChanged(string propertyName) { var handlers = PropertyChanged; if(handlers != null) handlers(this, new PropertyChangedEventArgs(propertyName)); } public event PropertyChangedEventHandler PropertyChanged; } This way of defining properties is error-prone and tedious.  Too much plumbing.  My base class eliminates much of that plumbing with the same functionality: After public class PropertyHelpersViewModel : ViewModelBase { public string Text { get { return Get<string>("Text"); } set { Set("Text", value);} } }   Strongly Typed Property Getters/Setters It turns out that we can do better than that.  We are using a strongly typed language where the use of “Magic Strings” is often frowned upon.  Lets make the names in the getters and setters strongly typed: A refinement public class PropertyHelpersViewModel : ViewModelBase { public string Text { get { return Get(() => Text); } set { Set(() => Text, value); } } }   Dynamic Properties In C# 4.0, we have the ability to program statically OR dynamically.  This base class lets us leverage the powerful dynamic capabilities in our ecosystem. (This is how the automatic commands are implemented, BTW)  By calling Set(“Foo”, 1), you have now created a dynamic property called Foo.  It can be bound against like any static property.  The opportunities are endless.  One great way to exploit this behavior is if you have a customizable view engine with templates that bind to properties defined by the user.  The base class just needs to create the dynamic properties at runtime from information in the model, and the custom template can bind even though the static properties do not exist. All dynamic properties still benefit from the notifiable capabilities that static properties do. For any nay-sayers out there that don’t like using the dynamic features of C#, just remember this: the act of binding the View to a ViewModel is dynamic already.  Why not exploit it?  Get over it :) Just declare the property dynamically public class DynamicPropertyViewModel : ViewModelBase { public DynamicPropertyViewModel() { Set("Foo", "Bar"); } } Then reference it normally <TextBlock Text="{Binding Foo}" />   Default Property Values The Get() method also allows for default properties to be set.  Don’t set them in the constructor.  Set them in the property and keep the related code together: public string Text { get { return Get(() => Text, "This is the default value"); } set { Set(() => Text, value);} }   Derived Properties This is something I blogged about a while back in more detail.  This feature came from the chaining of property notifications when one property affects the results of another, like this: Before public class DependantPropertiesViewModel : ViewModelBase { public double Score { get { return Get(() => Score); } set { Set(() => Score, value); RaisePropertyChanged("Percentage"); RaisePropertyChanged("Output"); } } public int Percentage { get { return (int)(100 * Score); } } public string Output { get { return "You scored " + Percentage + "%."; } } } The problem is: The setter for Score has to be responsible for notifying the world that Percentage and Output have also changed.  This, to me, is backwards.    It certainly violates the “Single Responsibility Principle.” I have been bitten in the rear more than once by problems created from code like this.  What we really want to do is invert the dependency.  Let the Percentage property declare that it changes when the Score Property changes. After public class DependantPropertiesViewModel : ViewModelBase { public double Score { get { return Get(() => Score); } set { Set(() => Score, value); } } [DependsUpon("Score")] public int Percentage { get { return (int)(100 * Score); } } [DependsUpon("Percentage")] public string Output { get { return "You scored " + Percentage + "%."; } } }   Automatic Method Execution This one is extremely similar to the previous, but it deals with method execution as opposed to property.  When you want to execute a method triggered by property changes, let the method declare the dependency instead of the other way around. Before public class DependantMethodsViewModel : ViewModelBase { public double Score { get { return Get(() => Score); } set { Set(() => Score, value); WhenScoreChanges(); } } public void WhenScoreChanges() { // Handle this case } } After public class DependantMethodsViewModel : ViewModelBase { public double Score { get { return Get(() => Score); } set { Set(() => Score, value); } } [DependsUpon("Score")] public void WhenScoreChanges() { // Handle this case } }   Command CanExecute Change Notification Back to Commands.  One of the responsibilities of commands that implement ICommand – it must fire an event declaring that CanExecute() needs to be re-evaluated.  I wanted to wait until we got past a few concepts before explaining this behavior.  You can use the same mechanism here to fire off the change.  In the CanExecute_ method, declare the property that it depends upon.  When that property changes, the command will fire a CanExecuteChanged event, telling the View to re-evaluate the state of the command.  The View will make appropriate adjustments, like disabling the button. DependsUpon works on CanExecute methods as well public class CanExecuteViewModel : ViewModelBase { public void Execute_MakeLower() { Output = Input.ToLower(); } [DependsUpon("Input")] public bool CanExecute_MakeLower() { return !string.IsNullOrWhiteSpace(Input); } public string Input { get { return Get(() => Input); } set { Set(() => Input, value);} } public string Output { get { return Get(() => Output); } set { Set(() => Output, value); } } }   Design-Time Detection If you want to add design-time data to your ViewModel, the base class has a property that lets you ask if you are in the designer.  You can then set some default values that let your designer see what things might look like in runtime. Use the IsInDesignMode property public DependantPropertiesViewModel() { if(IsInDesignMode) { Score = .5; } }   What About Silverlight? Some of the features in this base class only work in WPF.  As of version 4, Silverlight does not support binding to dynamic properties.  This, in my opinion, is a HUGE limitation.  Not only does it keep you from using many of the features in this ViewModel, it also keeps you from binding to ViewModels designed in IronRuby.  Does this mean that the base class will not work in Silverlight?  No.  Many of the features outlined in this article WILL work.  All of the property abstractions are functional, as long as you refer to them statically in the View.  This, of course, means that the automatic command hook-up doesn’t work in Silverlight.  You need to plumb it to a static property in order for the Silverlight View to bind to it.  Can I has a dynamic property in SL5?     Good to go? So, that concludes the feature explanation of my ViewModel base class.  Feel free to take it, fork it, whatever.  It is hosted on CodePlex.  When I find other useful additions, I will add them to the public repository.  I use this base class every day.  It is mature, and well tested.  If, however, you find any problems with it, please let me know!  Also, feel free to suggest patches to me via the CodePlex site.  :)

    Read the article

  • C# 4.0: Named And Optional Arguments

    - by Paulo Morgado
    As part of the co-evolution effort of C# and Visual Basic, C# 4.0 introduces Named and Optional Arguments. First of all, let’s clarify what are arguments and parameters: Method definition parameters are the input variables of the method. Method call arguments are the values provided to the method parameters. In fact, the C# Language Specification states the following on §7.5: The argument list (§7.5.1) of a function member invocation provides actual values or variable references for the parameters of the function member. Given the above definitions, we can state that: Parameters have always been named and still are. Parameters have never been optional and still aren’t. Named Arguments Until now, the way the C# compiler matched method call definition arguments with method parameters was by position. The first argument provides the value for the first parameter, the second argument provides the value for the second parameter, and so on and so on, regardless of the name of the parameters. If a parameter was missing a corresponding argument to provide its value, the compiler would emit a compilation error. For this call: Greeting("Mr.", "Morgado", 42); this method: public void Greeting(string title, string name, int age) will receive as parameters: title: “Mr.” name: “Morgado” age: 42 What this new feature allows is to use the names of the parameters to identify the corresponding arguments in the form: name:value Not all arguments in the argument list must be named. However, all named arguments must be at the end of the argument list. The matching between arguments (and the evaluation of its value) and parameters will be done first by name for the named arguments and than by position for the unnamed arguments. This means that, for this method definition: public static void Method(int first, int second, int third) this call declaration: int i = 0; Method(i, third: i++, second: ++i); will have this code generated by the compiler: int i = 0; int CS$0$0000 = i++; int CS$0$0001 = ++i; Method(i, CS$0$0001, CS$0$0000); which will give the method the following parameter values: first: 2 second: 2 third: 0 Notice the variable names. Although invalid being invalid C# identifiers, they are valid .NET identifiers and thus avoiding collision between user written and compiler generated code. Besides allowing to re-order of the argument list, this feature is very useful for auto-documenting the code, for example, when the argument list is very long or not clear, from the call site, what the arguments are. Optional Arguments Parameters can now have default values: public static void Method(int first, int second = 2, int third = 3) Parameters with default values must be the last in the parameter list and its value is used as the value of the parameter if the corresponding argument is missing from the method call declaration. For this call declaration: int i = 0; Method(i, third: ++i); will have this code generated by the compiler: int i = 0; int CS$0$0000 = ++i; Method(i, 2, CS$0$0000); which will give the method the following parameter values: first: 1 second: 2 third: 1 Because, when method parameters have default values, arguments can be omitted from the call declaration, this might seem like method overloading or a good replacement for it, but it isn’t. Although methods like this: public static StreamReader OpenTextFile( string path, Encoding encoding = null, bool detectEncoding = true, int bufferSize = 1024) allow to have its calls written like this: OpenTextFile("foo.txt", Encoding.UTF8); OpenTextFile("foo.txt", Encoding.UTF8, bufferSize: 4096); OpenTextFile( bufferSize: 4096, path: "foo.txt", detectEncoding: false); The complier handles default values like constant fields taking the value and useing it instead of a reference to the value. So, like with constant fields, methods with parameters with default values are exposed publicly (and remember that internal members might be publicly accessible – InternalsVisibleToAttribute). If such methods are publicly accessible and used by another assembly, those values will be hard coded in the calling code and, if the called assembly has its default values changed, they won’t be assumed by already compiled code. At the first glance, I though that using optional arguments for “bad” written code was great, but the ability to write code like that was just pure evil. But than I realized that, since I use private constant fields, it’s OK to use default parameter values on privately accessed methods.

    Read the article

  • CodePlex Daily Summary for Sunday, March 07, 2010

    CodePlex Daily Summary for Sunday, March 07, 2010New ProjectsAlgorithminator: Universal .NET algorithm visualizer, which helps you to illustrate any algorithm, written in any .NET language. Still in development.ALToolkit: Contains a set of handy .NET components/classes. Currently it contains: * A Numeric Text Box (an Extended NumericUpDown) * A Splash Screen base fo...Automaton Home: Automaton is a home automation software built with a n-Tier, MVVM pattern utilzing WCF, EF, WPF, Silverlight and XBAP.Developer Controls: Developer Controls contains various controls to help build applications that can script/write code.Dynamic Reference Manager: Dynamic Reference Manager is a set (more like a small group) of classes and attributes written in C# that allows any .NET program to reference othe...indiologic: Utilities of an IndioNeural Cryptography in F#: This project is my magistracy resulting work. It is intended to be an example of using neural networks in cryptography. Hashing functions are chose...Particle Filter Visualization: Particle Filter Visualization Program for the Intel Science and Engineering FairPólya: Efficient, immutable, polymorphic collections. .Net lacks them, we provide them*. * By we, we mean I; and by efficient, I mean hopefully so.project euler solutions from mhinze: mhinze project euler solutionsSilverlight 4 and WCF multi layer: Silverlight 4 and WCF multi layersqwarea: Project for a browser-based, minimalistic, massively multiplayer strategy game. Part of the "Génie logiciel et Cloud Computing" course of the ENS (...SuperSocket: SuperSocket, a socket application framework can build FTP/SMTP/POP server easilyToast (for ASP.NET MVC): Dynamic, developer & designer friendly content injection, compression and optimization for ASP.NET MVCNew ReleasesALToolkit: ALToolkit 1.0: Binary release of the libraries containing: NumericTextBox SplashScreen Based on the VB.NET code, but that doesn't really matter.Blacklist of Providers: 1.0-Milestone 1: Blacklist of Providers.Milestone 1In this development release implemented - Main interface (Work Item #5453) - Database (Work Item #5523)C# Linear Hash Table: Linear Hash Table b2: Now includes a default constructor, and will throw an exception if capacity is not set to a power of 2 or loadToMaintain is below 1.Composure: CassiniDev-Trunk-40745-VS2010.rc1.NET4: A simple port of the CassiniDev portable web server project for Visual Studio 2010 RC1 built against .NET 4.0. The WCF tests currently fail unless...Developer Controls: DevControls: These are the version 1.0 releases of these controls. Download the individually or all together (in a .zip file). More releases coming soon!Dynamic Reference Manager: DRM Alpha1: This is the first release. I'm calling it Alpha because I intend implementing other functions, but I do not intend changing the way current functio...ESB Toolkit Extensions: Tellago SOA ESB Extenstions v0.3: Windows Installer file that installs Library on a BizTalk ESB 2.0 system. This Install automatically configures the esb.config to use the new compo...GKO Libraries: GKO Libraries 0.1 Alpha: 0.1 AlphaHome Access Plus+: v3.0.3.0: Version 3.0.3.0 Release Change Log: Added Announcement Box Removed script files that aren't needed Fixed & issue in directory path Stylesheet...Icarus Scene Engine: Icarus Scene Engine 1.10.306.840: Icarus Professional, Icarus Player, the supporting software for Icarus Scene Engine, with some included samples, and the start of a tutorial (with ...mavjuz WndLpt: wndlpt-0.2.5: New: Response to 5 LPT inputs "test i 1" New: Reaction to 12 LPT outputs "test q 8" New: Reaction to all LPT pins "test pin 15" New: Syntax: ...Neural Cryptography in F#: Neural Cryptography 0.0.1: The most simple version of this project. It has a neural network that works just like logical AND and a possibility to recreate neural network from...Password Provider: 1.0.3: This release fixes a bug which caused the program to crash when double clicking on a generic item.RoTwee: RoTwee 6.2.0.0: New feature is as next. 16649 Add hashtag for tweet of tune.Now you can tweet your playing tune with hashtag.Visual Studio DSite: Picture Viewer (Visual C++ 2008): This example source code allows you to view any picture you want in the click of a button. All you got to do is click the button and browser via th...WatchersNET CKEditor™ Provider for DotNetNuke: CKEditor Provider 1.8.00: Whats New File Browser: Folders & Files View reworked File Browser: Folders & Files View reworked File Browser: Folders are displayed as TreeVi...WSDLGenerator: WSDLGenerator 0.0.0.4: - replaced CommonLibrary.dll by CommandLineParser.dll - added better support for custom complex typesMost Popular ProjectsMetaSharpSilverlight ToolkitASP.NET Ajax LibraryAll-In-One Code FrameworkWindows 7 USB/DVD Download Toolニコ生アラートWindows Double ExplorerVirtual Router - Wifi Hot Spot for Windows 7 / 2008 R2Caliburn: An Application Framework for WPF and SilverlightArkSwitchMost Active ProjectsUmbraco CMSRawrSDS: Scientific DataSet library and toolsBlogEngine.NETjQuery Library for SharePoint Web Servicespatterns & practices – Enterprise LibraryIonics Isapi Rewrite FilterFarseer Physics EngineFasterflect - A Fast and Simple Reflection APIFluent Assertions

    Read the article

  • Your thoughts on Best Practices for Scientific Computing?

    - by John Smith
    A recent paper by Wilson et al (2014) pointed out 24 Best Practices for scientific programming. It's worth to have a look. I would like to hear opinions about these points from experienced programmers in scientific data analysis. Do you think these advices are helpful and practical? Or are they good only in an ideal world? Wilson G, Aruliah DA, Brown CT, Chue Hong NP, Davis M, Guy RT, Haddock SHD, Huff KD, Mitchell IM, Plumbley MD, Waugh B, White EP, Wilson P (2014) Best Practices for Scientific Computing. PLoS Biol 12:e1001745. http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.1001745 Box 1. Summary of Best Practices Write programs for people, not computers. (a) A program should not require its readers to hold more than a handful of facts in memory at once. (b) Make names consistent, distinctive, and meaningful. (c) Make code style and formatting consistent. Let the computer do the work. (a) Make the computer repeat tasks. (b) Save recent commands in a file for re-use. (c) Use a build tool to automate workflows. Make incremental changes. (a) Work in small steps with frequent feedback and course correction. (b) Use a version control system. (c) Put everything that has been created manually in version control. Don’t repeat yourself (or others). (a) Every piece of data must have a single authoritative representation in the system. (b) Modularize code rather than copying and pasting. (c) Re-use code instead of rewriting it. Plan for mistakes. (a) Add assertions to programs to check their operation. (b) Use an off-the-shelf unit testing library. (c) Turn bugs into test cases. (d) Use a symbolic debugger. Optimize software only after it works correctly. (a) Use a profiler to identify bottlenecks. (b) Write code in the highest-level language possible. Document design and purpose, not mechanics. (a) Document interfaces and reasons, not implementations. (b) Refactor code in preference to explaining how it works. (c) Embed the documentation for a piece of software in that software. Collaborate. (a) Use pre-merge code reviews. (b) Use pair programming when bringing someone new up to speed and when tackling particularly tricky problems. (c) Use an issue tracking tool. I'm relatively new to serious programming for scientific data analysis. When I tried to write code for pilot analyses of some of my data last year, I encountered tremendous amount of bugs both in my code and data. Bugs and errors had been around me all the time, but this time it was somewhat overwhelming. I managed to crunch the numbers at last, but I thought I couldn't put up with this mess any longer. Some actions must be taken. Without a sophisticated guide like the article above, I started to adopt "defensive style" of programming since then. A book titled "The Art of Readable Code" helped me a lot. I deployed meticulous input validations or assertions for every function, renamed a lot of variables and functions for better readability, and extracted many subroutines as reusable functions. Recently, I introduced Git and SourceTree for version control. At the moment, because my co-workers are much more reluctant about these issues, the collaboration practices (8a,b,c) have not been introduced. Actually, as the authors admitted, because all of these practices take some amount of time and effort to introduce, it may be generally hard to persuade your reluctant collaborators to comply them. I think I'm asking your opinions because I still suffer from many bugs despite all my effort on many of these practices. Bug fix may be, or should be, faster than before, but I couldn't really measure the improvement. Moreover, much of my time has been invested on defence, meaning that I haven't actually done much data analysis (offence) these days. Where is the point I should stop at in terms of productivity? I've already deployed: 1a,b,c, 2a, 3a,b,c, 4b,c, 5a,d, 6a,b, 7a,7b I'm about to have a go at: 5b,c Not yet: 2b,c, 4a, 7c, 8a,b,c (I could not really see the advantage of using GNU make (2c) for my purpose. Could anyone tell me how it helps my work with MATLAB?)

    Read the article

  • Rob Blackwell on interoperability and Azure

    - by Eric Nelson
    At QCon in March we had a sample Azure application implemented in both Java and Ruby to demonstrate that the Windows Azure Platform is not just about .NET. The following is an interesting interview with Rob Blackwell, the R&D director of the partner who implemented the application. UK Interoperability Team Interviews Rob Blackwell, R&D Director at Active Web Solutions. Is Microsoft taking interoperability seriously? Yes. In the past, I think Microsoft has, quite rightly come in for criticism, but architects and developers should look at this again. The Interoperability Bridges site (http://www.interoperabilitybridges.com/ ) shows a wide range of projects that allow interoperability from Java, Ruby and PHP for example. The Windows Azure platform has been architected with interoperable APIs in mind. It's straightforward to access the various storage facilities from just about any language or platform. Azure compute is capable of running more than just C# applications! Why is interoperability important to you? My company provides consultancy and bespoke development services. We're a Microsoft Gold Partner, but we live in the real world where companies have a mix of technologies provided by a variety of vendors. When developing an enterprise software solution, you rarely have a completely blank canvas. We often see integration scenarios where we need to exchange data with legacy systems. It's not unusual to see modern Silverlight applications being built on top of Java or Mainframe based back ends. Could you give us some examples of where interoperability has been important for your projects? We developed an innovative Sea Safety system for the RNLI Lifeboats here in the UK. Commercial Fishing is one of the most dangerous professions and we helped developed the MOB Guardian System which uses satellite technology and man overboard devices to raise the alarm when a fisherman gets into trouble. The solution is implemented in .NET running on Windows, but without interoperable standards, it would have been impossible to communicate with the satellite gateway technology. For more information, please see the case study: http://www.microsoft.com/casestudies/Case_Study_Detail.aspx?CaseStudyID=4000005892 More recently, we were asked to build a web site to accompany the QCon 2010 conference in London to help demonstrate and promote interoperability. We built the site using Java and Restlet and hosted it in Windows Azure Compute. The site accepts feedback from visitors and all the data is stored in Windows Azure Storage. We also ported the application to Ruby on Rails for demonstration purposes. Visitors to the stand were surprised that this was even possible. Why should Java developers be interested in Windows Azure? Windows Azure Storage consists of Blobs, Queues and Tables. The storage is scalable, durable, secure and cost-effective. Using the WindowsAzure4j library, it's easy to use, and takes just a few lines of code. If you are writing an application with large data storage requirements, or you want an offsite backup, it makes a lot of sense. Running Java applications in Azure Compute is straightforward with tools like the Tomcat Solution Accelerator (http://code.msdn.microsoft.com/winazuretomcat )and AzureRunMe (http://azurerunme.codeplex.com/ ). The Windows Azure AppFabric Service Bus can also be used to connect heterogeneous systems running on different networks and in different data centres. How can The Service Bus be considered an interoperability solution? I think that the Windows Azure AppFabric Service Bus is one of Microsoft’s best kept secrets. Think of it as “a globally scalable application plumbing kit in the sky”. If you have used Enterprise Service Buses before, you’ll be familiar with the concept. Applications can connect to the service bus to securely exchange data – these can be point to point or multicast links. With the AppFabric Service Bus, the applications can exist anywhere that has access to the Internet and the connections can traverse firewalls. This makes it easy to extend or scale your application or reach out to other networks and technologies. For example, let’s say you have a SQL Server database running on premises and you want to expose the data to a Java application running in the cloud. You could set up a point to point Service Bus connection and use JDBC. Traditionally this would have been difficult or impossible without punching holes in firewalls and compromising security. Rob Blackwell is R&D Director at Active Web Solutions, www.aws.net , a Microsoft Gold Partner specialising in leading edge software solutions. He is an occasional writer and conference speaker and blogs at www.robblackwell.org.uk Related Links: UK Azure Online Community – join today. UK Windows Azure Site Start working with Windows Azure

    Read the article

  • SQL SERVER – Beginning of SQL Server Architecture – Terminology – Guest Post

    - by pinaldave
    SQL Server Architecture is a very deep subject. Covering it in a single post is an almost impossible task. However, this subject is very popular topic among beginners and advanced users.  I have requested my friend Anil Kumar who is expert in SQL Domain to help me write  a simple post about Beginning SQL Server Architecture. As stated earlier this subject is very deep subject and in this first article series he has covered basic terminologies. In future article he will explore the subject further down. Anil Kumar Yadav is Trainer, SQL Domain, Koenig Solutions. Koenig is a premier IT training firm that provides several IT certifications, such as Oracle 11g, Server+, RHCA, SQL Server Training, Prince2 Foundation etc. In this Article we will discuss about MS SQL Server architecture. The major components of SQL Server are: Relational Engine Storage Engine SQL OS Now we will discuss and understand each one of them. 1) Relational Engine: Also called as the query processor, Relational Engine includes the components of SQL Server that determine what your query exactly needs to do and the best way to do it. It manages the execution of queries as it requests data from the storage engine and processes the results returned. Different Tasks of Relational Engine: Query Processing Memory Management Thread and Task Management Buffer Management Distributed Query Processing 2) Storage Engine: Storage Engine is responsible for storage and retrieval of the data on to the storage system (Disk, SAN etc.). to understand more, let’s focus on the following diagram. When we talk about any database in SQL server, there are 2 types of files that are created at the disk level – Data file and Log file. Data file physically stores the data in data pages. Log files that are also known as write ahead logs, are used for storing transactions performed on the database. Let’s understand data file and log file in more details: Data File: Data File stores data in the form of Data Page (8KB) and these data pages are logically organized in extents. Extents: Extents are logical units in the database. They are a combination of 8 data pages i.e. 64 KB forms an extent. Extents can be of two types, Mixed and Uniform. Mixed extents hold different types of pages like index, System, Object data etc. On the other hand, Uniform extents are dedicated to only one type. Pages: As we should know what type of data pages can be stored in SQL Server, below mentioned are some of them: Data Page: It holds the data entered by the user but not the data which is of type text, ntext, nvarchar(max), varchar(max), varbinary(max), image and xml data. Index: It stores the index entries. Text/Image: It stores LOB ( Large Object data) like text, ntext, varchar(max), nvarchar(max),  varbinary(max), image and xml data. GAM & SGAM (Global Allocation Map & Shared Global Allocation Map): They are used for saving information related to the allocation of extents. PFS (Page Free Space): Information related to page allocation and unused space available on pages. IAM (Index Allocation Map): Information pertaining to extents that are used by a table or index per allocation unit. BCM (Bulk Changed Map): Keeps information about the extents changed in a Bulk Operation. DCM (Differential Change Map): This is the information of extents that have modified since the last BACKUP DATABASE statement as per allocation unit. Log File: It also known as write ahead log. It stores modification to the database (DML and DDL). Sufficient information is logged to be able to: Roll back transactions if requested Recover the database in case of failure Write Ahead Logging is used to create log entries Transaction logs are written in chronological order in a circular way Truncation policy for logs is based on the recovery model SQL OS: This lies between the host machine (Windows OS) and SQL Server. All the activities performed on database engine are taken care of by SQL OS. It is a highly configurable operating system with powerful API (application programming interface), enabling automatic locality and advanced parallelism. SQL OS provides various operating system services, such as memory management deals with buffer pool, log buffer and deadlock detection using the blocking and locking structure. Other services include exception handling, hosting for external components like Common Language Runtime, CLR etc. I guess this brief article gives you an idea about the various terminologies used related to SQL Server Architecture. In future articles we will explore them further. Guest Author  The author of the article is Anil Kumar Yadav is Trainer, SQL Domain, Koenig Solutions. Koenig is a premier IT training firm that provides several IT certifications, such as Oracle 11g, Server+, RHCA, SQL Server Training, Prince2 Foundation etc. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Security, SQL Server, SQL Tips and Tricks, SQL Training, T SQL, Technology

    Read the article

  • top Tweets SOA Partner Community – August 2012

    - by JuergenKress
    Send your tweets @soacommunity #soacommunity and follow us at http://twitter.com/soacommunity Lucas Jellema ?Published an article about organizing Fusion Middleware Administration: http://technology.amis.nl/2012/07/31/organizing-fusion-middleware-administration-in-a-smart-and-frugal-way … - many organizations are struggling with this. ServiceTechSymposium Countdown to the Early Bird Registration Discount deadline. Only 4 days left! http://ow.ly/cBCiv demed ?Good chatting w Bob Rhubart, Thomas Erl & Tim Hall on SOA & Cloud Symposium https://blogs.oracle.com/archbeat/entry/podcast_show_notes_thomas_erl … @soaschool @OTNArchBeat -- CU in London! SOA Community top Tweets SOA Partner Community July 2012 - are you one of them? If yes please rt! https://soacommunity.wordpress.com/2012/07/30/top-tweets-soa-partner-community-july-2012/ … #soacommunity SOA Community ?Are You a facebook member - do You follow http://www.facebook.com/soacommunity ? #soacommunity #soa SOA Community ?SOA 24/7 - Home Page: http://soa247.com/#.UBJsN8n3kyk.twitter … #soacommunity OracleBlogs ?Handling Large Payloads in SOA Suite 11g http://ow.ly/1lFAih OracleBlogs ?SOA Community Newsletter July 2012 http://ow.ly/1lFx6s OTNArchBeat Podcast Show Notes: Thomas Erl on SOA, Cloud, and Service Technology http://bit.ly/OOHTUJ SOA Community SOA Community Newsletter July 2012 http://wp.me/p10C8u-s7 OTNArchBeat ?OTN ArchBeat Podcast: Thomas Erl on SOA, Cloud, and Service Technology - Part 1 http://pub.vitrue.com/fMti OProcessAccel ?Just released! White Paper: Oracle Process Accelerators Best Practices http://www.oracle.com/technetwork/middleware/bpm/learnmore/processaccelbestpracticeswhitepaper-1708910.pdf … OTNArchBeat ?SOA, Cloud, and Service Technologies - Part 1 of 4 - A conversation with SOA, Cloud, and Service Technology Symposiu... http://ow.ly/1lDyAK OracleBlogs ?SOA Suite 11g PS5 Bundled Patch 3 (11.1.1.6.3) http://ow.ly/1lCW1S Simon Haslam My write-up of the virtues of the #ukoug App Server & Middleware SIG http://bit.ly/LMWdfY What's important to you for our next meeting? SOA Community SOA Partner Community Survey 2012 http://wp.me/p10C8u-qY Simone Geib ?RT @jswaroop: #Oracle positioned in the Leader's quadrant - Gartner Magic Quadrants for Application Infrastructure (SOA & SOA Gov)... ServiceTechSymposium New Supporting Organization, IBTI has joined the Symposium! http://www.servicetechsymposium.com/ orclateamsoa ?A-Team Blog #ateam: BPM 11g Task Form Version Considerations http://ow.ly/1lA7XS OTNArchBeat Oracle content at SOA, Cloud and Service Technology Symposium (and discount code!) http://pub.vitrue.com/FPcW OracleBlogs ?BPM 11g Task Form Version Considerations http://ow.ly/1lzOrX OTNArchBeat BPM 11g #ADF Task Form Versioning | Christopher Karl Chan #fusionmiddleware http://pub.vitrue.com/0qP2 OTNArchBeat Lightweight ADF Task Flow for BPM Human Tasks Overview | @AndrejusB #fusionmiddleware http://pub.vitrue.com/z7x9 SOA Community Oracle Fusion Middleware Summer Camps in Lisbon report by Link Consulting http://middlewarebylink.wordpress.com/2012/07/20/oracle-fusion-middleware-summer-camps-in-lisbon/ … #ofmsummercamps #soa #bpm SOA Community ?Clemens Utschig-Utschig & Manas Deb The Successful Execution of the SOA and BPM Vision Using a Business Capability Framework: Concepts… Simone Geib ?RT @oprocessaccel: Just released! White Paper: Oracle Process Accelerators Best Practices http://www.oracle.com/technetwork/middleware/bpm/learnmore/processaccelbestpracticeswhitepaper-1708910.pdf … jornica ?Report from Oracle Fusion Middleware Summer Camps in Munich: SOA Suite 11g advanced training experiences @soacommunity http://bit.ly/Mw3btE Simone Geib ?Bruce Tierney: Update - SOA & BPM Customer Insights Webcast Series: | https://blogs.oracle.com/SOA/entry/update_soa_bpm_customer_insights … OTNArchBeat Business SOA: Thinking is Dead | @mosesjones http://pub.vitrue.com/k8mw esentri ?had 3 great days in Munich at #Oracle #soacommunity Summercamp! Special thanks to Geoffroy de Lamalle from eProseed! Danilo Schmiedel ?Used my time in train to setup the ps5 soa/bpm vbox-image.Works like a dream. Setup-Readme is perfect! Saves a lot of time!!! @soacommunity 18 Jul SOA Community ?THANKS for the excellent OFM summer camps - save trip home - share your pictures at http://www.facebook.com/soacommunity #ofmsummercamps #soacommunity doors BBQ-party with Oracle @soacommunity. 5Star! #lovemunich #ofmsummercamps pic.twitter.com/ztfcGn2S leonsmiers ?New #Capgemini blog post "Continuous Improvement of Business Agility" http://bit.ly/Lr0EwG #bpm #yam Eric Elzinga ?MDS Explorer utility, http://see.sc/4qdb43 #soasuite ServiceTechSymposium ?@techsymp New speaker Demed L’Her from Oracle has been added to the symposium calendar. http://ow.ly/cjnyw SOA Community ?Last day of the Fusion Middleware summer camps - we continue at 9.00 am. send us your barbecue pictures! #ofmsummercamps #soacommunity SOA Community ?Delivering SOA Governance with EAMS and Oracle Enterprise Repository by Link Consulting http://middlewarebylink.wordpress.com/2012/06/26/delivering-soa-governance-with-eams-and-oracle-enterprise-repository/ … #soacommunity #soa #oer OracleBlogs ?Process Accelerator Kit http://ow.ly/1loaCw 15 Jul SOA Community ?Sun is back in Munich! Send your pictures Middleware summer camps! #ofmsummercamps We start tomorrow 11.00 at Oracle pic.twitter.com/6FStxomk Walter Montantes ?Gracias, Obrigado, Thank you, Danke a Lisboa y a @soacommunity @wlscommunity. From the Mexican guys!! cc @mikeintoch #ofmsummercamps Andrejus Baranovskis Tips & Tricks How to Run Oracle BPM 11g PS5 Workspace from Custom ADF 11g Application http://fb.me/1zOf3h2K8 JDeveloper & ADF ?Fusion Apps Enterprise Repository - Explained http://dlvr.it/1rpjWd Steve Walker ?Oracle #Exalogic is the logical choice for running business applications. Exalogic Software 2.0 launches 7/25. Reg at http://bit.ly/NedQ9L A. Chatziantoniou ?Landed in rainy Amsterdam after a great week in Lisbon for the #ofmsummercamps - multo obrigado for Jürgen for another fantastic event SOA Community ?Teams present #BPM11g POC results at #ofmsummercamps - great job! #soacommunity pic.twitter.com/0d4txkWF Sabine Leitner ?#DOAG SIG Middleware 29.08.2012 Köln über MW, Administration, Monitoring http://bit.ly/P47w82 @soacommunity @OracleMW @OracleFMW 12 Jul philmulhall ?Thanks @soacommunity for a great week at the #ofmsummercamps. Hard work done so time for a few cold ones in Lisboa. pic.twitter.com/LVUUuwTh peter230769 ?RT: andrea_rocco_31: RT @soacommunity: Enjoy the networking event at #ofmsummercamps want to attend next time ... pic.twitter.com/D1HRndi4 Niels Gorter ?#ofmsummercamps dinner in Lisbon. Great weather, scenery, training, people, on and on. Big THANKS @soacommunity JDeveloper & ADF ?Running Oracle BPM 11g PS5 Worklist Task Flow and Human Task Form on Non-SOA Domain http://dlvr.it/1r0c2j Andrea Rocco ?RT @soacommunity: Jamy pastry at cafe Belem - who is the ghost there?!? http://via.me/-2x33uk6 Simon Haslam ?Sounds great - sorry I couldn't make it. RT @soacommunity: 6pm BPM advanced training hard work to build the POC #ofmsummercamps philmulhall ?A well earned rest after a hard days work @soacommunity #summercamps pic.twitter.com/LKK7VOVS philmulhall ?Some more hard working delegates @soacommunity #summercamps pic.twitter.com/gWpk1HZh SOA Community ?Error message at the BPM POC - will The #ace director understand the message and solve it? #ofmsummercamps pic.twitter.com/LFTEzNck Daniel Kleine-Albers ?posted on the #thecattlecrew blog: Assigning more memory to JDeveloper http://thecattlecrew.wordpress.com/2012/07/10/jdeveloper-quicktip-assigning-more-memory/ … OTNArchBeat ?BAM design pointers | Kavitha Srinivasan http://pub.vitrue.com/TOhP SOA Community ?Did you receive the July SOA community newsletter? read it! Want to become a member http://www.oracle.com/goto/emea/soa #soacommunity #soa #opn OracleBlogs ?Markus Zirn, Big Data with CEP and SOA @ SOA, Cloud &amp; Service Technology Symposium 2012 http://ow.ly/1lcSkb Andrejus Baranovskis Running Oracle BPM 11g PS5 Worklist Task Flow and Human Task Form on Non-SOA Eric Elzinga ?Service Facade design pattern in OSB, http://bit.ly/NnOExN Eric Elzinga ?New BPEL Thread Pool in SOA 11g for Non-Blocking Invoke Activities from 11.1.1.6 (PS5), http://bit.ly/NnOc2G Gilberto Holms New Post: Siebel Connection Pool in Oracle Service Bus 11g http://wp.me/pRE8V-2z Oracle UPK & Tutor ?UPK Pre-Built Content Update: UPK pre-built content development efforts are always underway and growing. Ove... http://bit.ly/R2HeTj JDeveloper & ADF ?Troubleshooting BPMN process editor problems in 11.1.1.6 http://dlvr.it/1p0FfS orclateamsoa ?A-Team Blog #ateam: BAM design pointers - In working recently with a large Oracle customer on SOA and BAM, I discove... http://ow.ly/1kYqES SOA Community BPMN process editor problems in 11.1.1.6 by Mark Nelson http://redstack.wordpress.com/2012/06/27/bpmn-process-editor-problems-in-11-1-1-6 … #soacommunity #bpm OTNArchBeat ?SOA Learning Library: free short, topic-focused training on Oracle SOA & BPM products | @SOACommunity http://pub.vitrue.com/NE1G Andrejus Baranovskis ?ADF 11g PS5 Application with Customized BPM Worklist Task Flow (MDS Seeded Customization) http://fb.me/1coX4r1X1 OTNArchBeat ?A Universal JMX Client for Weblogic –Part 1: Monitoring BPEL Thread Pools in SOA 11g | Stefan Koser http://pub.vitrue.com/mQVZ OTNArchBeat ?BPM – Disable DBMS job to refresh B2B Materialized View | Mark Nelson http://pub.vitrue.com/3PR0 SOA & BPM Partner Community For regular information on Oracle SOA Suite become a member in the SOA & BPM Partner Community for registration please visit  www.oracle.com/goto/emea/soa (OPN account required) If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Mix Forum Technorati Tags: SOA Community twitter,SOA Community,Oracle SOA,Oracle BPM,BPM Community,OPN,Jürgen Kress

    Read the article

  • What’s New for Oracle Commerce? Executive QA with John Andrews, VP Product Management, Oracle Commerce

    - by Katrina Gosek
    Oracle Commerce was for the fifth time positioned as a leader by Gartner in the Magic Quadrant for E-Commerce. This inspired me to sit down with Oracle Commerce VP of Product Management, John Andrews to get his perspective on what continues to make Oracle a leader in the industry and what’s new for Oracle Commerce in 2013. Q: Why do you believe Oracle Commerce continues to be a leader in the industry? John: Oracle has a great acquisition strategy – it brings best-of-breed technologies into the product fold and then continues to grow and innovate them. This is particularly true with products unified into the Oracle Commerce brand. Oracle acquired ATG in late 2010 – and then Endeca in late 2011. This means that under the hood of Oracle Commerce you have market-leading technologies for cross-channel commerce and customer experience, both designed and developed in direct response to the unique challenges online businesses face. And we continue to innovate on capabilities core to what our customers need to be successful – contextual and personalized experience delivery, merchant-inspired tools, and architecture for performance and scalability. Q: It’s not a slow moving industry. What are you doing to keep the pace of innovation at Oracle Commerce? John: Oracle owes our customers the most innovative commerce capabilities. By unifying the core components of ATG and Endeca we are delivering on this promise. Oracle Commerce is continuing to innovate and redefine how commerce is done and in a way that drive business results and keeps customers coming back for experiences tailored just for them. Our January and May 2013 releases not only marked the seventh significant releases for the solution since the acquisitions of ATG and Endeca, we also continue to demonstrate rapid and significant progress on the unification of commerce and customer experience capabilities of the two commerce technologies. Q: Can you tell us what was notable about these latest releases under the Oracle Commerce umbrella? John: Specifically, our latest product innovations give businesses selling online the ability to get to market faster with more personalized commerce experiences in the following ways: Mobile: the latest Commerce Reference Application in this release offers a wider range of examples for online businesses to leverage for iOS development and specifically new iPad reference capabilities. This release marks the first release of the iOS Universal application that serves both the iPhone and iPad devices from a single download or binary. Business users can now drive page content management and layout of search results and category pages, as well as create additional storefront elements such as categories, facets / dimensions, and breadcrumbs through Experience Manager tools. Cross-Channel Commerce: key commerce platform capabilities have been added to support cross-channel commerce, including an expanded inventory model to maintain inventory for stores, pickup in stores and Web-based returns. Online businesses with in-store operations can now offer advanced shipping options on the web and make returns and exchange logic easily available on the web. Multi-Site Capabilities: significant enhancements to the Commerce Platform multi-site architecture that allows business users to quickly launch and manage multiple sites on the same cluster and share data, carts, and other components. First introduced in 2010, with this latest release business users can now partition or share customer profiles, control users’ site-based access, and manage personalization assets using site groups. Internationalization: continued language support and enhancements for business user tools as well and search and navigation. Guided Search now supports 35 total languages with 11 new languages (including Danish, Arabic, Norwegian, Serbian Cyrillic) added in this release. Commerce Platform tools now include localized support for 17 locales with 4 new languages (Danish, Portuguese (European), Finnish, and Thai). No development or customization is required in order for business users to use the applications in any of these supported languages. Business Tool Experience: valuable new Commerce Merchandising features include a new workflow for making emergency changes quickly and increased visibility into promotions rules and qualifications in preview mode. Oracle Commerce business tools continue to become more and more feature rich to provide intuitive, easy- to-use (yet powerful) capabilities to allow business users to manage content and the shopping experience. Commerce & Experience Unification: demonstrable unification of commerce and customer experience capabilities include – productized cartridges that provide supported integration between the Commerce Platform and Experience Management tools, cross-channel returns, Oracle Service Cloud integration, and integrated iPad application. The mission guiding our product development is to deliver differentiated, personalized user experiences across any device in a contextual manner – and to give the business the best tools to tune and optimize those user experiences to meet their business objectives. We also need to do this in a way that makes it operationally efficient for the business, keeping the overall total cost of ownership low – yet also allows the business to expand, whether it be to new business models, geographies or brands. To learn more about the latest Oracle Commerce releases and mission, visit the links below: • Hear more from John about the Oracle Commerce mission • Hear from Oracle Commerce customers • Documentation on the new releases • Listen to the Oracle ATG Commerce 10.2 Webcast • Listen to the Oracle Endeca Commerce 3.1.2 Webcast

    Read the article

  • Issuing Current Time Increments in StreamInsight (A Practical Example)

    The issuing of a Current Time Increment, Cti, in StreamInsight is very definitely one of the most important concepts to learn if you want your Streams to be responsive. A full discussion of how to issue Ctis is beyond the scope of this article but a very good explanation in addition to Books Online can be found in these three articles by a member of the StreamInsight team at Microsoft, Ciprian Gerea. Time in StreamInsight Series http://blogs.msdn.com/b/streaminsight/archive/2010/07/23/time-in-streaminsight-i.aspx http://blogs.msdn.com/b/streaminsight/archive/2010/07/30/time-in-streaminsight-ii.aspx http://blogs.msdn.com/b/streaminsight/archive/2010/08/03/time-in-streaminsight-iii.aspx A lot of the problems I see with unresponsive or stuck streams on the MSDN Forums are to do with how Ctis are enqueued or in a lot of cases not enqueued. If you enqueue events and never enqueue a Cti then StreamInsight will be perfectly happy. You, on the other hand, will never see data on the output as you have not told StreamInsight to flush the stream. This article deals with a specific implementation problem I had recently whilst working on a StreamInsight project. I look at some possible options and discuss why they would not work before showing the way I solved the problem. The stream of data I was dealing with on this project was very bursty that is to say when events were flowing they came through very quickly and in large numbers (1000 events/sec), but when the stream calmed down it could be a few seconds between each event. When enqueuing events into the StreamInsight engne it is best practice to do so with a StartTime that is given to you by the system producing the event . StreamInsight processes events and it doesn't matter whether those events are being pushed into the engine by a source system or the events are being read from something like a flat file in a directory somewhere. You can apply the same logic and temporal algebra to both situations. Reading from a file is an excellent example of where the time of the event on the source itself is very important. We could be reading that file a long time after it was written. Being able to read the StartTime from the events allows us to define windows that will hold the correct sets of events. I was able to do this with my stream but this is where my problems started. Below is a very simple script to create a SQL Server table and populate it with sample data that will show exactly the problem I had. CREATE TABLE [dbo].[t] ( [c1] [int] PRIMARY KEY, [c2] [datetime] NULL ) INSERT t VALUES (1,'20100810'),(2,'20100810'),(3,'20100810') Column c2 defines the StartTime of the event on the source and as you can see the values in all 3 rows of data is the same. If we read Ciprian’s articles we know that we can define how Ctis get injected into the stream in 3 different places The Stream Definition The Input Factory The Input Adapter I personally have always been a fan of enqueing Ctis through the factory. Below is code typical of what I would use to do this On the class itself I do some inheriting public class SimpleInputFactory : ITypedInputAdapterFactory<SimpleInputConfig>, ITypedDeclareAdvanceTimeProperties<SimpleInputConfig> And then I implement the following function public AdapterAdvanceTimeSettings DeclareAdvanceTimeProperties<TPayload>(SimpleInputConfig configInfo, EventShape eventShape) { return new AdapterAdvanceTimeSettings( new AdvanceTimeGenerationSettings(configInfo.CtiFrequency, TimeSpan.FromTicks(-1)), AdvanceTimePolicy.Adjust); } The configInfo .CtiFrequency property is a value I pass through to define after how many events I want a Cti to be injected and this in turn will flush through the stream of data. I usually pass a value of 1 for this setting. The second parameter determines the CTI timestamp in terms of a delay relative to the events. -1 ticks in the past results in 1 tick in the future, i.e., ahead of the event. The problem with this method though is that if consecutive events have the same StartTime then only one of those events will be enqueued. In this example I use the following to define how I assign the StartTime of my events currEvent.StartTime = (DateTimeOffset)dt.c2; If I go ahead and run my StreamInsight process with this configuration i can see on the output adapter that two events have been removed To see this in a little more depth I can use the StreamInsight Debugger and see what happens internally. What is happening here is that the first event arrives and a Cti is injected with a time of 1 tick after the StartTime of that event (Also the EndTime of the event). The second event arrives and it has a StartTime of before the Cti and even though we specified AdvanceTimePolicy.Adjust on the factory we know that a point event can never be adjusted like this and the event is dropped. The same happens for the third event as well (The second and third events get trumped by the Cti). For a more detailed discussion of why this happens look here http://www.sqlis.com/sqlis/post/AdvanceTimePolicy-and-Point-Event-Streams-In-StreamInsight.aspx We end up with a single event being pushed into the output adapter and our result now makes sense. The next way I tried to solve this problem by changing the value of the second parameter to TimeSpan.Zero Here is how my factory code now looks public AdapterAdvanceTimeSettings DeclareAdvanceTimeProperties<TPayload>(SimpleInputConfig configInfo, EventShape eventShape) { return new AdapterAdvanceTimeSettings( new AdvanceTimeGenerationSettings(configInfo.CtiFrequency, TimeSpan.Zero), AdvanceTimePolicy.Adjust); } What I am doing here is declaring a policy that says inject a Cti together with every event and stamp it with a StartTime that is equal to the start time of the event itself (TimeSpan.Zero). This method has plus points as well as a downside. The upside is that no events will be lost by having the same StartTime as previous events. The Downside is that because the Cti is declared with the StartTime of the event itself then it does not actually flush that particular event because in the StreamInsight algebra, a Cti commits only those events that occurred strictly before them. To flush the events we need a Cti to be enqueued with a greater StartTime than the events themselves. Here is what happened when I ran this configuration As you can see all we got through was the Cti and none of the events. The debugger output shows the stamps on the Cti and the events themselves. Because the Cti issued has the same timestamp (StartTime) as the events then none of the events get flushed. I was nearly there but not quite. Because my stream was bursty it was possible that the next event would not come along for a few seconds and this was far too long for an event to be enqueued and not be flushed to the output adapter. I needed another solution. Two possible solutions crossed my mind although only one of them made sense when I explored it some more. Where multiple events have the same StartTime I could add 1 tick to the first event, two to the second, three to third etc thereby giving them unique StartTime values. Add a timer to manually inject Ctis The problem with the first implementation is that I would be giving the events a new StartTime. This would cause me the following problems If I want to define windows over the stream then some events may not be captured in the right windows and therefore any calculations on those windows I did would be wrong What would happen if we had 10,000 events with the same StartTime? I would enqueue them with StartTime + n ticks. Along comes a genuine event with a StartTime of the very first event + 1 tick. It is now too far in the past as far as my stream is concerned and it would be dropped. Not what I would want to do at all. I decided then to look at the Timer based solution I created a timer on my input adapter that elapsed every 200ms. private Timer tmr; public SimpleInputAdapter(SimpleInputConfig configInfo) { ctx = new SimpleTimeExtractDataContext(configInfo.ConnectionString); this.configInfo = configInfo; tmr = new Timer(200); tmr.Elapsed += new ElapsedEventHandler(t_Elapsed); tmr.Enabled = true; } void t_Elapsed(object sender, ElapsedEventArgs e) { ts = DateTime.Now - dtCtiIssued; if (ts.TotalMilliseconds >= 200 && TimerIssuedCti == false) { EnqueueCtiEvent(System.DateTime.Now.AddTicks(-100)); TimerIssuedCti = true; } }   In the t_Elapsed event handler I find out the difference in time between now and when the last event was processed (dtCtiIssued). I then check to see if that is greater than or equal to 200ms and if the last issuing of a Cti was done by the timer or by a genuine event (TimerIssuedCti). If I didn’t do this check then I would enqueue a Cti every time the timer elapsed which is not something I wanted. If the difference between the two times is greater than or equal to 500ms and the last event enqueued was by a real event then I issue a Cti through the timer to flush the event Queue, otherwise I do nothing. When I enqueue the Ctis into my stream in my ProduceEvents method I also set the values of dtCtiIssued and TimerIssuedCti   currEvent = CreateInsertEvent(); currEvent.StartTime = (DateTimeOffset)dt.c2; TimerIssuedCti = false; dtCtiIssued = currEvent.StartTime; If I go ahead and run this configuration I see the following in my output. As we can see the first Cti gets enqueued as before but then another is enqueued by the timer and because this has a later timestamp it flushes the enqueued events through the engine. Conclusion Hopefully this has shown how the enqueuing of Ctis can have a dramatic effect on the responsiveness of your output in StreamInsight. Understanding the temporal nature of the product is for me one of the most important things you can learn. I have attached my solution for the demos. It is all in one project and testing each variation is a simple matter of commenting and un-commenting the parts in the code we have been dealing with here.

    Read the article

  • Restore Your PC from Windows Home Server

    - by Mysticgeek
    If your computer crashes or you get a virus infection that makes it unrecoverable, doing a clean install can be a hassle, let alone getting your data back. If you’re backing up your computers to Windows Home Server, you can completely restore them to the last successful backup. Note: For this process to work you need to verify the PC you want to restore is connected to your network via Ethernet. If you have it connected wirelessly it won’t work. Restore a PC from Windows Home Server On the computer you want to restore, pop in the Windows Home Server Home Computer Restore disc and boot from it. If you don’t have one already made, you can easily make one following these instructions. We have also included the link to the restore disc below. Boot from the CD then select if your machine has 512MB or RAM or more. The disc will initialize… Then choose your language and keyboard settings. Hopefully if everything goes correctly, your network card will be detected and you can continue. However, if it doesn’t like in our example, click on the Show Details button. In the Detect Hardware screen click on the Install Drivers button. Now you will need to have a USB flash drive with the correct drivers on it. It has to be a flash drive or a floppy (if you happen to still have one of those) because you can’t take out the Restore CD. If you want to make sure you have the correct drivers on the USB flash drive, open the Windows Home Server Console on another computer on your network. In the Computers and Backup section right-click on the computer you want to restore and select View Backups. Select the backup you want to restore from and click the Open button in the Restore or view Files section. Now drag the entire contents of the folder named Windows Home Server Drivers for Restore to the USB flash drive. Back to the machine you’re trying to restore, insert the USB flash drive with the correct drivers and click the Scan button. Wait a few moments while the drivers are found then click Ok then Continue.   The Restore Computer Wizard starts up… Enter in your home server password and click Next. Select the computer you want to restore. If it isn’t selected by default you can pull it up from the dropdown list under Another Computer. Make certain you’re selecting the correct machine. Now select the backup you want to restore. In this example we only have one but chances are you’ll have several. If you have several backups to choose from, you might want to check out the details for them. Now you can select the disk from backup and and restore it to the destination volume. You might need to initialize a disk, change a drive letter, or other disk management tasks, if so, then click on Run Disk Manger. For example we want to change the destination drive letter to (C:).   After you’ve made all the changes to the destination disk you can continue with the restore process. If everything looks correct, confirm the restore configuration. If you need to make any changes at this point, you can still go back and make them. Now Windows Home Server will restore your drive. The amount of time it takes will vary depend on the amount of data you have to restore, network connection speed, and hardware. You are notified when the restore successfully completes. Click Finish and the PC will reboot and be restored and should be working correctly. All the updates, programs, and files will be back that were saved to the last successful backup. Anything you might have installed after that backup will be gone. If you have your computers set to backup every night, then hopefully it won’t be a big issue.   Conclusion Backing up the computers on your network to Windows Home Server is a valuable tool in your backup strategy. Sometimes you may only need to restore a couple files and we’ve covered how to restore them from backups on WHS and that works really well. If the unthinkable happens and you need to restore the entire computer, WHS makes that easy too.  Download Windows Home Server Home Computer Restore CD Similar Articles Productive Geek Tips Restore Files from Backups on Windows Home ServerCreate A Windows Home Server Home Computer Restore DiscGMedia Blog: Setting Up a Windows Home ServerShare Ubuntu Home Directories using SambaInstalling Windows Home Server TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 PCmover Professional Make your Joomla & Drupal Sites Mobile with OSMOBI Integrate Twitter and Delicious and Make Life Easier Design Your Web Pages Using the Golden Ratio Worldwide Growth of the Internet How to Find Your Mac Address Use My TextTools to Edit and Organize Text

    Read the article

  • To ORM or Not to ORM. That is the question&hellip;

    - by Patrick Liekhus
    UPDATE:  Thanks for the feedback and comments.  I have adjusted my table below with your recommendations.  I had missed a point or two. I wanted to do a series on creating an entire project using the EDMX XAF code generation and the SpecFlow BDD Easy Test tools discussed in my earlier posts, but I thought it would be appropriate to start with a simple comparison and reasoning on why I choose to use these tools. Let’s start by defining the term ORM, or Object-Relational Mapping.  According to Wikipedia it is defined as the following: Object-relational mapping (ORM, O/RM, and O/R mapping) in computer software is a programming technique for converting data between incompatible type systems in object-oriented programming languages. This creates, in effect, a "virtual object database" that can be used from within the programming language. Why should you care?  Basically it allows you to map your business objects in code to their persistence layer behind them. And better yet, why would you want to do this?  Let me outline it in the following points: Development speed.  No more need to map repetitive tasks query results to object members.  Once the map is created the code is rendered for you. Persistence portability.  The ORM knows how to map SQL specific syntax for the persistence engine you choose.  It does not matter if it is SQL Server, Oracle and another database of your choosing. Standard/Boilerplate code is simplified.  The basic CRUD operations are consistent and case use database metadata for basic operations. So how does this help?  Well, let’s compare some of the ORM tools that I have used and/or researched.  I have been interested in ORM for some time now.  My ORM of choice for a long time was NHibernate and I still believe it has a strong case in some business situations.  However, you have to take business considerations into account and the law of diminishing returns.  Because of these two factors, my recent activity and experience has been around DevExpress eXpress Persistence Objects (XPO).  The primary reason for this is because they have the DevExpress eXpress Application Framework (XAF) that sits on top of XPO.  With this added value, the data model can be created (either database first of code first) and the Web and Windows client can be created from these maps.  While out of the box they provide some simple list and detail screens, you can verify easily extend and modify these to your liking.  DevExpress has done a tremendous job of providing enough framework while also staying out of the way when you need to extend it.  This sounds worse than it really is.  What I mean by this is that if you choose to follow DevExpress coding style and recommendations, the hooks and extension points provided allow you to do some pretty heavy lifting while also not worrying about the basics. I have put together a list of the top features that I have used to compare the limited list of ORM’s that I have exposure with.  Again, the biggest selling point in my opinion is that XPO is just a solid as any of the other ORM’s but with the added layer of XAF they become unstoppable.  And then couple that with the EDMX modeling tools and code generation, it becomes a no brainer. Designer Features Entity Framework NHibernate Fluent w/ Nhibernate Telerik OpenAccess DevExpress XPO DevExpress XPO/XAF plus Liekhus Tools Uses XML to map relationships - Yes - - -   Visual class designer interface Yes - - - - Yes Management integrated w/ Visual Studio Yes - - Yes - Yes Supports schema first approach Yes - - Yes - Yes Supports model first approach Yes - - Yes Yes Yes Supports code first approach Yes Yes Yes Yes Yes Yes Attribute driven coding style Yes - Yes - Yes Yes                 I have a very small team and limited resources with a lot of responsibilities.  In order to keep up with our customers, we must rely on tools like these.  We use the EDMX tool so that we can create a visual representation of the applications with our customers.  Second, we rely on the code generation so that we can focus on the business problems at hand and not whether a field is mapped correctly.  This keeps us from requiring as many junior level developers on our team.  I have also worked on multiple teams where they believed in writing their own “framework”.  In my experiences and opinion this is not the route to take unless you have a team dedicated to supporting just the framework.  Each time that I have worked on custom frameworks, the framework eventually becomes old, out dated and full of “performance” enhancements specific to one or two requirements.  With an ORM, there are a lot smarter people than me working on the bigger issue of persistence and performance.  Again, my recommendation would be to use an available framework and get to working on your business domain problems.  If your coding is not making money for you, why are you working on it?  Do you really need to be writing query to object member code again and again? Thanks

    Read the article

  • New .NET Library for Accessing the Survey Monkey API

    - by Ben Emmett
    I’ve used Survey Monkey’s API for a while, and though it’s pretty powerful, there’s a lot of boilerplate each time it’s used in a new project, and the json it returns needs a bunch of processing to be able to use the raw information. So I’ve finally got around to releasing a .NET library you can use to consume the API more easily. The main advantages are: Only ever deal with strongly-typed .NET objects, making everything much more robust and a lot faster to get going Automatically handles things like rate-limiting and paging through results Uses combinations of endpoints to get all relevant data for you, and processes raw response data to map responses to questions To start, either install it using NuGet with PM> Install-Package SurveyMonkeyApi (easier option), or grab the source from https://github.com/bcemmett/SurveyMonkeyApi if you prefer to build it yourself. You’ll also need to have signed up for a developer account with Survey Monkey, and have both your API key and an OAuth token. A simple usage would be something like: string apiKey = "KEY"; string token = "TOKEN"; var sm = new SurveyMonkeyApi(apiKey, token); List<Survey> surveys = sm.GetSurveyList(); The surveys object is now a list of surveys with all the information available from the /surveys/get_survey_list API endpoint, including the title, id, date it was created and last modified, language, number of questions / responses, and relevant urls. If there are more than 1000 surveys in your account, the library pages through the results for you, making multiple requests to get a complete list of surveys. All the filtering available in the API can be controlled using .NET objects. For example you might only want surveys created in the last year and containing “pineapple” in the title: var settings = new GetSurveyListSettings { Title = "pineapple", StartDate = DateTime.Now.AddYears(-1) }; List<Survey> surveys = sm.GetSurveyList(settings); By default, whenever optional fields can be requested with a response, they will all be fetched for you. You can change this behaviour if for some reason you explicitly don’t want the information, using var settings = new GetSurveyListSettings { OptionalData = new GetSurveyListSettingsOptionalData { DateCreated = false, AnalysisUrl = false } }; Survey Monkey’s 7 read-only endpoints are supported, and the other 4 which make modifications to data might be supported in the future. The endpoints are: Endpoint Method Object returned /surveys/get_survey_list GetSurveyList() List<Survey> /surveys/get_survey_details GetSurveyDetails() Survey /surveys/get_collector_list GetCollectorList() List<Collector> /surveys/get_respondent_list GetRespondentList() List<Respondent> /surveys/get_responses GetResponses() List<Response> /surveys/get_response_counts GetResponseCounts() Collector /user/get_user_details GetUserDetails() UserDetails /batch/create_flow Not supported Not supported /batch/send_flow Not supported Not supported /templates/get_template_list Not supported Not supported /collectors/create_collector Not supported Not supported The hierarchy of objects the library can return is Survey List<Page> List<Question> QuestionType List<Answer> List<Item> List<Collector> List<Response> Respondent List<ResponseQuestion> List<ResponseAnswer> Each of these classes has properties which map directly to the names of properties returned by the API itself (though using PascalCasing which is more natural for .NET, rather than the snake_casing used by SurveyMonkey). For most users, Survey Monkey imposes a rate limit of 2 requests per second, so by default the library leaves at least 500ms between requests. You can request higher limits from them, so if you want to change the delay between requests just use a different constructor: var sm = new SurveyMonkeyApi(apiKey, token, 200); //200ms delay = 5 reqs per sec There’s a separate cap of 1000 requests per day for each API key, which the library doesn’t currently enforce, so if you think you’ll be in danger of exceeding that you’ll need to handle it yourself for now.  To help, you can see how many requests the current instance of the SurveyMonkeyApi object has made by reading its RequestsMade property. If the library encounters any errors, including communicating with the API, it will throw a SurveyMonkeyException, so be sure to handle that sensibly any time you use it to make calls. Finally, if you have a survey (or list of surveys) obtained using GetSurveyList(), the library can automatically fill in all available information using sm.FillMissingSurveyInformation(surveys); For each survey in the list, it uses the other endpoints to fill in the missing information about the survey’s question structure, respondents, and responses. This results in at least 5 API calls being made per survey, so be careful before passing it a large list. It also joins up the raw response information to the survey’s question structure, so that for each question in a respondent’s set of replies, you can access a ProcessedAnswer object. For example, a response to a dropdown question (from the /surveys/get_responses endpoint) might be represented in json as { "answers": [ { "row": "9384627365", } ], "question_id": "615487516" } Separately, the question’s structure (from the /surveys/get_survey_details endpoint) might have several possible answers, one of which might look like { "text": "Fourth item in dropdown list", "visible": true, "position": 4, "type": "row", "answer_id": "9384627365" } The library understands how this mapping works, and uses that to give you the following ProcessedAnswer object, which first describes the family and type of question, and secondly gives you the respondent’s answers as they relate to the question. Survey Monkey has many different question types, with 11 distinct data structures, each of which are supported by the library. If you have suggestions or spot any bugs, let me know in the comments, or even better submit a pull request .

    Read the article

  • Editing Routes in ASP.NET MVC

    - by imran_ku07
    Introduction :        Phil Haack's had written two great articles about Editable Routes, Editable Routes or Editable Routes Using App_Code.These Article are great. But if you not need to unit test your Routes and don't care about restart Application Domian during editing your Routes then global.asax file is the fastest and easiest to achieve the same. In this Article I will use Global.asax file instead of Global.asax.cs file for defining Routes and you will also see how this whole process will works.   Description :          You just need to Cut (or Copy) the code inside Global.asax.cs and paste it in Global.asax inside runat server tag.          You can simply do this by cutting the code of Global.asax.cs,          and paste it inside Global.asax,               Easy and quick ,Now you can change Global.asax without compiling the application. How this works :        I think it is worth here to see what is happening here.        Actually, ASP.NET will use Global.asax file to create a class named global_asax within ASP namespace and place all the code in Global.asax inside the class global_asax class which is created at runtime,                namespace ASP               {                    public class global_asax: NerdDinner.MvcApplication                    {                         //Any definitions defined in Global.asax like Application_Start method                                     }               }         Which inherits from class defined in Application tag,      <%@ Application Codebehind="Global.asax.cs" Inherits="NerdDinner.MvcApplication" Language="C#" %>          Actually ASP.NET creates a pool of application objects of this class, which varies from 1 to 100. Every request take one of these application objects to a serve incoming requests. After receiving an application object then it will call application specific events, like Application_Start(for only firstRequest), Application_BeginRequest(for every request), and so on. Therefore if these methods are defined in global_asax class then ASP.NET will call these method from global_asax, if not then it will use base class methods may be defined in Global.asax.cs(the concept known as shadowing or hiding). Summary :        In this article, I showed how easily and quickly you can make your Routes Editable. But also note that any change in global.asax results in Application Domain restart and this technique also makes your Route Unit Test difficult.

    Read the article

  • [GEEK SCHOOL] Network Security 1: Securing User Accounts and Passwords in Windows

    - by Matt Klein
    This How-To Geek School class is intended for people who want to learn more about security when using Windows operating systems. You will learn many principles that will help you have a more secure computing experience and will get the chance to use all the important security tools and features that are bundled with Windows. Obviously, we will share everything you need to know about using them effectively. In this first lesson, we will talk about password security; the different ways of logging into Windows and how secure they are. In the proceeding lesson, we will explain where Windows stores all the user names and passwords you enter while working in this operating systems, how safe they are, and how to manage this data. Moving on in the series, we will talk about User Account Control, its role in improving the security of your system, and how to use Windows Defender in order to protect your system from malware. Then, we will talk about the Windows Firewall, how to use it in order to manage the apps that get access to the network and the Internet, and how to create your own filtering rules. After that, we will discuss the SmartScreen Filter – a security feature that gets more and more attention from Microsoft and is now widely used in its Windows 8.x operating systems. Moving on, we will discuss ways to keep your software and apps up-to-date, why this is important and which tools you can use to automate this process as much as possible. Last but not least, we will discuss the Action Center and its role in keeping you informed about what’s going on with your system and share several tips and tricks about how to stay safe when using your computer and the Internet. Let’s get started by discussing everyone’s favorite subject: passwords. The Types of Passwords Found in Windows In Windows 7, you have only local user accounts, which may or may not have a password. For example, you can easily set a blank password for any user account, even if that one is an administrator. The only exception to this rule are business networks where domain policies force all user accounts to use a non-blank password. In Windows 8.x, you have both local accounts and Microsoft accounts. If you would like to learn more about them, don’t hesitate to read the lesson on User Accounts, Groups, Permissions & Their Role in Sharing, in our Windows Networking series. Microsoft accounts are obliged to use a non-blank password due to the fact that a Microsoft account gives you access to Microsoft services. Using a blank password would mean exposing yourself to lots of problems. Local accounts in Windows 8.1 however, can use a blank password. On top of traditional passwords, any user account can create and use a 4-digit PIN or a picture password. These concepts were introduced by Microsoft to speed up the sign in process for the Windows 8.x operating system. However, they do not replace the use of a traditional password and can be used only in conjunction with a traditional user account password. Another type of password that you encounter in Windows operating systems is the Homegroup password. In a typical home network, users can use the Homegroup to easily share resources. A Homegroup can be joined by a Windows device only by using the Homegroup password. If you would like to learn more about the Homegroup and how to use it for network sharing, don’t hesitate to read our Windows Networking series. What to Keep in Mind When Creating Passwords, PINs and Picture Passwords When creating passwords, a PIN, or a picture password for your user account, we would like you keep in mind the following recommendations: Do not use blank passwords, even on the desktop computers in your home. You never know who may gain unwanted access to them. Also, malware can run more easily as administrator because you do not have a password. Trading your security for convenience when logging in is never a good idea. When creating a password, make it at least eight characters long. Make sure that it includes a random mix of upper and lowercase letters, numbers, and symbols. Ideally, it should not be related in any way to your name, username, or company name. Make sure that your passwords do not include complete words from any dictionary. Dictionaries are the first thing crackers use to hack passwords. Do not use the same password for more than one account. All of your passwords should be unique and you should use a system like LastPass, KeePass, Roboform or something similar to keep track of them. When creating a PIN use four different digits to make things slightly harder to crack. When creating a picture password, pick a photo that has at least 10 “points of interests”. Points of interests are areas that serve as a landmark for your gestures. Use a random mixture of gesture types and sequence and make sure that you do not repeat the same gesture twice. Be aware that smudges on the screen could potentially reveal your gestures to others. The Security of Your Password vs. the PIN and the Picture Password Any kind of password can be cracked with enough effort and the appropriate tools. There is no such thing as a completely secure password. However, passwords created using only a few security principles are much harder to crack than others. If you respect the recommendations shared in the previous section of this lesson, you will end up having reasonably secure passwords. Out of all the log in methods in Windows 8.x, the PIN is the easiest to brute force because PINs are restricted to four digits and there are only 10,000 possible unique combinations available. The picture password is more secure than the PIN because it provides many more opportunities for creating unique combinations of gestures. Microsoft have compared the two login options from a security perspective in this post: Signing in with a picture password. In order to discourage brute force attacks against picture passwords and PINs, Windows defaults to your traditional text password after five failed attempts. The PIN and the picture password function only as alternative login methods to Windows 8.x. Therefore, if someone cracks them, he or she doesn’t have access to your user account password. However, that person can use all the apps installed on your Windows 8.x device, access your files, data, and so on. How to Create a PIN in Windows 8.x If you log in to a Windows 8.x device with a user account that has a non-blank password, then you can create a 4-digit PIN for it, to use it as a complementary login method. In order to create one, you need to go to “PC Settings”. If you don’t know how, then press Windows + C on your keyboard or flick from the right edge of the screen, on a touch-enabled device, then press “Settings”. The Settings charm is now open. Click or tap the link that says “Change PC settings”, on the bottom of the charm. In PC settings, go to Accounts and then to “Sign-in options”. Here you will find all the necessary options for changing your existing password, creating a PIN, or a picture password. To create a PIN, press the “Add” button in the PIN section. The “Create a PIN” wizard is started and you are asked to enter the password of your user account. Type it and press “OK”. Now you are asked to enter a 4-digit pin in the “Enter PIN” and “Confirm PIN” fields. The PIN has been created and you can now use it to log in to Windows. How to Create a Picture Password in Windows 8.x If you log in to a Windows 8.x device with a user account that has a non-blank password, then you can also create a picture password and use it as a complementary login method. In order to create one, you need to go to “PC settings”. In PC Settings, go to Accounts and then to “Sign-in options”. Here you will find all the necessary options for changing your existing password, creating a PIN, or a picture password. To create a picture password, press the “Add” button in the “Picture password” section. The “Create a picture password” wizard is started and you are asked to enter the password of your user account. You are shown a guide on how the picture password works. Take a few seconds to watch it and learn the gestures that can be used for your picture password. You will learn that you can create a combination of circles, straight lines, and taps. When ready, press “Choose picture”. Browse your Windows 8.x device and select the picture you want to use for your password and press “Open”. Now you can drag the picture to position it the way you want. When you like how the picture is positioned, press “Use this picture” on the left. If you are not happy with the picture, press “Choose new picture” and select a new one, as shown during the previous step. After you have confirmed that you want to use this picture, you are asked to set up your gestures for the picture password. Draw three gestures on the picture, any combination you wish. Please remember that you can use only three gestures: circles, straight lines, and taps. Once you have drawn those three gestures, you are asked to confirm. Draw the same gestures one more time. If everything goes well, you are informed that you have created your picture password and that you can use it the next time you sign in to Windows. If you don’t confirm the gestures correctly, you will be asked to try again, until you draw the same gestures twice. To close the picture password wizard, press “Finish”. Where Does Windows Store Your Passwords? Are They Safe? All the passwords that you enter in Windows and save for future use are stored in the Credential Manager. This tool is a vault with the usernames and passwords that you use to log on to your computer, to other computers on the network, to apps from the Windows Store, or to websites using Internet Explorer. By storing these credentials, Windows can automatically log you the next time you access the same app, network share, or website. Everything that is stored in the Credential Manager is encrypted for your protection.

    Read the article

  • SQL SERVER – Concurrency Basics – Guest Post by Vinod Kumar

    - by pinaldave
    This guest post is by Vinod Kumar. Vinod Kumar has worked with SQL Server extensively since joining the industry over a decade ago. Working on various versions from SQL Server 7.0, Oracle 7.3 and other database technologies – he now works with the Microsoft Technology Center (MTC) as a Technology Architect. Let us read the blog post in Vinod’s own voice. Learning is always fun when it comes to SQL Server and learning the basics again can be more fun. I did write about Transaction Logs and recovery over my blogs and the concept of simplifying the basics is a challenge. In the real world we always see checks and queues for a process – say railway reservation, banks, customer supports etc there is a process of line and queue to facilitate everyone. Shorter the queue higher is the efficiency of system (a.k.a higher is the concurrency). Every database does implement this using checks like locking, blocking mechanisms and they implement the standards in a way to facilitate higher concurrency. In this post, let us talk about the topic of Concurrency and what are the various aspects that one needs to know about concurrency inside SQL Server. Let us learn the concepts as one-liners: Concurrency can be defined as the ability of multiple processes to access or change shared data at the same time. The greater the number of concurrent user processes that can be active without interfering with each other, the greater the concurrency of the database system. Concurrency is reduced when a process that is changing data prevents other processes from reading that data or when a process that is reading data prevents other processes from changing that data. Concurrency is also affected when multiple processes are attempting to change the same data simultaneously. Two approaches to managing concurrent data access: Optimistic Concurrency Model Pessimistic Concurrency Model Concurrency Models Pessimistic Concurrency Default behavior: acquire locks to block access to data that another process is using. Assumes that enough data modification operations are in the system that any given read operation is likely affected by a data modification made by another user (assumes conflicts will occur). Avoids conflicts by acquiring a lock on data being read so no other processes can modify that data. Also acquires locks on data being modified so no other processes can access the data for either reading or modifying. Readers block writer, writers block readers and writers. Optimistic Concurrency Assumes that there are sufficiently few conflicting data modification operations in the system that any single transaction is unlikely to modify data that another transaction is modifying. Default behavior of optimistic concurrency is to use row versioning to allow data readers to see the state of the data before the modification occurs. Older versions of the data are saved so a process reading data can see the data as it was when the process started reading and not affected by any changes being made to that data. Processes modifying the data is unaffected by processes reading the data because the reader is accessing a saved version of the data rows. Readers do not block writers and writers do not block readers, but, writers can and will block writers. Transaction Processing A transaction is the basic unit of work in SQL Server. Transaction consists of SQL commands that read and update the database but the update is not considered final until a COMMIT command is issued (at least for an explicit transaction: marked with a BEGIN TRAN and the end is marked by a COMMIT TRAN or ROLLBACK TRAN). Transactions must exhibit all the ACID properties of a transaction. ACID Properties Transaction processing must guarantee the consistency and recoverability of SQL Server databases. Ensures all transactions are performed as a single unit of work regardless of hardware or system failure. A – Atomicity C – Consistency I – Isolation D- Durability Atomicity: Each transaction is treated as all or nothing – it either commits or aborts. Consistency: ensures that a transaction won’t allow the system to arrive at an incorrect logical state – the data must always be logically correct.  Consistency is honored even in the event of a system failure. Isolation: separates concurrent transactions from the updates of other incomplete transactions. SQL Server accomplishes isolation among transactions by locking data or creating row versions. Durability: After a transaction commits, the durability property ensures that the effects of the transaction persist even if a system failure occurs. If a system failure occurs while a transaction is in progress, the transaction is completely undone, leaving no partial effects on data. Transaction Dependencies In addition to supporting all four ACID properties, a transaction might exhibit few other behaviors (known as dependency problems or consistency problems). Lost Updates: Occur when two processes read the same data and both manipulate the data, changing its value and then both try to update the original data to the new value. The second process might overwrite the first update completely. Dirty Reads: Occurs when a process reads uncommitted data. If one process has changed data but not yet committed the change, another process reading the data will read it in an inconsistent state. Non-repeatable Reads: A read is non-repeatable if a process might get different values when reading the same data in two reads within the same transaction. This can happen when another process changes the data in between the reads that the first process is doing. Phantoms: Occurs when membership in a set changes. It occurs if two SELECT operations using the same predicate in the same transaction return a different number of rows. Isolation Levels SQL Server supports 5 isolation levels that control the behavior of read operations. Read Uncommitted All behaviors except for lost updates are possible. Implemented by allowing the read operations to not take any locks, and because of this, it won’t be blocked by conflicting locks acquired by other processes. The process can read data that another process has modified but not yet committed. When using the read uncommitted isolation level and scanning an entire table, SQL Server can decide to do an allocation order scan (in page-number order) instead of a logical order scan (following page pointers). If another process doing concurrent operations changes data and move rows to a new location in the table, the allocation order scan can end up reading the same row twice. Also can happen if you have read a row before it is updated and then an update moves the row to a higher page number than your scan encounters later. Performing an allocation order scan under Read Uncommitted can cause you to miss a row completely – can happen when a row on a high page number that hasn’t been read yet is updated and moved to a lower page number that has already been read. Read Committed Two varieties of read committed isolation: optimistic and pessimistic (default). Ensures that a read never reads data that another application hasn’t committed. If another transaction is updating data and has exclusive locks on data, your transaction will have to wait for the locks to be released. Your transaction must put share locks on data that are visited, which means that data might be unavailable for others to use. A share lock doesn’t prevent others from reading but prevents them from updating. Read committed (snapshot) ensures that an operation never reads uncommitted data, but not by forcing other processes to wait. SQL Server generates a version of the changed row with its previous committed values. Data being changed is still locked but other processes can see the previous versions of the data as it was before the update operation began. Repeatable Read This is a Pessimistic isolation level. Ensures that if a transaction revisits data or a query is reissued the data doesn’t change. That is, issuing the same query twice within a transaction cannot pickup any changes to data values made by another user’s transaction because no changes can be made by other transactions. However, this does allow phantom rows to appear. Preventing non-repeatable read is a desirable safeguard but cost is that all shared locks in a transaction must be held until the completion of the transaction. Snapshot Snapshot Isolation (SI) is an optimistic isolation level. Allows for processes to read older versions of committed data if the current version is locked. Difference between snapshot and read committed has to do with how old the older versions have to be. It’s possible to have two transactions executing simultaneously that give us a result that is not possible in any serial execution. Serializable This is the strongest of the pessimistic isolation level. Adds to repeatable read isolation level by ensuring that if a query is reissued rows were not added in the interim, i.e, phantoms do not appear. Preventing phantoms is another desirable safeguard, but cost of this extra safeguard is similar to that of repeatable read – all shared locks in a transaction must be held until the transaction completes. In addition serializable isolation level requires that you lock data that has been read but also data that doesn’t exist. Ex: if a SELECT returned no rows, you want it to return no. rows when the query is reissued. This is implemented in SQL Server by a special kind of lock called the key-range lock. Key-range locks require that there be an index on the column that defines the range of values. If there is no index on the column, serializable isolation requires a table lock. Gets its name from the fact that running multiple serializable transactions at the same time is equivalent of running them one at a time. Now that we understand the basics of what concurrency is, the subsequent blog posts will try to bring out the basics around locking, blocking, deadlocks because they are the fundamental blocks that make concurrency possible. Now if you are with me – let us continue learning for SQL Server Locking Basics. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: Concurrency

    Read the article

  • On Contract Employment

    - by kerry
    I am going to post about something I don’t post about a lot, the business side of development.  Scott at the antipimp does a good job of explaining how contracts work from a business perspective.  I am going to give a view from the ground. First, a little background on myself.  I have recently taken a 6 month contract after about 8 years of fulltime employment.  I have 2 kids, and a stay at home wife.  I took this contract opportunity because I wanted to try it on for size.  I have always wondered whether I would like doing contracts over fulltime employment.  So, in keeping with the theme of this blog I will write this down now so that I may reference it later. ALL jobs are temporary! Right now you may not realize it, most people simply ignore it, but EVERY job is temporary.  Everyone should be planning for life after the money stops coming in.  Sadly, most people do not.  Contracting pushes this issue to the forefront, making you deal with it.  After a month on a contract, I am happy to say that I am saving more than I ever saved in a fulltime position.  Hopefully, I will be ready in case of an extended window of unemployment between contracts. Networking I find it extremely gratifying getting to know people.  It is especially beneficial when moving to a new city.  What better way to go out and meet people in your field than to work a few contracts?  6 months of working beside someone and you get to know them pretty well.  This is one of my favorite aspects. Technical Agility Moving between IS shops takes (or molds you into) a flexible person.  You have to be able to go in and hit the ground running.  This means you need to be able to sit down and start work on a large codebase working in a language that you may or may not have that much experience in.  It is also an excellent way to learn new languages and broaden your technical skill set.  I took my current position to learn Ruby.  A month ago, I had only used it in passing, but now I am using it every day.  It’s a tragedy in this field when people start coding for the joy and love of coding, then become deeply entrenched in their companies methods and technologies that it becomes a just a job. Less Stress I am not talking about the kind of stress you get from a jackass boss.  I am talking about the kind of stress I (or others) experience about planning and future proofing your code.  Not saying I stay up at night worrying whether we have done it right, if that code I wrote today is going to bite me later, but it still creeps around in the dark recesses of my mind.  Careful though, I am not suggesting you write sloppy code; just defer any large architectural or design decisions to the ‘code owners’. Flexible Scheduling It makes me very happy to be able to cut out a few hours early on a Friday (provided the work is done) and start the weekend off early by going to the pool, or taking the kids to the park.  Contracting provides you this opportunity (mileage may vary).  Most of your fulltime brethren will not care, they will be jealous that they’re corporate policy prevents them from doing the same.  However, you must be mindful of situations where this is not appropriate, and don’t over do it.  You are there to work after all. Affirmation of Need Have you ever been stuck in a job where you thought you were underpaid?  Have you ever been in a position where you felt like there was not enough workload for you?  This is not a problem for contractors.  When you start a contract it is understood that you are needed, and the employer knows that you are happy with the terms. Contracting may not be for everyone.  But, if you develop a relationship with a good consulting firm, keep their clients happy, then they will keep you happy.  They want you to work almost as much as you do.  Just be sure and plan financially for any windows of unemployment.

    Read the article

  • PASS Summit Feedback

    - by Rob Farley
    PASS Feedback came in last week. I also saw my dentist for some fillings... At the PASS Summit this year, I delivered a couple of regular sessions and a Lightning Talk. People told me they enjoyed it, but when the rankings came out, they showed that I didn’t score particularly well. Brent Ozar was keen to discuss it with me. Brent: PASS speaker feedback is out. You did two sessions and a Lightning Talk. How did you go? Rob: Not so well actually, thanks for asking. Brent: Ha! Sorry. Of course you know that's why I wanted to discuss this with you. I was in one of your sessions at SQLBits in the UK a month before PASS, and I thought you rocked. You've got a really good and distinctive delivery style.  Then I noticed your talks were ranked in the bottom quarter of the Summit ratings and wanted to discuss it. Rob: Yeah, I know. You did ask me if we could do this...  I should explain – my presentation style is not the stereotypical IT conference one. I throw in jokes, and try to engage the audience thoroughly. I find many talks amazingly dry, and I guess I try to buck that trend. I also run training courses, and find that I get a lot of feedback from people thanking me for keeping things interesting. That said, I also get feedback criticising me for my style, and that’s basically what’s happened here. For the rest of this discussion, let’s focus on my talk about the Incredible Shrinking Execution Plan, which I considered to be my main talk. Brent: I thought that session title was the very best one at the entire Summit, and I had it on my recommended sessions list.  In four words, you managed to sum up the topic and your sense of humor.  I read that and immediately thought, "People need to be in this session," and then it didn't score well.  Tell me about your scores. Rob: The questions on the feedback form covered the usefulness of the information, the speaker’s presentation skills, their knowledge of the subject, how well the session was described, the amount of time allocated, and the quality of the presentation materials. Brent: Presentation materials? But you don’t do slides.  Did they rate your thong? Rob: No-one saw my flip-flops in this talk, Brent. I created a script in Management Studio, and published that afterwards, but I think people will have scored that question based on the lack of slides. I wasn’t expecting to do particularly well on that one. That was the only section that didn’t have 5/5 as the most popular score. Brent: See, that sucks, because cookbook-style scripts are often some of my favorites.  Adam Machanic's Service Broker workbench series helped me immensely when I was prepping for the MCM.  As an attendee, I'd rather have a commented script than a slide deck.  So how did you rank so low? Rob: When I look at the scores that you got (based on your blog post), you got very few scores below 3 – people that felt strong enough about your talk to post a negative score. In my scores, between 5% and 10% were below 3 (except on the question about whether I knew my stuff – I guess I came as knowledgeable). Brent: Wow – so quite a few people really didn’t like your talk then? Rob: Yeah. Mind you, based on the comments, some people really loved it. I’d like to think that there would be a certain portion of the room who may have rated the talk as one of the best of the conference. Some of my comments included “amazing!”, “Best presentation so far!”, “Wow, best session yet”, “fantastic” and “Outstanding!”. I think lots of talks can be “Great”, but not so many talks can be “Outstanding” without the word losing its meaning. One wrote “Pretty amazing presentation, considering it was completely extemporaneous.” Brent: Extemporaneous, eh? Rob: Yeah. I guess they don’t realise how much preparation goes into coming across as unprepared. In many ways it’s much easier to give a written speech than to deliver a presentation without slides as a prompt. Brent: That delivery style, the really relaxed, casual, college-professor approach was one of the things I really liked about your presentation at SQLbits.  As somebody who presents a lot, I "get" it - I know how hard it is to come off as relaxed and comfortable with your own material.  It's like improv done by jazz players and comedians - if you've never tried it, you don't realize how hard it is.  People also don't realize how hard it is to make a tough subject fun. Rob: Yeah well... There will be people writing comments on this post that say I wasn't trying to make the subject fun, and that I was making it all about me. Sometimes the style works, sometimes it doesn't. Most of the comments mentioned the fact that I tell jokes, some in a nice way, but some not so much (and it wasn't just a PASS thing - that's the mix of feedback I generally get). One comment at PASS was: “great stand up comedian - not what I'm looking for at pass”, and there were certainly a few that said “too many jokes”. I’m not trying to do stand-up – jokes are my way of engaging with the audience while I demonstrate some of the amazing things that the Query Optimizer can do if you write your queries the right way. Some people didn’t think it was technical enough, but I’ve also had some people tell me that the concepts I’m explaining are deep and profound. Brent: To me, that's a hallmark of a great explanation - when someone says, "But of course it has to work that way - how could it work any other way?  It seems so simple and logical."  Well, sure it does when it's explained correctly, but now pick up any number of thick SQL Server books and try to understand the Redundant Joins concept.  I guarantee it'll take more than 45 minutes. Rob: Some people in my audiences realise that, but definitely not everyone. There's only so much you can tell someone that something is profound. Generally it's something that they either have an epiphany on or not. I like to lull my audience into knowing what's going on, and do something that surprises them. Gain their trust, build a rapport, and then show them the deeper truth of what just happened. Brent: So you've learned your lesson about presentation scores, right?  From here on out, you're going to be dry, humorless, and all your presentations will consist of you reading bullet points off the screen. Rob: No Brent, I’m not. I'm also not going to suggest that most presentations at PASS are like that. No-one tries to present like that. There's a big space to occupy between what "dry and humourless" and me. My difference is to focus on the relationship I have with the crowd, rather than focussing on delivering the perfect session. I want to see people smiling and know they're relaxed. I think most presenters focus on the material, which is completely reasonable and safe. I remember once hearing someone talking about product creation. They talked about mediocrity. They said that one of the worst things that people can ever say about your product is that it’s “good”. What you want is for 10% of the world to love it enough to want to buy it. If 10% the world gave me a dollar, I’d have more money than I could ever use (assuming it wasn’t the SAME dollar they were giving me I guess). Brent: It's the Raving Fans theory.  It's better to have a small number of raving customers than a large number of almost-but-not-really customers who don't care that much about your product or service.  I know exactly how you feel - when I got survey feedback from my Quest video presentation when I was dressed up in a Richard Simmons costume, some of the attendees said I was unprofessional and distracting.  Some of the attendees couldn't get enough and Photoshopped all kinds of stuff into the screen captures.  On a whole, I probably didn't score that well, and I'm fine with that.  It sucks to look at the scores though - do those lower scores bother you? Rob: Of course they do. It hurts deeply. I open myself up and give presentations in a very personal way. All presenters do that, and we all feel the pain of negative feedback. I hate coming 146th & 162nd out of 185, but have to acknowledge that many sessions did worse still. Plus, once I feel the wounds have healed, I’ll be able to remember that there are people in the world that rave about my presentation style, and figure that people will hopefully talk about me. One day maybe those people that don’t like my presentation style will stay away and I might be able to score better. You don’t pay to hear country music if you prefer western... Lots of people find chili too spicy, but it’s still a popular food. Brent: But don’t you want to appeal to everyone? Rob: I do, but I don’t want to be lukewarm as in Revelation 3:16. I’d rather disgust and be discussed. Well, maybe not ‘disgust’, but I don’t want to conform. Conformity just isn’t the same any more. I’m not sure I’ve ever been one to do that. I try not to offend, but definitely like to be different. Brent: Count me among your raving fans, sir.  Where can we see you next? Rob: Considering I live in Adelaide in Australia, I’m not about to appear at anyone’s local SQL Saturday. I’m still trying to plan which events I’ll get to in 2011. I’ve submitted abstracts for TechEd North America, but won’t hold my breath. I’m also considering the SQLBits conferences in the UK in April, PASS in October, and I’m sure I’ll do some LiveMeeting presentations for user groups. Online, people download some of my recent SQLBits presentations at http://bit.ly/RFSarg and http://bit.ly/Simplification though. And they can download a 5-minute MP3 of my Lightning Talk at http://www.lobsterpot.com.au/files/Collation.mp3, in which I try to explain the idea behind collation, using thongs as an example. Brent: I was in the audience for http://bit.ly/RFSarg. That was a great presentation. Rob: Thanks, Brent. Now where’s my dollar?

    Read the article

  • Demystifying Silverlight Dependency Properties

    - by dwahlin
    I have the opportunity to teach a lot of people about Silverlight (amongst other technologies) and one of the topics that definitely confuses people initially is the concept of dependency properties. I confess that when I first heard about them my initial thought was “Why do we need a specialized type of property?” While you can certainly use standard CLR properties in Silverlight applications, Silverlight relies heavily on dependency properties for just about everything it does behind the scenes. In fact, dependency properties are an essential part of the data binding, template, style and animation functionality available in Silverlight. They simply back standard CLR properties. In this post I wanted to put together a (hopefully) simple explanation of dependency properties and why you should care about them if you’re currently working with Silverlight or looking to move to it.   What are Dependency Properties? XAML provides a great way to define layout controls, user input controls, shapes, colors and data binding expressions in a declarative manner. There’s a lot that goes on behind the scenes in order to make XAML work and an important part of that magic is the use of dependency properties. If you want to bind data to a property, style it, animate it or transform it in XAML then the property involved has to be a dependency property to work properly. If you’ve ever positioned a control in a Canvas using Canvas.Left or placed a control in a specific Grid row using Grid.Row then you’ve used an attached property which is a specialized type of dependency property. Dependency properties play a key role in XAML and the overall Silverlight framework. Any property that you bind, style, template, animate or transform must be a dependency property in Silverlight applications. You can programmatically bind values to controls and work with standard CLR properties, but if you want to use the built-in binding expressions available in XAML (one of my favorite features) or the Binding class available through code then dependency properties are a necessity. Dependency properties aren’t needed in every situation, but if you want to customize your application very much you’ll eventually end up needing them. For example, if you create a custom user control and want to expose a property that consumers can use to change the background color, you have to define it as a dependency property if you want bindings, styles and other features to be available for use. Now that the overall purpose of dependency properties has been discussed let’s take a look at how you can create them. Creating Dependency Properties When .NET first came out you had to write backing fields for each property that you defined as shown next: Brush _ScheduleBackground; public Brush ScheduleBackground { get { return _ScheduleBackground; } set { _ScheduleBackground = value; } } Although .NET 2.0 added auto-implemented properties (for example: public Brush ScheduleBackground { get; set; }) where the compiler would automatically generate the backing field used by get and set blocks, the concept is still the same as shown in the above code; a property acts as a wrapper around a field. Silverlight dependency properties replace the _ScheduleBackground field shown in the previous code and act as the backing store for a standard CLR property. The following code shows an example of defining a dependency property named ScheduleBackgroundProperty: public static readonly DependencyProperty ScheduleBackgroundProperty = DependencyProperty.Register("ScheduleBackground", typeof(Brush), typeof(Scheduler), null);   Looking through the code the first thing that may stand out is that the definition for ScheduleBackgroundProperty is marked as static and readonly and that the property appears to be of type DependencyProperty. This is a standard pattern that you’ll use when working with dependency properties. You’ll also notice that the property explicitly adds the word “Property” to the name which is another standard you’ll see followed. In addition to defining the property, the code also makes a call to the static DependencyProperty.Register method and passes the name of the property to register (ScheduleBackground in this case) as a string. The type of the property, the type of the class that owns the property and a null value (more on the null value later) are also passed. In this example a class named Scheduler acts as the owner. The code handles registering the property as a dependency property with the call to Register(), but there’s a little more work that has to be done to allow a value to be assigned to and retrieved from the dependency property. The following code shows the complete code that you’ll typically use when creating a dependency property. You can find code snippets that greatly simplify the process of creating dependency properties out on the web. The MVVM Light download available from http://mvvmlight.codeplex.com comes with built-in dependency properties snippets as well. public static readonly DependencyProperty ScheduleBackgroundProperty = DependencyProperty.Register("ScheduleBackground", typeof(Brush), typeof(Scheduler), null); public Brush ScheduleBackground { get { return (Brush)GetValue(ScheduleBackgroundProperty); } set { SetValue(ScheduleBackgroundProperty, value); } } The standard CLR property code shown above should look familiar since it simply wraps the dependency property. However, you’ll notice that the get and set blocks call GetValue and SetValue methods respectively to perform the appropriate operation on the dependency property. GetValue and SetValue are members of the DependencyObject class which is another key component of the Silverlight framework. Silverlight controls and classes (TextBox, UserControl, CompositeTransform, DataGrid, etc.) ultimately derive from DependencyObject in their inheritance hierarchy so that they can support dependency properties. Dependency properties defined in Silverlight controls and other classes tend to follow the pattern of registering the property by calling Register() and then wrapping the dependency property in a standard CLR property (as shown above). They have a standard property that wraps a registered dependency property and allows a value to be assigned and retrieved. If you need to expose a new property on a custom control that supports data binding expressions in XAML then you’ll follow this same pattern. Dependency properties are extremely useful once you understand why they’re needed and how they’re defined. Detecting Changes and Setting Defaults When working with dependency properties there will be times when you want to assign a default value or detect when a property changes so that you can keep the user interface in-sync with the property value. Silverlight’s DependencyProperty.Register() method provides a fourth parameter that accepts a PropertyMetadata object instance. PropertyMetadata can be used to hook a callback method to a dependency property. The callback method is called when the property value changes. PropertyMetadata can also be used to assign a default value to the dependency property. By assigning a value of null for the final parameter passed to Register() you’re telling the property that you don’t care about any changes and don’t have a default value to apply. Here are the different constructor overloads available on the PropertyMetadata class: PropertyMetadata Constructor Overload Description PropertyMetadata(Object) Used to assign a default value to a dependency property. PropertyMetadata(PropertyChangedCallback) Used to assign a property changed callback method. PropertyMetadata(Object, PropertyChangedCalback) Used to assign a default property value and a property changed callback.   There are many situations where you need to know when a dependency property changes or where you want to apply a default. Performing either task is easily accomplished by creating a new instance of the PropertyMetadata class and passing the appropriate values to its constructor. The following code shows an enhanced version of the initial dependency property code shown earlier that demonstrates these concepts: public Brush ScheduleBackground { get { return (Brush)GetValue(ScheduleBackgroundProperty); } set { SetValue(ScheduleBackgroundProperty, value); } } public static readonly DependencyProperty ScheduleBackgroundProperty = DependencyProperty.Register("ScheduleBackground", typeof(Brush), typeof(Scheduler), new PropertyMetadata(new SolidColorBrush(Colors.LightGray), ScheduleBackgroundChanged)); private static void ScheduleBackgroundChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) { var scheduler = d as Scheduler; scheduler.Background = e.NewValue as Brush; } The code wires ScheduleBackgroundProperty to a property change callback method named ScheduleBackgroundChanged. What’s interesting is that this callback method is static (as is the dependency property) so it gets passed the instance of the object that owns the property that has changed (otherwise we wouldn’t be able to get to the object instance). In this example the dependency object is cast to a Scheduler object and its Background property is assigned to the new value of the dependency property. The code also handles assigning a default value of LightGray to the dependency property by creating a new instance of a SolidColorBrush. To Sum Up In this post you’ve seen the role of dependency properties and how they can be defined in code. They play a big role in XAML and the overall Silverlight framework. You can think of dependency properties as being replacements for fields that you’d normally use with standard CLR properties. In addition to a discussion on how dependency properties are created, you also saw how to use the PropertyMetadata class to define default dependency property values and hook a dependency property to a callback method. The most important thing to understand with dependency properties (especially if you’re new to Silverlight) is that they’re needed if you want a property to support data binding, animations, transformations and styles properly. Any time you create a property on a custom control or user control that has these types of requirements you’ll want to pick a dependency property over of a standard CLR property with a backing field. There’s more that can be covered with dependency properties including a related property called an attached property….more to come.

    Read the article

  • ASP.NET MVC 3 Hosting :: ASP.NET MVC 3 First Look

    - by mbridge
    MVC 3 View Enhancements MVC 3 introduces two improvements to the MVC view engine: - Ability to select the view engine to use. MVC 3 allows you to select from any of your  installed view engines from Visual Studio by selecting Add > View (including the newly introduced ASP.NET “Razor” engine”): - Support for the next ASP.NET “Razor” syntax. The newly previewed Razor syntax is a concise lightweight syntax. MVC 3 Control Enhancements - Global Filters: ASP.NET MVC 3  allows you to specify that a filter which applies globally to all Controllers within an app by adding it to the GlobalFilters collection.  The RegisterGlobalFilters() method is now included in the default Global.asax class template and so provides a convenient place to do this since is will then be called by the Application_Start() method: void RegisterGlobalFilters(GlobalFilterCollection filters) { filters.Add(new HandleLoggingAttribute()); filters.Add(new HandleErrorAttribute()); } void Application_Start() { RegisterGlobalFilters (GlobalFilters.Filters); } - Dynamic ViewModel Property : MVC 3 augments the ViewData API with a new “ViewModel” property on Controller which is of type “dynamic” – and therefore enables you to use the new dynamic language support in C# and VB pass ViewData items using a cleaner syntax than the current dictionary API. Public ActionResult Index() { ViewModel.Message = "Hello World"; return View(); } - New ActionResult Types : MVC 3 includes three new ActionResult types and helper methods: 1. HttpNotFoundResult – indicates that a resource which was requested by the current URL was not found. HttpNotFoundResult will return a 404 HTTP status code to the calling client. 2. PermanentRedirects – The HttpRedirectResult class contains a new Boolean “Permanent” property which is used to indicate that a permanent redirect should be done. Permanent redirects use a HTTP 301 status code.  The Controller class  includes three new methods for performing these permanent redirects: RedirectPermanent(), RedirectToRoutePermanent(), andRedirectToActionPermanent(). All  of these methods will return an instance of the HttpRedirectResult object with the Permanent property set to true. 3. HttpStatusCodeResult – used for setting an explicit response status code and its associated description. MVC 3 AJAX and JavaScript Enhancements MVC 3 ships with built-in JSON binding support which enables action methods to receive JSON-encoded data and then model-bind it to action method parameters. For example a jQuery client-side JavaScript could define a “save” event handler which will be invoked when the save button is clicked on the client. The code in the event handler then constructs a client-side JavaScript “product” object with 3 fields with their values retrieved from HTML input elements. Finally, it uses jQuery’s .ajax() method to POST a JSON based request which contains the product to a /theStore/UpdateProduct URL on the server: $('#save').click(function () { var product = { ProdName: $('#Name').val() Price: $('#Price').val(), } $.ajax({ url: '/theStore/UpdateProduct', type: "POST"; data: JSON.stringify(widget), datatype: "json", contentType: "application/json; charset=utf-8", success: function () { $('#message').html('Saved').fadeIn(), }, error: function () { $('#message').html('Error').fadeIn(), } }); return false; }); MVC will allow you to implement the /theStore/UpdateProduct URL on the server by using an action method as below. The UpdateProduct() action method will accept a strongly-typed Product object for a parameter. MVC 3 can now automatically bind an incoming JSON post value to the .NET Product type on the server without having to write any custom binding. [HttpPost] public ActionResult UpdateProduct(Product product) { // save logic here return null } MVC 3 Model Validation Enhancements MVC 3 builds on the MVC 2 model validation improvements by adding   support for several of the new validation features within the System.ComponentModel.DataAnnotations namespace in .NET 4.0: - Support for the new DataAnnotations metadata attributes like DisplayAttribute. - Support for the improvements made to the ValidationAttribute class which now supports a new IsValid overload that provides more info on  the current validation context, like what object is being validated. - Support for the new IValidatableObject interface which enables you to perform model-level validation and also provide validation error messages which are specific to the state of the overall model. MVC 3 Dependency Injection Enhancements MVC 3 includes better support for applying Dependency Injection (DI) and also integrating with Dependency Injection/IOC containers. Currently MVC 3 Preview 1 has support for DI in the below places: - Controllers (registering & injecting controller factories and injecting controllers) - Views (registering & injecting view engines, also for injecting dependencies into view pages) - Action Filters (locating and  injecting filters) And this is another important blog about Microsoft .NET and technology: - Windows 2008 Blog - SharePoint 2010 Blog - .NET 4 Blog And you can visit here if you're looking for ASP.NET MVC 3 hosting

    Read the article

  • Some New .NET Toys (Repost)

    - by Kevin Grossnicklaus
    Last week I was fortunate enough to spend time in Redmond on Microsoft’s campus for the 2011 Microsoft MVP Summit. It was great to hang out with a number of old friends and get the opportunity to talk tech with the various product teams up at Microsoft. The weather wasn’t exactly sunny but Microsoft always does a great job with the Summit and everyone had a blast (heck, I even got to run the bases at SafeCo field) While much of what we saw is covered under NDA, there a ton of great things in the pipeline from Microsoft and many things that are already available (or just became so) that I wasn’t necessarily aware of. The purpose of this post is to share some of the info I learned on resources and tools available to .NET developers today. Please let me know if you have any questions (or if you know of something else cool which might benefit others). Enjoy! Visual Studio 2010 SP1 Microsoft has issued the RTM release of Visual Studio 2010 SP1. You can download the full SP1 on MSDN as of today (March 10th to the general public) and take advantage of such things as: Silverlight 4 is included in the box (as opposed to a separate install) Silverlight 4 Profiling WCF RIA Services SP1 Intellitrace for 64-bit and SharePoint ASP.NET now easily supports IIS Express and SQL CE Want a description of all that’s new beyond the above biased list (which arguably only contains items I think are important)? Check out this KB article. Portable Library Tools CTP Without much fanfare Microsoft has released a CTP of a new add-in to Visual Studio 2010 which simplifies code sharing between projects targeting different runtimes (i.e. Silverlight, WPF, Win7 Phone, XBox). With this Add-In installed you can add a new project of type “Portable Library” and specify which platforms you wish to target. Once that is done, any code added to this library will be limited to use only features which are common to all selected frameworks. Other projects can now reference this portable library and be provided assemblies custom built to their environment. This greatly simplifies the current process of sharing linked files between platforms like WPF and Silverlight. You can find out more about this CTP and how it works on this great blog post. Visual Studio Async CTP Microsoft has also released a CTP of a set of language and framework enhancements to provide a much more powerful asynchronous programming model. Due to the focus on async programming in all types of platforms (and it being the ONLY option in Silverlight and Win7 phone) a move towards a simpler and more understandable model is always a good thing. This CTP (called Visual Studio Async CTP) can be downloaded here. You can read more about this CTP on this blog post. MSDN Code Samples Gallery Microsoft has also launched new code samples gallery on their MSDN site: http://code.msdn.microsoft.com/. This site allows you to easily search for small samples of code related to a particular technology or platform. If a sample of code you are looking for is not found, you can request one via the site and other developers can see your request and provide a sample to the site to suit your needs. You can also peruse requested samples and, if you find a scenario where you can provide value, upload your own sample for the benefit of others. Samples are packaged into the VS .vsix format and include any necessary references/dependencies. By using .vsix as the deployment mechanism, as samples are installed from the site they are kept in your Visual Studio 2010 Samples Gallery and kept for your future reference. If you get a chance, check out the site and see how it is done. Although a somewhat simple concept, I was very impressed with their implementation and the way they went about trying to suit a need. I’ll definitely be looking there in the future as need something or want to share something. MSDN Search Capabilities Another item I learned recently and was not aware of (that might seem trivial to some) is the power of the MSDN site’s search capabilities. Between the Code Samples Gallery described above and the search enhancements on MSDN, Microsoft is definitely investing in their platform to help provide developers of all skill levels the tools and resources they need to be successful. What do I mean by the MSDN search capability and why should you care? If you go to the MSDN home page (http://msdn.microsoft.com) and use the “Search MSDN with Big” box at the very top of the page you will see some very interesting results. First, the search actually doesn’t just search the MSDN library it searches: MSDN Library All Microsoft Blogs CodePlex StackOverflow Downloads MSDN Magazine Support Knowledgebase (I’m not sure it even ends there but the above are all I know of) Beyond just searching all the above locations, the results are formatted very nicely to give some contextual information based on where the result came from. For example, if a keyword search returned results from CodePlex, each row in the search results screen would include a large amount of information specific to CodePlex such as: Looking at the above results immediately tells you everything from the page views to the CodePlex ratings. All in all, knowing that this much information is indexed and available from a single search location will lead me to utilize this as one of my initial searches for development information.

    Read the article

  • A Rose by Any Other Name..

    - by Geoff N. Hiten
    It is always a good start when you can steal a title line from one of the best writers in the English language.  Let’s hope I can make the rest of this post live up to the opening.  One recurring problem with SQL server is moving databases to new servers.  Client applications use a variety of ways to resolve SQL Server names, some of which are not changed easily <cough SharePoint /cough>.  If you happen to be using default instances on both the source and target SQL Server, then the solution is pretty simple.  You create (or bug the network admin until she creates) two DNS “A” records. One points the old name to the new IP address.  The other creates a new alias for the old server, since the original system name is now redirected.  Note this will redirect ALL traffic from the old server to the new server, including RDP and file share connection attempts.    Figure 1 – Microsoft DNS MMC Snap-In   Figure 2 – DNS New Host Dialog Box Both records are necessary so you can still access the old server via an alternate name. Server Role IP Address Name Alias Source 10.97.230.60 SQL01 SQL01_Old Target 10.97.230.80 SQL02 SQL01 Table 1 – Alias List If you or somebody set up connections via IP address, you deserve to have to go to each app and fix it by hand.  That is the only way to fix that particular foul-up. If have to deal with Named Instances either as a source or a target, then it gets more complicated.  The standard fix is to use the SQL Server Configuration Manager (or one of its earlier incarnations) to create a SQL client alias to redirect the connection.  This can be a pain installing and configuring the app on multiple client servers.  The good news is that SQL Server Configuration Manager AND all of its earlier versions simply write a few registry keys.  Extracting the keys into a .reg file makes centralized automated deployment a snap. If the client is a 32-bit system, you have to extract the native key.  If it is a 64-bit, you have to extract the native key and the WoW (32 bit on 64 bit host) key. First, pick a development system to create the actual registry key.  If you do this repeatedly, you can simply edit an existing registry file.  Create the entry using the SQL Configuration Manager.  You must use a 64-bit system to create the WoW key.  The following example redirects from a named instance “SQL01\SQLUtiluty” to a default instance on “SQL02”.   Figure 3 – SQL Server Configuration Manager - Native Figure 3 shows the native key listing. Figure 4 – SQL Server Configuration Manager – WoW If you think you don’t need the WoW key because your app is 64 it, think again.  SQL Server Management Server is a 32-bit app, as are most SQL test utilities.  Always create both keys for 64-bit target systems. Now that the keys exist, we can extract them into a .reg file. Fire up REGEDIT and browse to the following location:  HKLM\Software\Microsoft\MSSQLServer\Client\ConnectTo.  You can also search the registry for the string value of one of the server names (old or new). Right click on the “ConnectTo” label and choose “Export”.  Save with an appropriate name and location.  The resulting file should look something like this: Figure 5 – SQL01_Alias.reg Repeat the process with the location: HKLM\Software\Wow6432Node\Microsoft\MSSQLServer\Client\ConnectTo Note that if you have multiple alias entries, ALL of the entries will be exported.  In that case, you can edit the file and remove the extra aliases. You can edit the files together into a single file.  Just leave a blank line between new keys like this: Figure 6 – SQL01_Alias_All.reg Of course if you have an automatic way to deploy, it makes sense to have an automatic way to Un-deploy.  To delete a registry key, simply edit the .reg file and replace the target with a “-“ sign like so. Figure 7 – SQL01_Alias_UNDO.reg Now we have the ability to move any database to any server without having to install or change any applications on any client server.  The whole process should be transparent to the applications, which makes planning and coordinating database moves a far simpler task.

    Read the article

  • NoSQL Memcached API for MySQL: Latest Updates

    - by Mat Keep
    With data volumes exploding, it is vital to be able to ingest and query data at high speed. For this reason, MySQL has implemented NoSQL interfaces directly to the InnoDB and MySQL Cluster (NDB) storage engines, which bypass the SQL layer completely. Without SQL parsing and optimization, Key-Value data can be written directly to MySQL tables up to 9x faster, while maintaining ACID guarantees. In addition, users can continue to run complex queries with SQL across the same data set, providing real-time analytics to the business or anonymizing sensitive data before loading to big data platforms such as Hadoop, while still maintaining all of the advantages of their existing relational database infrastructure. This and more is discussed in the latest Guide to MySQL and NoSQL where you can learn more about using the APIs to scale new generations of web, cloud, mobile and social applications on the world's most widely deployed open source database The native Memcached API is part of the MySQL 5.6 Release Candidate, and is already available in the GA release of MySQL Cluster. By using the ubiquitous Memcached API for writing and reading data, developers can preserve their investments in Memcached infrastructure by re-using existing Memcached clients, while also eliminating the need for application changes. Speed, when combined with flexibility, is essential in the world of growing data volumes and variability. Complementing NoSQL access, support for on-line DDL (Data Definition Language) operations in MySQL 5.6 and MySQL Cluster enables DevOps teams to dynamically update their database schema to accommodate rapidly changing requirements, such as the need to capture additional data generated by their applications. These changes can be made without database downtime. Using the Memcached interface, developers do not need to define a schema at all when using MySQL Cluster. Lets look a little more closely at the Memcached implementations for both InnoDB and MySQL Cluster. Memcached Implementation for InnoDB The Memcached API for InnoDB is previewed as part of the MySQL 5.6 Release Candidate. As illustrated in the following figure, Memcached for InnoDB is implemented via a Memcached daemon plug-in to the mysqld process, with the Memcached protocol mapped to the native InnoDB API. Figure 1: Memcached API Implementation for InnoDB With the Memcached daemon running in the same process space, users get very low latency access to their data while also leveraging the scalability enhancements delivered with InnoDB and a simple deployment and management model. Multiple web / application servers can remotely access the Memcached / InnoDB server to get direct access to a shared data set. With simultaneous SQL access, users can maintain all the advanced functionality offered by InnoDB including support for Foreign Keys, XA transactions and complex JOIN operations. Benchmarks demonstrate that the NoSQL Memcached API for InnoDB delivers up to 9x higher performance than the SQL interface when inserting new key/value pairs, with a single low-end commodity server supporting nearly 70,000 Transactions per Second. Figure 2: Over 9x Faster INSERT Operations The delivered performance demonstrates MySQL with the native Memcached NoSQL interface is well suited for high-speed inserts with the added assurance of transactional guarantees. You can check out the latest Memcached / InnoDB developments and benchmarks here You can learn how to configure the Memcached API for InnoDB here Memcached Implementation for MySQL Cluster Memcached API support for MySQL Cluster was introduced with General Availability (GA) of the 7.2 release, and joins an extensive range of NoSQL interfaces that are already available for MySQL Cluster Like Memcached, MySQL Cluster provides a distributed hash table with in-memory performance. MySQL Cluster extends Memcached functionality by adding support for write-intensive workloads, a full relational model with ACID compliance (including persistence), rich query support, auto-sharding and 99.999% availability, with extensive management and monitoring capabilities. All writes are committed directly to MySQL Cluster, eliminating cache invalidation and the overhead of data consistency checking to ensure complete synchronization between the database and cache. Figure 3: Memcached API Implementation with MySQL Cluster Implementation is simple: 1. The application sends reads and writes to the Memcached process (using the standard Memcached API). 2. This invokes the Memcached Driver for NDB (which is part of the same process) 3. The NDB API is called, providing for very quick access to the data held in MySQL Cluster’s data nodes. The solution has been designed to be very flexible, allowing the application architect to find a configuration that best fits their needs. It is possible to co-locate the Memcached API in either the data nodes or application nodes, or alternatively within a dedicated Memcached layer. The benefit of this flexible approach to deployment is that users can configure behavior on a per-key-prefix basis (through tables in MySQL Cluster) and the application doesn’t have to care – it just uses the Memcached API and relies on the software to store data in the right place(s) and to keep everything synchronized. Using Memcached for Schema-less Data By default, every Key / Value is written to the same table with each Key / Value pair stored in a single row – thus allowing schema-less data storage. Alternatively, the developer can define a key-prefix so that each value is linked to a pre-defined column in a specific table. Of course if the application needs to access the same data through SQL then developers can map key prefixes to existing table columns, enabling Memcached access to schema-structured data already stored in MySQL Cluster. Conclusion Download the Guide to MySQL and NoSQL to learn more about NoSQL APIs and how you can use them to scale new generations of web, cloud, mobile and social applications on the world's most widely deployed open source database See how to build a social app with MySQL Cluster and the Memcached API from our on-demand webinar or take a look at the docs Don't hesitate to use the comments section below for any questions you may have 

    Read the article

< Previous Page | 510 511 512 513 514 515 516 517 518 519 520 521  | Next Page >