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• Oracle Database 12c Spatial: Vector Performance Acceleration

  - by Okcan Yasin Saygili-Oracle

  Most business information has a location component, such as customer addresses, sales territories and physical assets. Businesses can take advantage of their geographic information by incorporating location analysis and intelligence into their information systems. This allows organizations to make better decisions, respond to customers more effectively, and reduce operational costs – increasing ROI and creating competitive advantage. Oracle Database, the industry’s most advanced database,  includes native location capabilities, fully integrated in the kernel, for fast, scalable, reliable and secure spatial and massive graph applications. It is a foundation for deploying enterprise-wide spatial information systems and locationenabled business applications. Developers can extend existing Oracle-based tools and applications, since they can easily incorporate location information directly in their applications, workflows, and services. Spatial Features The geospatial data features of Oracle Spatial and Graph option support complex geographic information systems (GIS) applications, enterprise applications and location services applications. Oracle Spatial and Graph option extends the spatial query and analysis features included in every edition of Oracle Database with the Oracle Locator feature, and provides a robust foundation for applications that require advanced spatial analysis and processing in the Oracle Database. It supports all major spatial data types and models, addressing challenging business-critical requirements from various industries, including transportation, utilities, energy, public sector, defense and commercial location intelligence. Network Data Model Graph Features The Network Data Model graph explicitly stores and maintains a persistent data model withnetwork connectivity and provides network analysis capability such as shortest path, nearest neighbors, within cost and reachability. It loads partitioned networks into memory on demand, overcomingthe limitations of in-memory analysis. Partitioning massive networks into manageable sub-networkssimplifies the network analysis. RDF Semantic Graph Features RDF Semantic Graph has native support for World Wide Web Consortium standards. It has open, scalable, and secure features for storing RDF/OWL ontologies anddata; native inference with OWL 2, SKOS and user-defined rules; and querying RDF/OWL data withSPARQL 1.1, Java APIs, and SPARQLgraph patterns in SQL. Video: Oracle Spatial and Graph Overview Oracle spatial is embeded on oracle database product. So ,we can use oracle installer (OUI).The Oracle Universal Installer (OUI) is used to install Oracle Database software. OUI is a graphical user interface utility that enables you to view the Oracle software that is installed on your machine, install new Oracle Database software, and delete Oracle software that you no longer need to use. Online Help is available to guide you through the installation process. One of the installation options is to create a database. If you select database creation, OUI automatically starts Oracle Database Configuration Assistant (DBCA) to guide you through the process of creating and configuring a database. If you do not create a database during installation, you must invoke DBCA after you have installed the software to create a database. You can also use DBCA to create additional databases. For installing Oracle Database 12c you may check the Installing Oracle Database Software and Creating a Database tutorial under the Oracle Database 12c 2-Day DBA Series.You can always check if spatial is available in your database using  "select comp_id, version, status, comp_name from dba_registry where comp_id='SDO';"   One of the most notable improvements with Oracle Spatial and Graph 12c can be seen in performance increases in vector data operations. Enabling the Spatial Vector Acceleration feature (available with the Spatial option) dramatically improves the performance of commonly used vector data operations, such as sdo_distance, sdo_aggr_union, and sdo_inside. With 12c, these operations also run more efficiently in parallel than in prior versions through the use of metadata caching. For organizations that have been facing processing limitations, these enhancements enable developers to make a small set of configuration changes and quickly realize significant performance improvements. Results include improved index performance, enhanced geometry engine performance, optimized secondary filter optimizations for Spatial operators, and improved CPU and memory utilization for many advanced vector functions. Vector performance acceleration is especially beneficial when using Oracle Exadata Database Machine and other large-scale systems. Oracle Spatial and Graph vector performance acceleration builds on general improvements available to all SDO_GEOMETRY operations in these areas: Caching of index metadata, Concurrent update mechanisms, and Optimized spatial predicate selectivity and cost functions. These optimizations enable more efficient use of: CPU, Memory, and Partitioning Resulting in substantial query performance improvements.UsageTo accelerate the performance of spatial operators, it is recommended that you set the SPATIAL_VECTOR_ACCELERATION database system parameter to the value TRUE. (This parameter is authorized for use only by licensed Oracle Spatial users, and its default value is FALSE.) You can set this parameter for the whole system or for a single session. To set the value for the whole system, do either of the following:Enter the following statement from a suitably privileged account:   ALTER SYSTEM SET SPATIAL_VECTOR_ACCELERATION = TRUE;Add the following to the database initialization file (xxxinit.ora):   SPATIAL_VECTOR_ACCELERATION = TRUE;To set the value for the current session, enter the following statement from a suitably privileged account:   ALTER SESSION SET SPATIAL_VECTOR_ACCELERATION = TRUE; Checkout the complete list of new features on Oracle.com @ http://www.oracle.com/technetwork/database/options/spatialandgraph/overview/index.html Spatial and Graph Data Sheet (PDF) Spatial and Graph White Paper (PDF)

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• SQL SERVER – Planned and Unplanned Availablity Group Failovers – Notes from the Field #031

  - by Pinal Dave

  [Note from Pinal]: This is a new episode of Notes from the Fields series. AlwaysOn is a very complex subject and not everyone knows many things about this. The matter of the fact is there is very little information available on this subject online and not everyone knows everything about this. This is why when a very common question related to AlwaysOn comes, people get confused. In this episode of the Notes from the Field series database expert John Sterrett (Group Principal at Linchpin People) explains a very common issue DBAs and Developer faces in their career and is related to Planned and Unplanned Availablity Group Failovers. Linchpin People are database coaches and wellness experts for a data driven world. Read the experience of John in his own words. Whenever a disaster occurs it will be a stressful scenario regardless of how small or big the disaster is. This gets multiplied when it is your first time working with newer technology or the first time you are going through a disaster without a proper run book. Today, were going to help you establish a run book for creating a planned failover with availability groups. To make today’s session simple were going to have two instances of SQL Server 2012 included in an availability group and walk through the steps of doing an unplanned failover.  We will focus on using the user interface and T-SQL to complete the failovers. We are going to use a two replica Availability Group where each replica is in another location. Therefore, we will be covering Asynchronous (non automatic failover) the following is a breakdown of our availability group utilized today. Seeing the following screen might be scary the first time you come across an unplanned failover.  It looks like our test database used in this Availability Group is not functional and it currently isn’t. The database status is not synchronizing which makes sense because the primary replica went down so it couldn’t synchronize. With that said, we can still failover and make it functional while we troubleshoot why we lost our primary replica. To start we are going to right click on the availability group that needs to be restarted and select failover. This will bring up the following wizard, which will walk you through several steps needed to complete the failover using the graphical user interface provided with SQL Server Management Studio (SSMS). You are going to see warning messages simply because we are in Asynchronous commit mode and can not guarantee ‘no data loss’ when we do failover. Just incase you missed it; you get another screen warning you about potential data loss because we are in Asynchronous mode. Next we get to connect to the specific replica we want to become the primary replica after the failover occurs. In our case, we only have two replicas so this is trivial. In order to failover, it’s required to connect to the replica that will become primary.  The following screen shows that the connection has been made successfully. Next, you will see the final summary screen. Once again, this reminds you that the failover action will cause data loss as were using Asynchronous commit mode due to the distance between instances used for disaster recovery. Finally, once the failover is completed you will see the following screen. If you followed along this long you might be wondering what T-SQL scripts are generated for clicking through all the sections of the wizard. If you have used Database Mirroring in the past you might be surprised.  It’s not too different, which makes sense because the data is being replicated via SQL Server endpoints just like the good old database mirroring. Now were going to take a look at how to do a failover with just T-SQL. First, were going to need to open a new query window and run our query in SQLCMD mode. Just incase you haven’t used SQLCMD mode before we will show you how to enable it below. Now you can run the following statement. Notice, we connect to the replica we want to become primary after failover and specify to force failover to allow data loss. We can use the following script to failback over when our primary instance comes back online. -- YOU MUST EXECUTE THE FOLLOWING SCRIPT IN SQLCMD MODE. :Connect SQL2012PROD1 ALTER AVAILABILITY GROUP [AGSQL2] FORCE_FAILOVER_ALLOW_DATA_LOSS; GO Are your servers running at optimal speed or are you facing any SQL Server Performance Problems? If you want to get started with the help of experts read more over here: Fix Your SQL Server. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: Notes from the Field, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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• F# for the C# Programmer

  - by mbcrump

  Are you a C# Programmer and can’t make it past a day without seeing or hearing someone mention F#?  Today, I’m going to walk you through your first F# application and give you a brief introduction to the language. Sit back this will only take about 20 minutes. Introduction Microsoft's F# programming language is a functional language for the .NET framework that was originally developed at Microsoft Research Cambridge by Don Syme. In October 2007, the senior vice president of the developer division at Microsoft announced that F# was being officially productized to become a fully supported .NET language and professional developers were hired to create a team of around ten people to build the product version. In September 2008, Microsoft released the first Community Technology Preview (CTP), an official beta release, of the F# distribution . In December 2008, Microsoft announced that the success of this CTP had encouraged them to escalate F# and it is now will now be shipped as one of the core languages in Visual Studio 2010 , alongside C++, C# 4.0 and VB. The F# programming language incorporates many state-of-the-art features from programming language research and ossifies them in an industrial strength implementation that promises to revolutionize interactive, parallel and concurrent programming. Advantages of F# F# is the world's first language to combine all of the following features: Type inference: types are inferred by the compiler and generic definitions are created automatically. Algebraic data types: a succinct way to represent trees. Pattern matching: a comprehensible and efficient way to dissect data structures. Active patterns: pattern matching over foreign data structures. Interactive sessions: as easy to use as Python and Mathematica. High performance JIT compilation to native code: as fast as C#. Rich data structures: lists and arrays built into the language with syntactic support. Functional programming: first-class functions and tail calls. Expressive static type system: finds bugs during compilation and provides machine-verified documentation. Sequence expressions: interrogate huge data sets efficiently. Asynchronous workflows: syntactic support for monadic style concurrent programming with cancellations. Industrial-strength IDE support: multithreaded debugging, and graphical throwback of inferred types and documentation. Commerce friendly design and a viable commercial market. Lets try a short program in C# then F# to understand the differences. Using C#: Create a variable and output the value to the console window: Sample Program. using System;   namespace ConsoleApplication9 {     class Program     {         static void Main(string[] args)         {             var a = 2;             Console.WriteLine(a);             Console.ReadLine();         }     } } A breeze right? 14 Lines of code. We could have condensed it a bit by removing the “using” statment and tossing the namespace. But this is the typical C# program. Using F#: Create a variable and output the value to the console window: To start, open Visual Studio 2010 or Visual Studio 2008. Note: If using VS2008, then please download the SDK first before getting started. If you are using VS2010 then you are already setup and ready to go. So, click File-> New Project –> Other Languages –> Visual F# –> Windows –> F# Application. You will get the screen below. Go ahead and enter a name and click OK. Now, you will notice that the Solution Explorer contains the following: Double click the Program.fs and enter the following information. Hit F5 and it should run successfully. Sample Program. open System let a = 2        Console.WriteLine a As Shown below: Hmm, what? F# did the same thing in 3 lines of code. Show me the interactive evaluation that I keep hearing about. The F# development environment for Visual Studio 2010 provides two different modes of execution for F# code: Batch compilation to a .NET executable or DLL. (This was accomplished above). Interactive evaluation. (Demo is below) The interactive session provides a > prompt, requires a double semicolon ;; identifier at the end of a code snippet to force evaluation, and returns the names (if any) and types of resulting definitions and values. To access the F# prompt, in VS2010 Goto View –> Other Window then F# Interactive. Once you have the interactive window type in the following expression: 2+3;; as shown in the screenshot below: I hope this guide helps you get started with the language, please check out the following books for further information. F# Books for further reading   Foundations of F# Author: Robert Pickering An introduction to functional programming with F#. Including many samples, this book walks through the features of the F# language and libraries, and covers many of the .NET Framework features which can be leveraged with F#.       Functional Programming for the Real World: With Examples in F# and C# Authors: Tomas Petricek and Jon Skeet An introduction to functional programming for existing C# developers written by Tomas Petricek and Jon Skeet. This book explains the core principles using both C# and F#, shows how to use functional ideas when designing .NET applications and presents practical examples such as design of domain specific language, development of multi-core applications and programming of reactive applications.

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• CodePlex Daily Summary for Wednesday, November 23, 2011

  CodePlex Daily Summary for Wednesday, November 23, 2011Popular ReleasesVisual Leak Detector for Visual C++ 2008/2010: v2.2.1: Enhancements: * strdup and _wcsdup functions support added. * Preliminary support for VS 11 added. Bugs Fixed: * Low performance after upgrading from VLD v2.1. * Memory leaks with static linking fixed (disabled calloc support). * Runtime error R6002 fixed because of wrong memory dump format. * version.h fixed in installer. * Some PVS studio warning fixed.NetSqlAzMan - .NET SQL Authorization Manager: 3.6.0.10: 3.6.0.10 22-Nov-2011 Update: Removed PreEmptive Platform integration (PreEmptive analytics) Removed all PreEmptive attributes Removed PreEmptive.dll assembly references from all projects Added first support to ADAM/AD LDS Thanks to PatBea. Work Item 9775: http://netsqlazman.codeplex.com/workitem/9775Developer Team Article System Management: DTASM v1.3: ?? ??? ???? 3 ????? ???? ???? ????? ??? : - ????? ?????? ????? ???? ?? ??? ???? ????? ?? ??? ? ?? ???? ?????? ???? ?? ???? ????? ?? . - ??? ?? ???? ????? ???? ????? ???? ???? ?? ????? , ?????? ????? ????? ?? ??? . - ??? ??????? ??? ??? ???? ?? ????? ????? ????? .SharePoint 2010 FBA Pack: SharePoint 2010 FBA Pack 1.2.0: Web parts are now fully customizable via html templates (Issue #323) FBA Pack is now completely localizable using resource files. Thank you David Chen for submitting the code as well as Chinese translations of the FBA Pack! The membership request web part now gives the option of having the user enter the password and removing the captcha (Issue # 447) The FBA Pack will now work in a zone that does not have FBA enabled (Another zone must have FBA enabled, and the zone must contain the me...SharePoint 2010 Education Demo Project: Release SharePoint SP1 for Education Solutions: This release includes updates to the Content Packs for SharePoint SP1. All Content Packs have been updated to install successfully under SharePoint SP1SQL Monitor - tracking sql server activities: SQLMon 4.1 alpha 6: 1. improved support for schema 2. added find reference when right click on object list 3. added object rename supportBugNET Issue Tracker: BugNET 0.9.126: First stable release of version 0.9. Upgrades from 0.8 are fully supported and upgrades to future releases will also be supported. This release is now compiled against the .NET 4.0 framework and is a requirement. Because of this the web.config has significantly changed. After upgrading, you will need to configure the authentication settings for user registration and anonymous access again. Please see our installation / upgrade instructions for more details: http://wiki.bugnetproject.c...Anno 2070 Assistant: v0.1.0 (STABLE): Version 0.1.0 Features Production Chains Eco Production Chains (Complete) Tycoon Production Chains (Disabled - Incomplete) Tech Production Chains (Disabled - Incomplete) Supply (Disabled - Incomplete) Calculator (Disabled - Incomplete) Building Layouts Eco Building Layouts (Complete) Tycoon Building Layouts (Disabled - Incomplete) Tech Building Layouts (Disabled - Incomplete) Credits (Complete)Free SharePoint 2010 Sites Templates: SharePoint Server 2010 Sites Templates: here is the list of sites templates to be downloadedVsTortoise - a TortoiseSVN add-in for Microsoft Visual Studio: VsTortoise Build 30 Beta: Note: This release does not work with custom VsTortoise toolbars. These get removed every time when you shutdown Visual Studio. (#7940) Build 30 (beta)New: Support for TortoiseSVN 1.7 added. (the download contains both setups, for TortoiseSVN 1.6 and 1.7) New: OpenModifiedDocumentDialog displays conflicted files now. New: OpenModifiedDocument allows to group items by changelist now. Fix: OpenModifiedDocumentDialog caused Visual Studio 2010 to freeze sometimes. Fix: The installer didn...nopCommerce. Open source shopping cart (ASP.NET MVC): nopcommerce 2.30: Highlight features & improvements: • Performance optimization. • Back in stock notifications. • Product special price support. • Catalog mode (based on customer role) To see the full list of fixes and changes please visit the release notes page (http://www.nopCommerce.com/releasenotes.aspx).WPF Converters: WPF Converters V1.2.0.0: support for enumerations, value types, and reference types in the expression converter's equality operators the expression converter now handles DependencyProperty.UnsetValue as argument values correctly (#4062) StyleCop conformance (more or less)Json.NET: Json.NET 4.0 Release 4: Change - JsonTextReader.Culture is now CultureInfo.InvariantCulture by default Change - KeyValurPairConverter no longer cares about the order of the key and value properties Change - Time zone conversions now use new TimeZoneInfo instead of TimeZone Fix - Fixed boolean values sometimes being capitalized when converting to XML Fix - Fixed error when deserializing ConcurrentDictionary Fix - Fixed serializing some Uris returning the incorrect value Fix - Fixed occasional error when...Media Companion: MC 3.423b Weekly: Ensure .NET 4.0 Full Framework is installed. (Available from http://www.microsoft.com/download/en/details.aspx?id=17718) Ensure the NFO ID fix is applied when transitioning from versions prior to 3.416b. (Details here) Replaced 'Rebuild' with 'Refresh' throughout entire code. Rebuild will now be known as Refresh. mc_com.exe has been fully updated TV Show Resolutions... Resolved issue #206 - having to hit save twice when updating runtime manually Shrunk cache size and lowered loading times f...Delta Engine: Delta Engine Beta Preview v0.9.1: v0.9.1 beta release with lots of refactoring, fixes, new samples and support for iOS, Android and WP7 (you need a Marketplace account however). If you want a binary release for the games (like v0.9.0), just say so in the Forum or here and we will quickly prepare one. It is just not much different from v0.9.0, so I left it out this time. See http://DeltaEngine.net/Wiki.Roadmap for details.ASP.net Awesome Samples (Web-Forms): 1.0 samples: Demos and Tutorials for ASP.net Awesome VS2008 are in .NET 3.5 VS2010 are in .NET 4.0 (demos for the ASP.net Awesome jQuery Ajax Controls)SharpMap - Geospatial Application Framework for the CLR: SharpMap-0.9-AnyCPU-Trunk-2011.11.17: This is a build of SharpMap from the 0.9 development trunk as per 2011-11-17 For most applications the AnyCPU release is the recommended, but in case you need an x86 build that is included to. For some dataproviders (GDAL/OGR, SqLite, PostGis) you need to also referense the SharpMap.Extensions assembly For SqlServer Spatial you need to reference the SharpMap.SqlServerSpatial assemblyAJAX Control Toolkit: November 2011 Release: AJAX Control Toolkit Release Notes - November 2011 Release Version 51116November 2011 release of the AJAX Control Toolkit. AJAX Control Toolkit .NET 4 - Binary – AJAX Control Toolkit for .NET 4 and sample site (Recommended). AJAX Control Toolkit .NET 3.5 - Binary – AJAX Control Toolkit for .NET 3.5 and sample site (Recommended). Notes: - The current version of the AJAX Control Toolkit is not compatible with ASP.NET 2.0. The latest version that is compatible with ASP.NET 2.0 can be found h...Microsoft Ajax Minifier: Microsoft Ajax Minifier 4.36: Fix for issue #16908: string literals containing ASP.NET replacement syntax fail if the ASP.NET code contains the same character as the string literal delimiter. Also, we shouldn't be changing the delimiter for those literals or combining them with other literals; the developer may have specifically chosen the delimiter used because of possible content inserted by ASP.NET code. This logic is normally off; turn it on via the -aspnet command-line flag (or the Code.Settings.AllowEmbeddedAspNetBl...MVC Controls Toolkit: Mvc Controls Toolkit 1.5.5: Added: Now the DateRanteAttribute accepts complex expressions containing "Now" and "Today" as static minimum and maximum. Menu, MenuFor helpers capable of handling a "currently selected element". The developer can choose between using a standard nested menu based on a standard SimpleMenuItem class or specifying an item template based on a custom class. Added also helpers to build the tree structure containing all data items the menu takes infos from. Improved the pager. Now the developer ...New ProjectsActiveWorlds World Server Admin PowerShell SnapIn: The purpose of this PowerShell SnapIn is to provide a set of tools to administer the world server from PowerShell. It leverages the ActiveWorlds SDK .NET Wrapper to provide this functionality.Aigu: Enter special characters like you would on your mobile phone. For instance, if you want to type 'é', you just hold down 'e' and a menu will appear. Selected the desired character using the arrow keys and press 'enter'. Simple but powerful.Are you workaholic?: Are you a workaholic? Did your Doctor advice you not to stare at the computer monitor for a long time? Then this app is perfectly made for you. It runs in the background, and alerts you to take periodic rests for your eyes and body. What's more, It's open source (MS-PL).ATDIS PoC: privateAuto Version Web Assets: The AVWA project is an HTTP Module written in C# that is designed to allow for versioning of various web assets such as .CSS and .JS files. This allows you to publish new versions of these files without having to force the server or the client browsers to expire cache.Bachelor Thesis Algorithm Test Bed: Algorithm Test Bed for my Bachelor ThesisBase64: Simple application helps converting strings and files from or to Base64 string. You can use any encoding to convert while a sidebar previews decoded string for all other encodings.BoracayExpress: BoracayExpressC++ Framework for Test Driven Development: A testing framework for C++ written in C++.Class2Table: Class2Table aka Entity2Table. Easy tool that allows creation of SQL tables from .Net types.Code for Demos & Experiments: This is where I will post code from demos and presentationsCodeMaker: CodeMaker?????????： 1、?????????? 2、???? 3、????? 4、??Python????????? ConsoleCommand: ConsoleCommand provides certain .Net commands for access from javascript console engines. Included are commands to set the text and background colors, as well as list and extract resources compiled in a .Net dll. Converter: Character code conversion tools ???????? CryptoInator - self contained, self-encrypting, self-decrypting image viewer: Original developed to encrypt and store NemID images in Denmark. DAiBears: Something, something, botDelicious Notify Plugin: Lets you push a blog post straight to Delicious from Live WriterDeveloperFile: Compresses Javascripts using the YUI .NET project. Loops through the root folder and subfolders for files matching the debug extension and creates new files using the release extension. (File extensions must match exactly).DotNetNuke SharePoint File Explorer: A DotNetNuke SharePoint File ExplorerDouban FM: WP7 Douban FM appGame Lib: Game Library is a open-source game library to allow focusing on the fun part of a game. It is developed in C#, but will be ported to C++ and VB.net.Google reader notes to Delicious Export tool (WPF): Google reader discontinued note in reader features. Current google reader allows to export users old notes in JSON format, This App will parse the JSON file & upload it to it delicious , delicious is a good alternative for note in readerHtml Source Transmitter Control: This web control allows getting a source of a web page, that will displayed before submit. So, developer can store a view of the html page, that was before server exception. It helps to reproduce bugs and can be used with other logging systems.Ideopuzzle: A puzzle gameImageShack-Uploader: This project demonstrates how to upload files automated to imageshack.us and other image hosters with C#.Insert Acronym Tags: Lets you insert <acronym> and <abbr> tags into your blog entry more easily.Insert Quick Link: Allows you to paste a link into the Writer window and have the a window similar to the one in Writer where you can change what text is to appear, open in new window, etc.Insert Video Plugin: Allows you to insert a video into a blog entry from a multitude of different sitesIoCWrap: Provides a wrapper to the various IoC container implementations so that it is possible to switch to a different provider without changing any application code.kaveepoj: sharepoint projectKinect Quiz Engine: Fun quiz game for the Kinect.Klaverjas: Test application for testing different new technologies in .NET (WCF, DataServices, C# stuff, Entity...etc.)Man In The Middle: A cyberpunk themed action with puzzle and strategy elements. Made with XNA as part of a game development course at the IT University of Copenhagen by Bo Bendtsen, Jonas Flensbak, Daniel Kromand, Jess Rahbek & Darryl Woodford.MediaSelektor: Simple tool to select mediasMicajah Mindtouch Deki Wiki Copier: Small C# application to move data between 2 Deki Wiki installs or, more importantly, from a wik.is account to a locally installed systemMineFlagger: MineFlagger is a mine clearing game modeled after Microsoft’s Minesweeper. In addition to standard play, MineFlagger incorporates an AI for fun and training.myXbyqwrhjadsfasfhgf: myXbyqwrhjadsfasfhgfnatoop: natoopNauplius.KeyStore: Provides secure application key storage backed by SQL 2008 and Active Directory.ObjectDB: An object database written using C# 4 and Mono.Cecil.PaceR: PaceR is an attempt to encapsulate a lot of the common code functionality I use on different projects. Instead of recreating functionality from memory or worse, copying from older projects, I'd like to have a central location to maintain this common code. Parseq: Parseq is a Parser Combinator library written in C# (version 2.0).PowerShell Network Adapter Configuration module: PowerShell Network Adapter Configuration module is a PowerShell module which provides functions for managing network adapters using WMI.public traffic tracker: This is a university project for a .net course. We develop a public traffic tracker applications for Windows Phone 7 devices, that can give information about the actual positions of the nearest vehicle on a given line. The speciality is that we use only the GPS information of the users' WP7 devices, so this is a completely software solution without any hardware investment. The disatvantage is that for the real operation we would need a lot of active WP7 user.puyo: puyoRadioTroll: Projeto web Radio TrollRead Feed Community: Read Feed CommunityReviewer: Reviewer.dk - Dansk spil og anmeldelsessite.Rollout Sharepoint Solutions - ROSS: ROSS performs the following actions: - Delete sitecollection and restart services - 'Get Latest Version' from SourceSafe - Rebuild Solution - Install all wsp solutions - Create SiteCollections - Check for build en provisioning errors - Send email to developers if errors occurredSchool Management: school managementSQL File Executer: This project is a class library written in c# which is used for executing *.sql files in remote server. Simply one dll file. You include it in your web project, add using statement at the top of your page, pass the parameters inside. Rest, it will do.Startup Manager: Startup Manager launches all startup programs at a managed rate therefore meaning that your computer doesn't crash everytime it starts up and you can use it immediately.stetic: ...Test Infrastructure Guidance: The purpose of this project is to provide guidance to testers in using TFS effectively as an ALM solution. TFS is much more than a simple code repository. Used with Visual Studio it can form a powerful testing solution and remove a lot of pain in dealing with test infrastructure overhead.Tête-à-tête: Tete-a-tete is an address book with a built-in function to send electronic mail over the Internet.Tipeysh! - Add-in that helps you creating C/C++ header files on a single click: Are you also feel miserable when you need to create a new header file in your Visual Studio C/C++ project? Repeatedly choosing "new header file", then writing the annoying (but needed) "#ifndef" section, then writing the class name with it's "private", "protected" and "public" access modifiers... too much clicks and typewriting! Well, there is a solution: Tipeysh! is a simple, easy to use, very handy and configurable Visual Studio Add-In, compatible for both the 2005 and 2008 versions. Once ...UMN Dashboard Project: academic projUsersMOSS: UsersMOSS est une petite application permettant de consulter sur un serveur MOSS les sites web (SPWeb) les users (SPUser), et les groupes (SPGroup). Cette application utilise le modèle objet de MOSS pour inspecter le contenu des objets d'un serveur MOSS. Cette application est loin d'être professionnelle, ou même terminée, mais elle me rend très souvent service. Surtout ne l'utilisez pas sur un serveur de production car le gestion du GC n'est pas faite, ce qui peut provoquer des plantages de v...UtilityLibrary.Win32: UtilityLibrary.Win32UW iLearn: The iLearn activity inference platform is a suite of desktop and mobile tools for logging, modeling, and classifying sensor data for mobile devices. It was created at the University of Washington.VsDocGen: Dynamic javascript documentation generation directly from xml comment documented source code.Windows Live Spaces Photo Album plugin: This is going to be a plugin for Windows Live Writer that will allow you to browse a Windows Live Space Photo Album.Windows Live Writer Plugin for Amazon Books using CueCat: This Windows Live Writer Plugin is for users who use WLW and wish to use their CueCat to scan books. ItemLookups are run against Amazon via its AWS and book image, title, author, and publisher is returned. This project was first created by Scott Hanselman on MSDN's Coding4Fun! X7: X7 makes it easier for win7user to clean the system. You'll no longer have to delete useless stuff in your win7. It's developed in bat.xDT - Commander: Using this application, the user can assign shortcuts (short texts) for various links/URLs. These short texts will be typed into a Textbox to then launch/go to the target (similar to the "Run" program in Windows).

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• Cloud Computing Architecture Patterns: Don’t Focus on the Client

  - by BuckWoody

  Normally I try to put topics in the positive in other words "Do this" not "Don't do that". Sometimes its clearer to focus on what *not* to do. Popular development processes often start with screen mockups, or user input descriptions. In a scale-out pattern like Cloud Computing on Windows Azure, that's the wrong place to start. Start with the Data    Instead, I recommend that you start with the data that a process requires. That data might be temporary or persisted, but starting with the data and its requirements helps to define not only the storage engine you need but also drives everything from security to the integrity of the application. For instance, assume the requirements show that the user must enter their phone number, and that this datum is used in a contact management system further down the application chain. For that datum, you can determine what data type you need (U.S. only or International?) the security requirements, whether it needs ACID compliance, how it will be searched, indexed and so on. From one small data point you can extrapolate out your options for storing and processing the data. Here's the interesting part, which begins to break the patterns that we've used for decades: all of the data doesn't have the same requirements. The phone number might be best suited for a list, or an element, or a string, with either BASE or ACID requirements, based on how it is used. That means we don't have to dump everything into XML, an RDBMS, a NoSQL engine, or a flat file exclusively. In fact, one record might use all of those depending on the use-case requirements. Next Is Data Management  With the data defined, we can move on to how to store the data. Again, the requirements now dictate whether we need a full relational calculus or set-based operations, or we can choose another method based on the requirements for the data. And breaking another pattern its OK to store in more than once, in more than one location. We do this all the time for reporting systems and Business Intelligence systems, so this is a pattern we need to think about even for OLTP data. Move to Data Transport How does the data get around? We can use a connection-based method, sending the data along a transport to the storage engine, but in some cases we may want to use a cache, a queue, the Service Bus, or Complex Event Processing. Finally, Data Processing Most RDBMS engines, NoSQL, and certainly Big Data engines not only store data, but can process and manipulate it as well. Its doubtful that you'll calculate that phone number right? Well, if you're the phone company, you most certainly will. And so we see that even once we've chosen the data type, storage and engine, the same element can have different computing requirements based on how it is used. Sure, We Need A Front-End At Some Point Not all data is entered by human hands in fact most data isn't. We don't really need a Graphical User Interface (GUI) we need some way for a GUI to get data into and out of the systems listed earlier.   But when we do need to allow users to enter or examine data, that should be left to the GUI that best fits the device the user has. Ever tried to use an application designed for a web browser on a phone? Or one designed for a tablet on a phone? Its usually quite painful. The siren song of "We'll just write one interface for all devices" is strong, and has beguiled many an unsuspecting architect. But they just don't work out.   Instead, focus on the data, its transport and processing. Create API calls or a message system that allows for resilient transport to the device or interface, and let it do what it does best. References Microsoft Architecture Journal:   http://msdn.microsoft.com/en-us/architecture/bb410935.aspx Patterns and Practices:   http://msdn.microsoft.com/en-us/library/ff921345.aspx Windows Azure iOS, Android, Windows 8 Mobile Devices SDK: http://www.windowsazure.com/en-us/develop/mobile/tutorials/get-started-ios/ Windows Azure Facebook SDK: http://ntotten.com/2013/03/14/using-windows-azure-mobile-services-with-the-facebook-sdk-for-windows-phone/

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• Demystified - BI in SharePoint 2010

  - by Sahil Malik

  Ad:: SharePoint 2007 Training in .NET 3.5 technologies (more information). Frequently, my clients ask me if there is a good guide on deciphering the seemingly daunting choice of products from Microsoft when it comes to business intelligence offerings in a SharePoint 2010 world. These are all described in detail in my book, but here is a one (well maybe two) page executive overview. Microsoft Excel: Yes, Microsoft Excel! Your favorite and most commonly used in the world database. No it isn’t a database in technical pure definitions, but this is the most commonly used ‘database’ in the world. You will find many business users craft up very compelling excel sheets with tonnes of logic inside them. Good for: Quick Ad-Hoc reports. Excel 64 bit allows the possibility of very large datasheets (Also see 32 bit vs 64 bit Office, and PowerPivot Add-In below). Audience: End business user can build such solutions. Related technologies: PowerPivot, Excel Services Microsoft Excel with PowerPivot Add-In: The powerpivot add-in is an extension to Excel that adds support for large-scale data. Think of this as Excel with the ability to deal with very large amounts of data. It has an in-memory data store as an option for Analysis services. Good for: Ad-hoc reporting and logic with very large amounts of data. Audience: End business user can build such solutions. Related technologies: Excel, and Excel Services Excel Services: Excel Services is a Microsoft SharePoint Server 2010 shared service that brings the power of Excel to SharePoint Server by providing server-side calculation and browser-based rendering of Excel workbooks. Thus, excel sheets can be created by end users, and published to SharePoint server – which are then rendered right through the browser in read-only or parameterized-read-only modes. They can also be accessed by other software via SOAP or REST based APIs. Good for: Sharing excel sheets with a larger number of people, while maintaining control/version control etc. Sharing logic embedded in excel sheets with other software across the organization via REST/SOAP interfaces Audience: End business users can build such solutions once your tech staff has setup excel services on a SharePoint server instance. Programmers can write software consuming functionality/complex formulae contained in your sheets. Related technologies: PerformancePoint Services, Excel, and PowerPivot. Visio Services: Visio Services is a shared service on the Microsoft SharePoint Server 2010 platform that allows users to share and view Visio diagrams that may or may not have data connected to them. Connected data can update these diagrams allowing a visual/graphical view into the data. The diagrams are viewable through the browser. They are rendered in silverlight, but will automatically down-convert to .png formats. Good for: Showing data as diagrams, live updating. Comes with a developer story. Audience: End business users can build such solutions once your tech staff has setup visio services on a SharePoint server instance. Developers can enhance the visualizations Related Technologies: Visio Services can be used to render workflow visualizations in SP2010 Reporting Services: SQL Server reporting services can integrate with SharePoint, allowing you to store reports and data sources in SharePoint document libraries, and render these reports and associated functionality such as subscriptions through a SharePoint site. In SharePoint 2010, you can also write reports against SharePoint lists (access services uses this technique). Good for: Showing complex reports running in a industry standard data store, such as SQL server. Audience: This is definitely developer land. Don’t expect end users to craft up reports, unless a report model has previously been published. Related Technologies: PerformancePoint Services PerformancePoint Services: PerformancePoint Services in SharePoint 2010 is now fully integrated with SharePoint, and comes with features that can either be used in the BI center site definition, or on their own as activated features in existing site collections. PerformancePoint services allows you to build reports and dashboards that target a variety of back-end datasources including: SQL Server reporting services, SQL Server analysis services, SharePoint lists, excel services, simple tables, etc. Using these you have the ability to create dashboards, scorecards/kpis, and simple reports. You can also create reports targeting hierarchical multidimensional data sources. The visual decomposition tree is a new report type that lets you quickly breakdown multi-dimensional data. Good for: Mostly everything :), except your wallet – it’s not free! But this is the most comprehensive offering. If you have SharePoint server, forget everything and go with performance point. Audience: Developers need to setup the back-end sources, manageability story. DBAs need to setup datawarehouses with cubes. Moderately sophisticated business users, or developers can craft up reports using dashboard designer which is a click-once App that deploys with PerformancePoint Related Technologies: Excel services, reporting services, etc.   Other relevant technologies to know about: Business Connectivity Services: Allows for consumption of external data in SharePoint as columns or external lists. This can be paired with one or more of the above BI offerings allowing insight into such data. Access Services: Allows the representation/publishing of an access database as a SharePoint 2010 site, leveraging many SharePoint features. Reporting services is used by Access services. Secure Store Service: The SP2010 Secure store service is a replacement for the SP2007 single sign on feature. This acts as a credential policeman providing credentials to various applications running with SharePoint. BCS, PerformancePoint Services, Excel Services, and many other apps use the SSS (Secure Store Service) for credential control. Comment on the article ....

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• Can you Trust Search?

  - by David Dorf

  An awful lot of referrals to e-commerce sites come from web searches. Retailers rely on search engine optimization (SEO) to correctly position their website so they can be found. Search on "blue jeans" and the results are determined by a semi-secret algorithm -- in my case Levi.com, Banana Republic, and ShopStyle show up. The NY Times recently uncovered a situation where JCPenney, via third-parties hired to help with SEO, was caught manipulating search results so they were erroneously higher in page rankings. No doubt this helped drive additional sales during this part Christmas. The article, The Dirty Little Secrets of Search, is well worth reading. My friend Ron Kleinman started an interesting discussion at the ARTS Linkedin forum. He posed the question: The ability of a single company to "punish" any retailer (by significantly impacting their on-line sales volume) who does not play by their rules ... is this a good thing or a bad thing? Clearly JCP was in the wrong and needed to be punished, but should that decision lie with Google alone? Don't get me wrong -- I'm certainly not advocating we create a Department of Search where bureaucrats think of ways to spend money, but Google wields an awful lot of power in this situation, and it makes me feel uncomfortable. Now Google is incorporating more social aspects into their search results. For example, when Google knows its me (i.e. I'm logged in when using Google) search results will be influenced by my Twitter network. In an effort to increase relevance, the blogs and re-tweeted articles from my network will be higher in the search results than they otherwise would be. So in the case of product searches, things discussed in my network will rise to the top. Continuing my blue jean example, if someone in my network had been discussing Macy's perhaps they would now be higher in the result set. soapbox: I already have lots of spammers posting bogus comments to this blog in an effort to create additional links to their sites and thus increase their search ranking. Should I expect a similar situation in Twitter and eventually Facebook? Now retailers need to expand their SEO efforts to incorporate social media as well, but do us all a favor and please don't cheat.

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• Architecture strategies for a complex competition scoring system

  - by mikewassmer

  Competition description: There are about 10 teams competing against each other over a 6-week period. Each team's total score (out of a 1000 total available points) is based on the total of its scores in about 25,000 different scoring elements. Most scoring elements are worth a small fraction of a point and there will about 10 X 25,000 = 250,000 total raw input data points. The points for some scoring elements are awarded at frequent regular time intervals during the competition. The points for other scoring elements are awarded at either irregular time intervals or at just one moment in time. There are about 20 different types of scoring elements. Each of the 20 types of scoring elements has a different set of inputs, a different algorithm for calculating the earned score from the raw inputs, and a different number of total available points. The simplest algorithms require one input and one simple calculation. The most complex algorithms consist of hundreds or thousands of raw inputs and a more complicated calculation. Some types of raw inputs are automatically generated. Other types of raw inputs are manually entered. All raw inputs are subject to possible manual retroactive adjustments by competition officials. Primary requirements: The scoring system UI for competitors and other competition followers will show current and historical total team scores, team standings, team scores by scoring element, raw input data (at several levels of aggregation, e.g. daily, weekly, etc.), and other metrics. There will be charts, tables, and other widgets for displaying historical raw data inputs and scores. There will be a quasi-real-time dashboard that will show current scores and raw data inputs. Aggregate scores should be updated/refreshed whenever new raw data inputs arrive or existing raw data inputs are adjusted. There will be a "scorekeeper UI" for manually entering new inputs, manually adjusting existing inputs, and manually adjusting calculated scores. Decisions: Should the scoring calculations be performed on the database layer (T-SQL/SQL Server, in my case) or on the application layer (C#/ASP.NET MVC, in my case)? What are some recommended approaches for calculating updated total team scores whenever new raw inputs arrives? Calculating each of the teams' total scores from scratch every time a new input arrives will probably slow the system to a crawl. I've considered some kind of "diff" approach, but that approach may pose problems for ad-hoc queries and some aggegates. I'm trying draw some sports analogies, but it's tough because most games consist of no more than 20 or 30 scoring elements per game (I'm thinking of a high-scoring baseball game; football and soccer have fewer scoring events per game). Perhaps a financial balance sheet analogy makes more sense because financial "bottom line" calcs may be calculated from 250,000 or more transactions. Should I be making heavy use of caching for this application? Are there any obvious approaches or similar case studies that I may be overlooking?

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• SQL Server 2008 Compression

  - by Peter Larsson

  Hi! Today I am going to talk about compression in SQL Server 2008. The data warehouse I currently design and develop holds historical data back to 1973. The data warehouse will have an other blog post laster due to it's complexity. However, the server has 60GB of memory (of which 48 is dedicated to SQL Server service), so all data didn't fit in memory and the SAN is not the fastest one around. So I decided to give compression a go, since we use Enterprise Edition anyway. This is the code I use to compress all tables with PAGE compression. DECLARE @SQL VARCHAR(MAX)   DECLARE curTables CURSOR FOR             SELECT 'ALTER TABLE ' + QUOTENAME(OBJECT_SCHEMA_NAME(object_id))                     + '.' + QUOTENAME(OBJECT_NAME(object_id))                     + ' REBUILD PARTITION = ALL WITH (DATA_COMPRESSION = PAGE)'             FROM    sys.tables   OPEN    curTables   FETCH   NEXT FROM    curTables INTO    @SQL   WHILE @@FETCH_STATUS = 0     BEGIN         IF @SQL IS NOT NULL             RAISERROR(@SQL, 10, 1) WITH NOWAIT           FETCH   NEXT         FROM    curTables         INTO    @SQL     END   CLOSE       curTables DEALLOCATE  curTables Copy and paste the result to a new code window and execute the statements. One thing I noticed when doing this, is that the database grows with the same size as the table. If the database cannot grow this size, the operation fails. For me, I first ended up with orphaned connection. Not good. And this is the code I use to create the index compression statements DECLARE @SQL VARCHAR(MAX)   DECLARE curIndexes CURSOR FOR             SELECT      'ALTER INDEX ' + QUOTENAME(name)                         + ' ON '                         + QUOTENAME(OBJECT_SCHEMA_NAME(object_id))                         + '.'                         + QUOTENAME(OBJECT_NAME(object_id))                         + ' REBUILD PARTITION = ALL WITH (FILLFACTOR = 100, DATA_COMPRESSION = PAGE)'             FROM        sys.indexes             WHERE       OBJECTPROPERTY(object_id, 'IsMSShipped') = 0                         AND OBJECTPROPERTY(object_id, 'IsTable') = 1             ORDER BY    CASE type_desc                             WHEN 'CLUSTERED' THEN 1                             ELSE 2                         END   OPEN    curIndexes   FETCH   NEXT FROM    curIndexes INTO    @SQL   WHILE @@FETCH_STATUS = 0     BEGIN         IF @SQL IS NOT NULL             RAISERROR(@SQL, 10, 1) WITH NOWAIT           FETCH   NEXT         FROM    curIndexes         INTO    @SQL     END   CLOSE       curIndexes DEALLOCATE  curIndexes When this was done, I noticed that the 90GB database now only was 17GB. And most important, complete database now could reside in memory! After this I took care of the administrative tasks, backups. Here I copied the code from Management Studio because I didn't want to give too much time for this. The code looks like (notice the compression option). BACKUP DATABASE [Yoda] TO              DISK = N'D:\Fileshare\Backup\Yoda.bak' WITH            NOFORMAT,                 INIT,                 NAME = N'Yoda - Full Database Backup',                 SKIP,                 NOREWIND,                 NOUNLOAD,                 COMPRESSION,                 STATS = 10,                 CHECKSUM GO   DECLARE @BackupSetID INT   SELECT  @BackupSetID = Position FROM    msdb..backupset WHERE   database_name = N'Yoda'         AND backup_set_id =(SELECT MAX(backup_set_id) FROM msdb..backupset WHERE database_name = N'Yoda')   IF @BackupSetID IS NULL     RAISERROR(N'Verify failed. Backup information for database ''Yoda'' not found.', 16, 1)   RESTORE VERIFYONLY FROM    DISK = N'D:\Fileshare\Backup\Yoda.bak' WITH    FILE = @BackupSetID,         NOUNLOAD,         NOREWIND GO After running the backup, the file size was even more reduced due to the zip-like compression algorithm used in SQL Server 2008. The file size? Only 9 GB. //Peso

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• Infinite detail inside Perlin noise procedural mapping

  - by Dave Jellison

  I am very new to game development but I was able to scour the internet to figure out Perlin noise enough to implement a very simple 2D tile infinite procedural world. Here's the question and it's more conceptual than code-based in answer, I think. I understand the concept of "I plug in (x, y) and get back from Perlin noise p" (I'll call it p). P will always be the same value for the same (x, y) (as long as the Perlin algorithm parameters haven't changed, like altering number of octaves, et cetera). What I want to do is be able to zoom into a square and be able to generate smaller squares inside of the already generated overhead tile of terrain. Let's say I have a jungle tile for overhead terrain but I want to zoom in and maybe see a small river tile that would only be a creek and not large enough to be a full "big tile" of water in the overhead. Of course, I want the same net effect as a Perlin equation inside a Perlin equation if that makes sense? (aka. I want two people playing the game with the same settings to get the same terrain and details every time). I can conceptually wrap my head around the large tile being based on an "zoomed out" coordinate leaving enough room to drill into but this approach doesn't make sense in my head (maybe I'm wrong). I'm guessing with this approach my overhead terrain would lose all of the cohesiveness delivered by the Perlin. Imagine I calculate (0, 0) as overhead tile 1 and then to the east of that I plug in (50, 0). OK, great, I now have 49 pixels of detail I could then "drill down" into. The issue I have in my head with this approach (without attempting it) is that there's no guarantee from my Perlin noise that (0,0) would be a good neighbor to (50,0) as they could have wildly different "elevations" or p/resultant values returning from the Perlin equation when I generate the overhead map. I think I can conceive of using the Perlin noise for the overhead tile to then reuse the p value as a seed for the "detail" level of noise once I zoom in. That would ensure my detail Perlin is always the same configuration for (0,0), (1,0), etc. ad nauseam but I'm not sure if there are better approaches out there or if this is a sound approach at all.

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• Is commented out code really always bad?

  - by nikie

  Practically every text on code quality I've read agrees that commented out code is a bad thing. The usual example is that someone changed a line of code and left the old line there as a comment, apparently to confuse people who read the code later on. Of course, that's a bad thing. But I often find myself leaving commented out code in another situation: I write a computational-geometry or image processing algorithm. To understand this kind of code, and to find potential bugs in it, it's often very helpful to display intermediate results (e.g. draw a set of points to the screen or save a bitmap file). Looking at these values in the debugger usually means looking at a wall of numbers (coordinates, raw pixel values). Not very helpful. Writing a debugger visualizer every time would be overkill. I don't want to leave the visualization code in the final product (it hurts performance, and usually just confuses the end user), but I don't want to loose it, either. In C++, I can use #ifdef to conditionally compile that code, but I don't see much differnce between this: /* // Debug Visualization: draw set of found interest points for (int i=0; i<count; i++) DrawBox(pts[i].X, pts[i].Y, 5,5); */ and this: #ifdef DEBUG_VISUALIZATION_DRAW_INTEREST_POINTS for (int i=0; i<count; i++) DrawBox(pts[i].X, pts[i].Y, 5,5); #endif So, most of the time, I just leave the visualization code commented out, with a comment saying what is being visualized. When I read the code a year later, I'm usually happy I can just uncomment the visualization code and literally "see what's going on". Should I feel bad about that? Why? Is there a superior solution? Update: S. Lott asks in a comment Are you somehow "over-generalizing" all commented code to include debugging as well as senseless, obsolete code? Why are you making that overly-generalized conclusion? I recently read Robert Glass' "Clean Code", which says: Few practices are as odious as commenting-out code. Don't do this!. I've looked at the paragraph in the book again (p. 68), there's no qualification, no distinction made between different reasons for commenting out code. So I wondered if this rule is over-generalizing (or if I misunderstood the book) or if what I do is bad practice, for some reason I didn't know.

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• Why lock statements don't scale

  - by Alex.Davies

  We are going to have to stop using lock statements one day. Just like we had to stop using goto statements. The problem is similar, they're pretty easy to follow in small programs, but code with locks isn't composable. That means that small pieces of program that work in isolation can't necessarily be put together and work together. Of course actors scale fine :) Why lock statements don't scale as software gets bigger Deadlocks. You have a program with lots of threads picking up lots of locks. You already know that if two of your threads both try to pick up a lock that the other already has, they will deadlock. Your program will come to a grinding halt, and there will be fire and brimstone. "Easy!" you say, "Just make sure all the threads pick up the locks in the same order." Yes, that works. But you've broken composability. Now, to add a new lock to your code, you have to consider all the other locks already in your code and check that they are taken in the right order. Algorithm buffs will have noticed this approach means it takes quadratic time to write a program. That's bad. Why lock statements don't scale as hardware gets bigger Memory bus contention There's another headache, one that most programmers don't usually need to think about, but is going to bite us in a big way in a few years. Locking needs exclusive use of the entire system's memory bus while taking out the lock. That's not too bad for a single or dual-core system, but already for quad-core systems it's a pretty large overhead. Have a look at this blog about the .NET 4 ThreadPool for some numbers and a weird analogy (see the author's comment). Not too bad yet, but I'm scared my 1000 core machine of the future is going to go slower than my machine today! I don't know the answer to this problem yet. Maybe some kind of per-core work queue system with hierarchical work stealing. Definitely hardware support. But what I do know is that using locks specifically prevents any solution to this. We should be abstracting our code away from the details of locks as soon as possible, so we can swap in whatever solution arrives when it does. NAct uses locks at the moment. But my advice is that you code using actors (which do scale well as software gets bigger). And when there's a better way of implementing actors that'll scale well as hardware gets bigger, only NAct needs to work out how to use it, and your program will go fast on it's own.

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• 2D OBB collision detection, resolving collisions?

  - by Milo

  I currently use OBBs and I have a vehicle that is a rigid body and some buildings. Here is my update() private void update() { camera.setPosition((vehicle.getPosition().x * camera.getScale()) - ((getWidth() ) / 2.0f), (vehicle.getPosition().y * camera.getScale()) - ((getHeight() ) / 2.0f)); //camera.move(input.getAnalogStick().getStickValueX() * 15.0f, input.getAnalogStick().getStickValueY() * 15.0f); if(input.isPressed(ControlButton.BUTTON_GAS)) { vehicle.setThrottle(1.0f, false); } if(input.isPressed(ControlButton.BUTTON_BRAKE)) { vehicle.setBrakes(1.0f); } vehicle.setSteering(input.getAnalogStick().getStickValueX()); vehicle.update(16.6666f / 1000.0f); ArrayList<Building> buildings = city.getBuildings(); for(Building b : buildings) { if(vehicle.getRect().overlaps(b.getRect())) { vehicle.update(-17.0f / 1000.0f); break; } } } The collision detection works well. What doesn't is how they are dealt with. My goal is simple. If the vehicle hits a building, it should stop, and never go into the building. When I apply negative torque to reverse the car should not feel buggy and move away from the building. I don't want this to look buggy. This is my rigid body class: class RigidBody extends Entity { //linear private Vector2D velocity = new Vector2D(); private Vector2D forces = new Vector2D(); private float mass; //angular private float angularVelocity; private float torque; private float inertia; //graphical private Vector2D halfSize = new Vector2D(); private Bitmap image; public RigidBody() { //set these defaults so we don't get divide by zeros mass = 1.0f; inertia = 1.0f; } //intialize out parameters public void initialize(Vector2D halfSize, float mass, Bitmap bitmap) { //store physical parameters this.halfSize = halfSize; this.mass = mass; image = bitmap; inertia = (1.0f / 20.0f) * (halfSize.x * halfSize.x) * (halfSize.y * halfSize.y) * mass; RectF rect = new RectF(); float scalar = 10.0f; rect.left = (int)-halfSize.x * scalar; rect.top = (int)-halfSize.y * scalar; rect.right = rect.left + (int)(halfSize.x * 2.0f * scalar); rect.bottom = rect.top + (int)(halfSize.y * 2.0f * scalar); setRect(rect); } public void setLocation(Vector2D position, float angle) { getRect().set(position, getWidth(), getHeight(), angle); } public Vector2D getPosition() { return getRect().getCenter(); } @Override public void update(float timeStep) { //integrate physics //linear Vector2D acceleration = Vector2D.scalarDivide(forces, mass); velocity = Vector2D.add(velocity, Vector2D.scalarMultiply(acceleration, timeStep)); Vector2D c = getRect().getCenter(); c = Vector2D.add(getRect().getCenter(), Vector2D.scalarMultiply(velocity , timeStep)); setCenter(c.x, c.y); forces = new Vector2D(0,0); //clear forces //angular float angAcc = torque / inertia; angularVelocity += angAcc * timeStep; setAngle(getAngle() + angularVelocity * timeStep); torque = 0; //clear torque } //take a relative Vector2D and make it a world Vector2D public Vector2D relativeToWorld(Vector2D relative) { Matrix mat = new Matrix(); float[] Vector2Ds = new float[2]; Vector2Ds[0] = relative.x; Vector2Ds[1] = relative.y; mat.postRotate(JMath.radToDeg(getAngle())); mat.mapVectors(Vector2Ds); return new Vector2D(Vector2Ds[0], Vector2Ds[1]); } //take a world Vector2D and make it a relative Vector2D public Vector2D worldToRelative(Vector2D world) { Matrix mat = new Matrix(); float[] Vectors = new float[2]; Vectors[0] = world.x; Vectors[1] = world.y; mat.postRotate(JMath.radToDeg(-getAngle())); mat.mapVectors(Vectors); return new Vector2D(Vectors[0], Vectors[1]); } //velocity of a point on body public Vector2D pointVelocity(Vector2D worldOffset) { Vector2D tangent = new Vector2D(-worldOffset.y, worldOffset.x); return Vector2D.add( Vector2D.scalarMultiply(tangent, angularVelocity) , velocity); } public void applyForce(Vector2D worldForce, Vector2D worldOffset) { //add linear force forces = Vector2D.add(forces ,worldForce); //add associated torque torque += Vector2D.cross(worldOffset, worldForce); } @Override public void draw( GraphicsContext c) { c.drawRotatedScaledBitmap(image, getPosition().x, getPosition().y, getWidth(), getHeight(), getAngle()); } } Essentially, when any rigid body hits a building it should exhibit the same behavior. How is collision solving usually done? Thanks

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• How to implement an email unsubscribe system for a site with many kinds of emails?

  - by Mike Liu

  I'm working on a website that features many different types of emails. Users have accounts, and when logged in they have access to a setting page that they can use to customize what types of emails they receive. However, I'd like to also give users an easy way to unsubscribe directly in the emails they receive. I've looked into list unsubscribe headers as well as creating some type of one click link that would unsubscribe a user from that type of email without requiring login or further action. The later would probably require me to break convention and make changes to the database in response to a GET on the link. However, am I incorrect in thinking that either of these would require me to generate and permanently store a unique identifier in my database for every email I ever send, really complicating email delivery? Without that, I'm not sure how I would be able to uniquely identify a user and a type of email in order to change their email preferences, and this identifier would need to be stored forever as a user could have an email sitting in their inbox for a long time before they decide to act on it. Alternatively, I was considering having a no-login page for managing email preferences. In contrast to above where I would need one of these identifiers for each email, this would only need one identifier per user, with no generation or other action required on sending an email. All of these raise security issues, and they could potentially be used by people to tamper with others' email preferences. This could be mitigated somewhat by ensuring that the identifier is really difficult to guess. For the once per user identifier approach, I was considering generating the identifier by passing a user's ID through some type of encryption algorithm, is this a sound approach? For the per-email identifiers, perhaps I could use a user's ID appended to the time. However, even this would not eliminate the problem entirely, as this would really just be security through obscurity, and anyone with the URL could tamper, and in the end the main defense would have to be that most people aren't so bored as to tamper with other people's email preferences. Are there any other alternatives I've missed, or issues or solutions with these that anyone can provide insight on? What are best practices in this area?

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• It's called College.

  - by jeffreyabecker

  Today I saw yet another 'GUID vs int as your primary key' article. Like most of the ones I've read this was filled with technical misrepresentations and out-right fallices. Chef's famous line that "There's a time and a place for everything children" applies here. GUIDs have distinct advantages and disadvantages which should be considered when choosing a data type for the primary key. Fallacy 1: "Its easier" An integer data type(tinyint, smallint, int, bigint) is a better artifical key than a GUID because its easier to remember. I'm a firm believer that your artifical primary keys should be opaque gibberish. PK's are an implementation detail which should never be exposed to the user or relied on for business logic. If you want things to come back in an order, add and ORDER BY clause and SortOrder fields. If you want a human-usable look-up add a business key with a unique constraint. If you want to know what order things were inserted into a table add a timestamp. Fallacy 2: "Size Matters" For many applications, the size of the artifical primary key is going to be irrelevant. The particular article which kicked this post off stated repeatedly that joining against an int has better performance than joining against a GUID. In computer science the performance of your algorithm is always a function of the number of data points. This still holds true for databases. Unless your table is very large, the performance difference between an int and a guid probably isnt going to be mesurable let alone noticeable. My personal experience is that the performance becomes an issue when you start having billions of rows in the table. At this point, you should probably start looking to move from int to bigint so the effective space/performance gain isnt as much as you'd think. GUID Advantages: Insert-ability / Mergeability: You can reliably insert guids into tables without key collisions. Database Independence: Saving entities to the database often requires knowing ids. With identity based ids the id must be selected back after every insert. GUIDs can be generated application-side allowing much faster inserts. GUID Disadvantages: Generatability: You can calculate the next id for an integer pk pretty easily in your head but will need a program to generate GUIDs. Solution: "Select top 100 newid() from sysobjects" Fragmentation: most GUID generation algorithms generate pseudo random GUIDs. This can cause inserts into the middle of your clustered index. Solutions: add a default of newsequentialid() or use GuidComb in NHibernate.

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• Did I lost my RAID again?

  - by BarsMonster

  Hi! A little history: 2 years ago I was really excited to find out that mdadm is so powerful so it even can reshape arrays so you can start with a smaller array and the grow it as you need. I've bought 3x1Tb drives and made RAID-5. It was fine for a year. Then I bought 2x more, and tried to reshape to RAID-6 out of 5 drives, and due to some mess with superblock versions, lost all content. Had to rebuild it from scratch, but 2Tb of data were gone. Yesterday I bought 2 more drives, and this time I had everything: properly built array, UPS. I've disabled write intent map, added 2 new drives as a spare and run a command to grow array to 7-disk. It started working, but speed was ridiculously slow, ~100kb/sec. AFter processing first 37Mb at such an amasing speed, one of old HDDs fails. I properly shutdown PC and disconnected failed drive. After bootup it appeared it recreated intent map as it was still in mdadm config, so I removed it from config and rebooted again. Now all I see is that all mdadm processes deadlocks, and don't do anything. PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 1937 root 20 0 12992 608 444 D 0 0.1 0:00.00 mdadm 2283 root 20 0 12992 852 704 D 0 0.1 0:00.01 mdadm 2287 root 20 0 0 0 0 D 0 0.0 0:00.01 md0_reshape 2288 root 18 -2 12992 820 676 D 0 0.1 0:00.01 mdadm And all I see in mdstat is: $ cat /proc/mdstat Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] md0 : active raid6 sdb1[1] sdg1[4] sdf1[7] sde1[6] sdd1[0] sdc1[5] 2929683456 blocks super 1.2 level 6, 1024k chunk, algorithm 2 [7/6] [UU_UUUU] [>....................] reshape = 0.0% (37888/976561152) finish=567604147.2min speed=0K/sec I've already tried mdadm 2.6.7, 3.1.4 and 3.2 - nothing helps. Did I lost my data again? Any suggestions how can I make it work? OS is Ubuntu Server 10.04.2... PS. Needless to say that data is unaccessible - I cannot mount /dev/md0 as save the most valuable data. You can see my disappointment - the very specific thing I was excited about failed twice taking 5Tb of my data with it.

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• How to load stacking chunks on the fly?

  - by Brettetete

  I'm currently working on an infinite world, mostly inspired by minecraft. A Chunk consists of 16x16x16 blocks. A block(cube) is 1x1x1. This runs very smoothly with a ViewRange of 12 Chunks (12x16) on my computer. Fine. When I change the Chunk height to 256 this becomes - obviously - incredible laggy. So what I basically want to do is stacking chunks. That means my world could be [8,16,8] Chunks large. The question is now how to generate chunks on the fly? At the moment I generate not existing chunks circular around my position (near to far). Since I don't stack chunks yet, this is not very complex. As important side note here: I also want to have biomes, with different min/max height. So in Biome Flatlands the highest layer with blocks would be 8 (8x16) - in Biome Mountains the highest layer with blocks would be 14 (14x16). Just as example. What I could do would be loading 1 Chunk above and below me for example. But here the problem would be, that transitions between different bioms could be larger than one chunk on y. My current chunk loading in action For the completeness here my current chunk loading "algorithm" private IEnumerator UpdateChunks(){ for (int i = 1; i < VIEW_RANGE; i += ChunkWidth) { float vr = i; for (float x = transform.position.x - vr; x < transform.position.x + vr; x += ChunkWidth) { for (float z = transform.position.z - vr; z < transform.position.z + vr; z += ChunkWidth) { _pos.Set(x, 0, z); // no y, yet _pos.x = Mathf.Floor(_pos.x/ChunkWidth)*ChunkWidth; _pos.z = Mathf.Floor(_pos.z/ChunkWidth)*ChunkWidth; Chunk chunk = Chunk.FindChunk(_pos); // If Chunk is already created, continue if (chunk != null) continue; // Create a new Chunk.. chunk = (Chunk) Instantiate(ChunkFab, _pos, Quaternion.identity); } } // Skip to next frame yield return 0; } }

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• Do I have to worry about "error: superfluous RAID member"?

  - by 0xC0000022L

  When running update-grub on the newly installed Ubuntu 12.04 with an older software RAID (md), I get: error: superfluous RAID member (5 found). error: superfluous RAID member (5 found). Generating grub.cfg ... error: superfluous RAID member (5 found). error: superfluous RAID member (5 found). error: superfluous RAID member (5 found). error: superfluous RAID member (5 found). error: superfluous RAID member (5 found). error: superfluous RAID member (5 found). error: superfluous RAID member (5 found). error: superfluous RAID member (5 found). error: superfluous RAID member (5 found). error: superfluous RAID member (5 found). error: superfluous RAID member (5 found). Found linux image: /boot/vmlinuz-3.2.0-24-generic Found initrd image: /boot/initrd.img-3.2.0-24-generic error: superfluous RAID member (5 found). error: superfluous RAID member (5 found). error: superfluous RAID member (5 found). error: superfluous RAID member (5 found). Found linux image: /boot/vmlinuz-3.2.0-23-generic Found initrd image: /boot/initrd.img-3.2.0-23-generic error: superfluous RAID member (5 found). error: superfluous RAID member (5 found). error: superfluous RAID member (5 found). error: superfluous RAID member (5 found). error: superfluous RAID member (5 found). Found memtest86+ image: /boot/memtest86+.bin error: superfluous RAID member (5 found). error: superfluous RAID member (5 found). error: superfluous RAID member (5 found). error: superfluous RAID member (5 found). error: superfluous RAID member (5 found). Found Debian GNU/Linux (5.0.9) on /dev/sdb1 Found Debian GNU/Linux (5.0.9) on /dev/sdc1 done I would be less worried if the message would say warning: ..., but since it says error: ... I'm wondering what the problem is. # cat /proc/mdstat Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] md2 : active raid1 sdc1[1] sdb1[0] 48829440 blocks [2/2] [UU] md3 : active raid1 sdc2[1] sdb2[0] 263739008 blocks [2/2] [UU] md1 : active raid5 sdg1[3] sdf1[2] sde1[1] sdh1[0] sdi1[4] sdd1[5](S) 1250274304 blocks level 5, 64k chunk, algorithm 2 [5/5] [UUUUU] unused devices: <none> Do I have to worry or is this harmless? btw: disregard the mentioning of Debian 5.0.9, that was the previously installed system and is going to be overwritten. It's on /dev/md2 actually.

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• What does the `dmesg` error: "composite sync not supported" mean?

  - by M. Tibbits

  Question: I see [ 20.473125] composite sync not supported and several such entries when I run dmesg. What do they mean? Background: I'm trying to debug a problem where my laptop won't suspend. Since acpi seems happy and I can suspend easily from the command line, I've turned to tracking down all boot-up errors/warnings. So I run dmesg | grep not and, amongst other shtuff, I get: 728:[ 17.267120] composite sync not supported 733:[ 18.009061] composite sync not supported 740:[ 18.159289] registered panic notifier 749:[ 18.162500] vga16fb: not registering due to another framebuffer present 757:[ 18.598251] composite sync not supported 776:[ 20.473125] composite sync not supported 777:[ 20.932266] composite sync not supported 778:[ 28.350231] composite sync not supported 779:[ 28.924913] composite sync not supported 780:[ 35.480658] composite sync not supported And the full log for the few lines right around that first appearance (line 728) is listed at the bottom of my post (I'd happily include anything else). Any ideas what could be causing this? I've read several sites: Ubuntuforums #1 IRC Chat #1 One post talks about ??Adobe flash?? causing this error? Some others also suggest that it might be an nvidia related problem, but I've got a Dell Latitude D630 with an integrated Intel graphics -- so nvidia isn't the problem. [ 17.207142] phy0: Selected rate control algorithm 'minstrel' [ 17.207833] Registered led device: b43-phy0::tx [ 17.207849] Registered led device: b43-phy0::rx [ 17.207865] Registered led device: b43-phy0::radio [ 17.207927] Broadcom 43xx driver loaded [ Features: PL, Firmware-ID: FW13 ] [ 17.267120] composite sync not supported [ 17.415795] EXT4-fs (sda2): mounted filesystem with ordered data mode [ 17.602131] [drm] initialized overlay support [ 17.620201] input: DualPoint Stick as /devices/platform/i8042/serio1/input/input7 [ 17.641192] input: AlpsPS/2 ALPS DualPoint TouchPad as /devices/platform/i8042/serio1/input/input8 [ 18.009061] composite sync not supported [ 18.106042] pcmcia_socket pcmcia_socket0: cs: IO port probe 0x100-0x3af: clean. [ 18.108115] pcmcia_socket pcmcia_socket0: cs: IO port probe 0x3e0-0x4ff: clean. [ 18.108941] pcmcia_socket pcmcia_socket0: cs: IO port probe 0x820-0x8ff: clean. [ 18.109676] pcmcia_socket pcmcia_socket0: cs: IO port probe 0xc00-0xcf7: clean. [ 18.110356] pcmcia_socket pcmcia_socket0: cs: IO port probe 0xa00-0xaff: clean. [ 18.159286] fb0: inteldrmfb frame buffer device [ 18.159289] registered panic notifier [ 18.160218] input: Video Bus as /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A03:00/LNXVIDEO:01/input/input9 [ 18.160286] ACPI: Video Device [VID1] (multi-head: yes rom: no post: no) [ 18.160334] ACPI Warning for \_SB_.PCI0.VID2._DOD: Return Package has no elements (empty) (20090903/nspredef-433) [ 18.160432] input: Video Bus as /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A03:00/LNXVIDEO:02/input/input10 [ 18.160491] ACPI: Video Device [VID2] (multi-head: yes rom: no post: no) [ 18.160539] [drm] Initialized i915 1.6.0 20080730 for 0000:00:02.0 on minor 0 [ 18.162494] vga16fb: initializing [ 18.162497] vga16fb: mapped to 0xc00a0000 [ 18.162500] vga16fb: not registering due to another framebuffer present [ 18.176091] HDA Intel 0000:00:1b.0: PCI INT A -> GSI 21 (level, low) -> IRQ 21 [ 18.176123] HDA Intel 0000:00:1b.0: setting latency timer to 64 [ 18.285752] input: HDA Digital PCBeep as /devices/pci0000:00/0000:00:1b.0/input/input11 [ 18.312497] input: HDA Intel Mic at Ext Left Jack as /devices/pci0000:00/0000:00:1b.0/sound/card0/input12 [ 18.312586] input: HDA Intel HP Out at Ext Left Jack as /devices/pci0000:00/0000:00:1b.0/sound/card0/input13 [ 18.328043] usbcore: registered new interface driver ndiswrapper [ 18.460909] Console: switching to colour frame buffer device 180x56 [ 18.598251] composite sync not supported

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• SQL – Contest to Get The Date – Win USD 50 Amazon Gift Cards and Cool Gift

  - by Pinal Dave

  If you are a regular reader of this blog – you will find no issue at all in resolving this puzzle. This contest is based on my experience with NuoDB. If you are not familiar with NuoDB, here are few pointers for you. Step by Step Guide to Download and Install NuoDB – Getting Started with NuoDB Quick Start with Admin Sections of NuoDB – Manage NuoDB Database Quick Start with Explorer Sections of NuoDB – Query NuoDB Database In today’s contest you have to answer following questions: Q 1: Precision of NOW() What is the precision of the NuoDB’s NOW() function, which returns current date time? Hint: Run following script on NuoDB Console Explorer section: SELECT NOW() AS CurrentTime FROM dual; Here is the image. I have masked the area where the time precision is displayed. Q 2: Executing Date and Time Script When I execute following script - SELECT 'today' AS Today, 'tomorrow' AS Tomorrow, 'yesterday' AS Yesterday FROM dual; I will get the following result:   NOW – What will be the answer when we execute following script? and WHY? SELECT CAST('today' AS DATE) AS Today, CAST('tomorrow' AS DATE) AS Tomorrow, CAST('yesterday'AS DATE) AS Yesterday FROM dual; HINT: Install NuoDB (it takes 90 seconds). Prizes: 2 Amazon Gifts 2 Limited Edition Hoodies (US resident only)   Rules: Please leave an answer in the comments section below. You must answer both the questions together in a single comment. US resident who wants to qualify to win NuoDB apparel please mention your country in the comment. You can resubmit your answer multiple times, the latest entry will be considered valid. Last day to participate in the puzzle is June 24, 2013. All valid answer will be kept hidden till June 24, 2013. The winner will be announced on June 25, 2013. Two Winners will get USD 25 worth Amazon Gift Card. (Total Value = 25 x 2 = 50 USD) The winner will be selected using a random algorithm from all the valid answers. Anybody with a valid email address can take part in the contest. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Big Data, PostADay, SQL, SQL Authority, SQL Puzzle, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: NuoDB

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• How to Tell If Your Computer is Overheating and What to Do About It

  - by Chris Hoffman

  Heat is a computer’s enemy. Computers are designed with heat dispersion and ventilation in mind so they don’t overheat. If too much heat builds up, your computer may become unstable or suddenly shut down. The CPU and graphics card produce much more heat when running demanding applications. If there’s a problem with your computer’s cooling system, an excess of heat could even physically damage its components. Is Your Computer Overheating? When using a typical computer in a typical way, you shouldn’t have to worry about overheating at all. However, if you’re encountering system instability issues like abrupt shut downs, blue screens, and freezes — especially while doing something demanding like playing PC games or encoding video — your computer may be overheating. This can happen for several reasons. Your computer’s case may be full of dust, a fan may have failed, something may be blocking your computer’s vents, or you may have a compact laptop that was never designed to run at maximum performance for hours on end. Monitoring Your Computer’s Temperature First, bear in mind that different CPUs and GPUs (graphics cards) have different optimal temperature ranges. Before getting too worried about a temperature, be sure to check your computer’s documentation — or its CPU or graphics card specifications — and ensure you know the temperature ranges your hardware can handle. You can monitor your computer’s temperatures in a variety of different ways. First, you may have a way to monitor temperature that is already built into your system. You can often view temperature values in your computer’s BIOS or UEFI settings screen. This allows you to quickly see your computer’s temperature if Windows freezes or blue screens on you — just boot the computer, enter the BIOS or UEFI screen, and check the temperatures displayed there. Note that not all BIOSes or UEFI screens will display this information, but it is very common. There are also programs that will display your computer’s temperature. Such programs just read the sensors inside your computer and show you the temperature value they report, so there are a wide variety of tools you can use for this, from the simple Speccy system information utility to an advanced tool like SpeedFan. HWMonitor also offer this feature, displaying a wide variety of sensor information. Be sure to look at your CPU and graphics card temperatures. You can also find other temperatures, such as the temperature of your hard drive, but these components will generally only overheat if it becomes extremely hot in the computer’s case. They shouldn’t generate too much heat on their own. If you think your computer may be overheating, don’t just glance as these sensors once and ignore them. Do something demanding with your computer, such as running a CPU burn-in test with Prime 95, playing a PC game, or running a graphical benchmark. Monitor the computer’s temperature while you do this, even checking a few hours later — does any component overheat after you push it hard for a while? Preventing Your Computer From Overheating If your computer is overheating, here are some things you can do about it: Dust Out Your Computer’s Case: Dust accumulates in desktop PC cases and even laptops over time, clogging fans and blocking air flow. This dust can cause ventilation problems, trapping heat and preventing your PC from cooling itself properly. Be sure to clean your computer’s case occasionally to prevent dust build-up. Unfortunately, it’s often more difficult to dust out overheating laptops. Ensure Proper Ventilation: Put the computer in a location where it can properly ventilate itself. If it’s a desktop, don’t push the case up against a wall so that the computer’s vents become blocked or leave it near a radiator or heating vent. If it’s a laptop, be careful to not block its air vents, particularly when doing something demanding. For example, putting a laptop down on a mattress, allowing it to sink in, and leaving it there can lead to overheating — especially if the laptop is doing something demanding and generating heat it can’t get rid of. Check if Fans Are Running: If you’re not sure why your computer started overheating, open its case and check that all the fans are running. It’s possible that a CPU, graphics card, or case fan failed or became unplugged, reducing air flow. Tune Up Heat Sinks: If your CPU is overheating, its heat sink may not be seated correctly or its thermal paste may be old. You may need to remove the heat sink and re-apply new thermal paste before reseating the heat sink properly. This tip applies more to tweakers, overclockers, and people who build their own PCs, especially if they may have made a mistake when originally applying the thermal paste. This is often much more difficult when it comes to laptops, which generally aren’t designed to be user-serviceable. That can lead to trouble if the laptop becomes filled with dust and needs to be cleaned out, especially if the laptop was never designed to be opened by users at all. Consult our guide to diagnosing and fixing an overheating laptop for help with cooling down a hot laptop. Overheating is a definite danger when overclocking your CPU or graphics card. Overclocking will cause your components to run hotter, and the additional heat will cause problems unless you can properly cool your components. If you’ve overclocked your hardware and it has started to overheat — well, throttle back the overclock! Image Credit: Vinni Malek on Flickr     

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• Creating predefinied camera views - How do I move the camera to make sense while using Controller?

  - by Deukalion

  I'm trying to understand 3D but the one thing I can't seem to understand is the Camera. Right now I'm rendering four 3D Cubes with textures and I set the Project Matrix: public BasicCamera3D(float fieldOfView, float aspectRatio, float clipStart, float clipEnd, Vector3 cameraPosition, Vector3 cameraLookAt) { projection_fieldOfView = MathHelper.ToRadians(fieldOfView); projection_aspectRatio = aspectRatio; projection_clipstart = clipStart; projection_clipend = clipEnd; matrix_projection = Matrix.CreatePerspectiveFieldOfView(projection_fieldOfView, aspectRatio, clipStart, clipEnd); view_cameraposition = cameraPosition; view_cameralookat = cameraLookAt; matrix_view = Matrix.CreateLookAt(cameraPosition, cameraLookAt, Vector3.Up); } BasicCamera3D gameCamera = new BasicCamera3D(45f, GraphicsDevice.Viewport.AspectRatio, 1.0f, 1000f, new Vector3(0, 0, 8), new Vector3(0, 0, 0)); This creates a sort of "Top-Down" camera, with 8 (still don't get the unit type here - it's not pixels I guess?) But, if I try to position the camera at the side to make "Side-View" or "Reverse Side View" camera, the camera is rotating to much until it's turned around it a couple of times. I render the boxes at: new Vector3(-1, 0, 0) new Vector3(0, 0, 0) new Vector3(1, 0, 0) new Vector3(1, 0, 1) and with the Top-Down camera it shows good, but I don't get how I can make the camera show the side or 45 degrees from top (Like 3rd person action games) because the logic doesn't make sense. Also, since every object you render needs a new BasicEffect with a new projection/view/world - can you still use the "same" camera always so you don't have to create a new View/Matrix and such for each object. It's seems weird. If someone could help me get the camera to navigate around my objects "naturally" so I can be able to set a few predtermined views to choose from it would be really helpful. Are there some sort of algorithm to calculate the view for this and perhaps not simply one value? Examples: Top-Down-View: I have an object at 0, 0, 0 when I turn the right stick on the Xbox 360 Controller it should rotate around that object kind of, not flip and turn upside down, disappear and then magically appear as a tiny dot somewhere I have no clue where it is like it feels like it does now. Side-View: I have an object at 0, 0, 0 when I rotate to sides or up and down, the camera should be able to show a little more of the periphery to each side (depending on which you look at), and the same while moving up or down.

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• Declarative Architectures in Infrastructure as a Service (IaaS)

  - by BuckWoody

  I deal with computing architectures by first laying out requirements, and then laying in any constraints for it's success. Only then do I bring in computing elements to apply to the system. As an example, a requirement might be "world-side availability" and a constraint might be "with less than 80ms response time and full HA" or something similar. Then I can choose from the best fit of technologies which range from full-up on-premises computing to IaaS, PaaS or SaaS. I also deal in abstraction layers - on-premises systems are fully under your control, in IaaS the hardware is abstracted (but not the OS, scale, runtimes and so on), in PaaS the hardware and the OS is abstracted and you focus on code and data only, and in SaaS everything is abstracted - you merely purchase the function you want (like an e-mail server or some such) and simply use it. When you think about solutions this way, the architecture moves to the primary factor in your decision. It's problem-first architecting, and then laying in whatever technology or vendor best fixes the problem. To that end, most architects design a solution using a graphical tool (I use Visio) and then creating documents that  let the rest of the team (and business) know what is required. It's the template, or recipe, for the solution. This is extremely easy to do for SaaS - you merely point out what the needs are, research the vendor and present the findings (and bill) to the business. IT might not even be involved there. In PaaS it's not much more complicated - you use the same Application Lifecycle Management and design tools you always have for code, such as Visual Studio or some other process and toolset, and you can "stamp out" the application in multiple locations, update it and so on. IaaS is another story. Here you have multiple machines, operating systems, patches, virus scanning, run-times, scale-patterns and tools and much more that you have to deal with, since essentially it's just an in-house system being hosted by someone else. You can certainly automate builds of servers - we do this as technical professionals every day. From Windows to Linux, it's simple enough to create a "build script" that makes a system just like the one we made yesterday. What is more problematic is being able to tie those systems together in a coherent way (as a solution) and then stamp that out repeatedly, especially when you might want to deploy that solution on-premises, or in one cloud vendor or another. Lately I've been working with a company called RightScale that does exactly this. I'll point you to their site for more info, but the general idea is that you document out your intent for a set of servers, and it will deploy them to on-premises clouds, Windows Azure, and other cloud providers all from the same script. In other words, it doesn't contain the images or anything like that - it contains the scripts to build them on-premises or on a cloud vendor like Microsoft. Using a tool like this, you combine the steps of designing a system (all the way down to passwords and accounts if you wish) and then the document drives the distribution and implementation of that intent. As time goes on and more and more companies implement solutions on various providers (perhaps for HA and DR) then this becomes a compelling investigation. The RightScale information is here, if you want to investigate it further. Yes, there are other methods I've found, but most are tied to a single kind of cloud, and I'm not into vendor lock-in. Poppa Bear Level - Hands-on EvaluateRightScale at no cost.  Just bring your Windows Azurecredentials and follow the these tutorials: Sign Up for Windows Azure Add     Windows Azure to a RightScale Account Windows Azure Virtual Machines     3-tier Deployment Momma Bear Level - Just the Right level... ;0)  WindowsAzure Evaluation Guide - if you are new toWindows Azure Virtual Machines and new to RightScale, we recommend that youread the entire evaluation guide to gain a more complete understanding of theWindows Azure + RightScale solution.    WindowsAzure Support Page @ support.rightscale.com - FAQ's, tutorials,etc. for  Windows Azure Virtual Machines (Work in Progress) Baby Bear Level - Marketing WindowsAzure Page @ www.rightscale.com - find overview informationincluding solution briefs and presentation & demonstration videos   Scale     and Automate Applications on Windows Azure  Solution Brief     - how RightScale makes Windows Azure Virtual Machine even better SQL     Server on Windows Azure  Solution Brief   -       Run Highly Available SQL Server on Windows Azure Virtual Machines

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• Are there deprecated practices for multithread and multiprocessor programming that I should no longer use?

  - by DeveloperDon

  In the early days of FORTRAN and BASIC, essentially all programs were written with GOTO statements. The result was spaghetti code and the solution was structured programming. Similarly, pointers can have difficult to control characteristics in our programs. C++ started with plenty of pointers, but use of references are recommended. Libraries like STL can reduce some of our dependency. There are also idioms to create smart pointers that have better characteristics, and some version of C++ permit references and managed code. Programming practices like inheritance and polymorphism use a lot of pointers behind the scenes (just as for, while, do structured programming generates code filled with branch instructions). Languages like Java eliminate pointers and use garbage collection to manage dynamically allocated data instead of depending on programmers to match all their new and delete statements. In my reading, I have seen examples of multi-process and multi-thread programming that don't seem to use semaphores. Do they use the same thing with different names or do they have new ways of structuring protection of resources from concurrent use? For example, a specific example of a system for multithread programming with multicore processors is OpenMP. It represents a critical region as follows, without the use of semaphores, which seem not to be included in the environment. th_id = omp_get_thread_num(); #pragma omp critical { cout << "Hello World from thread " << th_id << '\n'; } This example is an excerpt from: http://en.wikipedia.org/wiki/OpenMP Alternatively, similar protection of threads from each other using semaphores with functions wait() and signal() might look like this: wait(sem); th_id = get_thread_num(); cout << "Hello World from thread " << th_id << '\n'; signal(sem); In this example, things are pretty simple, and just a simple review is enough to show the wait() and signal() calls are matched and even with a lot of concurrency, thread safety is provided. But other algorithms are more complicated and use multiple semaphores (both binary and counting) spread across multiple functions with complex conditions that can be called by many threads. The consequences of creating deadlock or failing to make things thread safe can be hard to manage. Do these systems like OpenMP eliminate the problems with semaphores? Do they move the problem somewhere else? How do I transform my favorite semaphore using algorithm to not use semaphores anymore?

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• How can I convert a 2D bitmap (Used for terrain) to a 2D polygon mesh for collision?

  - by Megadanxzero

  So I'm making an artillery type game, sort of similar to Worms with all the usual stuff like destructible terrain etc... and while I could use per-pixel collision that doesn't give me collision normals or anything like that. Converting it all to a mesh would also mean I could use an existing physics library, which would be better than anything I can make by myself. I've seen people mention doing this by using Marching Squares to get contours in the bitmap, but I can't find anything which mentions how to turn these into a mesh (Unless it refers to a 3D mesh with contour lines defining different heights, which is NOT what I want). At the moment I can get a basic Marching Squares contour which looks something like this (Where the grid-like lines in the background would be the Marching Squares 'cells'): That needs to be interpolated to get a smoother, more accurate result but that's the general idea. I had a couple ideas for how to turn this into a mesh, but many of them wouldn't work in certain cases, and the one which I thought would work perfectly has turned out to be very slow and I've not even finished it yet! Ideally I'd like whatever I end up using to be fast enough to do every frame for cases such as rapidly-firing weapons, or digging tools. I'm thinking there must be some kind of existing algorithm/technique for turning something like this into a mesh, but I can't seem to find anything. I've looked at some things like Delaunay Triangulation, but as far as I can tell that won't correctly handle concave shapes like the above example, and also wouldn't account for holes within the terrain. I'll go through the technique I came up with for comparison and I guess I'll see if anyone has a better idea. First of all interpolate the Marching Squares contour lines, creating vertices from the line ends, and getting vertices where lines cross cell edges (Important). Then, for each cell containing vertices create polygons by using 2 vertices, and a cell corner as the 3rd vertex (Probably the closest corner). Do this for each cell and I think you should have a mesh which accurately represents the original bitmap (Though there will only be polygons at the edges of the bitmap, and large filled in areas in between will be empty). The only problem with this is that it involves lopping through every pixel once for the initial Marching Squares, then looping through every cell (image height + 1 x image width + 1) at least twice, which ends up being really slow for any decently sized image...

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