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• Can prefixing a dash reduce the search engine rating?

  - by LeoMaheo

  Hi anyone! If I prefix a dash to GUIDs in my URLs on my Web site, in this manner: example.com/some/folders/-35x2ne5r579n32/page-name Will my SEO rating be affected? Background: On my site, people can look up pages by GUID, and by path. For example, both example.com/forum/-3v32nirn32/eat-animals-without-friends and example.com/forum/eat-animals-without-friends could map to the same page. To indicate that 3v32nirn32 is a GUID and not a page name, I thought I could prefix a - and then my webapp would understand. But I wouldn't want my search engine rating to drop. And prefixing a dash in this manner seems weird, so perhaps Googlebot lowers my rating. Hence my question: Do you know if my search engine rating might drop? (Today or in the future?) (I could also e.g. prefix id-, so the URL becomes example.com/forum/id-3v32nirn32, but then people cannot create pages that start with the word "id".) (I think I don't want URLs like this one: example.com/id/some-guid.) Kind regards, Magnus

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• Unexpected SQL Server 2008 Performance Tip: Avoid local variables in WHERE clause

  - by Jim Duffy

  Sometimes an application needs to have every last drop of performance it can get, others not so much. We’re in the process of converting some legacy Visual FoxPro data into SQL Server 2008 for an application and ran into a situation that required some performance tweaking. I figured the Making Microsoft SQL Server 2008 Fly session that Yavor Angelov (SQL Server Program Manager – Query Processing) presented at PDC 2009 last November would be a good place to start. I was right. One tip among the list of incredibly useful tips Yavor presented was “local variables are bad news for the Query Optimizer and they cause the Query Optimizer to guess”. What that means is you should be avoiding code like this in your stored procs even though it seems such an intuitively good idea. DECLARE @StartDate datetime SET @StartDate = '20091125' SELECT * FROM Orders WHERE OrderDate = @StartDate Instead you should be referencing the value directly in the WHERE clause so the Query Optimizer can create a better execution plan. SELECT * FROM Orders WHERE OrderDate = '20091125' My first thought about this one was we reference variables in the form of passed in parameters in WHERE clauses in many of our stored procs. Not to worry though because parameters ARE available to the Query Optimizer as it compiles the execution plan. I highly recommend checking out Yavor’s session for additional tips to help you squeeze every last drop of performance out of your queries. Have a day. :-|

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• Top 5 Developer Enabling Nuggets in MySQL 5.6

  - by Rob Young

  MySQL 5.6 is truly a better MySQL and reflects Oracle's commitment to the evolution of the most popular and widelyused open source database on the planet.  The feature-complete 5.6 release candidate was announced at MySQL Connect in late September and the production-ready, generally available ("GA") product should be available in early 2013.  While the message around 5.6 has been focused mainly on mass appeal, advanced topics like performance/scale, high availability, and self-healing replication clusters, MySQL 5.6 also provides many developer-friendly nuggets that are designed to enable those who are building the next generation of web-based and embedded applications and services. Boiling down the 5.6 feature set into a smaller set, of simple, easy to use goodies designed with developer agility in mind, these things deserve a quick look:Subquery Optimizations Using semi-JOINs and late materialization, the MySQL 5.6 Optimizer delivers greatly improved subquery performance. Specifically, the optimizer is now more efficient in handling subqueries in the FROM clause; materialization of subqueries in the FROM clause is now postponed until their contents are needed during execution. Additionally, the optimizer may add an index to derived tables during execution to speed up row retrieval. Internal tests run using the DBT-3 benchmark Query #13, shown below, demonstrate an order of magnitude improvement in execution times (from days to seconds) over previous versions. select c_name, c_custkey, o_orderkey, o_orderdate, o_totalprice, sum(l_quantity)from customer, orders, lineitemwhere o_orderkey in (                select l_orderkey                from lineitem                group by l_orderkey                having sum(l_quantity) > 313  )  and c_custkey = o_custkey  and o_orderkey = l_orderkeygroup by c_name, c_custkey, o_orderkey, o_orderdate, o_totalpriceorder by o_totalprice desc, o_orderdateLIMIT 100;What does this mean for developers?  For starters, simplified subqueries can now be coded instead of complex joins for cross table lookups: SELECT title FROM film WHERE film_id IN (SELECT film_id FROM film_actor GROUP BY film_id HAVING count(*) > 12); And even more importantly subqueries embedded in packaged applications no longer need to be re-written into joins.  This is good news for both ISVs and their customers who have access to the underlying queries and who have spent development cycles writing, testing and maintaining their own versions of re-written queries across updated versions of a packaged app.The details are in the MySQL 5.6 docs. Online DDL OperationsToday's web-based applications are designed to rapidly evolve and adapt to meet business and revenue-generationrequirements. As a result, development SLAs are now most often measured in minutes vs days or weeks. For example, when an application must quickly support new product lines or new products within existing product lines, the backend database schema must adapt in kind, and most commonly while the application remains available for normal business operations.  MySQL 5.6 supports this level of online schema flexibility and agility by providing the following new ALTER TABLE online DDL syntax additions:  CREATE INDEX DROP INDEX Change AUTO_INCREMENT value for a column ADD/DROP FOREIGN KEY Rename COLUMN Change ROW FORMAT, KEY_BLOCK_SIZE for a table Change COLUMN NULL, NOT_NULL Add, drop, reorder COLUMN Again, the details are in the MySQL 5.6 docs. Key-value access to InnoDB via Memcached APIMany of the next generation of web, cloud, social and mobile applications require fast operations against simple Key/Value pairs. At the same time, they must retain the ability to run complex queries against the same data, as well as ensure the data is protected with ACID guarantees. With the new NoSQL API for InnoDB, developers have allthe benefits of a transactional RDBMS, coupled with the performance capabilities of Key/Value store.MySQL 5.6 provides simple, key-value interaction with InnoDB data via the familiar Memcached API.  Implemented via a new Memcached daemon plug-in to mysqld, the new Memcached protocol is mapped directly to the native InnoDB API and enables developers to use existing Memcached clients to bypass the expense of query parsing and go directly to InnoDB data for lookups and transactional compliant updates.  The API makes it possible to re-use standard Memcached libraries and clients, while extending Memcached functionality by integrating a persistent, crash-safe, transactional database back-end.  The implementation is shown here:So does this option provide a performance benefit over SQL?  Internal performance benchmarks using a customized Java application and test harness show some very promising results with a 9X improvement in overall throughput for SET/INSERT operations:You can follow the InnoDB team blog for the methodology, implementation and internal test cases that generated these results here. How to get started with Memcached API to InnoDB is here. New Instrumentation in Performance SchemaThe MySQL Performance Schema was introduced in MySQL 5.5 and is designed to provide point in time metrics for key performance indicators.  MySQL 5.6 improves the Performance Schema in answer to the most common DBA and Developer problems.  New instrumentations include: Statements/Stages What are my most resource intensive queries? Where do they spend time? Table/Index I/O, Table Locks Which application tables/indexes cause the most load or contention? Users/Hosts/Accounts Which application users, hosts, accounts are consuming the most resources? Network I/O What is the network load like? How long do sessions idle? Summaries Aggregated statistics grouped by statement, thread, user, host, account or object. The MySQL 5.6 Performance Schema is now enabled by default in the my.cnf file with optimized and auto-tune settings that minimize overhead (< 5%, but mileage will vary), so using the Performance Schema ona production server to monitor the most common application use cases is less of an issue.  In addition, new atomic levels of instrumentation enable the capture of granular levels of resource consumption by users, hosts, accounts, applications, etc. for billing and chargeback purposes in cloud computing environments.The MySQL docs are an excellent resource for all that is available and that can be done with the 5.6 Performance Schema. Better Condition Handling - GET DIAGNOSTICSMySQL 5.6 enables developers to easily check for error conditions and code for exceptions by introducing the new MySQL Diagnostics Area and corresponding GET DIAGNOSTICS interface command. The Diagnostic Area can be populated via multiple options and provides 2 kinds of information:Statement - which provides affected row count and number of conditions that occurredCondition - which provides error codes and messages for all conditions that were returned by a previous operation The addressable items for each are: The new GET DIAGNOSTICS command provides a standard interface into the Diagnostics Area and can be used via the CLI or from within application code to easily retrieve and handle the results of the most recent statement execution.  An example of how it is used might be:mysql> DROP TABLE test.no_such_table; ERROR 1051 (42S02): Unknown table 'test.no_such_table' mysql> GET DIAGNOSTICS CONDITION 1 -> @p1 = RETURNED_SQLSTATE, @p2 = MESSAGE_TEXT; mysql> SELECT @p1, @p2; +-------+------------------------------------+| @p1   | @p2                                | +-------+------------------------------------+| 42S02 | Unknown table 'test.no_such_table' | +-------+------------------------------------+ Options for leveraging the MySQL Diagnotics Area and GET DIAGNOSTICS are detailed in the MySQL Docs.While the above is a summary of some of the key developer enabling 5.6 features, it is by no means exhaustive. You can dig deeper into what MySQL 5.6 has to offer by reading this developer zone article or checking out "What's New in MySQL 5.6" in the MySQL docs.BONUS ALERT!  If you are developing on Windows or are considering MySQL as an alternative to SQL Server for your next project, application or shipping product, you should check out the MySQL Installer for Windows.  The installer includes the MySQL 5.6 RC database, all drivers, Visual Studio and Excel plugins, tray monitor and development tools all a single download and GUI installer.   So what are your next steps? Register for Dec. 13 "MySQL 5.6: Building the Next Generation of Web-Based Applications and Services" live web event.  Hurry!  Seats are limited. Download the MySQL 5.6 Release Candidate (look under the Development Releases tab) Provide Feedback <link to http://bugs.mysql.com/> Join the Developer discussion on the MySQL Forums Explore all MySQL Products and Developer Tools As always, thanks for your continued support of MySQL!

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• SQL SERVER – Select Columns from Stored Procedure Resultset

  - by Pinal Dave

  It is fun to go back to basics often. Here is the one classic question: “How to select columns from Stored Procedure Resultset?” Though Stored Procedure has been introduced many years ago, the question about retrieving columns from Stored Procedure is still very popular with beginners. Let us see the solution in quick steps. First we will create a sample stored procedure. CREATE PROCEDURE SampleSP AS SELECT 1 AS Col1, 2 AS Col2 UNION SELECT 11, 22 GO Now we will create a table where we will temporarily store the result set of stored procedures. We will be using INSERT INTO and EXEC command to retrieve the values and insert into temporary table. CREATE TABLE #TempTable (Col1 INT, Col2 INT) GO INSERT INTO #TempTable EXEC SampleSP GO Next we will retrieve our data from stored procedure. SELECT * FROM #TempTable GO Finally we will clean up all the objects which we have created. DROP TABLE #TempTable DROP PROCEDURE SampleSP GO Let me know if you want me to share such back to basic tips. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Stored Procedure, SQL Tips and Tricks, T SQL

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• Silverlight Cream for May 18, 2010 -- #864

  - by Dave Campbell

  In this Issue: Jesse Liberty, Chris Koenig, Kyle McClellan, Kunal Chowdhury(-2-), Tim Heuer, and Jonathan van de Veen. Shoutout: René Schulte has posted a SLARToolkit Beginner's Guide Erik Mork and the Sparkling Podcast crew posted Silverlight Week – Silverlight Android? John Papa opens up a dialog: Ask the Experts on Silverlight TV ... get your questions answered! From SilverlightCream.com: Windows Phone 7 For Silverlight Programmers Jesse Liberty's starting a series on WP7, so you obviously don't want to miss this... source, commentary, external links, how-to's... what more could you ask for?? WP7 Part 3: Navigation Chris Koenig is revamping his WP7 application to use Community Megaphone instead of Nerd Dinner and in this episode 3 he's looking into Navigation ... definitely good stuff here. RIA Services Authentication Out-Of-Browser Kyle McClellan has code up demonstrating how to get around the fact that the Browser networking stack handles cookies differently than the client networking stack used OOB, and achieve forms authentication OOB. How to work with the Silverlight BusyIndicator? Kunal Chowdhury has a post up talking about the busy indicator and how to use it to show an active indicator while disabling other content. Drag and Drop Operation in Silverlight ListBox In a second entry, Kunal Chowdhury has a nice long post displaying drag-and-drop within and between ListBox controls. Silverlight 4 Tools, WCF RIA Services and Themes Released As usual, Tim Heuer has a great post up about the new releases not only for those with 'clean' machines, but also instructions for those that have been playing along. Advanced printing in Silverlight 4 Just after a post on printing yesterday, Jonathan van de Veen has a post up at SilverlightShow on printing as well, and is demonstrating fitting the text to the page and printing multiple pages. Stay in the 'Light! Twitter SilverlightNews | Twitter WynApse | WynApse.com | Tagged Posts | SilverlightCream Join me @ SilverlightCream | Phoenix Silverlight User Group Technorati Tags: Silverlight    Silverlight 3    Silverlight 4    Windows Phone MIX10

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• New release of Microsoft All-In-One Code Framework is available for download - March 2011

  - by Jialiang

  A new release of Microsoft All-In-One Code Framework is available on March 8th. Download address: http://1code.codeplex.com/releases/view/62267#DownloadId=215627 You can download individual code samples or browse code samples grouped by technology in the updated code sample index. If it’s the first time that you hear about Microsoft All-In-One Code Framework, please read this Microsoft News Center article http://www.microsoft.com/presspass/features/2011/jan11/01-13codeframework.mspx, or watch the introduction video on YouTube http://www.youtube.com/watch?v=cO5Li3APU58, or read the introduction on our homepage http://1code.codeplex.com/. -------------- New Silverlight code samples CSSLTreeViewCRUDDragDrop Download: http://1code.codeplex.com/releases/view/62253#DownloadId=215808 The code sample was created by Amit Dey. It demonstrates a custom TreeView with added functionalities of CRUD (Create, Read, Update, Delete) and drag-and-drop operations. Silverlight TreeView control with CRUD and drag & drop is a frequently asked programming question in Silverlight  forums. Many customers also requested this code sample in our code sample request service. We hope that this sample can reduce developers' efforts in handling this typical programming scenario. The following blog article introduces the sample in detail: http://blogs.msdn.com/b/codefx/archive/2011/02/15/silverlight-treeview-control-with-crud-and-drag-amp-drop.aspx. CSSL4FileDragDrop and VBSL4FileDragDrop Download: http://1code.codeplex.com/releases/view/62253#DownloadId=215809 http://1code.codeplex.com/releases/view/62253#DownloadId=215810 The code sample demonstrates the new drag&drop feature of Silverlight 4 to implement dragging picures from the local file system to a Silverlight application.   Sometimes we want to change SiteMapPath control's titles and paths according to Query String values. And sometimes we want to create the SiteMapPath dynamically. This code sample shows how to achieve these goals by handling SiteMap.SiteMapResolve event. CSASPNETEncryptAndDecryptConfiguration, VBASPNETEncryptAndDecryptConfiguration Download: http://1code.codeplex.com/releases/view/62253#DownloadId=215027 http://1code.codeplex.com/releases/view/62253#DownloadId=215106 In this sample, we encrypt and decrypt some sensitive information in the config file of a web application by using the RSA asymmetric encryption. This project contains two snippets. The first one demonstrates how to use RSACryptoServiceProvider to generate public key and the corresponding private key and then encrypt/decrypt string value on page. The second part shows how to use RSA configuration provider to encrypt and decrypt configuration section in web.config of web application. connectionStrings section in plain text: Encrypted connectionString:  Note that if you store sensitive data in any of the following configuration sections, we cannot encrypt it by using a protected configuration provider <processModel> <runtime> <mscorlib> <startup> <system.runtime.remoting> <configProtectedData> <satelliteassemblies> <cryptographySettings> <cryptoNameMapping> CSASPNETFileUploadStatus Download: http://1code.codeplex.com/releases/view/62253#DownloadId=215028 I believe ASP.NET programmers will like this sample, because in many cases we need customers know the current status of the uploading files, including the upload speed and completion percentage and so on. Under normal circumstances, we need to use COM components to accomplish this function, such as Flash, Silverlight, etc. The uploading data can be retrieved in two places, the client-side and the server-side. For the client, for the safety factors, the file upload status information cannot be got from JavaScript or server-side code, so we need COM component, like Flash and Silverlight to accomplish this, I do not like this approach because the customer need to install these components, but also we need to learn another programming framework. For the server side, we can get the information through coding, but the key question is how to tell the client results. In this case, We will combine custom HTTPModule and AJAX technology to illustrate how to analyze the HTTP protocol, how to break the file request packets, how to customize the location of the server-side file caching, how to return the file uploading status back to the client and so on . CSASPNETHighlightCodeInPage, VBASPNETHighlightCodeInPage Download: http://1code.codeplex.com/releases/view/62253#DownloadId=215029 http://1code.codeplex.com/releases/view/62253#DownloadId=215108 This sample imitates a system that needs display the highlighted code in an ASP.NET page . As a matter of fact, sometimes we input code like C# or HTML in a web page and we need these codes to be highlighted for a better reading experience. It is convenient for us to keep the code in mind if it is highlighted. So in this case, the sample shows how to highlight the code in an ASP.NET page. It is not difficult to highlight the code in a web page by using String.Replace method directly. This  method can return a new string in which all occurrences of a specified string in the current instance are replaced with another specified string. However, it may not be a good idea, because it's not extremely fast, in fact, it's pretty slow. In addition, it is hard to highlight multiple keywords by using String.Replace method directly. Sometimes we need to copy source code from visual studio to a web page, for readability purpose, highlight the code is important while set the different types of keywords to different colors in a web page by using String.Replace method directly is not available. To handle this issue, we need to use a hashtable variable to store the different languages of code and their related regular expressions with matching options. Furthermore, define the css styles which used to highlight the code in a web page. The sample project can auto add the style object to the matching string of code. A step-by-step guide illustrating how to highlight the code in an ASP.NET page: 1. the HighlightCodePage.aspx page Choose a type of language in the dropdownlist control and paste the code in the textbox control, then click the HighLight button. 2.  Display the highlighted code in an ASP.NET page After user clicks the HighLight button, the highlighted code will be displayed at right side of the page.        CSASPNETPreventMultipleWindows Download: http://1code.codeplex.com/releases/view/62253#DownloadId=215032 This sample demonstrates a step-by-step guide illustrating how to detect and prevent multiple windows or tab usage in Web Applications. The sample imitates a system that need to prevent multiple windows or tabs to solve some problems like sharing sessions, protect duplicated login, data concurrency, etc. In fact, there are many methods achieving this goal. Here we give a solution of use JavaScript, Sample shows how to use window.name property check the correct links and throw other requests to invalid pages. This code-sample use two user controls to make a distinction between base page and target page, user only need drag different controls to appropriate web form pages. so user need not write repetitive code in every page, it will make coding work lightly and convenient for modify your code.  JSVirtualKeyboard Download: http://1code.codeplex.com/releases/view/62253#DownloadId=215093 This article describes an All-In-One framework sample that demonstrates a step-by-step guide illustrating how to build a virtual keyboard in your HTML page. Sometimes we may need to offer a virtual keyboard to let users input something without their real keyboards. This scenario often occurs when users will enter their password to get access to our sites and we want to protect the password from some kinds of back-door software, a Key-logger for example, and we will find a virtual keyboard on the page will be a good choice here. To create a virtual keyboard, we firstly need to add some buttons to the page. And when users click on a certain button, the JavaScript function handling the onclick event will input an appropriated character to the textbox. That is the simple logic of this feature. However, if we indeed want a virtual keyboard to substitute for the real keyboard completely, we will need more advanced logic to handle keys like Caps-Lock and Shift etc. That will be a complex work to achieve. CSASPNETDataListImageGallery Download: http://1code.codeplex.com/releases/view/62261#DownloadId=215267 This code sample demonstrates how to create an Image Gallery application by using the DataList control in ASP.NET. You may find the Image Gallery is widely used in many social networking sites, personal websites and E-Business websites. For example, you may use the Image Gallery to show a library of personal uploaded images on a personal website. Slideshow is also a popular tool to display images on websites. This code sample demonstrates how to use the DataList and ImageButton controls in ASP.NET to create an Image Gallery with image navigation. You can click on a thumbnail image in the Datalist control to display a larger version of the image on the page. This sample code reads the image paths from a certain directory into a FileInfo array. Then, the FileInfo array is used to populate a custom DataTable object which is bound to the Datalist control. This code sample also implements a custom paging system that allows five images to be displayed horizontally on one page. The following link buttons are used to implement a custom paging system:   •     First •     Previous •     Next •     Last Note We recommend that you use this method to load no more than five images at a time. You can also set the SelectedIndex property for the DataList control to limit the number of the thumbnail images that can be selected. To indicate which image is selected, you can set the SelectedStyle property for the DataList control. VBASPNETSearchEngine Download: http://1code.codeplex.com/releases/view/62253#DownloadId=215112 This sample shows how to implement a simple search engine in an ASP.NET web site. It uses LIKE condition in SQL statement to search database. Then it highlights keywords in search result by using Regular Expression and JavaScript. New Windows General code samples CSCheckEXEType, VBCheckEXEType Downloads: http://1code.codeplex.com/releases/view/62253#DownloadId=215045 http://1code.codeplex.com/releases/view/62253#DownloadId=215120 The sample demonstrates how to check an executable file type.  For a given executable file, we can get 1 whether it is a console application 2 whether it is a .Net application 3 whether it is a 32bit native application. 4 The full display name of a .NET application, e.g. System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089, processorArchitecture=MSIL New Internet Explorer code samples CSIEExplorerBar, VBIEExplorerBar Downloads: http://1code.codeplex.com/releases/view/62253#DownloadId=215060 http://1code.codeplex.com/releases/view/62253#DownloadId=215133 The sample demonstrates how to create and deploy an IE Explorer Bar which could list all the images in a web page. CSBrowserHelperObject, VBBrowserHelperObject Downloads: http://1code.codeplex.com/releases/view/62253#DownloadId=215044 http://1code.codeplex.com/releases/view/62253#DownloadId=215119 The sample demonstrates how to create and deploy a Browser Helper Object,  and the BHO in this sample is used to disable the context menu in IE. New Windows Workflow Foundation code samples CSWF4ActivitiesCorrelation Download: http://1code.codeplex.com/releases/view/62253#DownloadId=215085 Consider that there are two such workflow instances:       start                                   start          |                                           | Receive activity      Receive activity         |                                           | Receive2 activity      Receive2 activity         |                                           | A WCF request comes to call the second Receive2 activity. Which one should take care of the request? The answer is Correlation. This sample will show you how to correlate two workflow service to work together. -------------- New ASP.NET code samples CSASPNETBreadcrumbWithQueryString Download: http://1code.codeplex.com/releases/view/62253#DownloadId=215022

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• Issue 55 - Skin Object Tokens, Optimized Control Panel, OWS Validation and Security, RAD

  April 2010 Welcome to Issue 55 of DNN Creative Magazine In this issue we focus on the new Skin Object token method introduced in DotNetNuke 5 for adding tokens into a DotNetNuke skin. A Skin Object Token is a web user control which covers skin elements such as the logo, menu, search, login links, date, copyright, languages, links, banners, privacy, terms of use, etc. Following this we demonstrate how to install and use two Advanced DotNetNuke Admin Control Panels which are available for free from Oliver Hine. These control panels provide an optimized version of the admin control panel to improve performance and page load times, as well as a ribbon bar control panel which adds additional features. Next, we continue the Open Web Studio tutorials, this month we demonstrate some very advanced techniques for building a car parts application in Open Web Studio. Throughout the tutorial we cover form input, validation, how to use dependant drop down lists, populating checkbox lists and introduce a new concept of data level security. Data level security allows you to control which data a user can access within a module. To finish, we have part five of the "How to Build a News Application with DotNetMushroom Rapid Application Developer (RAD)" article, where we demonstrate how to implement paging. This issue comes complete with 14 videos. Skinning: Skin Object Tokens for DotNetNuke 5 (8 videos - 64mins) Free Module: Advanced Optimized Control Panel by Oliver Hine (1 video - 11mins) Module Development Series: Form Validation, Dependant Drop Downs and Data Level Security in OWS (5 videos - 44mins) How to Implement Paging with DotNetMushroom RAD View issue 55 to download all of the videos in one zip file DNN Creative Magazine for DotNetNuke Web Designers Covering DotNetNuke module video reviews, video tutorials, mp3 interviews, resources and web design tips for working with DotNetNuke. In 55 issues we have created 563 videos!Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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• C# Performance Pitfall – Interop Scenarios Change the Rules

  - by Reed

  C# and .NET, overall, really do have fantastic performance in my opinion.  That being said, the performance characteristics dramatically differ from native programming, and take some relearning if you’re used to doing performance optimization in most other languages, especially C, C++, and similar.  However, there are times when revisiting tricks learned in native code play a critical role in performance optimization in C#. I recently ran across a nasty scenario that illustrated to me how dangerous following any fixed rules for optimization can be… The rules in C# when optimizing code are very different than C or C++.  Often, they’re exactly backwards.  For example, in C and C++, lifting a variable out of loops in order to avoid memory allocations often can have huge advantages.  If some function within a call graph is allocating memory dynamically, and that gets called in a loop, it can dramatically slow down a routine. This can be a tricky bottleneck to track down, even with a profiler.  Looking at the memory allocation graph is usually the key for spotting this routine, as it’s often “hidden” deep in call graph.  For example, while optimizing some of my scientific routines, I ran into a situation where I had a loop similar to: for (i=0; i<numberToProcess; ++i) { // Do some work ProcessElement(element[i]); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } This loop was at a fairly high level in the call graph, and often could take many hours to complete, depending on the input data.  As such, any performance optimization we could achieve would be greatly appreciated by our users. After a fair bit of profiling, I noticed that a couple of function calls down the call graph (inside of ProcessElement), there was some code that effectively was doing: // Allocate some data required DataStructure* data = new DataStructure(num); // Call into a subroutine that passed around and manipulated this data highly CallSubroutine(data); // Read and use some values from here double values = data->Foo; // Cleanup delete data; // ... return bar; Normally, if “DataStructure” was a simple data type, I could just allocate it on the stack.  However, it’s constructor, internally, allocated it’s own memory using new, so this wouldn’t eliminate the problem.  In this case, however, I could change the call signatures to allow the pointer to the data structure to be passed into ProcessElement and through the call graph, allowing the inner routine to reuse the same “data” memory instead of allocating.  At the highest level, my code effectively changed to something like: DataStructure* data = new DataStructure(numberToProcess); for (i=0; i<numberToProcess; ++i) { // Do some work ProcessElement(element[i], data); } delete data; Granted, this dramatically reduced the maintainability of the code, so it wasn’t something I wanted to do unless there was a significant benefit.  In this case, after profiling the new version, I found that it increased the overall performance dramatically – my main test case went from 35 minutes runtime down to 21 minutes.  This was such a significant improvement, I felt it was worth the reduction in maintainability. In C and C++, it’s generally a good idea (for performance) to: Reduce the number of memory allocations as much as possible, Use fewer, larger memory allocations instead of many smaller ones, and Allocate as high up the call stack as possible, and reuse memory I’ve seen many people try to make similar optimizations in C# code.  For good or bad, this is typically not a good idea.  The garbage collector in .NET completely changes the rules here. In C#, reallocating memory in a loop is not always a bad idea.  In this scenario, for example, I may have been much better off leaving the original code alone.  The reason for this is the garbage collector.  The GC in .NET is incredibly effective, and leaving the allocation deep inside the call stack has some huge advantages.  First and foremost, it tends to make the code more maintainable – passing around object references tends to couple the methods together more than necessary, and overall increase the complexity of the code.  This is something that should be avoided unless there is a significant reason.  Second, (unlike C and C++) memory allocation of a single object in C# is normally cheap and fast.  Finally, and most critically, there is a large advantage to having short lived objects.  If you lift a variable out of the loop and reuse the memory, its much more likely that object will get promoted to Gen1 (or worse, Gen2).  This can cause expensive compaction operations to be required, and also lead to (at least temporary) memory fragmentation as well as more costly collections later. As such, I’ve found that it’s often (though not always) faster to leave memory allocations where you’d naturally place them – deep inside of the call graph, inside of the loops.  This causes the objects to stay very short lived, which in turn increases the efficiency of the garbage collector, and can dramatically improve the overall performance of the routine as a whole. In C#, I tend to: Keep variable declarations in the tightest scope possible Declare and allocate objects at usage While this tends to cause some of the same goals (reducing unnecessary allocations, etc), the goal here is a bit different – it’s about keeping the objects rooted for as little time as possible in order to (attempt) to keep them completely in Gen0, or worst case, Gen1.  It also has the huge advantage of keeping the code very maintainable – objects are used and “released” as soon as possible, which keeps the code very clean.  It does, however, often have the side effect of causing more allocations to occur, but keeping the objects rooted for a much shorter time. Now – nowhere here am I suggesting that these rules are hard, fast rules that are always true.  That being said, my time spent optimizing over the years encourages me to naturally write code that follows the above guidelines, then profile and adjust as necessary.  In my current project, however, I ran across one of those nasty little pitfalls that’s something to keep in mind – interop changes the rules. In this case, I was dealing with an API that, internally, used some COM objects.  In this case, these COM objects were leading to native allocations (most likely C++) occurring in a loop deep in my call graph.  Even though I was writing nice, clean managed code, the normal managed code rules for performance no longer apply.  After profiling to find the bottleneck in my code, I realized that my inner loop, a innocuous looking block of C# code, was effectively causing a set of native memory allocations in every iteration.  This required going back to a “native programming” mindset for optimization.  Lifting these variables and reusing them took a 1:10 routine down to 0:20 – again, a very worthwhile improvement. Overall, the lessons here are: Always profile if you suspect a performance problem – don’t assume any rule is correct, or any code is efficient just because it looks like it should be Remember to check memory allocations when profiling, not just CPU cycles Interop scenarios often cause managed code to act very differently than “normal” managed code. Native code can be hidden very cleverly inside of managed wrappers

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• Simple ADF page using BAM Data Control

  - by [email protected]

  var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www."); document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E")); try { var pageTracker = _gat._getTracker("UA-15829414-1"); pageTracker._trackPageview(); } catch(err) {} Purpose : In this blog I will walk you through very simple steps to create an ADF page using BAM data control connection.Details : Create the projectOpen JDeveloper (make sure you have installed the SOA extension for JDev)Create new Application using "Generic Application" template.Click on "Next"Shuttle  "ADF Faces" to right pane for the project technology.Click "Finish"Create a BAM connectionIn the resource palette click on "Folder->New Connection -> BAM"Enter the connection name and click "Next"Enter Connection details Click on "Test connection" and "Finish"Create the BAM Data Control Open the IDE connection created in above step.Drag and drop "Employees" to "Data controls" palette.Select "Flat Query" and Click "Finish".Create the View Create a new JSF page.From Data control Panel drag and drop "Employees->Query->ADF Read Only table"Right click and Run the page.

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• Introduction to Extended Events

  - by extended_events

  For those fighting with all the Extended Event terminology, let's step back and have a small overall Introduction to Extended Events. This post will give you a simplified end to end view through some of the elements in Extended Events. Before we start, let’s review the first Extented Events that we are going to use: -          Events: The SQL Server code is populated with event calls that, by default, are disabled. Adding events to a session enables those event calls. Once enabled, they will execute the set of functionality defined by the session. -          Target: This is an Extended Event Object that can be used to log event information. Also it is important to understand the following Extended Event concept: -          Session: Server Object created by the user that defines functionality to be executed every time a set of events happen.   It’s time to write a small “Hello World” using Extended Events. This will help understand the above terms. We will use: -          Event sqlserver. error_reported: This event gets fired every time that an error happens in the server. -          Target package0.asynchronous_file_target: This target stores the event data in disk. -          Session: We will create a session that sends all the error_reported events to the ring buffer. Before we get started, a quick note: Don’t run this script in a production environment. Even though, we are going just going to be raise very low severity user errors, we don't want to introduce noise in our servers. -- TRIES TO ELIMINATE PREVIOUS SESSIONS BEGIN TRY       DROP EVENT SESSION test_session ON SERVER END TRY BEGIN CATCH END CATCH GO   -- CREATES THE SESSION CREATE EVENT SESSION test_session ON SERVER ADD EVENT sqlserver.error_reported ADD TARGET package0.asynchronous_file_target -- CONFIGURES THE FILE TARGET (set filename = 'c:\temp\data1.xel' , metadatafile = 'c:\temp\data1.xem') GO   -- STARTS THE SESSION ALTER EVENT SESSION test_session ON SERVER STATE = START GO   -- GENERATES AN ERROR RAISERROR (N'HELLO WORLD', -- Message text.            1, -- Severity,            1, 7, 3, N'abcde'); -- Other parameters GO   -- STOPS LISTENING FOR THE EVENT ALTER EVENT SESSION test_session ON SERVER STATE = STOP GO   -- REMOVES THE EVENT SESSION FROM THE SERVER DROP EVENT SESSION test_session ON SERVER GO -- REMOVES THE EVENT SESSION FROM THE SERVER select CAST(event_data as XML) as event_data from sys.fn_xe_file_target_read_file ('c:\temp\data1*.xel','c:\temp\data1*.xem', null, null) This query will output the event data with our first hello world in the Extended Event format: <event name="error_reported" package="sqlserver" id="100" version="1" timestamp="2010-02-27T03:08:04.210Z"><data name="error"><value>50000</value><text /></data><data name="severity"><value>1</value><text /></data><data name="state"><value>1</value><text /></data><data name="user_defined"><value>true</value><text /></data><data name="message"><value>HELLO WORLD</value><text /></data></event> More on parsing event data in this post: Reading event data 101 Now let's move that lets move on to the other three Extended Event objects: -          Actions. This Extended Objects actions get executed before events are published (stored in buffers to be transferred to the targets). Currently they are used additional data (like the TSQL Statement related to an event, the session, the user) or generate a mini dump.   -          Predicates: Predicates express are logical expressions that specify what predicates to fire (E.g. only listen to errors with a severity greater than 16). This are composed of two Extended Objects: o   Predicate comparators: Defines an operator for a pair of values. Examples: §  Severity > 16 §  error_message = ‘Hello World!!’ o   Predicate sources: These are values that can be also used by the predicates. They are generic data that isn’t usually provided in the event (similar to the actions). §  Sqlserver.username = ‘Tintin’ As logical expressions they can be combined using logical operators (and, or, not).  Note: This pair always has to be first an event field or predicate source and then a value         Let’s do another small Example. We will trigger errors but we will use the ones that have severity >= 10 and the error message != ‘filter’. To verify this we will use the action sql_text that will attach the sql statement to the event data: -- TRIES TO ELIMINATE PREVIOUS SESSIONS BEGIN TRY       DROP EVENT SESSION test_session ON SERVER END TRY BEGIN CATCH END CATCH GO   -- CREATES THE SESSION CREATE EVENT SESSION test_session ON SERVER ADD EVENT sqlserver.error_reported       (ACTION (sqlserver.sql_text) WHERE severity = 2 and (not (message = 'filter'))) ADD TARGET package0.asynchronous_file_target -- CONFIGURES THE FILE TARGET (set filename = 'c:\temp\data2.xel' , metadatafile = 'c:\temp\data2.xem') GO   -- STARTS THE SESSION ALTER EVENT SESSION test_session ON SERVER STATE = START GO   -- THIS EVENT WILL BE FILTERED BECAUSE SEVERITY != 2 RAISERROR (N'PUBLISH', 1, 1, 7, 3, N'abcde'); GO -- THIS EVENT WILL BE FILTERED BECAUSE MESSAGE = 'FILTER' RAISERROR (N'FILTER', 2, 1, 7, 3, N'abcde'); GO -- THIS ERROR WILL BE PUBLISHED RAISERROR (N'PUBLISH', 2, 1, 7, 3, N'abcde'); GO   -- STOPS LISTENING FOR THE EVENT ALTER EVENT SESSION test_session ON SERVER STATE = STOP GO   -- REMOVES THE EVENT SESSION FROM THE SERVER DROP EVENT SESSION test_session ON SERVER GO -- REMOVES THE EVENT SESSION FROM THE SERVER select CAST(event_data as XML) as event_data from sys.fn_xe_file_target_read_file ('c:\temp\data2*.xel','c:\temp\data2*.xem', null, null)   This last statement will output one event with the following data: <event name="error_reported" package="sqlserver" id="100" version="1" timestamp="2010-03-05T23:15:05.481Z">   <data name="error">     <value>50000</value>     <text />   </data>   <data name="severity">     <value>2</value>     <text />   </data>   <data name="state">     <value>1</value>     <text />   </data>   <data name="user_defined">     <value>true</value>     <text />   </data>   <data name="message">     <value>PUBLISH</value>     <text />   </data>   <action name="sql_text" package="sqlserver">     <value>-- THIS ERROR WILL BE PUBLISHED RAISERROR (N'PUBLISH', 2, 1, 7, 3, N'abcde'); </value>     <text />   </action> </event> If you see more events, check if you have deleted previous event files. If so, please run   -- Deletes previous event files EXEC SP_CONFIGURE GO EXEC SP_CONFIGURE 'xp_cmdshell', 1 GO RECONFIGURE GO XP_CMDSHELL 'del c:\temp\data*.xe*' GO   or delete them manually.   More Info on Events: Extended Event Events More Info on Targets: Extended Event Targets More Info on Sessions: Extended Event Sessions More Info on Actions: Extended Event Actions More Info on Predicates: Extended Event Predicates Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

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• How do I Delete a View? How do I Create a View?

  - by Paula DiTallo

  Before I create views, I generally work out what I want to retrieve in my SELECT statement ahead of time so I'll just  have to cut and  paste the query. The example below is done  in T-SQL/Sybase format, however for Oracle and MySQL, just  place a semi-colon ';' at the end of your statement and remove the  'GO' command.          To drop (delete) an existing view: DROP VIEW vw_rpt_metroBestCustomers GO To create a view: CREATE VIEW vw_rpt_metroBestCustomers ( CustomerName,    OfficeNum,    City,    StateOrProv,    Country,    ZipCode   ) AS SELECT a.FirstName + ', ' + a.LastName,           b.OfficePhoneNum,           c.City,           c.StateOrProvAbbr,           c.Country,           c.PostalCode     FROM Customer a,          CustLocAssoc x,          CustContactAssoc y,          Location c,          Contact b     WHERE a.CustID = x.CustID       AND a.CustID = y.CustID       AND y.ContactID = b.ContactID       AND x.LocID = c.LocID       AND a.LoyaltyMedian > 85.5 GO        I frequently rename columns when developing views to makeit easier for simple, text-based reporting--however, renamingthe columns isn't necessary.The create view statement above could have been writtenas follows:CREATE VIEW vw_rpt_metroBestCustomersAS (SELECT a.FirstName + ', ' + a.LastName, b.OfficePhoneNum, c.City, c.StateOrProvAbbr, c.Country, c.PostalCode FROM Customer a, CustLocAssoc x, CustContactAssoc y, Location c, Contact b WHERE a.CustID = x.CustID AND a.CustID = y.CustID AND y.ContactID = b.ContactID AND x.LocID = c.LocID AND a.LoyaltyMedian > 85.5 )GO

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• DBCC CHECKDB on VVLDB and latches (Or: My Pain is Your Gain)

  - by Argenis

    Does your CHECKDB hurt, Argenis? There is a classic blog series by Paul Randal [blog|twitter] called “CHECKDB From Every Angle” which is pretty much mandatory reading for anybody who’s even remotely considering going for the MCM certification, or its replacement (the Microsoft Certified Solutions Master: Data Platform – makes my fingers hurt just from typing it). Of particular interest is the post “Consistency Options for a VLDB” – on it, Paul provides solid, timeless advice (I use the word “timeless” because it was written in 2007, and it all applies today!) on how to perform checks on very large databases. Well, here I was trying to figure out how to make CHECKDB run faster on a restored copy of one of our databases, which happens to exceed 7TB in size. The whole thing was taking several days on multiple systems, regardless of the storage used – SAS, SATA or even SSD…and I actually didn’t pay much attention to how long it was taking, or even bothered to look at the reasons why - as long as it was finishing okay and found no consistency errors. Yes – I know. That was a huge mistake, as corruption found in a database several days after taking place could only allow for further spread of the corruption – and potentially large data loss. In the last two weeks I increased my attention towards this problem, as we noticed that CHECKDB was taking EVEN LONGER on brand new all-flash storage in the SAN! I couldn’t really explain it, and were almost ready to blame the storage vendor. The vendor told us that they could initially see the server driving decent I/O – around 450Mb/sec, and then it would settle at a very slow rate of 10Mb/sec or so. “Hum”, I thought – “CHECKDB is just not pushing the I/O subsystem hard enough”. Perfmon confirmed the vendor’s observations. Dreaded @BlobEater What was CHECKDB doing all the time while doing so little I/O? Eating Blobs. It turns out that CHECKDB was taking an extremely long time on one of our frankentables, which happens to be have 35 billion rows (yup, with a b) and sucks up several terabytes of space in the database. We do have a project ongoing to purge/split/partition this table, so it’s just a matter of time before we deal with it. But the reality today is that CHECKDB is coming to a screeching halt in performance when dealing with this particular table. Checking sys.dm_os_waiting_tasks and sys.dm_os_latch_stats showed that LATCH_EX (DBCC_OBJECT_METADATA) was by far the top wait type. I remembered hearing recently about that wait from another post that Paul Randal made, but that was related to computed-column indexes, and in fact, Paul himself reminded me of his article via twitter. But alas, our pathologic table had no non-clustered indexes on computed columns. I knew that latches are used by the database engine to do internal synchronization – but how could I help speed this up? After all, this is stuff that doesn’t have a lot of knobs to tweak. (There’s a fantastic level 500 talk by Bob Ward from Microsoft CSS [blog|twitter] called “Inside SQL Server Latches” given at PASS 2010 – and you can check it out here. DISCLAIMER: I assume no responsibility for any brain melting that might ensue from watching Bob’s talk!) Failed Hypotheses Earlier on this week I flew down to Palo Alto, CA, to visit our Headquarters – and after having a great time with my Monkey peers, I was relaxing on the plane back to Seattle watching a great talk by SQL Server MVP and fellow MCM Maciej Pilecki [twitter] called “Masterclass: A Day in the Life of a Database Transaction” where he discusses many different topics related to transaction management inside SQL Server. Very good stuff, and when I got home it was a little late – that slow DBCC CHECKDB that I had been dealing with was way in the back of my head. As I was looking at the problem at hand earlier on this week, I thought “How about I set the database to read-only?” I remembered one of the things Maciej had (jokingly) said in his talk: “if you don’t want locking and blocking, set the database to read-only” (or something to that effect, pardon my loose memory). I immediately killed the CHECKDB which had been running painfully for days, and set the database to read-only mode. Then I ran DBCC CHECKDB against it. It started going really fast (even a bit faster than before), and then throttled down again to around 10Mb/sec. All sorts of expletives went through my head at the time. Sure enough, the same latching scenario was present. Oh well. I even spent some time trying to figure out if NUMA was hurting performance. Folks on Twitter made suggestions in this regard (thanks, Lonny! [twitter]) …Eureka? This past Friday I was still scratching my head about the whole thing; I was ready to start profiling with XPERF to see if I could figure out which part of the engine was to blame and then get Microsoft to look at the evidence. After getting a bunch of good news I’ll blog about separately, I sat down for a figurative smack down with CHECKDB before the weekend. And then the light bulb went on. A sparse column. I thought that I couldn’t possibly be experiencing the same scenario that Paul blogged about back in March showing extreme latching with non-clustered indexes on computed columns. Did I even have a non-clustered index on my sparse column? As it turns out, I did. I had one filtered non-clustered index – with the sparse column as the index key (and only column). To prove that this was the problem, I went and setup a test. Yup, that'll do it The repro is very simple for this issue: I tested it on the latest public builds of SQL Server 2008 R2 SP2 (CU6) and SQL Server 2012 SP1 (CU4). First, create a test database and a test table, which only needs to contain a sparse column: CREATE DATABASE SparseColTest; GO USE SparseColTest; GO CREATE TABLE testTable (testCol smalldatetime SPARSE NULL); GO INSERT INTO testTable (testCol) VALUES (NULL); GO 1000000 That’s 1 million rows, and even though you’re inserting NULLs, that’s going to take a while. In my laptop, it took 3 minutes and 31 seconds. Next, we run DBCC CHECKDB against the database: DBCC CHECKDB('SparseColTest') WITH NO_INFOMSGS, ALL_ERRORMSGS; This runs extremely fast, as least on my test rig – 198 milliseconds. Now let’s create a filtered non-clustered index on the sparse column: CREATE NONCLUSTERED INDEX [badBadIndex] ON testTable (testCol) WHERE testCol IS NOT NULL; With the index in place now, let’s run DBCC CHECKDB one more time: DBCC CHECKDB('SparseColTest') WITH NO_INFOMSGS, ALL_ERRORMSGS; In my test system this statement completed in 11433 milliseconds. 11.43 full seconds. Quite the jump from 198 milliseconds. I went ahead and dropped the filtered non-clustered indexes on the restored copy of our production database, and ran CHECKDB against that. We went down from 7+ days to 19 hours and 20 minutes. Cue the “Argenis is not impressed” meme, please, Mr. LaRock. My pain is your gain, folks. Go check to see if you have any of such indexes – they’re likely causing your consistency checks to run very, very slow. Happy CHECKDBing, -Argenis ps: I plan to file a Connect item for this issue – I consider it a pretty serious bug in the engine. After all, filtered indexes were invented BECAUSE of the sparse column feature – and it makes a lot of sense to use them together. Watch this space and my twitter timeline for a link.

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• Reading a large SQL Errorlog

  - by steveh99999

  I came across an interesting situation recently where a SQL instance had been configured with the Audit of successful and failed logins being written to the errorlog. ie This meant… every time a user or the application connected to the SQL instance – an entry was written to the errorlog. This meant…  huge SQL Server errorlogs. Opening an errorlog in the usual way, using SQL management studio, was extremely slow… Luckily, I was able to use xp_readerrorlog to work around this – here’s some example queries..   To show errorlog entries from the currently active log, just for today :- DECLARE @now DATETIME DECLARE @midnight DATETIME SET @now = GETDATE() SET @midnight =  DATEADD(d, DATEDIFF(d, 0, getdate()), 0) EXEC xp_readerrorlog 0,1,NULL,NULL,@midnight,@now   To find out how big the current errorlog actually is, and what the earliest and most recent entries are in the errorlog :- CREATE TABLE #temp_errorlog (Logdate DATETIME, ProcessInfo VARCHAR(20),Text VARCHAR(4000)) INSERT INTO #temp_errorlog EXEC xp_readerrorlog 0 -- for current errorlog SELECT COUNT(*) AS 'Number of entries in errorlog', MIN(logdate) AS 'ErrorLog Starts', MAX(logdate) AS 'ErrorLog Ends' FROM #temp_errorlog DROP TABLE #temp_errorlog To show just DBCC history  information in the current errorlog :- EXEC xp_readerrorlog 0,1,'dbcc'   To show backup errorlog entries in the current errorlog :- CREATE TABLE #temp_errorlog (Logdate DATETIME, ProcessInfo VARCHAR(20),Text VARCHAR(4000)) INSERT INTO #temp_errorlog EXEC xp_readerrorlog 0 -- for current errorlog SELECT * from #temp_errorlog WHERE ProcessInfo = 'Backup' ORDER BY Logdate DROP TABLE #temp_errorlog XP_Errorlog is an undocumented system stored procedure – so no official Microsoft link describing the parameters it takes – however,  there’s a good blog on this here And, if you do have a problem with huge errorlogs – please consider running system stored procedure  sp_cycle_errorlog on a nightly or regular basis.  But if you do this,  remember to change the amount of errorlogs you do retain – the default of 6 might not be sufficient for you….

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• Using Exception Handler in an ADF Task Flow

  - by anmprs

  Problem Statement: Exception thrown in a task flow gets wrapped in an exception that gives an unintelligible error message to the user. Figure 1 Solution 1. Over-writing the error message with a user-friendly error message. Figure 2 Steps to code 1. Generating an exception: Write a method that throws an exception and drop it in the task flow.2. Adding an Exception Handler: Write a method (example below) to overwrite the Error in the bean or data control and drop the method in the task flow. Figure 3 This method is marked as the Exception Handler by Right-Click on method > Mark Activity> Exception Handler or by the button that is displayed in this screenshot Figure 4 The Final task flow should look like this. This will overwrite the exception with the error message in figure 2. Note: There is no need for a control flow between the two method calls (as shown below). Figure 5 Solution 2: Re-Routing the task flow to display an error page Figure 6 Steps to code 1. This is the same as step 1 of solution 1.2. Adding an Exception Handler: The Exception handler is not always a method; in this case it is implemented on a task flow return.  The task flow looks like this. Figure 7 In the figure below you will notice that the task flow return points to a control flow ‘error’ in the calling task flow. Figure 8 This control flow in turn goes to a view ‘error.jsff’ which contains the error message that one wishes to display.  This can be seen in the figure below. (‘withErrorHandling’ is a  call to the task flow in figure 7) Figure 9

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• Quaternion Camera Orbiting around a Sphere

  - by jessejuicer

  Background: I'm trying to create a game where the camera is always rotating around a single sphere. I'm using the DirectX D3DX math functions in C++ on Windows. The Problem: I cannot get both the camera position and orientation both working properly at the same time. Either one works but not both together. Here's the code for my quaternion camera that revolves around a sphere, always looking at the centerpoint of the sphere, ... as far as I understand it (but which isn't working properly): (I'm only going to present rotation around the X axis here, to simplify this post) Whenever the UP key is pressed or held down, the camera should rotate around the X axis, while looking at the centerpoint of the sphere (which is at 0,0,0 in the world). So, I build a quaternion that represents a small angle of rotation around the x axis like this (where 'deltaAngle' is a small enough number for a slow rotation): D3DXVECTOR3 rotAxis; D3DXQUATERNION tempQuat; tempQuat.x = 0.0f; tempQuat.y = 0.0f; tempQuat.z = 0.0f; tempQuat.w = 1.0f; rotAxis.x = 1.0f; rotAxis.y = 0.0f; rotAxis.z = 0.0f; D3DXQuaternionRotationAxis(&tempQuat, &rotAxis, deltaAngle); ...and I accumulate the result into the camera's current orientation quat, like this: D3DXQuaternionMultiply(&cameraOrientationQuat, &cameraOrientationQuat, &tempQuat); ...which all works fine. Now I need to build a view matrix to pass to DirectX SetTransform function. So I build a rotation matrix from the camera orientation quat as follows: D3DXMATRIXA16 rotationMatrix; D3DXMatrixIdentity(&rotationMatrix); D3DXMatrixRotationQuaternion(&rotationMatrix, &cameraOrientationQuat); ...Now (as seen below) if I just transpose that rotationMatrix and plug it into the 3x3 section of the view matrix, then negate the camera's position and plug it into the translation section of the view matrix, the rotation magically works. Perfectly. (even when I add in rotations for all three axes). There's no gimbal lock, just a smooth rotation all around in any direction. BUT- this works even though I never change the camera's position. At all. Which sorta blows my mind. I even display the camera position and can watch it stay constant at it's starting point (0.0, 0.0, -4000.0). It never moves, but the rotation around the sphere is perfect. I don't understand that. For proper view rotation, the camera position should be revolving around the sphere. Here's the rest of building the view matrix (I'll talk about the commented code below). Note that the camera starts out at (0.0, 0.0, -4000.0) and m_camDistToTarget is 4000.0: /* D3DXVECTOR3 vec1; D3DXVECTOR4 vec2; vec1.x = 0.0f; vec1.y = 0.0f; vec1.z = -1.0f; D3DXVec3Transform(&vec2, &vec1, &rotationMatrix); g_cameraActor->pos.x = vec2.x * g_cameraActor->m_camDistToTarget; g_cameraActor->pos.y = vec2.y * g_cameraActor->m_camDistToTarget; g_cameraActor->pos.z = vec2.z * g_cameraActor->m_camDistToTarget; */ D3DXMatrixTranspose(&g_viewMatrix, &rotationMatrix); g_viewMatrix._41 = -g_cameraActor->pos.x; g_viewMatrix._42 = -g_cameraActor->pos.y; g_viewMatrix._43 = -g_cameraActor->pos.z; g_viewMatrix._44 = 1.0f; g_direct3DDevice9->SetTransform( D3DTS_VIEW, &g_viewMatrix ); ...(The world matrix is always an identity, and the perspective projection works fine). ...So, without the commented code being compiled, the rotation works fine. But to be proper, for obvious reasons, the camera position should be rotating around the sphere, which it currently is not. That's what the commented code is supposed to do. And when I add in that chunk of code to do that, and look at all the data as I hold the keys down (using UP, DOWN, LEFT, RIGHT to rotate different directions) all the values look correct! The camera position is rotating around the sphere just fine, and I can watch that happen visually too. The problem is that the camera orientation does not lookat the center of the sphere. It always looks straight forward down the z axis (toward positive z) as it revolves around the sphere. Yet the values of both the rotation matrix and the view matrix seem to be behaving correctly. (The view matrix orientation is the same as the rotation matrix, just transposed). For instance if I just hold down the key to spin around the x axis, I can watch the values of the three axes represented in the view matrix (x, y, and z axes)... view x-axis stays at (1.0, 0.0, 0.0), and view y-axis and z-axis both spin around the x axis just fine. All the numbers are changing as they should be... well, almost. As far as I can tell, the position of the view matrix is spinning around the sphere one direction (like clockwise), and the orientation (the axes in the view matrix) are spinning the opposite direction (like counter-clockwise). Which I guess explains why the orientation appears to stay straight ahead. I know the position is correct. It revolves properly. It's the orientation that's wrong. Can anyone see what am I doing wrong? Am I using these functions incorrectly? Or is my algorithm flawed? As usual I've been combing my code for simple mistakes for many hours. I'm willing to post the actual code, and a video of the behavior, but that will take much more effort. Thought I'd ask this way first.

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• How to disable the Social Reader Application in Facebook?

  - by Rekha

  Social Reader Application has made the process of sharing in Facebook easy but it looks like whatever we read is being displayed in our Facebook’s page. How to avoid this sharing? In the recent days, everyone’s Facebook Page is being flooded with various news from all the Social Reader Applications we have enabled. Even though this is a good idea to share the current news to everyone, it still seems to have taken away our privacy of what content we actually read. To avoid displaying the news on our Facebook page: 1. If you want the feeds to be displayed in your page but not to be shown to public or friends, just select from the options that are listed when you give permission for the Social Reader when you first read a feed. 2. Select Account Settings from the drop down menu on the top right corner of your FB page. Select Apps Tab which is available in the left side of the page. Here you can change the App Settings or completely delete the App. 3. You can also block Social Reader and other applications’ feeds that are read by your friends. In the right corner of the feed, click the drop-down icon and select “Hide all by ‘Application’” option. By selecting this, you would not be able to see any feeds from your friends too. 4. If you are intrigued by the feeds, you can just copy the title in your search engine and then read directly from their sites. This will not list the feed in your Facebook page.

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• Penne alla MVP

  - by Valter Minute

  I’m sorry for the long silence on this blog and the long delay in replying to the friends that commented on my articles. I’ve been quite busy in the last weeks and I spent a lot of time traveling around Italy (not for pleasure!). In the meantime I’ve been renewed as an MVP on April the 1st (nice date to renew someone with such a bad sense of humor…). I decided to celebrate my MVP award with a new recipe (to be honest, I celebrated by eating the results of this recipe!) and I decided to call it “penne alla MVP”… just because I’m not good in finding nice names for my recipes. Ingredients (for 4 people): 360g pasta (penne or other short pasta) 300g small shrimps 1 cup of whipped cream 2 tablespoons of olive oil 1 small leek 1 glass of beer (I used Hoegaarden dutch white beer… but just because I like it and I finished the rest of the bootle while cooking) Chives Salt, pepper Prepare the pasta by boiling it in salted water, as usual. In the meantime chop the leek in very small bits, heat the oil inside a pan and when the oil is hot, drop the leek chops and let them cook for a few minutes. Add the shrimps and the glass of beer. Let them cook inside beer until they are cooked (if you used pre-cooked shrimps a couple of minutes would be enough to heat them and gave them the flavour of beer). Add the whipped cream and mix it well with the shrimps and the sauce. Dry the pasta and drop the sauce on top of it and then add the chives finely chopped.

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• How do I ensure my Apple keyboard connects on boot?

  - by Stacey Richards

  I am using Ubuntu 10.04 on a laptop and have an Apple wireless keyboard which pairs fine. Every time I turn my computer off and back on again my keyboard stops working. I have to use the keyboard on my laptop to log in. Once I've logged in, in order to get the wireless keyboard to work, I need disconnect and reconnect it by: Clicking on the Bluetooth icon, select Apple Wireless Keyboard from the drop down menu, then click on Disconnect. Clicking on the Bluetooth icon, select Apple Wireless Keyboard from the drop down menu, then click on Connect. Looking through syslog, to see what's happening during boot, I find: Nov 25 10:29:21 sony kernel: [ 24.525372] apple 0005:05AC:0239.0002: parse failed Nov 25 10:29:21 sony kernel: [ 24.525379] apple: probe of 0005:05AC:0239.0002 failed with error -14 and then later in syslog, once I've disconnected then connected the keyboard, I find: Nov 25 10:30:14 sony bluetoothd[1247]: link_key_request (sba=00:21:4F:49:8A:DB, dba=E8:06:88:5A:E0:D4) Nov 25 10:30:14 sony kernel: [ 79.427277] input: Apple Wireless Keyboard as /devices/pci0000:00/0000:00:1d.2/usb8/8-1/8-1:1.0/bluetooth/hci0/hci0:12/input11 Nov 25 10:30:14 sony kernel: [ 79.427611] apple 0005:05AC:0239.0003: input,hidraw1: BLUETOOTH HID v0.50 Keyboard [Apple Wireless Keyboard] on 00:21:4F:49:8A:DB I can't find anything helpful when Googling "apple: probe of failed with error -14".

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• Cannot restart Ubuntu after replacing Unity with Gnome and purging lightdm

  - by OtagoHarbour

  I am running Ubuntu 11.10. I used the directions here to replace Unity with Gnome. It seemed to work fine until the end of step 2 when I rebooted the computer. When I chose the default option, I just got a black screen. When I choose the restore option and then "Restore normal boot" I get Starting load fallback graphics devices [fail] Starting GNOME Display Manager [ok] Starting Userspace bootsplash [ok] Stopping GNOME Display Manager [ok] Stopping Userspace bootsplash [ok] Starting web server apach22 [fail] (among a lot of OKs) It finally gets to Stopping System V runlevel compatibility [ok] where it hangs. I left it overnight and just had a blank screen when I checked it in the morning. I can "Drop to root shell prompt" and "Drop to root shell prompt with networking". I did see here that one should be able to fix the problem by choosing remount and then doing apt-get install lightdm I tried this as root shell with and without networking and got the message Err http://us.archive.ubuntu.com/ubuntu/ oneric-updates/main lightdm i386 1.0.6-0ubuntu1.7 Could not resolve 'us.archive.ubuntu.com/ubuntu' What is the best way to resolve this problem? Thanks, Peter.

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• Tree Surgeon 2.0 - The future on the T4 Express

  - by Malcolm Anderson

  If you've never been a fan of TreeSurgeon (http://treesurgeon.codeplex.com/) then skip this post.However, if have been there have been some interesting developments over the last couple of years.The biggest one is T4Recently Bill Simser wrote a detailed post about the potential future of tree surgeon, called "Tree Surgeon - Alive and Kicking or Dead and Buried" He raised the question:Times have changed. Since that last release in 2008 so much has changed for .NET developers. The question is, today is the project still viable? Do we still need a tool to generate a project tree given that we have things like scaffolding systems, NuGet, and T4 templates. Or should we just give the project its rightful and respectful send off as its had a good life and has outlived its usefulness.For myself, the answer is, keep it.I've spent the last couple of years doing agile engineering coaching and architecture and from my experience, I can tell you, there are a lot of shops out there that would benefit from having Tree Surgeon as a viable product.  Many would benefit simply from having the software engineering information that is embedded in the tree surgeon site be floating around their conversation.Little things like, keep all of your software needed to run the build, with the build in the version control system.Have your developers and the build system using the same build.Have a one-touch buildSeparate your code from your interfacePut unit tests in first, not lastI've seen companies with great developers suffer from the problems that naturally come from builds taking 3 and 4 hours to run.  It takes work to get that build down to 10 minutes, but the benefits are always worth it.  Tree Surgeon gives you a leg up, by starting you off with a project that you can drop into your Continuous Integration system, right out of the box.Well, it used to be right out of the box.  Today, you have to play with the project to make it work for you, but even with the issues (it hasn't been updated since 2008) it still gives you a framework, with logical separations that you can build from.If you have used Tree Surgeon in the past, take a few minutes and drop a comment about what difference it made in your development style, and what you are doing differently today because of it.

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• notification icons in Gnome Shell cause lag

  - by Relik

  Before marking this as a duplicate please read my question throughly. OK I am having a bit of a problem with Gnome Shell (3.3.90); Any time there are any icons in the bottom notification bar it causes massive lag when opening/closing and interacting with the Activities panel. If I close all applications that have a notification icon the lag goes away 100%. In My case it's drop box, but any program that requires a icon in the notification area will cause this issue to happen. I am using an AMD A6-3420M running Catalyst 11.11, however I can confirm that this is not a driver issue. I had the same issue on a system running a GeForce 8600GT,and a HD6850, and there is another question on here titled "Gnome Shell lags after a while" where the user is having the same exact issue and He is also using a nVidia card, a 9800GT to be specific. Please, this question has been asked several time and every time people say its a fglrx issue and close the question, or they mark the question as a duplicate and link to a question that says its an fglrx issue. This is not a driver issue, I understand that the AMD drivers caught heat for quite some time for Gnome Shell compatibility issues but those issues have been resolved. Aside from this issue Gnome Shell runs beautiful on my HD650, my A6-3420M, and my 8600GT. Having said that, does anyone know how to correct this issue? Closing Drop Box is not an option for me either.

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• Do large number of internal broken links affect SEO?

  - by TheBigK

  We've a WordPress blog and had disqus plugin in stalled for several months. Around late August this year, the plugin created a ton of URLs that linked to non-existent location on our website. For example - Correct URL: domain.com/correct-URL/ Disqus created - domain.com/correct-URL/344322/ - Throws 404 domain.com/correct-URL/433466/ - Throws 404 So essentially, Google found a LARGE number of broken links that pointed to unknown locations on our own domain. As the count of those errors (404) rose, our site suffered massive drop in traffic and crawl rate dropped to 10% of what it was earlier. I wish to know - Can large number of (we've over 99k of them) internal broken links cause rankings to drop? I've fixed the issue in one go by creating 301 redirects for each bad URL to correct URL and removing disqus. Google however drops the count by ~1000 daily, as I mark errors as 'fixed' in Google Webmaster Tools. Is there any way to speed this up? Should I setup custom crawl rate to 'Fast' in GWT to make Google crawl our website faster? I'd appreciate your inputs and experience sharing.

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• Ubuntu One has high CPU usage but no syncing

  - by Peter

  over the weekend I updated my computer to Windows 8. So far Ubuntu One was running smoothly, but ever since the update (clean, new install) Ubuntu doesn't sync any more. In Windows 7 it would start to sync at full internet speed as soon as I drop a file. But now in Windows 8, as soon as I drop a new file into the Ubuntu One folder, CPU usage goes up to about 50 % and no network traffic occurs. This stays like that for a couple of minutes, CPU usage goes back to normal and then the client says that all is in sync - which isn't true. Is it too early for Windows 8? Do others have the same problem or is there something I can do about it? I try a couple of different things, and realized that if the file size is 20 MB the files get uploaded. The original file was 1.5 GB. I also didn't work with 200, 100 and 50 MB large files. But even with 20 MB large files, the upload is very slow and not steady. The log give plenty of this error: - twisted - ERROR - Failure: exceptions.TypeError About which I don't know the meaning. By the way, the account works just fine on the Ubuntu 12.04 partition. Any help is greatly appreciated. -Peter

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• Mixing JavaFX, HTML 5, and Bananas with the NetBeans Platform

  - by Geertjan

  The banana in the image below can be dragged. Whenever the banana is dropped, the current date is added to the viewer: What's interesting is that the banana, and the viewer that contains it, is defined in HTML 5, with the help of a JavaScript and CSS file. The HTML 5 file is embedded within the JavaFX browser, while the JavaFX browser is embedded within a NetBeans TopComponent class. The only really interesting thing is how drop events of the banana, which is defined within JavaScript, are communicated back into the Java class. Here's how, i.e., in the Java class, parse the HTML's DOM tree to locate the node of interest and then set a listener on it. (In this particular case, the event listener adds the current date to the InstanceContent which is in the Lookup.) Here's the crucial bit of code: WebView view = new WebView(); view.setMinSize(widthDouble, heightDouble); view.setPrefSize(widthDouble, heightDouble); final WebEngine webengine = view.getEngine(); URL url = getClass().getResource("home.html"); webengine.load(url.toExternalForm()); webengine.getLoadWorker().stateProperty().addListener( new ChangeListener() { @Override public void changed(ObservableValue ov, State oldState, State newState) { if (newState == State.SUCCEEDED) { Document document = (Document) webengine.executeScript("document"); EventTarget banana = (EventTarget) document.getElementById("banana"); banana.addEventListener("click", new MyEventListener(), true); } } }); It seems very weird to me that I need to specify "click" as a string. I actually wanted the drop event, but couldn't figure out what the arbitrary string was for that. Which is exactly why strings suck in this context. Many thanks to Martin Kavuma from the Technical University of Eindhoven, who I met today and who inspired me to go down this interesting trail.

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• Save Actions in NetBeans IDE 7.3

  - by Geertjan

  Several developers, especially those familiar with equivalent functionality in Eclipse, have been asking for so-called "Save Actions", that is, support for actions that are automatically performed when a file is saved. Here's the related NetBeans issue: http://netbeans.org/bugzilla/show_bug.cgi?id=140719   In NetBeans IDE 7.3, the issue is resolved as follows: A new "On Save" tab is found in the "Editor" tab of the Options window. Defaults for all languages are set via the "All Languages" item in the drop-down. Here, for all languages, you can specify what kind (all, none, or only modified lines) of formatting and space removal will occur automatically when a file is saved: Via the drop-down, you see all the languages supported by the IDE: You can pick a language and then override the default On Save settings: Per language, there may be additional On Save settings. For example, for Java, you can specify that, when saving a Java file, unused import statements should be removed and/or the rules you've set for organizing import statements should be applied: There's also a set of new NetBeans IDE APIs for adding new On Save functionality via custom plugins. Via MIME type registration of OnSaveTask.Factory, you can register new On Save actions that will be run for files conforming to the relevant MIME type. There's also extensions via the Editor Options API for registering new panels (one per language) to the On Save panel in the Options window. I'll demonstrate some examples of the APIs in upcoming blog entries.

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