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  • An Alphabet of Eponymous Aphorisms, Programming Paradigms, Software Sayings, Annoying Alliteration

    - by Brian Schroer
    Malcolm Anderson blogged about “Einstein’s Razor” yesterday, which reminded me of my favorite software development “law”, the name of which I can never remember. It took much Wikipedia-ing to find it (Hofstadter’s Law – see below), but along the way I compiled the following list: Amara’s Law: We tend to overestimate the effect of a technology in the short run and underestimate the effect in the long run. Brook’s Law: Adding manpower to a late software project makes it later. Clarke’s Third Law: Any sufficiently advanced technology is indistinguishable from magic. Law of Demeter: Each unit should only talk to its friends; don't talk to strangers. Einstein’s Razor: “Make things as simple as possible, but not simpler” is the popular paraphrase, but what he actually said was “It can scarcely be denied that the supreme goal of all theory is to make the irreducible basic elements as simple and as few as possible without having to surrender the adequate representation of a single datum of experience”, an overly complicated quote which is an obvious violation of Einstein’s Razor. (You can tell by looking at a picture of Einstein that the dude was hardly an expert on razors or other grooming apparati.) Finagle's Law of Dynamic Negatives: Anything that can go wrong, will—at the worst possible moment. - O'Toole's Corollary: The perversity of the Universe tends towards a maximum. Greenspun's Tenth Rule: Any sufficiently complicated C or Fortran program contains an ad hoc, informally-specified, bug-ridden, slow implementation of half of Common Lisp. (Morris’s Corollary: “…including Common Lisp”) Hofstadter's Law: It always takes longer than you expect, even when you take into account Hofstadter's Law. Issawi’s Omelet Analogy: One cannot make an omelet without breaking eggs - but it is amazing how many eggs one can break without making a decent omelet. Jackson’s Rules of Optimization: Rule 1: Don't do it. Rule 2 (for experts only): Don't do it yet. Kaner’s Caveat: A program which perfectly meets a lousy specification is a lousy program. Liskov Substitution Principle (paraphrased): Functions that use pointers or references to base classes must be able to use objects of derived classes without knowing it Mason’s Maxim: Since human beings themselves are not fully debugged yet, there will be bugs in your code no matter what you do. Nils-Peter Nelson’s Nil I/O Rule: The fastest I/O is no I/O.    Occam's Razor: The simplest explanation is usually the correct one. Parkinson’s Law: Work expands so as to fill the time available for its completion. Quentin Tarantino’s Pie Principle: “…you want to go home have a drink and go and eat pie and talk about it.” (OK, he was talking about movies, not software, but I couldn’t find a “Q” quote about software. And wouldn’t it be cool to write a program so great that the users want to eat pie and talk about it?) Raymond’s Rule: Computer science education cannot make anybody an expert programmer any more than studying brushes and pigment can make somebody an expert painter.  Sowa's Law of Standards: Whenever a major organization develops a new system as an official standard for X, the primary result is the widespread adoption of some simpler system as a de facto standard for X. Turing’s Tenet: We shall do a much better programming job, provided we approach the task with a full appreciation of its tremendous difficulty, provided that we respect the intrinsic limitations of the human mind and approach the task as very humble programmers.  Udi Dahan’s Race Condition Rule: If you think you have a race condition, you don’t understand the domain well enough. These rules didn’t exist in the age of paper, there is no reason for them to exist in the age of computers. When you have race conditions, go back to the business and find out actual rules. Van Vleck’s Kvetching: We know about as much about software quality problems as they knew about the Black Plague in the 1600s. We've seen the victims' agonies and helped burn the corpses. We don't know what causes it; we don't really know if there is only one disease. We just suffer -- and keep pouring our sewage into our water supply. Wheeler’s Law: All problems in computer science can be solved by another level of indirection... Except for the problem of too many layers of indirection. Wheeler also said “Compatibility means deliberately repeating other people's mistakes.”. The Wrong Road Rule of Mr. X (anonymous): No matter how far down the wrong road you've gone, turn back. Yourdon’s Rule of Two Feet: If you think your management doesn't know what it's doing or that your organisation turns out low-quality software crap that embarrasses you, then leave. Zawinski's Law of Software Envelopment: Every program attempts to expand until it can read mail. Zawinski is also responsible for “Some people, when confronted with a problem, think 'I know, I'll use regular expressions.' Now they have two problems.” He once commented about X Windows widget toolkits: “Using these toolkits is like trying to make a bookshelf out of mashed potatoes.”

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  • Who broke the build?

    - by Martin Hinshelwood
    I recently sent round a list of broken builds at SSW and asked for them to be fixed or deleted if they are not being used. My colleague Peter came back with a couple of questions which I love as it tells me that at least one person reads my email I think first we need to answer a couple of other questions related to builds in general.   Why do we want the build to pass? Any developer can pick up a project and build it Standards can be enforced Constant quality is maintained Problems in code are identified early What could a failed build signify? Developers have not built and tested their code properly before checking in. Something added depends on a local resource that is not under version control or does not exist on the target computer. Developers are not writing tests to cover common problems. There are not enough tests to cover problems. Now we know why, lets answer Peters questions: Where is this list? (can we see it somehow) You can normally only see the builds listed for each project. But, you have a little application called “Build Notifications” on your computer. It is installed when you install Visual Studio 2010. Figure: Staring the build notification application on Windows 7. Once you have it open (it may disappear into your system tray) you should click “Options” and select all the projects you are involved in. This application only lists projects that have builds, so don’t worry if it is not listed. This just means you are about to setup a build, right? I just selected ALL projects that have builds. Figure: All builds are listed here In addition to seeing the list you will also get toast notification of build failure’s. How can we get more info on what broke the build? (who is interesting too, to point the finger but more important is what) The only thing worse than breaking the build, is continuing to develop on a broken build! Figure: I have highlighted the users who either are bad for braking the build, or very bad for not fixing it. To find out what is wrong with a build you need to open the build definition. You can open a web version by double clicking the build in the image above, or you can open it from “Team Explorer”. Just connect to your project and open out the “Builds” tree. Then Open the build by double clicking on it. Figure: Opening a build is easy, but double click it and then open a build run from the list. Figure: Good example, the build and tests have passed Figure: Bad example, there are 133 errors preventing POK from being built on the build server. For identifying failures see: Solution: Getting Silverlight to build on Team Build 2010 RC Solution: Testing Web Services with MSTest on Team Build Finding the problem on a partially succeeded build So, Peter asked about blame, let’s have a look and see: Figure: The build has been broken for so long I have no idea when it was broken, but everyone on this list is to blame (I am there too) The rest of the history is lost in the sands of time, there is no way to tell when the build was originally broken, or by whom, or even if it ever worked in the first place. Build should be protected by the team that uses them and the only way to do that is to have them own them. It is fine for me to go in and setup a build, but the ownership for a build should always reside with the person who broke it last. Conclusion This is an example of a pointless build. Lets be honest, if you have a system like TFS in place and builds are constantly left broken, or not added to projects then your developers don’t yet understand the value. I have found that adding a Gated Check-in helps instil that understanding of value. If you prevent them from checking in without passing that basic quality gate of “your code builds on another computer” then it makes them look more closely at why they can’t check-in. I have had builds fail because one developer had a “d” drive, but the build server did not. That is what they are there to catch.   If you want to know what builds to create and why I wrote a post on “Do you know the minimum builds to create on any branch?”   Technorati Tags: TFS2010,Gated Check-in,Builds,Build Failure,Broken Build

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  • DBCC CHECKDB (BatmanDb, REPAIR_ALLOW_DATA_LOSS) &ndash; Are you Feeling Lucky?

    - by David Totzke
    I’m currently working for a client on a PowerBuilder to WPF migration.  It’s one of those “I could tell you, but I’d have to kill you” kind of clients and the quick-lime pits are currently occupied by the EMC tech…but I’ve said too much already. At approximately 3 or 4 pm that day users of the Batman[1] application here in Gotham[1] started to experience problems accessing the application.  Batman[2] is a document management system here that also integrates with the ERP system.  Very little goes on here that doesn’t involve Batman in some way.  The errors being received seemed to point to network issues (TCP protocol error, connection forcibly closed by the remote host etc…) but the real issue was much more insidious. Connecting to the database via SSMS and performing selects on certain tables underlying the application areas that were having problems started to reveal the issue.  You couldn’t do a SELECT * FROM MyTable without it bombing and giving the same error noted above.  A run of DBCC CHECKDB revealed 14 tables with corruption.  One of the tables with issues was the Document table.  Pretty central to a “document management” system.  Information was obtained from IT that a single drive in the SAN went bad in the night.  A new drive was in place and was working fine.  The partition that held the Batman database is configured for RAID Level 5 so a single drive failure shouldn’t have caused any trouble and yet, the database is corrupted.  They do hourly incremental backups here so the first thing done was to try a restore.  A restore of the most recent backup failed so they worked backwards until they hit a good point.  This successful restore was for a backup at 3AM – a full day behind.  This time also roughly corresponds with the time the SAN started to report the drive failure.  The plot thickens… I got my hands on the output from DBCC CHECKDB and noticed a pattern.  What’s sad is that nobody that should have noticed the pattern in the DBCC output did notice.  There was a rush to do things to try and recover the data before anybody really understood what was wrong with it in the first place.  Cooler heads must prevail in these circumstances and some investigation should be done and a plan of action laid out or you could end up making things worse[3].  DBCC CHECKDB also told us that: repair_allow_data_loss is the minimum repair level for the errors found by DBCC CHECKDB Yikes.  That means that the database is so messed up that you’re definitely going to lose some stuff when you repair it to get it back to a consistent state.  All the more reason to do a little more investigation into the problem.  Rescuing this database is preferable to having to export all of the data possible from this database into a new one.  This is a fifteen year old application with about seven hundred tables.  There are TRIGGERS everywhere not to mention the referential integrity constraints to deal with.  Only fourteen of the tables have an issue.  We have a good backup that is missing the last 24 hours of business which means we could have a “do-over” of yesterday but that’s not a very palatable option either. All of the affected tables had TEXT columns and all of the errors were about LOB data types and orphaned off-row data which basically means TEXT, IMAGE or NTEXT columns.  If we did a SELECT on an affected table and excluded those columns, we got all of the rows.  We exported that data into a separate database.  Things are looking up.  Working on a copy of the production database we then ran DBCC CHECKDB with REPAIR_ALLOW_DATA_LOSS and that “fixed” everything up.   The allow data loss option will delete the bad rows.  This isn’t too horrible as we have all of those rows minus the text fields from out earlier export.  Now I could LEFT JOIN to the exported data to find the missing rows and INSERT them minus the TEXT column data. We had the restored data from the good 3AM backup that we could now JOIN to and, with fingers crossed, recover the missing TEXT column information.  We got lucky in that all of the affected rows were old and in the end we didn’t lose anything.  :O  All of the row counts along the way worked out and it looks like we dodged a major bullet here. We’ve heard back from EMC and it turns out the SAN firmware that they were running here is apparently buggy.  This thing is only a couple of months old.  Grrr…. They dispatched a technician that night to come and update it .  That explains why RAID didn’t save us. All-in-all this could have been a lot worse.  Given the root cause here, they basically won the lottery in not losing anything. Here are a few links to some helpful posts on the SQL Server Engine blog.  I love the title of the first one: Which part of 'REPAIR_ALLOW_DATA_LOSS' isn't clear? CHECKDB (Part 8): Can repair fix everything? (in fact, read the whole series) Ta da! Emergency mode repair (we didn’t have to resort to this one thank goodness)   Dave Just because I can…   [1] Names have been changed to protect the guilty. [2] I'm Batman. [3] And if I'm the coolest head in the room, you've got even bigger problems...

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  • Check Your Spelling, Grammar, and Style in Firefox and Chrome

    - by Matthew Guay
    Are you tired of making simple writing mistakes that get past your browser’s spell-check?  Here’s how you can get advanced grammar check and more in Firefox and Chrome with After the Deadline. Microsoft Word has spoiled us with grammar, syntax, and spell checking, but the default spell check in Firefox and Chrome still only does basic checks.  Even webapps like Google Docs don’t check more than basic spelling errors.  However, WordPress.com is an exception; it offers advanced spelling, grammar, and syntax checking with its After the Deadline proofing system.  This helps you keep from making embarrassing mistakes on your blog posts, and now, thanks to a couple free browser plugins, it can help you keep from making these mistakes in any website or webapp. After the Deadline in Google Chrome Add the After the Deadline extension (link below) to Chrome as usual. As soon as it’s installed, you’re ready to start improving your online writing.  To check spelling, grammar, and more, click the ABC button that you’ll now see at the bottom of most text boxes online. After a quick scan, grammar mistakes are highlighted in green, complex expressions and other syntax problems are highlighted in blue, and spelling mistakes are highlighted in red as would be expected.  Click on an underlined word to choose one of its recommended changes or ignore the suggestion. Or, if you want more explanation about what was wrong with that word or phrase, click Explain for more info. And, if you forget to run an After the Deadline scan before submitting a text entry, it will automatically check to make sure you still want to submit it.  Click Cancel to go back and check your writing first.   To change the After the Deadline settings, click its icon in the toolbar and select View Options.  Additionally, if you want to disable it on the site you’re on, you can click Disable on this site directly from the popup. From the settings page, you can choose extra things to check for such as double negatives and redundant phrases, as well as add sites and words to ignore. After the Deadline in Firefox Add the After the Deadline add-on to Firefox (link below) as normal. After the Deadline basically the same in Firefox as it does in Chrome.  Select the ABC icon in the lower right corner of textboxes to check them for problems, and After the Deadline will underline the problems as it did in Chrome.  To view a suggested change in Firefox, right-click on the underlined word and select the recommended change or ignore the suggestion. And, if you forget to check, you’ll see a friendly reminder asking if you’re sure you want to submit your text like it is. You can access the After the Deadline settings in Firefox from the menu bar.  Click Tools, then select AtD Preferences.  In Firefox, the settings are in a options dialog with three tabs, but it includes the same options as the Chrome settings page.  Here you can make After the Deadline as correction-happy as you like.   Conclusion The web has increasingly become an interactive place, and seldom does a day go by that we aren’t entering text in forms and comments that may stay online forever.  Even our insignificant tweets are being archived in the Library of Congress.  After the Deadline can help you make sure that your permanent internet record is as grammatically correct as possible.  Even though it doesn’t catch every problem, and even misses some spelling mistakes, it’s still a great help. Links Download the After the Deadline extension for Google Chrome Download the After the Deadline add-on for Firefox Similar Articles Productive Geek Tips Quick Tip: Disable Favicons in FirefoxStupid Geek Tricks: Duplicate a Tab with a Shortcut Key in Chrome or FirefoxHow to Disable the New Geolocation Feature in Google ChromeStupid Geek Tricks: Compare Your Browser’s Memory Usage with Google ChromeStop YouTube Videos from Automatically Playing in Chrome TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips Acronis Online Backup DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows Easily Search Food Recipes With Recipe Chimp Tech Fanboys Field Guide Check these Awesome Chrome Add-ons iFixit Offers Gadget Repair Manuals Online Vista style sidebar for Windows 7 Create Nice Charts With These Web Based Tools

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  • Monitoring almost anything with BizTalk 360

    - by Michael Stephenson
    When you work in an integration environment it is common that you will find yourself in a situation where you integrate with some unusual applications or have some unusual dependencies. That is the nature of integration. When you work with BizTalk one of the common problems is that BizTalk often is the place where problems with applications you integrate with are highlighted and these external applications may have poor monitoring solutions. Fortunately if you are a working with a customer who uses BizTalk 360 then it contains a feature called the "Web Endpoint Manager". Typically the web endpoint manager is used to monitor web services that you integrate with and will ping them at appropriate times to make sure they return the expected HTTP status code. When you have an usual situation where you want to monitor something which is key to the success to your solution but you find yourself having to consider a significant custom solution to monitor the external dependency then the Web Endpoint Manager could be your friend. The endpoint manager monitors a url and checks for a certain status code. This means that you can create your own aspx web page and then make BizTalk 360 monitor this web page. Behind the web page you could write any code you wished. An example of this is architecture is shown in the below diagram.     In the custom web page you would implement some custom code to do whatever it is that you want to monitor. In the below code snippet you can see how the Page_Load default method is doing some kind of check then depending on the result of the check it returns a certain HTTP code. protected void Page_Load(object sender, EventArgs e) { var result = CheckSomething();   if (result == "Success") Response.StatusCode = 202; else if (result == "DatabaseError") Response.StatusCode = 510; else if (result == "SystemError") Response.StatusCode = 512; else Response.StatusCode = 513;   }   In BizTalk 360 you would go into the Monitor and Notify tab and then to BizTalk Environment which gives you access to the Web Endpoint Manager. You need an alarm setup which configures how the endpoint will be checked. I'm not going to go through the details of creating the alarm as this is already documented in the BizTalk 360 documentation. One point to note is that in the example I am using I setup a threshold alarm which means that the url is checked about every minute and if there is an error that persists for a period of time then the alarm will raise the alert notification. In my example I configured the alarm to fire if the error persisted for 3 minutes. The below picture shows accessing the endpoint manager.   In the web endpoint manager you would then configure your endpoint to monitor and the HTTP response code which indicates all is working fine. The below picture shows this. I now have my endpoint monitoring setup and BizTalk 360 should be checking my custom endpoint to see that it is available. If I wanted to manually sanity check that the endpoints I have registered are working fine then clicking the Refresh button will show if they are all good or not. If my custom ASP.net page which is checking my dependency gets a problem you will see in the endpoint manager that the status code does not match the expected return code and your endpoints will display in red and you can see the problem. The below picture shows this. If I use specific HTTP response codes for the errors the custom ASP.net page might encounter I can easily interpret these to know what the problem is. Using the alarms and notifications with BizTalk 360 it means when your endpoint goes into an error state you can easily configure email or SMS notifications from BizTalk 360 to tell you that your endpoint is having problems and you can use BizTalk 360 to help correlate what the problem is to allow you to investigate further. Below you can see the email which tells me my endpoint is not working.   When everything returns to normal you will see the status is now fixed and you will see a situation like below where you can see the WebEndpoints are now green and the return code matches what is expected.   Conclusion As you can see it is really easy to plug your own custom ASP.net page into the BizTalk 360 web endpoint monitoring feature. This extension then gives you the power to really extend the monitoring to almost anything you want as long as you can write some .net code to check that the dependency is available and working. It would be interesting to hear of any ideas people have around things they would monitor with this extension. More details on the end point monitor can be found on the following link: http://www.biztalk360.com/tour/monitoring_notifications

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  • CodePlex Daily Summary for Saturday, December 04, 2010

    CodePlex Daily Summary for Saturday, December 04, 2010Popular ReleasesMiniTwitter: 1.62: MiniTwitter 1.62 ???? ?? ??????????????????????????????????????? 140 ?????????????????????????? ???????????????????????????????? ?? ??????????????????????????????????Chronos WPF: Chronos v2.0 Beta 3: Release notes: Updated introduction document. Updated Visual Studio 2010 Extension (vsix) package. Added horizontal scrolling to the main window TaskBar. Added new styles for ListView, ListViewItem, GridViewColumnHeader, ... Added a new WindowViewModel class (allowing to fetch data). Added a new Navigate method (with several overloads) to the NavigationViewModel class (protected). Reimplemented Task usage for the WorkspaceViewModel.OnDelete method. Removed the reflection effect...MDownloader: MDownloader-0.15.26.7024: Fixed updater; Fixed MegauploadDJ - jQuery WebControls for ASP.NET: DJ 1.2: What is new? Update to support jQuery 1.4.2 Update to support jQuery ui 1.8.6 Update to Visual Studio 2010 New WebControls with samples added Autocomplete WebControl Button WebControl ToggleButt WebControl The example web site is including in source code project.LateBindingApi.Excel: LateBindingApi.Excel Release 0.7g: Unterschiede zur Vorgängerversion: - Zusätzliche Interior Properties - Group / Ungroup Methoden für Range - Bugfix COM Reference Handling für Application Objekt in einigen Klassen Release+Samples V0.7g: - Enthält Laufzeit DLL und Beispielprojekte Beispielprojekte: COMAddinExample - Demonstriert ein versionslos angebundenes COMAddin Example01 - Background Colors und Borders für Cells Example02 - Font Attributes undAlignment für Cells Example03 - Numberformats Example04 - Shapes, WordArts, P...ESRI ArcGIS Silverlight Toolkit: November 2010 - v2.1: ESRI ArcGIS Silverlight Toolkit v2.1 Added Windows Phone 7 build. New controls added: InfoWindow ChildPage (Windows Phone 7 only) See what's new here full details for : http://help.arcgis.com/en/webapi/silverlight/help/#/What_s_new_in_2_1/016600000025000000/ Note: Requires Visual Studio 2010, .NET 4.0 and Silverlight 4.0.ASP .NET MVC CMS (Content Management System): Atomic CMS 2.1.1: Atomic CMS 2.1.1 release notes Atomic CMS installation guide Winware: Winware 3.0 (.Net 4.0): Winware 3.0 is base on .Net 4.0 with C#. Please open it with Visual Studio 2010. This release contains a lab web application.WTV-MetaRenamer: Build 6910: Includes two new areas of functionality - the ability to move renamed files and not just rename them, and the ability to "remap" characters that might cause problems. These address #308, #281 and #417. Please read the documentation carefully as the configuration file has new options to support this functionality. There are now TWO XML files included in the download Zip file. The 2nd one has some additional lines for example reasons. This version is considered to be stable enough and feature...Free Silverlight & WPF Chart Control - Visifire: Visifire SL and WPF Charts v3.6.5 beta Released: Hi, Today we are releasing Visifire 3.6.5 beta with the following new feature: New property AutoFitToPlotArea has been introduced in DataSeries. AutoFitToPlotArea will bring bubbles inside the PlotArea in order to avoid clipping of bubbles in bubble chart. Also this release includes few bug fixes: AxisXLabel label were getting clipped if angle was set for AxisLabels and ScrollingEnabled was not set in Chart. If LabelStyle property was set as 'Inside', size of the Pie was not proper. Yo...EnhSim: EnhSim 2.1.1: 2.1.1This release adds in the changes for 4.03a. To use this release, you must have the Microsoft Visual C++ 2010 Redistributable Package installed. This can be downloaded from http://www.microsoft.com/downloads/en/details.aspx?FamilyID=A7B7A05E-6DE6-4D3A-A423-37BF0912DB84 To use the GUI you must have the .NET 4.0 Framework installed. This can be downloaded from http://www.microsoft.com/downloads/en/details.aspx?FamilyID=9cfb2d51-5ff4-4491-b0e5-b386f32c0992 - Switched Searing Flames bac...Microsoft - Domain Oriented N-Layered .NET 4.0 App Sample (Microsoft Spain): V1.0 - N-Layer DDD Sample App .NET 4.0: Required Software (Microsoft Base Software needed for Development environment) Visual Studio 2010 RTM & .NET 4.0 RTM (Final Versions) Expression Blend 4 SQL Server 2008 R2 Express/Standard/Enterprise Unity Application Block 2.0 - Published May 5th 2010 http://www.microsoft.com/downloads/en/details.aspx?FamilyID=2D24F179-E0A6-49D7-89C4-5B67D939F91B&displaylang=en http://unity.codeplex.com/releases/view/31277 PEX & MOLES 0.94.51023.0, 29/Oct/2010 - Visual Studio 2010 Power Tools http://re...Sense/Net Enterprise Portal & ECMS: SenseNet 6.0.1 Community Edition: Sense/Net 6.0.1 Community Edition This half year we have been working quite fiercely to bring you the long-awaited release of Sense/Net 6.0. Download this Community Edition to see what we have been up to. These months we have worked on getting the WebCMS capabilities of Sense/Net 6.0 up to par. New features include: New, powerful page and portlet editing experience. HTML and CSS cleanup, new, powerful site skinning system. Upgraded, lightning-fast indexing and query via Lucene. Limita...Minecraft GPS: Minecraft GPS 1.1.1: New Features Compass! New style. Set opacity on main window to allow overlay of Minecraft. Open World in any folder. Fixes Fixed style so listbox won't grow the window size. Fixed open file dialog issue on non-vista kernel machines.DotSpatial: DotSpatial 11-28-2001: This release introduces some exciting improvements. Support for big raster, both in display and changing the scheme. Faster raster scheme creation for all rasters. Caching of the "sample" values so once obtained the raster symbolizer dialog loads faster. Reprojection supported for raster and image classes. Affine transform fully supported for images and rasters, so skewed images are now possible. Projection uses better checks when loading unprojected layers. GDAL raster support f...Virtu: Virtu 0.9.0: Source Requirements.NET Framework 4 Visual Studio 2010 or Visual Studio 2010 Express Silverlight 4 Tools for Visual Studio 2010 Windows Phone 7 Developer Tools (which includes XNA Game Studio 4) Binaries RequirementsSilverlight 4 .NET Framework 4 XNA Framework 4SuperWebSocket: SuperWebSocket(60438): It is the first release of SuperWebSocket. Because it is base on SuperSocket, most features of SuperSocket are supported in SuperWebSocket. The source code include a LiveChat demo.Cropper: 1.9.4: Mostly fixes for issues with a few feature requests. Fixed Issues 2730 & 3638 & 14467 11044 11447 11448 11449 14665 Implemented Features 6123 11581PFC: PFC for PB 11.5: This is just a migration from the 11.0 code. No changes have been made yet (and they are needed) for it to work properly with 11.5.PDF Rider: PDF Rider 0.5: This release does not add any new feature for pdf manipulation, but enables automatic updates checking, so it is reccomended to install it in order to stay updated with next releases. Prerequisites * Microsoft Windows Operating Systems (XP - Vista - 7) * Microsoft .NET Framework 3.5 runtime * A PDF rendering software (i.e. Adobe Reader) that can be opened inside Internet Explorer. Installation instructionsChoose one of the following methods: 1. Download and run the "pdfRider0...New ProjectsAnimal Rescue: Animal Rescue will provide a single application for animal rescue groups to maintain any group, animal, foster, medical, etc information and publish the information to various locations. AR is developed in C# and will provide Web and WinForm presentations. ASP.NET 4.0 in practice: ASP.NET 4.0 in Practice contains real world techniques from well-known professionals who have been using ASP.NET since the first previews. Published by Manning, 2011 - Contains code samples from the book.Aspx to Razor Converter: An experimental project to create ASP.NET MVC webform view pages to Razor view pages.AutoWinUI: Automate Application on Windows by UI AutomationBookstore_web: lame ass comment C++ Galois Field Arithmetic Library: The C++ Galois Field Arithmetic Library, implements a specialised version of Galois Fields known as extension fields or in other words fields of the form GF(2^m) and was developed as a base for programming tasks that involved cryptography and error correcting codes.C++ TCP Proxy Server: The C++ TCP Proxy server is a simple utility using the ASIO networking library, for proxying (tunneling or redirecting) connections from external clients to a specific server. The TCP Proxy server can be used to easily and efficiently.Cache Providers For .NET: Cache Provider for .NET helps enterprise applications use popular Provider model. It ships with AppFabric Cache Provider (code named Velocity) and Classic Cache Provider and can be used with ASP.NET, Windows Forms, Windows Services, WCF and WPF.Columbus: Windows Phone 7 MVC framework: Columbus is MVC framework designed specifically for WP7 platform and supports: - Strongly typed navigation with history - View Models that can survive tombstoning - Asynchronous and cancelable controller actions with execution progress - Commands (CAB style)ComplexCode: complex codeDice Shaker: Coding4Fun Windows Phone 7 Dice Shaker applicationEscola do Futuro: Escola do Futuro será mais do que um simples repositório de aulas (mp3 ou mp4) ! Nosso intuito é gerar um projeto que além de ensinar ou repassar o conhecimento, iremos formar as pessoas. O usuário do projeto será capaz de obter o conhecimento com apenas poucos clicks! ExpressionParser: A library designed to read user entered string and evaluate it as an math expression. - Able to understand all the operators that Excel users are used to. - Expose the System.Math functions, but allow additional functions to be added by API - Allow variables access via delegategrouptalk: grouptalkIn-House Normal Report: it is a normal report, just for practice, thanks very much.Jetnett Common Controls: Controls used related to and used by various JetNett productsJSON Tiny Serializer dedicated to output JavaScript string fom C# object: This C# JSon Serializer is dedicated to output JavaScript string from .Net managed object. The code is oriented performance and running more than twice fast as the standard .Net 4 JavaScriptSerializer. Recursive Check and Size limit are implemented. MSX jIDE: Kit de Ferramentas , IDE e Framework para MSX feitos em JAVAMy Text Editor: This is a simple text editor in C# written and compiled in Visual studio 2005. It's in a beta version and needs feedbacks and comments..........Online Course Feedback System: Online Course Feedback System is used to automate the collection of Course Feedback in an academic institution.PerformanceTester: Application to test performance using 5 criteriaPersonal Activity Monitor: simple, personal activity monitor. See how much time do you spend using different applications. Localize your time wasters and minimize them and be happy with more time for your productivityphuongnamco: Products of PhuongNam companypocketpalireader: PocketPC application for reading Pali Tipitaka. Includes Pali Canon library and Pali-English dictionary.Powershell Script for associating Workflow for a library iteratively: Workflow associator powershell script makes easier for associating the workflows for a particular document library to all webs inside a particular site collection. It is no longer a manual activity. Its developed in Powershell 2.0Rotempco.Core: Rotempco.CoreTkalm - A Social Chat System: Tkalm is a social chat system. Important Note: This is part of an ASP.NET Development training, so don't expect too muchTrueForecast: Just a test-project...Weak-coupling Develop Framework: Use like csla objectWeather Report: I Was feeling very cold from last two days and wanted to plan an outing so got to see weather forcast and from there got idea to develop this software which is a kind of Desktop Gadget.Windows Phone Notification Pusher: Application to push notifications to Windows Phone.Words Reminder: A software for people with Persian language who want to learn English language. It reminds the words that user marked them to remind. This software is also a perfect English-to-Persian dictionary with ability to pronounce the words.XEMail: XEMail is a webservice that provides SMTP / POP3 / IMAP functionality

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  • What Counts For A DBA: Foresight

    - by drsql
    Of all the valuable attributes of a DBA covered so far in this series, ranging from passion to humility to practicality, perhaps one of the most important attributes may turn out to be the most seemingly-nebulous: foresight. According to Free Dictionary foresight is the "perception of the significance and nature of events before they have occurred". Foresight does not come naturally to most people, as the parent of any teenager will attest. No matter how clearly you see their problems coming they won't listen, and have to fail before eventually (hopefully) learning for themselves. Having graduated from the school of hard knocks, the DBA, the naive teenager no longer, acquires the ability to foretell how events will unfold in response to certain actions or attitudes with the unerring accuracy of a doom-laden prophet. Like Simba in the Lion King, after a few blows to the head, we foretell that a sore head that will be the inevitable consequence of a swing of Rafiki's stick, and we take evasive action. However, foresight is about more than simply learning when to duck. It's about taking the time to understand and prevent the habits that caused the stick to swing in the first place. And based on this definition, I often think there is a lot less foresight on display in my industry than there ought to be. Most DBAs reading this blog will spot a line such as the following in a piece of "working" code, understand immediately why it is less than optimimum, and take evasive action. …WHERE CAST (columnName as int) = 1 However, the programmers who regularly write this sort of code clearly lack that foresight, and this and numerous other examples of similarly-malodorous code prevail throughout our industry (and provide premium-grade fertilizer for the healthy growth of many a consultant's bank account). Sometimes, perhaps harried by impatient managers and painfully tight deadlines, everyone makes mistakes. Yes, I too occasionally write code that "works", but basically stinks. When the problems manifest, it is sometimes accompanied by a sense of grim recognition that somewhere in me existed the foresight to know that that approach would lead to this problem. However, in the headlong rush, warning signs got overlooked, lessons learned previously, which could supply the foresight to the current project, were lost and not applied.   Of course, the problem often is a simple lack of skills, training and knowledge in the relevant technology and/or business space; programmers and DBAs forced to do their best in the face of inadequate training, or to apply their skills in areas where they lack experience. However, often the problem goes deeper than this; I detect in some DBAs and programmers a certain laziness of attitude.   They veer from one project to the next, going with "whatever works", unwilling or unable to take the time to understand where their actions are leading them. Of course, the whole "Agile" mindset is often interpreted to favor flexibility and rapid production over aiming to get things right the first time. The faster you try to travel in the dark, frequently changing direction, the more important it is to have someone who has the foresight to know at least roughly where you are heading. This is doubly true for the data tier which, no matter how you try to deny it, simply cannot be "redone" every month as you learn aspects of the world you are trying to model that, with a little bit of foresight, you would have seen coming.   Sometimes, when as a DBA you can glance briefly at 200 lines of working SQL code and know instinctively why it will cause problems, foresight can feel like magic, but it isn't; it's more like muscle memory. It is acquired as the consequence of good experience, useful communication with those around you, and a willingness to learn continually, through continued education as well as from failure. Foresight can be deployed only by finding time to understand how the lessons learned from other DBAs, and other projects, can help steer the current project in the right direction.   C.S. Lewis once said "The future is something which everyone reaches at the rate of sixty minutes an hour, whatever he does, whoever he is." It cannot be avoided; the quality of what you build now is going to affect you, and others, at some point in the future. Take the time to acquire foresight; it is a love letter to your future self, to say you cared.

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  • SQLAuthority News – Great Time Spent at Great Indian Developers Summit 2014

    - by Pinal Dave
    The Great Indian Developer Conference (GIDS) is one of the most popular annual event held in Bangalore. This year GIDS is scheduled on April 22, 25. I will be presented total four sessions at this event and each session is very different from each other. Here are the details of four of my sessions, which I presented there. Pluralsight Shades This event was a great event and I had fantastic fun presenting a technology over here. I was indeed very excited that along with me, I had many of my friends presenting at the event as well. I want to thank all of you to attend my session and having standing room every single time. I have already sent resources in my newsletter. You can sign up for the newsletter over here. Indexing is an Art I was amazed with the crowd present in the sessions at GIDS. There was a great interest in the subject of SQL Server and Performance Tuning. Audience at GIDS I believe event like such provides a great platform to meet and share knowledge. Pinal at Pluralsight Booth Here are the abstract of the sessions which I had presented. They were recorded so at some point in time they will be available, but if you want the content of all the courses immediately, I suggest you check out my video courses on the same subject on Pluralsight. Indexes, the Unsung Hero Relevant Pluralsight Course Slow Running Queries are the most common problem that developers face while working with SQL Server. While it is easy to blame SQL Server for unsatisfactory performance, the issue often persists with the way queries have been written, and how Indexes has been set up. The session will focus on the ways of identifying problems that slow down SQL Server, and Indexing tricks to fix them. Developers will walk out with scripts and knowledge that can be applied to their servers, immediately post the session. Indexes are the most crucial objects of the database. They are the first stop for any DBA and Developer when it is about performance tuning. There is a good side as well evil side to indexes. To master the art of performance tuning one has to understand the fundamentals of indexes and the best practices associated with the same. We will cover various aspects of Indexing such as Duplicate Index, Redundant Index, Missing Index as well as best practices around Indexes. SQL Server Performance Troubleshooting: Ancient Problems and Modern Solutions Relevant Pluralsight Course Many believe Performance Tuning and Troubleshooting is an art which has been lost in time. However, truth is that art has evolved with time and there are more tools and techniques to overcome ancient troublesome scenarios. There are three major resources that when bottlenecked creates performance problems: CPU, IO, and Memory. In this session we will focus on High CPU scenarios detection and their resolutions. If time permits we will cover other performance related tips and tricks. At the end of this session, attendees will have a clear idea as well as action items regarding what to do when facing any of the above resource intensive scenarios. Developers will walk out with scripts and knowledge that can be applied to their servers, immediately post the session. To master the art of performance tuning one has to understand the fundamentals of performance, tuning and the best practices associated with the same. We will discuss about performance tuning in this session with the help of Demos. Pinal Dave at GIDS MySQL Performance Tuning – Unexplored Territory Relevant Pluralsight Course Performance is one of the most essential aspects of any application. Everyone wants their server to perform optimally and at the best efficiency. However, not many people talk about MySQL and Performance Tuning as it is an extremely unexplored territory. In this session, we will talk about how we can tune MySQL Performance. We will also try and cover other performance related tips and tricks. At the end of this session, attendees will not only have a clear idea, but also carry home action items regarding what to do when facing any of the above resource intensive scenarios. Developers will walk out with scripts and knowledge that can be applied to their servers, immediately post the session. To master the art of performance tuning one has to understand the fundamentals of performance, tuning and the best practices associated with the same. You will also witness some impressive performance tuning demos in this session. Hidden Secrets and Gems of SQL Server We Bet You Never Knew Relevant Pluralsight Course SQL Trio Session! It really amazes us every time when someone says SQL Server is an easy tool to handle and work with. Microsoft has done an amazing work in making working with complex relational database a breeze for developers and administrators alike. Though it looks like child’s play for some, the realities are far away from this notion. The basics and fundamentals though are simple and uniform across databases, the behavior and understanding the nuts and bolts of SQL Server is something we need to master over a period of time. With a collective experience of more than 30+ years amongst the speakers on databases, we will try to take a unique tour of various aspects of SQL Server and bring to you life lessons learnt from working with SQL Server. We will share some of the trade secrets of performance, configuration, new features, tuning, behaviors, T-SQL practices, common pitfalls, productivity tips on tools and more. This is a highly demo filled session for practical use if you are a SQL Server developer or an Administrator. The speakers will be able to stump you and give you answers on almost everything inside the Relational database called SQL Server. I personally attended the session of Vinod Kumar, Balmukund Lakhani, Abhishek Kumar and my favorite Govind Kanshi. Summary If you have missed this event here are two action items 1) Sign up for Resource Newsletter 2) Watch my video courses on Pluralsight Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: MySQL, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority Author Visit, SQLAuthority News, T SQL Tagged: GIDS

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  • Caveat utilitor - Can I run two versions of Microsoft Project side-by-side?

    - by Martin Hinshelwood
    A number of out customers have asked if there are any problems in installing and running multiple versions of Microsoft Project on a single client. Although this is a case of Caveat utilitor (Let the user beware), as long as the user understands and accepts the issues that can occur then they can do this. Although Microsoft provide the ability to leave old versions of Office products (except Outlook) on your client when you are installing a new version of the product they certainly do not endorse doing so. Figure: For Project you can choose to keep the old stuff   That being the case I would have preferred that they put a “(NOT RECOMMENDED)” after the options to impart that knowledge to the rest of us, but they did not. The default and recommended behaviour is for the newer version installer to remove the older versions. Of course this does not apply in the revers. There are no forward compatibility packs for Office. There are a number of negative behaviours (or bugs) that can occur in this configuration: There is only one MS Project In Windows a file extension can only be associated with a single program.  In this case, MPP files can be associated with only one version of winproj.exe.  The executables are in different folders so if a user double-clicks a Project file on the desktop, file explorer, or Outlook email, Windows will launch the winproj.exe associated with MPP and then load the MPP file.  There are problems associated with this situation and in some cases workarounds. The user double-clicks on a Project 2010 file, Project 2007 launches but is unable to open the file because it is a newer version.  The workaround is for the user to launch Project 2010 from the Start menu then open the file.  If the file is attached to an email they will need to first drag the file to the desktop. All your linked MS Project files need to be of the same version There are a number of problems that occur when people use on Microsoft’s Object Linking and Embedding (OLE) technology.  The three common uses of OLE are: for inserted projects where a Master project contains sub-projects and each sub-project resides in its own MPP file shared resource pools where multiple MPP files share a common resource pool kept in a single MPP file cross-project links where a task or milestone in one MPP file has a  predecessor/successor relationship with a task or milestone in a different MPP file What I’ve seen happen before is that if you are running in a version of Project that is not associated with the MPP extension and then try and activate an OLE link then Project tries to launch the other version of Project.  Things start getting very confused since different MPP files are being controlled by different versions of Project running at the same time.  I haven’t tried this in awhile so I can’t give you exact symptoms but I suspect that if Project 2010 is involved the symptoms will be different then in a Project 2003/2007 scenario.  I’ve noticed that Project 2010 gives different error messages for the exact same problem when it occurs in Project 2003 or 2007.  -Anonymous The recommendation would be either not to use this feature if you have to have multiple versions of Project installed or to use only a single version of Project. You may get unexpected negative behaviours if you are using shared resource pools or resource pools even when you are not running multiple versions as I have found that they can get broken very easily. If you need these thing then it is probably best to use Project Server as it was created to solve many of these specific issues. Note: I would not even allow multiple people to access a network copy of a Project file because of the way Windows locks files in write mode. This can cause write-locks that get so bad a server restart is required I’ve seen user’s files get write-locked to the point where the only resolution is to reboot the server. Changing the default version to run for an extension So what if you want to change the default association from Project 2007 to Project 2010?   Figure: “Control Panel | Folder Options | Change the file associated with a file extension” Windows normally only lists the last version installed for a particular extension. You can select a specific version by selecting the program you want to change and clicking “Change program… | Browse…” and then selecting the .exe you want to use on the file system. Figure: You will need to select the exact version of “winproj.exe” that you want to run Conclusion Although it is possible to run multiple versions of Project on one system in the main it does not really make sense.

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  • Career guidance/advice for Junior-level Software Engineer [closed]

    - by John Do
    I have quite a few questions on my mind, so please bare with me. Please don't feel obligated to answer all of them, any as you choose will do. I'd appreciate if you could share some insight on any of these. Before I begin, some context: I currently have almost two years of professional experience as a Software Engineer, mainly developing software in Java. At this point, I feel that I have reached the peak in my career growth at the current company I am at and therefore I am looking for a new job, ideally again, as a Software Engineer. I have been interviewing for the past few months casually but have not had luck with companies I have a passion for. So, in no particular order - 1) In general, what are your thoughts on having graduate degrees in CS / Software Engineering. How much does it influence a salary increase, and do you think it's beneficial when working on real-world problems? I get the sense that a graduate degree in the field is trivial unless you really have a passion for research. 2) In general, in professional practice, how often had you have to write your own data structures and "complex" algorithms from scratch? In my own work, I have found myself relying mainly on third-party frameworks and the Java standard library to implement solutions as per business requirements. What are your thoughts on this? 3) In terms of resume, I feel the most ambivalent here. I want to be able to "blemish" my resume to a certain extent so that it stands out from others', but at the same time I do not want to over-exagerate my abilities. How do you strike a balance here? For example: I say that I am proficient in Java with data structures and algorithms. This is obviously a subjective and relative statement. I've taken the classes in my undergrad, and I've applied it in my work experience. What I feel as "prociency" can be seen as junior-level to others. How do you know what to say? Most of the time, recruiters (with no technical background) will be looking for keywords that stand out. This leads me to my next question (4). 4) Just from interviewing for the past few months (and getting plenty of rejections), I've come to realize that I may not be as proficient in data structures and algorithms as I thought I was. Do you think it's a good idea to remove the "proficient in java/data structure and algorithms"? I feel that being too hoenst on the resume will impede me from scoring opportunities to even have an interview with top-notch companies. What are your thoughts? 5) What is the absolute "must-have" knowledge going into a technical interview? I've been practicing several algorithmic and data sturcture problems now, and I feel that my abilities to solve arbitrary problems efficiently has not gotten significantly better. Do you think these abilities are something innate - it's either you have in you, or you don't? How can you teach yourself to learn, if you will? 6) How easy is it to go from industry/function to the next? I work mainly with backend technologies and I'm now interested in working with the frontend, i.e javascript,jquery,php or even mobile development. In your own experience, how did you not get pidgeon holed in your career? I feel that the choices you make now ultimately decide your future. As cliche as it sounds, I think it may be true. Here's what I mean: you've worked mainly as a backend engineer, people are interested in you doing the same thing since you've already accumulated experience in that function. How do get experience in a new function if people won't accept you because you don't already have it? It's a catch 22, you see... Are side projects the only real way to help you move from one function to another that you're truly interested in? For example: I could start writing my own mobile applications, even though I've worked mainly on the backend. Thanks so much for the long read. As a relatively new engineer to the real world, I am very humble and would like those who are experienced to shed some light. Thank you so much.

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  • Developing Schema Compare for Oracle (Part 5): Query Snapshots

    - by Simon Cooper
    If you've emailed us about a bug you've encountered with the EAP or beta versions of Schema Compare for Oracle, we probably asked you to send us a query snapshot of your databases. Here, I explain what a query snapshot is, and how it helps us fix your bug. Problem 1: Debugging users' bug reports When we started the Schema Compare project, we knew we were going to get problems with users' databases - configurations we hadn't considered, features that weren't installed, unicode issues, wierd dependencies... With SQL Compare, users are generally happy to send us a database backup that we can restore using a single RESTORE DATABASE command on our test servers and immediately reproduce the problem. Oracle, on the other hand, would be a lot more tricky. As Oracle generally has a 1-to-1 mapping between instances and databases, any databases users sent would have to be restored to their own instance. Furthermore, the number of steps required to get a properly working database, and the size of most oracle databases, made it infeasible to ask every customer who came across a bug during our beta program to send us their databases. We also knew that there would be lots of issues with data security that would make it hard to get backups. So we needed an easier way to be able to debug customers issues and sort out what strange schema data Oracle was returning. Problem 2: Test execution time Another issue we knew we would have to solve was the execution time of the tests we would produce for the Schema Compare engine. Our initial prototype showed that querying the data dictionary for schema information was going to be slow (at least 15 seconds per database), and this is generally proportional to the size of the database. If you're running thousands of tests on the same databases, each one registering separate schemas, not only would the tests would take hours and hours to run, but the test servers would be hammered senseless. The solution To solve these, we needed to be able to populate the schema of a database without actually connecting to it. Well, the IDataReader interface is the primary way we read data from an Oracle server. The data dictionary queries we use return their data in terms of simple strings and numbers, which we then process and reconstruct into an object model, and the results of these queries are identical for identical schemas. So, we can record the raw results of the queries once, and then replay these results to construct the same object model as many times as required without needing to actually connect to the original database. This is what query snapshots do. They are binary files containing the raw unprocessed data we get back from the oracle server for all the queries we run on the data dictionary to get schema information. The core of the query snapshot generation takes the results of the IDataReader we get from running queries on Oracle, and passes the row data to a BinaryWriter that writes it straight to a file. The query snapshot can then be replayed to create the same object model; when the results of a specific query is needed by the population code, we can simply read the binary data stored in the file on disk and present it through an IDataReader wrapper. This is far faster than querying the server over the network, and allows us to run tests in a reasonable time. They also allow us to easily debug a customers problem; using a simple snapshot generation program, users can generate a query snapshot that could be sent along with a bug report that we can immediately replay on our machines to let us debug the issue, rather than having to obtain database backups and restore databases to test systems. There are also far fewer problems with data security; query snapshots only contain schema information, which is generally less sensitive than table data. Query snapshots implementation However, actually implementing such a feature did have a couple of 'gotchas' to it. My second blog post detailed the development of the dependencies algorithm we use to ensure we get all the dependencies in the database, and that algorithm uses data from both databases to find all the needed objects - what database you're comparing to affects what objects get populated from both databases. We get information on these additional objects using an appropriate WHERE clause on all the population queries. So, in order to accurately replay the results of querying the live database, the query snapshot needs to be a snapshot of a comparison of two databases, not just populating a single database. Furthermore, although the code population queries (eg querying all_tab_cols to get column information) can simply be passed straight from the IDataReader to the BinaryWriter, we need to hook into and run the live dependencies algorithm while we're creating the snapshot to ensure we get the same WHERE clauses, and the same query results, as if we were populating straight from a live system. We also need to store the results of the dependencies queries themselves, as the resulting dependency graph is stored within the OracleDatabase object that is produced, and is later used to help order actions in synchronization scripts. This is significantly helped by the dependencies algorithm being a deterministic algorithm - given the same input, it will always return the same output. Therefore, when we're replaying a query snapshot, and processing dependency information, we simply have to return the results of the queries in the order we got them from the live database, rather than trying to calculate the contents of all_dependencies on the fly. Query snapshots are a significant feature in Schema Compare that really helps us to debug problems with the tool, as well as making our testers happier. Although not really user-visible, they are very useful to the development team to help us fix bugs in the product much faster than we otherwise would be able to.

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  • Breaking 1NF to model subset constraints. Does this sound sane?

    - by Chris Travers
    My first question here. Appologize if it is in the wrong forum but this seems pretty conceptual. I am looking at doing something that goes against conventional wisdom and want to get some feedback as to whether this is totally insane or will result in problems, so critique away! I am on PostgreSQL 9.1 but may be moving to 9.2 for this part of this project. To re-iterate: Does it seem sane to break 1NF in this way? I am not looking for debugging code so much as where people see problems that this might lead. The Problem In double entry accounting, financial transactions are journal entries with an arbitrary number of lines. Each line has either a left value (debit) or a right value (credit) which can be modelled as a single value with negatives as debits and positives as credits or vice versa. The sum of all debits and credits must equal zero (so if we go with a single amount field, sum(amount) must equal zero for each financial journal entry). SQL-based databases, pretty much required for this sort of work, have no way to express this sort of constraint natively and so any approach to enforcing it in the database seems rather complex. The Write Model The journal entries are append only. There is a possibility we will add a delete model but it will be subject to a different set of restrictions and so is not applicable here. If and when we allow deletes, we will probably do them using a simple ON DELETE CASCADE designation on the foreign key, and require that deletes go through a dedicated stored procedure which can enforce the other constraints. So inserts and selects have to be accommodated but updates and deletes do not for this task. My Proposed Solution My proposed solution is to break first normal form and model constraints on arrays of tuples, with a trigger that breaks the rows out into another table. CREATE TABLE journal_line ( entry_id bigserial primary key, account_id int not null references account(id), journal_entry_id bigint not null, -- adding references later amount numeric not null ); I would then add "table methods" to extract debits and credits for reporting purposes: CREATE OR REPLACE FUNCTION debits(journal_line) RETURNS numeric LANGUAGE sql IMMUTABLE AS $$ SELECT CASE WHEN $1.amount < 0 THEN $1.amount * -1 ELSE NULL END; $$; CREATE OR REPLACE FUNCTION credits(journal_line) RETURNS numeric LANGUAGE sql IMMUTABLE AS $$ SELECT CASE WHEN $1.amount > 0 THEN $1.amount ELSE NULL END; $$; Then the journal entry table (simplified for this example): CREATE TABLE journal_entry ( entry_id bigserial primary key, -- no natural keys :-( journal_id int not null references journal(id), date_posted date not null, reference text not null, description text not null, journal_lines journal_line[] not null ); Then a table method and and check constraints: CREATE OR REPLACE FUNCTION running_total(journal_entry) returns numeric language sql immutable as $$ SELECT sum(amount) FROM unnest($1.journal_lines); $$; ALTER TABLE journal_entry ADD CONSTRAINT CHECK (((journal_entry.running_total) = 0)); ALTER TABLE journal_line ADD FOREIGN KEY journal_entry_id REFERENCES journal_entry(entry_id); And finally we'd have a breakout trigger: CREATE OR REPLACE FUNCTION je_breakout() RETURNS TRIGGER LANGUAGE PLPGSQL AS $$ BEGIN IF TG_OP = 'INSERT' THEN INSERT INTO journal_line (journal_entry_id, account_id, amount) SELECT NEW.id, account_id, amount FROM unnest(NEW.journal_lines); RETURN NEW; ELSE RAISE EXCEPTION 'Operation Not Allowed'; END IF; END; $$; And finally CREATE TRIGGER AFTER INSERT OR UPDATE OR DELETE ON journal_entry FOR EACH ROW EXECUTE_PROCEDURE je_breaout(); Of course the example above is simplified. There will be a status table that will track approval status allowing for separation of duties, etc. However the goal here is to prevent unbalanced transactions. Any feedback? Does this sound entirely insane? Standard Solutions? In getting to this point I have to say I have looked at four different current ERP solutions to this problems: Represent every line item as a debit and a credit against different accounts. Use of foreign keys against the line item table to enforce an eventual running total of 0 Use of constraint triggers in PostgreSQL Forcing all validation here solely through the app logic. My concerns are that #1 is pretty limiting and very hard to audit internally. It's not programmer transparent and so it strikes me as being difficult to work with in the future. The second strikes me as being very complex and required a series of contraints and foreign keys against self to make work, and therefore it strikes me as complex, hard to sort out at least in my mind, and thus hard to work with. The fourth could be done as we force all access through stored procedures anyway and this is the most common solution (have the app total things up and throw an error otherwise). However, I think proof that a constraint is followed is superior to test cases, and so the question becomes whether this in fact generates insert anomilies rather than solving them. If this is a solved problem it isn't the case that everyone agrees on the solution....

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  • Soft lockup after upgrade - cannot install from live CD

    - by nbm
    I dual-boot MacIntel Core 2 duo. nVidia graphics. Ran upgrade from ubuntu 13.10 to 14.04 (64 bit). On restart ran into {numbers} Bug: soft lockup - CPU#0 stuck for 22s! [swapper/0:1] Tried loading earlier kernel: same problem Tried re-installing ubuntu from a liveCD that has worked in the past: version 13.04. Same problem. Tried re-partitioning hard drive using Mac OS X disk utility and then installing ubuntu 14.04LTS from liveCD. Same problem. Not possible to verify liveCD disk (creates same "soft lockup" bug.) Tried installing from the liveCD with version 13.04 that I know works (that's how I got Ubuntu on this machine in the first place.) Same problem. I know this is not a hardware problem as OS X works just fine, I am using it right now on the same machine. I have been using various versions of Ubuntu for 2 years. Things I cannot do: Open a terminal Verify CD image Start ubuntu from CD (same soft lockup problem) This problem is similar to some other questions, none of which have been satisfactorily answered: Ubuntu 14.04 soft lockup on Vostro 3500 Cannot do fresh install of Ubuntu 13.04 while booting from DVD: "soft lockup" bug Live CD stalls when installing Ubuntu 13.10 UPDATE 6/11/14: Following some much-appreciated advice from bain (see below) I burned a 12.04LTS disk and started with kernel parameters: noapic, no1apic, acpi=off, nomodeset, elevator=deadline, and clocksource=jiffies. With all of these parameters I was able to load the 12.04LTS CD ("Try without installing"). It worked fine. However, as soon as I tried to install Ubuntu from the CD, my wired ethernet (eth0) connection would hang. There are already various askubuntu questions and bug reports about this problem, none of which had answers for me. (E.g., dhclient eth0 does nothing, none of the various reset commands does anything, manually setting IP &etc does nothing. I could reliably kill the ethernet connection by clicking "install ubuntu" every single time.) I could go ahead and install 12.04 without an internet connection, but the install would freeze after mostly completing (I tried several times.) There were some relevant error messages in the details of the install output script that, IIRC, had to do with searching for missing files and not being able to access eth0 (internet) to get them. To be honest I gave up at that point and I'm not sure I wrote those down. If I find some notes I will post them. At this point I no longer have Ubuntu on my system. I wiped the partitions and am using exclusively OS X. I am leaving this question in case it helps anyone else with similar problems. I love open source and I love Linux, and the next machine I get I will probably just build from Arch. At the moment I miss repositories and a lot of other things about Ubuntu, but the OS X terminal is 'nix, I can pretty much use all the open source apps I like, and while I am not a fan of the Apple software it gets the job done for me. Unlike Ubuntu, which can't even install. I realize this isn't necessarily a place for a soapbox speech, but when I first installed 12.04 several years ago there were already people in the community complaining that Canonical was going too "commercial". But I loved it. Several years later and all I've seen is Canonical adding more not-so-useful bells and whistles to Ubuntu while continually failing to fix basic problems on upgrades. With a dual-boot (and sometimes triple-boot) system it always took me some tweaking to get an upgrade to work, and to some extent that is okay. But at this point I feel like Canonical ought to just put a price tag on Ubuntu. All I see is more commercialism and advertising and product tie-ins, and ongoing problems do not get fixed. I am a big fan of open-source, not-for profit enterprise. I am also a big fan of for-profit enterprise, which certainly has its place and usefulness. I am not a fan of companies who pretend to be in favor of open source but really are just out to make a buck, and IMNSHO that is what Canonical has become. This is a great community and I wish you all the best, but my next install of Linux will not be Ubuntu.

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  • No More NCrunch For Me

    - by Steve Wilkes
    When I opened up Visual Studio this morning, I was greeted with this little popup: NCrunch is a Visual Studio add-in which runs your tests while you work so you know if and when you've broken anything, as well as providing coverage indicators in the IDE and coverage metrics on demand. It recently went commercial (which I thought was fair enough), and time is running out for the free version I've been using for the last couple of months. From my experiences using NCrunch I'm going to let it expire, and go about my business without it. Here's why. Before I start, let me say that I think NCrunch is a good product, which is to say it's had a positive impact on my programming. I've used it to help test-drive a library I'm making right from the start of the project, and especially at the beginning it was very useful to have it run all my tests whenever I made a change. The first problem is that while that was cool to start with, it’s recently become a bit of a chore. Problems Running Tests NCrunch has two 'engine modes' in which it can run tests for you - it can run all your tests when you make a change, or it can figure out which tests were impacted and only run those. Unfortunately, it became clear pretty early on that that second option (which is marked as 'experimental') wasn't really working for me, so I had to have it run everything. With a smallish number of tests and while I was adding new features that was great, but I've now got 445 tests (still not exactly loads) and am more in a 'clean and tidy' mode where I know that a change I'm making will probably only affect a particular subset of the tests. With that in mind it's a bit of a drag sitting there after I make a change and having to wait for NCrunch to run everything. I could disable it and manually run the tests I know are impacted, but then what's the point of having NCrunch? If the 'impacted only' engine mode worked well this problem would go away, but that's not what I found. Secondly, what's wrong with this picture? I've got 445 tests, and NCrunch has queued 455 tests to run. So it's queued duplicate tests - in this quickly-screenshotted case 10, but I've seen the total queue get up over 600. If I'm already itchy waiting for it to run all my tests against a change I know only affects a few, I'm even itchier waiting for it to run a lot of them twice. Problems With Code Coverage NCrunch marks each line of code with a dot to say if it's covered by tests - a black dot says the line isn't covered, a red dot says it's covered but at least one of the covering tests is failing, and a green dot means all the covering tests pass. It also calculates coverage statistics for you. Unfortunately, there's a couple of flaws in the coverage. Firstly, it doesn't support ExcludeFromCodeCoverage attributes. This feature has been requested and I expect will be included in a later release, but right now it doesn't. So this: ...is counted as a non-covered line, and drags your coverage statistics down. Hmph. As well as that, coverage of certain types of code is missed. This: ...is definitely covered. I am 100% absolutely certain it is, by several tests. NCrunch doesn't pick it up, down go my coverage statistics. I've had NCrunch find genuinely uncovered code which I've been able to remove, and that's great, but what's the coverage percentage on this project? Umm... I don't know. Conclusion None of these are major, tool-crippling problems, and I expect NCrunch to get much better in future releases. The current version has some great features, like this: ...that's a line of code with a failing test covering it, and NCrunch can run that failing test and take me to that line exquisitely easily. That's awesome! I'd happily pay for a tool that can do that. But here's the thing: NCrunch (currently) costs $159 (about £100) for a personal licence and $289 (about £180) for a commercial one. I'm not sure which one I'd need as my project is a personal one which I'm intending to open-source, but I'm a professional, self-employed developer, but in any case - that seems like a lot of money for an imperfect tool. If it did everything it's advertised to do more or less perfectly I'd consider it, but it doesn't. So no more NCrunch for me.

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  • The Dreaded Startup Repair Loop on Win 7

    - by HighAltitudeCoder
    For most people, upgrading to Windows 7 has been a relatively painless process.  Not me.  I am in the unlucky 1% or less who had a somewhat less pleasant experience.  First, I cloned my entire onto a larger (and much faster) solid state hard drive, only experiencing minimal problems. Then, I bought the Retail version of Windows 7 Ultimate, took a deep breath and... oh yeah, I almost forgot - BACK UP THE COMPUTER.  The next morning I upgraded to Win 7 and everything seemed fine, until... I rebooted the system, the nice Windows 7 launch graphics come up, it's about to launch and AWWW, are you kidding me?!?!  Back to the BIOS splash screen?  Next comes the sequence of failure - attempt repair - unable to repair - do you want to wipe your hard drive decisions. Because I purchased the retail version, a number is provided where I could call Microsoft Tech support.  When I did, they instructed me to click "Install" from my installation CD, which did not work.  When I tried the "Upgrade" option, it reaches an impasse, telling you that yoiu have a newer version of Win 7, and thus cannot Upgrade.  If you choose "Install" you willl lose everything... files, programs, EVERYTHING.  Or at least this is what it tells you.  I was not willing to take the risk. To make things worse, I had installed a new antivirus software application before I realized my system was unstable (Trend Micro Titanium Internet Security), and this was causing additional problems. One interesting thing, and the only saving grace as it turns out, was that my system WOULD successfully reboot into the OS if I chose to restart it, rather than shut it down.  If I chose to shut down, I would have to go through the loop again until I was given the option to restart. As it turned out, I needed to update my BIOS.  I assumed that since I had updated my BIOS a long time ago to settings that were stable under Windows Vista Ultimate x64, I incorrectly expected Win 7 to adopt the same settings and didn't expect there to be any problems.  WRONG. My BIOS had a setting to halt the boot cycle if various kinds of errors were detected.  Windows Vista didn't care about this, but forget it under Windows 7.  I turned immediately corrected that BIOS setting.  Next, there were the two separate BIOS settings: enable USB mouse and enable USB keyboard.  The only sequence of events that would work were to start my reboot process over from stratch with a hard-wired non-usb keyboard and mouse.  Whent the system booted under these settings, it doesn't detect any errors due to either the mouse or keyboard, and actually booted for the first time in a long while (let me tell ya, that's an amazing experience after fiddling with settings for two entire weekends!) Next step: leave your old mouse and keyboard connected, but also connect your other two devices (mouse, keyboard) that use USB connections.  During the boot cycle, the operating system will not fail due to missing requirements during startup, and it will then pick up the new drivers necessary to use your new hardware. If you think you are in the clear here, you are wrong.  The next VERY IMPORTANT step is to remember to change your settings in the BIOS upon next startup.  Specifically, yoiu will need ot change your BIOS to enable USB mouse and enable USB keyboard input.  If you don't, Windows will detect an incompatibility upon the next startup, and you will be stuck once again in the endless cycle of reboot/Startup Repair/reboot/Startup Repair, without ever reaching a successful boot. Here's the thing - the BIOS and the drivers registered in Win 7 need to match.  If they don't, you're going to lose another weekend worrying and fiddling, all the while wondering if you've permanently damaged your hard drive beyond repair. (Sigh).  In the end, things worked out.  I must note that it is saddening to see how many posts there are out there that recommend just doing a clean install, as if it's the only option.  How many countless poor souls have lost their data, their backups, their pictures and videos, all for nothing other than the fact that the person giving advice just didn't know what to do at that point? My advice to you, try having a look at your BIOS settings first and making sure Win 7 can find your BIOS settings, and also disabling in your BIOS anything that might halt your system boot-up process if it encounters errors.

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  • Electronics Recycling

    - by Evan Carroll
    Is it common practice to not pay for recycling electronics? I find it kind of funny that scrap metal demands such a premium but electronics recycling gets nothing. My dad owns a stereostore and throws away hundreds of radio head-units a month is there anything useful or profitable that can be done with electronics on such a mass scale? http://stselectronicrecyclinginc.com/index.php/electronics-recycling http://www.basscomputerrecycling.com/?page_id=30 http://www.computerrecyclecenter.com/services.htm None of them seem to pay anything for the scrap.

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  • How to get used of trackpoint on a thinkpad?

    - by AZ
    Recently my shoulder hurts due to frequently arm movement switching between keyboard and mouse. Then I start using trackpoint. The problem is, while everyone saying the trackpoint is more accurate than touchpad, I find it very hard to accurately move the cursor using trackpoint. Large movements are ok, but when it comes to fine movements, such as click a close button or check a checkbox, it takes longer time. Should I just practice more, or are there any good tips or tutorials around?

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  • Using hdparm for better performance on Web Servers

    - by Rishav
    I just heard about using hdparams to optimize the Hard Disk Performance of a server ? Is this common practice ? What file systems do you use ? I generally deploy on the second last release of Ubuntu for stability reasons, do you some other filesystems or use distributed file systems from the get go ? Do the hdparam settings change for different File systems ? I haven't tried this yet, so how much difference do changes like this make ?

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  • Amazon EBS for web site files

    - by MattB
    I'm new to the Amazon EC2/EBS system. I'm trying to figure out the "best practice" for hosting a web application (php, ASP.NET, etc.). The way I see it, I have 2 options: Have the instance hold my web files - Don't need to worry about attaching volume's etc.? Have EBS volume hold my web files - Easily update with new code without needing to recreate the AMI for new updates? How do others handle this?

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  • Making Linux smart about partition or filesystem moves with a UUID selection dialog?

    - by Luke Stanley
    It seems to me a major part of frustration n00bs have with Linux is due to UUID changes not matching peoples intuition and just working. Does anyone know a way of making GRUB and /etc/fstab just ASK PEOPLE about UUID changes, instead of just failing after people try moving hard disk? Could this be done in Bash or such? Is there a different flag or two somewhere we could simply change? Seems like this, if made to work in common practice could be a major advantage.

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  • How important is sender validation, and what matters?

    - by Charles Stewart
    When I started learning how to configure email, SPF existed but there were doubts about whether it was a good thing, and the value of offering SPF records in DNS. Now it seems that it is widely accepted that some form of well-known sender validation is good practice. Is this really true? Am I being a bad postmaster by not supporting SPF/DKIM/whatever?

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  • How can we use Microsoft Groove with peers existing in both secure and unsecured network segments?

    - by MikeHerrera
    We have been instructed to implement a Microsoft Groove workspace. This would normally not be a concern, but the workspace will be utilized by machines which exist in our internal/restricted network as well as from peers from an outside/unknown network. Does there exist a best-practice for such an implementation?... or would this potentially expose the restricted network too broadly?

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  • Does purchasing a registered domain name extend the expiration date?

    - by Mike
    I recently purchased an existing domain name through the site name.com and after I made the payment, I realized that the domain expired about 10 days earlier. Is it legal/good practice to sell already expired domains as-is, or would most domain selling companies also extend the expiration date by an extra year. It wouldn't be such a big deal, however domains with this particular TLD cost $89/year to renew.

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