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  • [Windows 8] An application bar toggle button

    - by Benjamin Roux
    To stay in the application bar stuff, here’s another useful control which enable to create an application bar button that can be toggled between two different contents/styles/commands (used to create a favorite/unfavorite or a play/pause button for example). namespace Indeed.Controls { public class AppBarToggleButton : Button { public bool IsChecked { get { return (bool)GetValue(IsCheckedProperty); } set { SetValue(IsCheckedProperty, value); } } public static readonly DependencyProperty IsCheckedProperty = DependencyProperty.Register("IsChecked", typeof(bool), typeof(AppBarToggleButton), new PropertyMetadata(false, (o, e) => (o as AppBarToggleButton).IsCheckedChanged())); public string CheckedContent { get { return (string)GetValue(CheckedContentProperty); } set { SetValue(CheckedContentProperty, value); } } public static readonly DependencyProperty CheckedContentProperty = DependencyProperty.Register("CheckedContent", typeof(string), typeof(AppBarToggleButton), null); public ICommand CheckedCommand { get { return (ICommand)GetValue(CheckedCommandProperty); } set { SetValue(CheckedCommandProperty, value); } } public static readonly DependencyProperty CheckedCommandProperty = DependencyProperty.Register("CheckedCommand", typeof(ICommand), typeof(AppBarToggleButton), null); public Style CheckedStyle { get { return (Style)GetValue(CheckedStyleProperty); } set { SetValue(CheckedStyleProperty, value); } } public static readonly DependencyProperty CheckedStyleProperty = DependencyProperty.Register("CheckedStyle", typeof(Style), typeof(AppBarToggleButton), null); public bool AutoToggle { get { return (bool)GetValue(AutoToggleProperty); } set { SetValue(AutoToggleProperty, value); } } public static readonly DependencyProperty AutoToggleProperty = DependencyProperty.Register("AutoToggle", typeof(bool), typeof(AppBarToggleButton), null); private object content; private ICommand command; private Style style; private void IsCheckedChanged() { if (IsChecked) { // backup the current content and command content = Content; command = Command; style = Style; if (CheckedStyle == null) Content = CheckedContent; else Style = CheckedStyle; Command = CheckedCommand; } else { if (CheckedStyle == null) Content = content; else Style = style; Command = command; } } protected override void OnTapped(Windows.UI.Xaml.Input.TappedRoutedEventArgs e) { base.OnTapped(e); if (AutoToggle) IsChecked = !IsChecked; } } } .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; } To use it, it’s very simple. <ic:AppBarToggleButton Style="{StaticResource PlayAppBarButtonStyle}" CheckedStyle="{StaticResource PauseAppBarButtonStyle}" Command="{Binding Path=PlayCommand}" CheckedCommand="{Binding Path=PauseCommand}" IsChecked="{Binding Path=IsPlaying}" /> .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; } When the IsPlaying property (in my ViewModel) is true the button becomes a Pause button, when it’s false it becomes a Play button. Warning: Just make sure that the IsChecked property is set in last in your control !! If you don’t use style you can alternatively use Content and CheckedContent. Furthermore you can set the AutoToggle to true if you don’t want to control is IsChecked property through binding. With this control and the AppBarPopupButton, you can now create awesome application bar for your apps ! Stay tuned for more awesome Windows 8 tricks !

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  • Computer Networks UNISA - Chap 14 &ndash; Insuring Integrity &amp; Availability

    - by MarkPearl
    After reading this section you should be able to Identify the characteristics of a network that keep data safe from loss or damage Protect an enterprise-wide network from viruses Explain network and system level fault tolerance techniques Discuss issues related to network backup and recovery strategies Describe the components of a useful disaster recovery plan and the options for disaster contingencies What are integrity and availability? Integrity – the soundness of a networks programs, data, services, devices, and connections Availability – How consistently and reliably a file or system can be accessed by authorized personnel A number of phenomena can compromise both integrity and availability including… security breaches natural disasters malicious intruders power flaws human error users etc Although you cannot predict every type of vulnerability, you can take measures to guard against the most damaging events. The following are some guidelines… Allow only network administrators to create or modify NOS and application system users. Monitor the network for unauthorized access or changes Record authorized system changes in a change management system’ Install redundant components Perform regular health checks on the network Check system performance, error logs, and the system log book regularly Keep backups Implement and enforce security and disaster recovery policies These are just some of the basics… Malware Malware refers to any program or piece of code designed to intrude upon or harm a system or its resources. Types of Malware… Boot sector viruses Macro viruses File infector viruses Worms Trojan Horse Network Viruses Bots Malware characteristics Some common characteristics of Malware include… Encryption Stealth Polymorphism Time dependence Malware Protection There are various tools available to protect you from malware called anti-malware software. These monitor your system for indications that a program is performing potential malware operations. A number of techniques are used to detect malware including… Signature Scanning Integrity Checking Monitoring unexpected file changes or virus like behaviours It is important to decide where anti-malware tools will be installed and find a balance between performance and protection. There are several general purpose malware policies that can be implemented to protect your network including… Every compute in an organization should be equipped with malware detection and cleaning software that regularly runs Users should not be allowed to alter or disable the anti-malware software Users should know what to do in case the anti-malware program detects a malware virus Users should be prohibited from installing any unauthorized software on their systems System wide alerts should be issued to network users notifying them if a serious malware virus has been detected. Fault Tolerance Besides guarding against malware, another key factor in maintaining the availability and integrity of data is fault tolerance. Fault tolerance is the ability for a system to continue performing despite an unexpected hardware or software malfunction. Fault tolerance can be realized in varying degrees, the optimal level of fault tolerance for a system depends on how critical its services and files are to productivity. Generally the more fault tolerant the system, the more expensive it is. The following describe some of the areas that need to be considered for fault tolerance. Environment (Temperature and humidity) Power Topology and Connectivity Servers Storage Power Typical power flaws include Surges – a brief increase in voltage due to lightening strikes, solar flares or some idiot at City Power Noise – Fluctuation in voltage levels caused by other devices on the network or electromagnetic interference Brownout – A sag in voltage for just a moment Blackout – A complete power loss The are various alternate power sources to consider including UPS’s and Generators. UPS’s are found in two categories… Standby UPS – provides continuous power when mains goes down (brief period of switching over) Online UPS – is online all the time and the device receives power from the UPS all the time (the UPS is charged continuously) Servers There are various techniques for fault tolerance with servers. Server mirroring is an option where one device or component duplicates the activities of another. It is generally an expensive process. Clustering is a fault tolerance technique that links multiple servers together to appear as a single server. They share processing and storage responsibilities and if one unit in the cluster goes down, another unit can be brought in to replace it. Storage There are various techniques available including the following… RAID Arrays NAS (Storage (Network Attached Storage) SANs (Storage Area Networks) Data Backup A backup is a copy of data or program files created for archiving or safekeeping. Many different options for backups exist with various media including… These vary in cost and speed. Optical Media Tape Backup External Disk Drives Network Backups Backup Strategy After selecting the appropriate tool for performing your servers backup, devise a backup strategy to guide you through performing reliable backups that provide maximum data protection. Questions that should be answered include… What data must be backed up At what time of day or night will the backups occur How will you verify the accuracy of the backups Where and for how long will backup media be stored Who will take responsibility for ensuring that backups occurred How long will you save backups Where will backup and recovery documentation be stored Different backup methods provide varying levels of certainty and corresponding labour cost. There are also different ways to determine which files should be backed up including… Full backup – all data on all servers is copied to storage media Incremental backup – Only data that has changed since the last full or incremental backup is copied to a storage medium Differential backup – Only data that has changed since the last backup is coped to a storage medium Disaster Recovery Disaster recovery is the process of restoring your critical functionality and data after an enterprise wide outage has occurred. A disaster recovery plan is for extreme scenarios (i.e. fire, line fault, etc). A cold site is a place were the computers, devices, and connectivity necessary to rebuild a network exist but they are not appropriately configured. A warm site is a place where the computers, devices, and connectivity necessary to rebuild a network exists with some appropriately configured devices. A hot site is a place where the computers, devices, and connectivity necessary to rebuild a network exists and all are appropriately configured.

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  • Composing Silverlight Applications With MEF

    - by PeterTweed
    Anyone who has written an application with complexity enough to warrant multiple controls on multiple pages/forms should understand the benefit of composite application development.  That is defining your application architecture that can be separated into separate pieces each with it’s own distinct purpose that can then be “composed” together into the solution. Composition can be useful in any layer of the application, from the presentation layer, the business layer, common services or data access.  Historically people have had different options to achieve composing applications from distinct well known pieces – their own version of dependency injection, containers to aid with composition like Unity, the composite application guidance for WPF and Silverlight and before that the composite application block. Microsoft has been working on another mechanism to aid composition and extension of applications for some time now – the Managed Extensibility Framework or MEF for short.  With Silverlight 4 it is part of the Silverlight environment.  MEF allows a much simplified mechanism for composition and extensibility compared to other mechanisms – which has always been the primary issue for adoption of the earlier mechanisms/frameworks. This post will guide you through the simple use of MEF for the scenario of composition of an application – using exports, imports and composition.  Steps: 1.     Create a new Silverlight 4 application. 2.     Add references to the following assemblies: System.ComponentModel.Composition.dll System.ComponentModel.Composition.Initialization.dll 3.     Add a new user control called LeftControl. 4.     Replace the LayoutRoot Grid with the following xaml:     <Grid x:Name="LayoutRoot" Background="Beige" Margin="40" >         <Button Content="Left Content" Margin="30"></Button>     </Grid> 5.     Add the following statement to the top of the LeftControl.xaml.cs file using System.ComponentModel.Composition; 6.     Add the following attribute to the LeftControl class     [Export(typeof(LeftControl))]   This attribute tells MEF that the type LeftControl will be exported – i.e. made available for other applications to import and compose into the application. 7.     Add a new user control called RightControl. 8.     Replace the LayoutRoot Grid with the following xaml:     <Grid x:Name="LayoutRoot" Background="Green" Margin="40"  >         <TextBlock Margin="40" Foreground="White" Text="Right Control" FontSize="16" VerticalAlignment="Center" HorizontalAlignment="Center" ></TextBlock>     </Grid> 9.     Add the following statement to the top of the RightControl.xaml.cs file using System.ComponentModel.Composition; 10.   Add the following attribute to the RightControl class     [Export(typeof(RightControl))] 11.   Add the following xaml to the LayoutRoot Grid in MainPage.xaml:         <StackPanel Orientation="Horizontal" HorizontalAlignment="Center">             <Border Name="LeftContent" Background="Red" BorderBrush="Gray" CornerRadius="20"></Border>             <Border Name="RightContent" Background="Red" BorderBrush="Gray" CornerRadius="20"></Border>         </StackPanel>   The borders will hold the controls that will be imported and composed via MEF. 12.   Add the following statement to the top of the MainPage.xaml.cs file using System.ComponentModel.Composition; 13.   Add the following properties to the MainPage class:         [Import(typeof(LeftControl))]         public LeftControl LeftUserControl { get; set; }         [Import(typeof(RightControl))]         public RightControl RightUserControl { get; set; }   This defines properties accepting LeftControl and RightControl types.  The attrributes are used to tell MEF the discovered type that should be applied to the property when composition occurs. 14.   Replace the MainPage constructore with the following code:         public MainPage()         {             InitializeComponent();             CompositionInitializer.SatisfyImports(this);             LeftContent.Child = LeftUserControl;             RightContent.Child = RightUserControl;         }   The CompositionInitializer.SatisfyImports(this) function call tells MEF to discover types related to the declared imports for this object (the MainPage object).  At that point, types matching those specified in the import defintions are discovered in the executing assembly location of the application and instantiated and assigned to the matching properties of the current object. 15.   Run the application and you will see the left control and right control types displayed in the MainPage:   Congratulations!  You have used MEF to dynamically compose user controls into a parent control in a composite application model. In the next post we will build on this topic to cover using MEF to compose Silverlight applications dynamically in download on demand scenarios – so .xap packages can be downloaded only when needed, avoiding large initial download for the main application xap. Take the Slalom Challenge at www.slalomchallenge.com!

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  • How to move MOSS 2007 to another SharePoint Farm

    - by DipeshBhanani
    It was time of my first onsite client assignment on SharePoint. Client had one server production environment. They wanted to upgrade the topology with completely new SharePoint Farm of three servers. So, the task was to move whole MOSS 2007 stuff to the new server environment without impacting data. The last three words “… without impacting data…” were actually putting pressure on my head. Moreover SSP was required to move because additional information has been added for users apart from AD import.   I thought I had to do only backup and restore. It appeared pretty easy at first thought. Just because of these three damn scary words, I thought to check out on internet for guidance related to this scenario. I couldn’t get anything except general guidance of moving server on Microsoft TechNet site. I promised myself for starting blogs with this post if I would be successful in this task. Well, I took long time to write this but finally made it. I hope it will be useful to all guys looking for SharePoint server movement.   Before beginning restoration, make sure that, there is no difference in versions of SharePoint at source and destination server. Also check whether the state of SharePoint Installation at the time of backup and restore is same or not. (E.g. SharePoint related service packs and patches if any)   The main tasks of the server movement are as follow:   1.        Backup all the databases 2.        Install and configure SharePoint on new environment 3.        Deploy all solutions (WSP Files) globally to destination server- for installing features attached to the solutions 4.        Install all the custom features 5.        Deploy/Copy custom pages/files which are added to the “12Hive” folder later 6.        Restore SSP 7.        Restore My Site 8.        Restore other web application   Tasks 3 to 5 are for making sure that we have configured the environment well enough for the web application to be restored successfully. The main and complex task was restoring SSP. I have started restoring SSP through Central Admin. After a while, the restoration status was updated to “unsuccessful”. “Damn it, what went wrong?” I thought looking at the error detail down the page. I couldn’t remember the error message but I had corrected and restored it again.   Actually once you fail restoring SSP, until and unless you don’t clean all related stuff well, your restoration will be failed again and again. I wanted to find the actual reason. So cleaned, restored, cleaned, restored… I had tried almost 5-6 times and finally, I succeeded. I had realized how pleasant it is, to see the word “Successful” on the screen. Without wasting your much time to read, let me write all the detailed steps of restoring SSP:   1.        Delete the SSP through following STSADM command. stsadm -o deletessp -title <SSP name> -deletedatabases -force e.g.: stsadm -o deletessp -title SharedServices1 -deletedatabases –force 2.        Check and delete the web application associated with SSP if it exists. 3.        Remove Link from Check and remove “Alternate Access Mapping” associated with SSP if it exists. 4.        Check and delete IIS site as well as application pool associated with SSP if it exists. 5.        Stop following services: ·         Office SharePoint Server Search ·         Windows SharePoint Services Search ·         Windows SharePoint Services Help Search   6.        Delete all the databases associated/related to SSP from SQL Server. 7.        Reset IIS. 8.        Start again following services: ·         Office SharePoint Server Search ·         Windows SharePoint Services Search ·         Windows SharePoint Services Help Search   9.        Restore the new SSP.   After the SSP restoration, all other stuffs had completed very smoothly without any more issues. I did few modifications to sites for change of server name and finally, the new environment was ready.

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  • Scripting Part 1

    - by rbishop
    Dynamic Scripting is a large topic, so let me get a couple of things out of the way first. If you aren't familiar with JavaScript, I can suggest CodeAcademy's JavaScript series. There are also many other websites and books that cover JavaScript from every possible angle.The second thing we need to deal with is JavaScript as a programming language versus a JavaScript environment running in a web browser. Many books, tutorials, and websites completely blur these two together but they are in fact completely separate. What does this really mean in relation to DRM? Since DRM isn't a web browser, there are no document, window, history, screen, or location objects. There are no events like mousedown or click. Trying to call alert('hello!') in DRM will just cause an error. Those concepts are all related to an HTML document (web page) and are part of the Browser Object Model or Document Object Model. DRM has its own object model that exposes DRM-related objects. In practice, feel free to use those sorts of tutorials or practice within your browser; Many of the concepts are directly translatable to writing scripts in DRM. Just don't try to call document.getElementById in your property definition!I think learning by example tends to work the best, so let's try getting a list of all the unique property values for a given node and its children. var uniqueValues = {}; var childEnumerator = node.GetChildEnumerator(); while(childEnumerator.MoveNext()) { var propValue = childEnumerator.GetCurrent().PropValue("Custom.testpropstr1"); print(propValue); if(propValue != null && propValue != '' && !uniqueValues[propValue]) uniqueValues[propValue] = true; } var result = ''; for(var value in uniqueValues){ result += "Found value " + value + ","; } return result;  Now lets break this down piece by piece. var uniqueValues = {}; This declares a variable and initializes it as a new empty Object. You could also have written var uniqueValues = new Object(); Why use an object here? JavaScript objects can also function as a list of keys and we'll use that later to store each property value as a key on the object. var childEnumerator = node.GetChildEnumerator(); while(childEnumerator.MoveNext()) { This gets an enumerator for the node's children. The enumerator allows us to loop through the children one by one. If we wanted to get a filtered list of children, we would instead use ChildrenWith(). When we reach the end of the child list, the enumerator will return false for MoveNext() and that will stop the loop. var propValue = childEnumerator.GetCurrent().PropValue("Custom.testpropstr1"); print(propValue); if(propValue != null && propValue != '' && !uniqueValues[propValue]) uniqueValues[propValue] = true; } This gets the node the enumerator is currently pointing at, then calls PropValue() on it to get the value of a property. We then make sure the prop value isn't null or the empty string, then we make sure the value doesn't already exist as a key. Assuming it doesn't we add it as a key with a value (true in this case because it makes checking for an existing value faster when the value exists). A quick word on the print() function. When viewing the prop grid, running an export, or performing normal DRM operations it does nothing. If you have a lot of print() calls with complicated arguments it can slow your script down slightly, but otherwise has no effect. But when using the script editor, all the output of print() will be shown in the Warnings area. This gives you an extremely useful debugging tool to see what exactly a script is doing. var result = ''; for(var value in uniqueValues){ result += "Found value " + value + ","; } return result; Now we build a string by looping through all the keys in uniqueValues and adding that value to our string. The last step is to simply return the result. Hopefully this small example demonstrates some of the core Dynamic Scripting concepts. Next time, we can try checking for node references in other hierarchies to see if they are using duplicate property values.

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  • Agile Executives

    - by Robert May
    Over the years, I have experienced many different styles of software development. In the early days, most of the development was Waterfall development. In the last few years, I’ve become an advocate of Scrum. As I talked about last month, many people have misconceptions about what Scrum really is. The reason why we do Scrum at Veracity is because of the difference it makes in the life of the team doing Scrum. Software is for people, and happy motivated people will build better software. However, not all executives understand Scrum and how to get the information from development teams that use Scrum. I think that these executives need a support system for managing Agile teams. Historical Software Management When Henry Ford pioneered the assembly line, I doubt he realized the impact he’d have on Management through the ages. Historically, management was about managing the process of building things. The people were just cogs in that process. Like all cogs, they were replaceable. Unfortunately, most of the software industry followed this same style of management. Many of today’s senior managers learned how to manage companies before software was a significant influence on how the company did business. Software development is a very creative process, but too many managers have treated it like an assembly line. Idea’s go in, working software comes out, and we just have to figure out how to make sure that the ideas going in are perfect, then the software will be perfect. Lean Manufacturing In the manufacturing industry, Lean manufacturing has revolutionized Henry Ford’s assembly line. Derived from the Toyota process, Lean places emphasis on always providing value for the customer. Anything the customer wouldn’t be willing to pay for is wasteful. Agile is based on similar principles. We’re building software for people, and anything that isn’t useful to them doesn’t add value. Waterfall development would have teams build reams and reams of documentation about how the software should work. Agile development dispenses with this work because excessive documentation doesn’t add value. Instead, teams focus on building documentation only when it truly adds value to the customer. Many other Agile principals are similar. Playing Catch-up Just like in the manufacturing industry, many managers in the software industry have yet to understand the value of the principles of Lean and Agile. They think they can wrap the uncertainties of software development up in a nice little package and then just execute, usually followed by failure. They spend a great deal of time and money trying to exactly predict the future. That expenditure of time and money doesn’t add value to the customer. Managers that understand that Agile know that there is a better way. They will instead focus on the priorities of the near term in detail, and leave the future to take care of itself. They have very detailed two week plans with less detailed quarterly plans. These plans are guided by a general corporate strategy that doesn’t focus on the exact implementation details. These managers also think in smaller features rather than large functionality. This adds a great deal of value to customers, since the features that matter most are the ones that the team focuses on in the near term and then are able to deliver to the customers that are paying for them. Agile managers also realize that stale software is very costly. They know that keeping the technology in their software current is much less expensive and risky than large rewrites that occur infrequently and schedule time in each release for refactoring of the existing software. Agile Executives Even though Agile is a better way, I’ve still seen failures using the Agile process. While some of these failures can be attributed to the team, most of them are caused by managers, not the team. Managers fail to understand what Agile is, how it works, and how to get the information that they need to make good business decisions. I think this is a shame. I’m very pleased that Veracity understands this problem and is trying to do something about it. Veracity is a key sponsor of Agile Executives. In fact, Galen is this year’s acting president for Agile Executives. The purpose of Agile Executives is to help managers better manage Agile teams and see better success. Agile Executives is trying to build a community of executives that range from managers interested in Agile to managers that have successfully adopted Agile. Together, these managers can form a community of support and ideas that will help make Agile teams more successful. Helping Your Team You can help too! Talk with your manager and get them involved in Agile Executives. Help Veracity build the community. If your manager understands Agile better, he’ll understand how to help his teams, which will result in software that adds more value for customers. If you have any questions about how you can be involved, please let me know. Technorati Tags: Agile,Agile Executives

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  • SQL SERVER – Weekly Series – Memory Lane – #004

    - by pinaldave
    Here is the list of curetted articles of SQLAuthority.com across all these years. Instead of just listing all the articles I have selected a few of my most favorite articles and have listed them here with additional notes below it. Let me know which one of the following is your favorite article from memory lane. 2006 Auto Generate Script to Delete Deprecated Fields in Current Database In early career everytime I have to drop a column, I had hard time doing it because I was scared what if that column was needed somewhere in the code. Due to this fear I never dropped any column. I just renamed the column. If the column which I renamed was needed afterwards it was very easy to rename it back again. However, it is not recommended to keep the deleted column renamed in the database. At every interval I used to drop the columns which was prefixed with specific word. This script is 6 years old but still works. Give it a look, I am open for improvements. 2007 Shrinking Truncate Log File – Log Full – Part 2 Shrinking database or mdf file is indeed bad thing and it creates lots of problems. However, once in a while there is legit requirement to shrink the log file – a very rare one. In the rare occasion shrinking or truncating the log file may be the only solution. However, one should make sure to take backup before and after the truncate or shrink as in case of a disaster they can be very useful. Remember that truncating log file will break the log chain and while restore it can create major issue. Anyway, use this feature with caution. 2008 Simple Use of Cursor to Print All Stored Procedures of Database Including Schema This is a very interesting requirement I used to face in my early career days, I needed to print all the Stored procedures of my database. Interesting enough I had written a cursor to do so. Today when I look back at this stored procedure, I believe there will be a much cleaner way to do the same task, however, I still use this SP quite often when I have to document all the stored procedures of my database. Interesting Observation about Order of Resultset without ORDER BY In industry many developers avoid using ORDER BY clause to display the result in particular order thinking that Index is enforcing the order. In this interesting example, I demonstrate that without using ORDER BY, same table and similar query can return different results. Query optimizer always returns results using any method which is optimized for performance. The learning is There is no order unless ORDER BY is used. 2009 Size of Index Table – A Puzzle to Find Index Size for Each Index on Table I asked this puzzle earlier where I asked how to find the Index size for each of the tables. The puzzle was very well received and lots of interesting answers were received. To answer this question I have written following blog posts. I suggest this weekend you try to solve this problem and see if you can come up with a better solution. If not, well here are the solutions. Solution 1 | Solution 2 | Solution 3 Understanding Table Hints with Examples Hints are options and strong suggestions specified for enforcement by the SQL Server query processor on DML statements. The hints override any execution plan the query optimizer might select for a query. The SQL Server Query optimizer is a very smart tool and it makes a better selection of execution plan. Suggesting hints to the Query Optimizer should be attempted when absolutely necessary and by experienced developers who know exactly what they are doing (or in development as a way to experiment and learn). Interesting Observation – TOP 100 PERCENT and ORDER BY I have seen developers and DBAs using TOP very causally when they have to use the ORDER BY clause. Theoretically, there is no need of ORDER BY in the view at all. All the ordering should be done outside the view and view should just have the SELECT statement in it. It was quite common that to save this extra typing by including ordering inside of the view. At several instances developers want a complete resultset and for the same they include TOP 100 PERCENT along with ORDER BY, assuming that this will simulate the SELECT statement with ORDER BY. 2010 SQLPASS Nov 8-11, 2010-Seattle – An Alternative Look at Experience In year 2010 I attended most prestigious SQL Server event SQLPASS between Nov 8-11, 2010 at Seattle. I have only one expression for the event - Best Summit Ever. Instead of writing about my usual routine or the event, I wrote about the interesting things I did and how I felt about it! When I go back and read it, I feel that this is the best event I attended in year 2010. Change Database Access to Single User Mode Using SSMS Image says all. 2011 SQL Server 2012 has introduced new analytic functions. These functions were long awaited and I am glad that they are now here. Before when any of this function was needed, people used to write long T-SQL code to simulate these functions. But now there’s no need of doing so. Having available native function also helps performance as well readability. Function SQLAuthority MSDN CUME_DIST CUME_DIST CUME_DIST FIRST_VALUE FIRST_VALUE FIRST_VALUE LAST_VALUE LAST_VALUE LAST_VALUE LEAD LEAD LEAD LAG LAG LAG PERCENTILE_CONT PERCENTILE_CONT PERCENTILE_CONT PERCENTILE_DISC PERCENTILE_DISC PERCENTILE_DISC PERCENT_RANK PERCENT_RANK PERCENT_RANK Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Memory Lane, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • Session Report - Modern Software Development Anti-Patterns

    - by Janice J. Heiss
    In this standing-room-only session, building upon his 2011 JavaOne Rock Star “Diabolical Developer” session, Martijn Verburg, this time along with Ben Evans, identified and explored common “anti-patterns” – ways of doing things that keep developers from doing their best work. They emphasized the importance of social interaction and team communication, along with identifying certain psychological pitfalls that lead developers astray. Their emphasis was less on technical coding errors and more how to function well and to keep one’s focus on what really matters. They are the authors of the highly regarded The Well-Grounded Java Developer and are both movers and shakers in the London JUG community and on the Java Community Process. The large room was packed as they gave a fast-moving, witty presentation with lots of laughs and personal anecdotes. Below are a few of the anti-patterns they discussed.Anti-Pattern One: Conference-Driven DeliveryThe theme here is the belief that “Real pros hack code and write their slides minutes before their talks.” Their response to this anti-pattern is an expression popular in the military – PPPPPP, which stands for, “Proper preparation prevents piss-poor performance.”“Communication is very important – probably more important than the code you write,” claimed Verburg. “The more you speak in front of large groups of people the easier it gets, but it’s always important to do dry runs, to present to smaller groups. And important to be members of user groups where you can give presentations. It’s a great place to practice speaking skills; to gain new skills; get new contacts, to network.”They encouraged attendees to record themselves and listen to themselves giving a presentation. They advised them to start with a spouse or friends if need be. Learning to communicate to a group, they argued, is essential to being a successful developer. The emphasis here is that software development is a team activity and good, clear, accessible communication is essential to the functioning of software teams. Anti-Pattern Two: Mortgage-Driven Development The main theme here was that, in a period of worldwide recession and economic stagnation, people are concerned about keeping their jobs. So there is a tendency for developers to treat knowledge as power and not share what they know about their systems with their colleagues, so when it comes time to fix a problem in production, they will be the only one who knows how to fix it – and will have made themselves an indispensable cog in a machine so you cannot be fired. So developers avoid documentation at all costs, or if documentation is required, put it on a USB chip and lock it in a lock box. As in the first anti-pattern, the idea here is that communicating well with your colleagues is essential and documentation is a key part of this. Social interactions are essential. Both Verburg and Evans insisted that increasingly, year by year, successful software development is more about communication than the technical aspects of the craft. Developers who understand this are the ones who will have the most success. Anti-Pattern Three: Distracted by Shiny – Always Use the Latest Technology to Stay AheadThe temptation here is to pick out some obscure framework, try a bit of Scala, HTML5, and Clojure, and always use the latest technology and upgrade to the latest point release of everything. Don’t worry if something works poorly because you are ahead of the curve. Verburg and Evans insisted that there need to be sound reasons for everything a developer does. Developers should not bring in something simply because for some reason they just feel like it or because it’s new. They recommended a site run by a developer named Matt Raible with excellent comparison spread sheets regarding Web frameworks and other apps. They praised it as a useful tool to help developers in their decision-making processes. They pointed out that good developers sometimes make bad choices out of boredom, to add shiny things to their CV, out of frustration with existing processes, or just from a lack of understanding. They pointed out that some code may stay in a business system for 15 or 20 years, but not all code is created equal and some may change after 3 or 6 months. Developers need to know where the code they are contributing fits in. What is its likely lifespan? Anti-Pattern Four: Design-Driven Design The anti-pattern: If you want to impress your colleagues and bosses, use design patents left, right, and center – MVC, Session Facades, SOA, etc. Or the UML modeling suite from IBM, back in the day… Generate super fast code. And the more jargon you can talk when in the vicinity of the manager the better.Verburg shared a true story about a time when he was interviewing a guy for a job and asked him what his previous work was. The interviewee said that he essentially took patterns and uses an approved book of Enterprise Architecture Patterns and applied them. Verburg was dumbstruck that someone could have a job in which they took patterns from a book and applied them. He pointed out that the idea that design is a separate activity is simply wrong. He repeated a saying that he uses, “You should pay your junior developers for the lines of code they write and the things they add; you should pay your senior developers for what they take away.”He explained that by encouraging people to take things away, the code base gets simpler and reflects the actual business use cases developers are trying to solve, as opposed to the framework that is being imposed. He told another true story about a project to decommission a very long system. 98% of the code was decommissioned and people got a nice bonus. But the 2% remained on the mainframe so the 98% reduction in code resulted in zero reduction in costs, because the entire mainframe was needed to run the 2% that was left. There is an incentive to get rid of source code and subsystems when they are no longer needed. The session continued with several more anti-patterns that were equally insightful.

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  • FAQ&ndash;Highlight GridView Row on Click and Retain Selected Row on Postback

    - by Vincent Maverick Durano
    A couple of months ago I’ve written a simple demo about “Highlighting GridView Row on MouseOver”. I’ve noticed many members in the forums (http://forums.asp.net) are asking how to highlight row in GridView and retain the selected row across postbacks. So I’ve decided to write this post to demonstrate how to implement it as reference to others who might need it. In this demo I going to use a combination of plain JavaScript and jQuery to do the client-side manipulation. I presumed that you already know how to bind the grid with data because I will not include the codes for populating the GridView here. For binding the gridview you can refer this post: Binding GridView with Data the ADO.Net way or this one: GridView Custom Paging with LINQ. To get started let’s implement the highlighting of GridView row on row click and retain the selected row on postback.  For simplicity I set up the page like this: <asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server"> <h2>You have selected Row: (<asp:Label ID="Label1" runat="server" />)</h2> <asp:HiddenField ID="hfCurrentRowIndex" runat="server"></asp:HiddenField> <asp:HiddenField ID="hfParentContainer" runat="server"></asp:HiddenField> <asp:Button ID="Button1" runat="server" onclick="Button1_Click" Text="Trigger Postback" /> <asp:GridView ID="grdCustomer" runat="server" AutoGenerateColumns="false" onrowdatabound="grdCustomer_RowDataBound"> <Columns> <asp:BoundField DataField="Company" HeaderText="Company" /> <asp:BoundField DataField="Name" HeaderText="Name" /> <asp:BoundField DataField="Title" HeaderText="Title" /> <asp:BoundField DataField="Address" HeaderText="Address" /> </Columns> </asp:GridView> </asp:Content>   Note: Since the action is done at the client-side, when we do a postback like (clicking on a button) the page will be re-created and you will lose the highlighted row. This is normal because the the server doesn't know anything about the client/browser not unless if you do something to notify the server that something has changed. To persist the settings we will use some HiddenFields control to store the data so that when it postback we can reference the value from there. Now here’s the JavaScript functions below: <asp:content id="Content1" runat="server" contentplaceholderid="HeadContent"> <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.4/jquery.min.js" type="text/javascript"></script> <script type="text/javascript">       var prevRowIndex;       function ChangeRowColor(row, rowIndex) {           var parent = document.getElementById(row);           var currentRowIndex = parseInt(rowIndex) + 1;                 if (prevRowIndex == currentRowIndex) {               return;           }           else if (prevRowIndex != null) {               parent.rows[prevRowIndex].style.backgroundColor = "#FFFFFF";           }                 parent.rows[currentRowIndex].style.backgroundColor = "#FFFFD6";                 prevRowIndex = currentRowIndex;                 $('#<%= Label1.ClientID %>').text(currentRowIndex);                 $('#<%= hfParentContainer.ClientID %>').val(row);           $('#<%= hfCurrentRowIndex.ClientID %>').val(rowIndex);       }             $(function () {           RetainSelectedRow();       });             function RetainSelectedRow() {           var parent = $('#<%= hfParentContainer.ClientID %>').val();           var currentIndex = $('#<%= hfCurrentRowIndex.ClientID %>').val();           if (parent != null) {               ChangeRowColor(parent, currentIndex);           }       }          </script> </asp:content>   The ChangeRowColor() is the function that sets the background color of the selected row. It is also where we set the previous row and rowIndex values in HiddenFields.  The $(function(){}); is a short-hand for the jQuery document.ready function. This function will be fired once the page is posted back to the server that’s why we call the function RetainSelectedRow(). The RetainSelectedRow() function is where we referenced the current selected values stored from the HiddenFields and pass these values to the ChangeRowColor) function to retain the highlighted row. Finally, here’s the code behind part: protected void grdCustomer_RowDataBound(object sender, GridViewRowEventArgs e) { if (e.Row.RowType == DataControlRowType.DataRow) { e.Row.Attributes.Add("onclick", string.Format("ChangeRowColor('{0}','{1}');", e.Row.ClientID, e.Row.RowIndex)); } } The code above is responsible for attaching the javascript onclick event for each row and call the ChangeRowColor() function and passing the e.Row.ClientID and e.Row.RowIndex to the function. Here’s the sample output below:   That’s it! I hope someone find this post useful! Technorati Tags: jQuery,GridView,JavaScript,TipTricks

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  • How many developers before continuous integration becomes effective for us?

    - by Carnotaurus
    There is an overhead associated with continuous integration, e.g., set up, re-training, awareness activities, stoppage to fix "bugs" that turn out to be data issues, enforced separation of concerns programming styles, etc. At what point does continuous integration pay for itself? EDIT: These were my findings The set-up was CruiseControl.Net with Nant, reading from VSS or TFS. Here are a few reasons for failure, which have nothing to do with the setup: Cost of investigation: The time spent investigating whether a red light is due a genuine logical inconsistency in the code, data quality, or another source such as an infrastructure problem (e.g., a network issue, a timeout reading from source control, third party server is down, etc., etc.) Political costs over infrastructure: I considered performing an "infrastructure" check for each method in the test run. I had no solution to the timeout except to replace the build server. Red tape got in the way and there was no server replacement. Cost of fixing unit tests: A red light due to a data quality issue could be an indicator of a badly written unit test. So, data dependent unit tests were re-written to reduce the likelihood of a red light due to bad data. In many cases, necessary data was inserted into the test environment to be able to accurately run its unit tests. It makes sense to say that by making the data more robust then the test becomes more robust if it is dependent on this data. Of course, this worked well! Cost of coverage, i.e., writing unit tests for already existing code: There was the problem of unit test coverage. There were thousands of methods that had no unit tests. So, a sizeable amount of man days would be needed to create those. As this would be too difficult to provide a business case, it was decided that unit tests would be used for any new public method going forward. Those that did not have a unit test were termed 'potentially infra red'. An intestesting point here is that static methods were a moot point in how it would be possible to uniquely determine how a specific static method had failed. Cost of bespoke releases: Nant scripts only go so far. They are not that useful for, say, CMS dependent builds for EPiServer, CMS, or any UI oriented database deployment. These are the types of issues that occured on the build server for hourly test runs and overnight QA builds. I entertain that these to be unnecessary as a build master can perform these tasks manually at the time of release, esp., with a one man band and a small build. So, single step builds have not justified use of CI in my experience. What about the more complex, multistep builds? These can be a pain to build, especially without a Nant script. So, even having created one, these were no more successful. The costs of fixing the red light issues outweighed the benefits. Eventually, developers lost interest and questioned the validity of the red light. Having given it a fair try, I believe that CI is expensive and there is a lot of working around the edges instead of just getting the job done. It's more cost effective to employ experienced developers who do not make a mess of large projects than introduce and maintain an alarm system. This is the case even if those developers leave. It doesn't matter if a good developer leaves because processes that he follows would ensure that he writes requirement specs, design specs, sticks to the coding guidelines, and comments his code so that it is readable. All this is reviewed. If this is not happening then his team leader is not doing his job, which should be picked up by his manager and so on. For CI to work, it is not enough to just write unit tests, attempt to maintain full coverage, and ensure a working infrastructure for sizable systems. The bottom line: One might question whether fixing as many bugs before release is even desirable from a business prespective. CI involves a lot of work to capture a handful of bugs that the customer could identify in UAT or the company could get paid for fixing as part of a client service agreement when the warranty period expires anyway.

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  • XmlWriter and lower ASCII characters

    - by Rick Strahl
    Ran into an interesting problem today on my CodePaste.net site: The main RSS and ATOM feeds on the site were broken because one code snippet on the site contained a lower ASCII character (CHR(3)). I don't think this was done on purpose but it was enough to make the feeds fail. After quite a bit of debugging and throwing in a custom error handler into my actual feed generation code that just spit out the raw error instead of running it through the ASP.NET MVC and my own error pipeline I found the actual error. The lovely base exception and error trace I got looked like this: Error: '', hexadecimal value 0x03, is an invalid character. at System.Xml.XmlUtf8RawTextWriter.InvalidXmlChar(Int32 ch, Byte* pDst, Boolean entitize)at System.Xml.XmlUtf8RawTextWriter.WriteElementTextBlock(Char* pSrc, Char* pSrcEnd)at System.Xml.XmlUtf8RawTextWriter.WriteString(String text)at System.Xml.XmlWellFormedWriter.WriteString(String text)at System.Xml.XmlWriter.WriteElementString(String localName, String ns, String value)at System.ServiceModel.Syndication.Rss20FeedFormatter.WriteItemContents(XmlWriter writer, SyndicationItem item, Uri feedBaseUri)at System.ServiceModel.Syndication.Rss20FeedFormatter.WriteItem(XmlWriter writer, SyndicationItem item, Uri feedBaseUri)at System.ServiceModel.Syndication.Rss20FeedFormatter.WriteItems(XmlWriter writer, IEnumerable`1 items, Uri feedBaseUri)at System.ServiceModel.Syndication.Rss20FeedFormatter.WriteFeed(XmlWriter writer)at System.ServiceModel.Syndication.Rss20FeedFormatter.WriteTo(XmlWriter writer)at CodePasteMvc.Controllers.ApiControllerBase.GetFeed(Object instance) in C:\Projects2010\CodePaste\CodePasteMvc\Controllers\ApiControllerBase.cs:line 131 XML doesn't like extended ASCII Characters It turns out the issue is that XML in general does not deal well with lower ASCII characters. According to the XML spec it looks like any characters below 0x09 are invalid. If you generate an XML document in .NET with an embedded &#x3; entity (as mine did to create the error above), you tend to get an XML document error when displaying it in a viewer. For example, here's what the result of my  feed output looks like with the invalid character embedded inside of Chrome which displays RSS feeds as raw XML by default: Other browsers show similar error messages. The nice thing about Chrome is that you can actually view source and jump down to see the line that causes the error which allowed me to track down the actual message that failed. If you create an XML document that contains a 0x03 character the XML writer fails outright with the error: '', hexadecimal value 0x03, is an invalid character. The good news is that this behavior is overridable so XML output can at least be created by using the XmlSettings object when configuring the XmlWriter instance. In my RSS configuration code this looks something like this:MemoryStream ms = new MemoryStream(); var settings = new XmlWriterSettings() { CheckCharacters = false }; XmlWriter writer = XmlWriter.Create(ms,settings); and voila the feed now generates. Now generally this is probably NOT a good idea, because as mentioned above these characters are illegal and if you view a raw XML document you'll get validation errors. Luckily though most RSS feed readers however don't care and happily accept and display the feed correctly, which is good because it got me over an embarrassing hump until I figured out a better solution. How to handle extended Characters? I was glad to get the feed fixed for the time being, but now I was still stuck with an interesting dilemma. CodePaste.net accepts user input for code snippets and those code snippets can contain just about anything. This means that ASP.NET's standard request filtering cannot be applied to this content. The code content displayed is encoded before display so for the HTML end the CHR(3) input is not really an issue. While invisible characters are hardly useful in user input it's not uncommon that odd characters show up in code snippets. You know the old fat fingering that happens when you're in the middle of a coding session and those invisible characters do end up sometimes in code editors and then end up pasted into the HTML textbox for pasting as a Codepaste.net snippet. The question is how to filter this text? Looking back at the XML Charset Spec it looks like all characters below 0x20 (space) except for 0x09 (tab), 0x0A (LF), 0x0D (CR) are illegal. So applying the following filter with a RegEx should work to remove invalid characters:string code = Regex.Replace(item.Code, @"[\u0000-\u0008,\u000B,\u000C,\u000E-\u001F]", ""); Applying this RegEx to the code snippet (and title) eliminates the problems and the feed renders cleanly.© Rick Strahl, West Wind Technologies, 2005-2012Posted in .NET  XML   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • Trying to detect collision between two polygons using Separating Axis Theorem

    - by Holly
    The only collision experience i've had was with simple rectangles, i wanted to find something that would allow me to define polygonal areas for collision and have been trying to make sense of SAT using these two links Though i'm a bit iffy with the math for the most part i feel like i understand the theory! Except my implementation somewhere down the line must be off as: (excuse the hideous font) As mentioned above i have defined a CollisionPolygon class where most of my theory is implemented and then have a helper class called Vect which was meant to be for Vectors but has also been used to contain a vertex given that both just have two float values. I've tried stepping through the function and inspecting the values to solve things but given so many axes and vectors and new math to work out as i go i'm struggling to find the erroneous calculation(s) and would really appreciate any help. Apologies if this is not suitable as a question! CollisionPolygon.java: package biz.hireholly.gameplay; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import biz.hireholly.gameplay.Types.Vect; public class CollisionPolygon { Paint paint; private Vect[] vertices; private Vect[] separationAxes; CollisionPolygon(Vect[] vertices){ this.vertices = vertices; //compute edges and separations axes separationAxes = new Vect[vertices.length]; for (int i = 0; i < vertices.length; i++) { // get the current vertex Vect p1 = vertices[i]; // get the next vertex Vect p2 = vertices[i + 1 == vertices.length ? 0 : i + 1]; // subtract the two to get the edge vector Vect edge = p1.subtract(p2); // get either perpendicular vector Vect normal = edge.perp(); // the perp method is just (x, y) => (-y, x) or (y, -x) separationAxes[i] = normal; } paint = new Paint(); paint.setColor(Color.RED); } public void draw(Canvas c, int xPos, int yPos){ for (int i = 0; i < vertices.length; i++) { Vect v1 = vertices[i]; Vect v2 = vertices[i + 1 == vertices.length ? 0 : i + 1]; c.drawLine( xPos + v1.x, yPos + v1.y, xPos + v2.x, yPos + v2.y, paint); } } /* consider changing to a static function */ public boolean intersects(CollisionPolygon p){ // loop over this polygons separation exes for (Vect axis : separationAxes) { // project both shapes onto the axis Vect p1 = this.minMaxProjection(axis); Vect p2 = p.minMaxProjection(axis); // do the projections overlap? if (!p1.overlap(p2)) { // then we can guarantee that the shapes do not overlap return false; } } // loop over the other polygons separation axes Vect[] sepAxesOther = p.getSeparationAxes(); for (Vect axis : sepAxesOther) { // project both shapes onto the axis Vect p1 = this.minMaxProjection(axis); Vect p2 = p.minMaxProjection(axis); // do the projections overlap? if (!p1.overlap(p2)) { // then we can guarantee that the shapes do not overlap return false; } } // if we get here then we know that every axis had overlap on it // so we can guarantee an intersection return true; } /* Note projections wont actually be acurate if the axes aren't normalised * but that's not necessary since we just need a boolean return from our * intersects not a Minimum Translation Vector. */ private Vect minMaxProjection(Vect axis) { float min = axis.dot(vertices[0]); float max = min; for (int i = 1; i < vertices.length; i++) { float p = axis.dot(vertices[i]); if (p < min) { min = p; } else if (p > max) { max = p; } } Vect minMaxProj = new Vect(min, max); return minMaxProj; } public Vect[] getSeparationAxes() { return separationAxes; } public Vect[] getVertices() { return vertices; } } Vect.java: package biz.hireholly.gameplay.Types; /* NOTE: Can also be used to hold vertices! Projections, coordinates ect */ public class Vect{ public float x; public float y; public Vect(float x, float y){ this.x = x; this.y = y; } public Vect perp() { return new Vect(-y, x); } public Vect subtract(Vect other) { return new Vect(x - other.x, y - other.y); } public boolean overlap(Vect other) { if( other.x <= y || other.y >= x){ return true; } return false; } /* used specifically for my SAT implementation which i'm figuring out as i go, * references for later.. * http://www.gamedev.net/page/resources/_/technical/game-programming/2d-rotated-rectangle-collision-r2604 * http://www.codezealot.org/archives/55 */ public float scalarDotProjection(Vect other) { //multiplier = dot product / length^2 float multiplier = dot(other) / (x*x + y*y); //to get the x/y of the projection vector multiply by x/y of axis float projX = multiplier * x; float projY = multiplier * y; //we want to return the dot product of the projection, it's meaningless but useful in our SAT case return dot(new Vect(projX,projY)); } public float dot(Vect other){ return (other.x*x + other.y*y); } }

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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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  • Oracle Romania Summer School

    - by Maria Sandu
    Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 What would you say about a Summer School within a corporation where you can learn, play and practice? You might think that this is something usually uncommon for a company and you would be right. However, Oracle’s main value being innovation, we came up with a new project for Romanian students and graduates. We organised Oracle Summer School , offering them the opportunity to develop their soft skills and gain valuable business knowledge and exposure. How was Oracle Summer School programme organised? We focused on students and graduates’ needs and combined business experience with training and practice. The twenty four participants had different backgrounds, being interested in Software, Hardware, Finance, Marketing or other areas. The programme fulfilled each of these needs, bringing them in contact with Specialists and Managers. The first two weeks were dedicated to the company visits, business presentations and networking. The participants got an insight about employees’ activities and projects. Storytelling was also part of the program and people from different departments spent a couple of hours with the participants, sharing their experiences, knowledge and interesting stories. The Recruitment team delivered a training about the job interview skills in order to make the participants feel better prepared for a Recruitment process. The second module consisted of two weeks of Soft Skills trainings delivered by professional trainers from different departments. The participants gained useful insight on the competencies required within a business environment. The evenings were dedicated to social activities and it not very long until they started feel part of a team. The third module will take place at the end of September and will put the participants in contact with senior people from the business who will become their Mentors. What do the participants say about Oracle Summer School? “ As a fresh computer science graduate, Oracle Summer School gave me the opportunity of finding what are the technical and nontechnical skills required in a large multinational company. It was a great way of seeing how the theoretical knowledge I received during college is applied in real-life scenarios and what skills I still need to develop. “  (Cosmin Radu) “ When arriving at Oracle I had high expectations, but did not know exactly what was going to unfold because of the program's lack of precedence. Right after the first day, my feedback outgrew the initial forecast and the following weeks continued to build upon it. I had the pleasure to acquaint with brilliant people. The program was outlined on various profiles, delivering a comprehensive experience. It was very engaging, informative and nevertheless fun. “ (Vlad Manciu) „ Oracle Summer School is by far the best summer school that I have ever attended. For me it has been a great experience so far, because I’ve learned not only how to use soft skills in a corporate environment, but I’ve learned a great deal about myself as well. However, the most valuable asset of this 3-week period were the people that I’ve met: great individuals and great professionals, whom I really grew fond of.” (Alexandru Purcarea) “Applying to Oracle Summer School has been the best decision I took in regard to how to spend my summer holiday. I had the chance to do job shadowing at some of the departments I was interested in and I attended great trainings on various subjects such as time management and emotional intelligence. Moreover, I made friends with the other participants and we enjoyed going out together after “classes”.(Andreea Tudor) If you are interested in joining our team and attending our events please follow us on https://campus.oracle.com/campus/HR/emea_main.html /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-family:"Calibri","sans-serif"; mso-ascii- mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi- mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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  • Lazy HTML attributes wrapping in Internet Explorer

    - by AGS777
    Having encountered this Internet Explorer (all versions) behavior several times previously, I eventually decided to share this most probably useless knowledge. Excuse my lengthy explanations because I am going to show the behavior along with a very simple case when one can come across it inadvertently. Let's say I want to implement some simple templating solution in JavaScript. I wrote an HTML template with an intention to bind data to it on the client side: Please note, that name of the “sys-template” class is just a coincidence. I do not use any ASP.NET AJAX code in this simple example. As you can see we need to replace placeholders (property name wrapped with curly braces) with actual data. Also, as you can see, many of the placeholders are situated within attribute values and it is where the danger lies. I am going to use <a /> element HTML as a template and replace each placeholder pattern with respective properties’ values with a little bit of jQuery like this: You can find complete code along with the contextFormat() method definition at the end of the post. Let’s assume that value for the name property (that we want to put in the title attribute) of the first data item is “first tooltip”. So it consists of two words. When the replacement occurred, title attribute should contain the “first tooltip” text which we are going to see as a tooltip for the <a /> element. But let’s run the sample code in Internet Explorer and check it out. What you’ll see is that only the first word of the supposed “title” attribute’s content is shown. So, were is the rest of my attribute and what happened? The answer is obvious once you see the result of jQuery(“.sys-template”).html() line for the given HTML markup. In IE you’ll get the following <A id={id} class={cssClass} title={name} href="{source}" myAttr="{attr}">Link to {source}</A> See any difference between this HTML and the one shown earlier? No? Then look carefully. While the original HTML of the <a /> element is well-formed and all the attributes are correctly quoted, when you take the same HTML back in Internet Explorer (it doesn’t matter whether you use html() method from jQuery library or IE’s innerHTML directly), you lose attributes’ quotes for some of the attributes. Then, after replacement, we’ll get following HTML for our first data item. I marked the attribute value in question with italic: <A id=1 class=first title=first tooltip href="first.html" myAttr="firstAttr">Link to first.html</A> Now you can easily imagine for yourself what happens when this HTML is inserted into the document and why we do not see the second (and any subsequent words if any) of our title attribute in the tooltip. There are still two important things to note. The first one (and it actually the reason why I named the post “lazy wrapping” is that if value of the HTML attribute does contains spaces in the original HTML, then it WILL be wrapped with quotation marks. For example, if I wrote following on my page (note the trailing space for the title attribute value) <a href="{source}" title="{name}  " id="{id}" myAttr="{attr}" class="{cssClass}">Link to {source}</a> then I would have my placeholder quoted correctly and the result of the replacement would render as expected: The second important thing to note is that there are exceptions for the lazy attributes wrapping rule in IE. As you can see href attribute value did not contain spaces exactly as all the other attributes with placeholders, but it was still returned correctly quoted Custom attribute myAttr is also quoted correctly when returned back from document, though its placeholder value does not contain spaces either. Now, on account of the highly unlikely probability that you found this information useful and need a solution to the problem the aforementioned behavior introduces for Internet Explorer browser, I can suggest a simple workaround – manually quote the mischievous attributes prior the placeholder pattern is replaced. Using the code of contextFormat() method shown below, you would need to add following line right before the return statement: result = result.replace(/=({([^}]+)})/g, '="$1"'); Below please find original sample code:

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  • Error in my Separating Axis Theorem collision code

    - by Holly
    The only collision experience i've had was with simple rectangles, i wanted to find something that would allow me to define polygonal areas for collision and have been trying to make sense of SAT using these two links Though i'm a bit iffy with the math for the most part i feel like i understand the theory! Except my implementation somewhere down the line must be off as: (excuse the hideous font) As mentioned above i have defined a CollisionPolygon class where most of my theory is implemented and then have a helper class called Vect which was meant to be for Vectors but has also been used to contain a vertex given that both just have two float values. I've tried stepping through the function and inspecting the values to solve things but given so many axes and vectors and new math to work out as i go i'm struggling to find the erroneous calculation(s) and would really appreciate any help. Apologies if this is not suitable as a question! CollisionPolygon.java: package biz.hireholly.gameplay; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import biz.hireholly.gameplay.Types.Vect; public class CollisionPolygon { Paint paint; private Vect[] vertices; private Vect[] separationAxes; int x; int y; CollisionPolygon(Vect[] vertices){ this.vertices = vertices; //compute edges and separations axes separationAxes = new Vect[vertices.length]; for (int i = 0; i < vertices.length; i++) { // get the current vertex Vect p1 = vertices[i]; // get the next vertex Vect p2 = vertices[i + 1 == vertices.length ? 0 : i + 1]; // subtract the two to get the edge vector Vect edge = p1.subtract(p2); // get either perpendicular vector Vect normal = edge.perp(); // the perp method is just (x, y) => (-y, x) or (y, -x) separationAxes[i] = normal; } paint = new Paint(); paint.setColor(Color.RED); } public void draw(Canvas c, int xPos, int yPos){ for (int i = 0; i < vertices.length; i++) { Vect v1 = vertices[i]; Vect v2 = vertices[i + 1 == vertices.length ? 0 : i + 1]; c.drawLine( xPos + v1.x, yPos + v1.y, xPos + v2.x, yPos + v2.y, paint); } } public void update(int xPos, int yPos){ x = xPos; y = yPos; } /* consider changing to a static function */ public boolean intersects(CollisionPolygon p){ // loop over this polygons separation exes for (Vect axis : separationAxes) { // project both shapes onto the axis Vect p1 = this.minMaxProjection(axis); Vect p2 = p.minMaxProjection(axis); // do the projections overlap? if (!p1.overlap(p2)) { // then we can guarantee that the shapes do not overlap return false; } } // loop over the other polygons separation axes Vect[] sepAxesOther = p.getSeparationAxes(); for (Vect axis : sepAxesOther) { // project both shapes onto the axis Vect p1 = this.minMaxProjection(axis); Vect p2 = p.minMaxProjection(axis); // do the projections overlap? if (!p1.overlap(p2)) { // then we can guarantee that the shapes do not overlap return false; } } // if we get here then we know that every axis had overlap on it // so we can guarantee an intersection return true; } /* Note projections wont actually be acurate if the axes aren't normalised * but that's not necessary since we just need a boolean return from our * intersects not a Minimum Translation Vector. */ private Vect minMaxProjection(Vect axis) { float min = axis.dot(new Vect(vertices[0].x+x, vertices[0].y+y)); float max = min; for (int i = 1; i < vertices.length; i++) { float p = axis.dot(new Vect(vertices[i].x+x, vertices[i].y+y)); if (p < min) { min = p; } else if (p > max) { max = p; } } Vect minMaxProj = new Vect(min, max); return minMaxProj; } public Vect[] getSeparationAxes() { return separationAxes; } public Vect[] getVertices() { return vertices; } } Vect.java: package biz.hireholly.gameplay.Types; /* NOTE: Can also be used to hold vertices! Projections, coordinates ect */ public class Vect{ public float x; public float y; public Vect(float x, float y){ this.x = x; this.y = y; } public Vect perp() { return new Vect(-y, x); } public Vect subtract(Vect other) { return new Vect(x - other.x, y - other.y); } public boolean overlap(Vect other) { if(y > other.x && other.y > x){ return true; } return false; } /* used specifically for my SAT implementation which i'm figuring out as i go, * references for later.. * http://www.gamedev.net/page/resources/_/technical/game-programming/2d-rotated-rectangle-collision-r2604 * http://www.codezealot.org/archives/55 */ public float scalarDotProjection(Vect other) { //multiplier = dot product / length^2 float multiplier = dot(other) / (x*x + y*y); //to get the x/y of the projection vector multiply by x/y of axis float projX = multiplier * x; float projY = multiplier * y; //we want to return the dot product of the projection, it's meaningless but useful in our SAT case return dot(new Vect(projX,projY)); } public float dot(Vect other){ return (other.x*x + other.y*y); } }

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  • Solaris 11.2: Functional Deprecation

    - by alanc
    In Solaris 11.1, I updated the system headers to enable use of several attributes on functions, including noreturn and printf format, to give compilers and static analyzers more information about how they are used to give better warnings when building code. In Solaris 11.2, I've gone back in and added one more attribute to a number of functions in the system headers: __attribute__((__deprecated__)). This is used to warn people building software that they’re using function calls we recommend no longer be used. While in many cases the Solaris Binary Compatibility Guarantee means we won't ever remove these functions from the system libraries, we still want to discourage their use. I made passes through both the POSIX and C standards, and some of the Solaris architecture review cases to come up with an initial list which the Solaris architecture review committee accepted to start with. This set is by no means a complete list of Obsolete function interfaces, but should be a reasonable start at functions that are well documented as deprecated and seem useful to warn developers away from. More functions may be flagged in the future as they get deprecated, or if further passes are made through our existing deprecated functions to flag more of them. Header Interface Deprecated by Alternative Documented in <door.h> door_cred(3C) PSARC/2002/188 door_ucred(3C) door_cred(3C) <kvm.h> kvm_read(3KVM), kvm_write(3KVM) PSARC/1995/186 Functions on kvm_kread(3KVM) man page kvm_read(3KVM) <stdio.h> gets(3C) ISO C99 TC3 (Removed in ISO C11), POSIX:2008/XPG7/Unix08 fgets(3C) gets(3C) man page, and just about every gets(3C) reference online from the past 25 years, since the Morris worm proved bad things happen when it’s used. <unistd.h> vfork(2) PSARC/2004/760, POSIX:2001/XPG6/Unix03 (Removed in POSIX:2008/XPG7/Unix08) posix_spawn(3C) vfork(2) man page. <utmp.h> All functions from getutent(3C) man page PSARC/1999/103 utmpx functions from getutentx(3C) man page getutent(3C) man page <varargs.h> varargs.h version of va_list typedef ANSI/ISO C89 standard <stdarg.h> varargs(3EXT) <volmgt.h> All functions PSARC/2005/672 hal(5) API volmgt_check(3VOLMGT), etc. <sys/nvpair.h> nvlist_add_boolean(3NVPAIR), nvlist_lookup_boolean(3NVPAIR) PSARC/2003/587 nvlist_add_boolean_value, nvlist_lookup_boolean_value nvlist_add_boolean(3NVPAIR) & (9F), nvlist_lookup_boolean(3NVPAIR) & (9F). <sys/processor.h> gethomelgroup(3C) PSARC/2003/034 lgrp_home(3LGRP) gethomelgroup(3C) <sys/stat_impl.h> _fxstat, _xstat, _lxstat, _xmknod PSARC/2009/657 stat(2) old functions are undocumented remains of SVR3/COFF compatibility support If the above table is cut off when viewing in the blog, try viewing this standalone copy of the table. To See or Not To See To see these warnings, you will need to be building with either gcc (versions 3.4, 4.5, 4.7, & 4.8 are available in the 11.2 package repo), or with Oracle Solaris Studio 12.4 or later (which like Solaris 11.2, is currently in beta testing). For instance, take this oversimplified (and obviously buggy) implementation of the cat command: #include <stdio.h> int main(int argc, char **argv) { char buf[80]; while (gets(buf) != NULL) puts(buf); return 0; } Compiling it with the Studio 12.4 beta compiler will produce warnings such as: % cc -V cc: Sun C 5.13 SunOS_i386 Beta 2014/03/11 % cc gets_test.c "gets_test.c", line 6: warning: "gets" is deprecated, declared in : "/usr/include/iso/stdio_iso.h", line 221 The exact warning given varies by compilers, and the compilers also have a variety of flags to either raise the warnings to errors, or silence them. Of couse, the exact form of the output is Not An Interface that can be relied on for automated parsing, just shown for example. gets(3C) is actually a special case — as noted above, it is no longer part of the C Standard Library in the C11 standard, so when compiling in C11 mode (i.e. when __STDC_VERSION__ >= 201112L), the <stdio.h> header will not provide a prototype for it, causing the compiler to complain it is unknown: % gcc -std=c11 gets_test.c gets_test.c: In function ‘main’: gets_test.c:6:5: warning: implicit declaration of function ‘gets’ [-Wimplicit-function-declaration] while (gets(buf) != NULL) ^ The gets(3C) function of course is still in libc, so if you ignore the error or provide your own prototype, you can still build code that calls it, you just have to acknowledge you’re taking on the risk of doing so yourself. Solaris Studio 12.4 Beta % cc gets_test.c "gets_test.c", line 6: warning: "gets" is deprecated, declared in : "/usr/include/iso/stdio_iso.h", line 221 % cc -errwarn=E_DEPRECATED_ATT gets_test.c "gets_test.c", line 6: "gets" is deprecated, declared in : "/usr/include/iso/stdio_iso.h", line 221 cc: acomp failed for gets_test.c This warning is silenced in the 12.4 beta by cc -erroff=E_DEPRECATED_ATT No warning is currently issued by Studio 12.3 & earler releases. gcc 3.4.3 % /usr/sfw/bin/gcc gets_test.c gets_test.c: In function `main': gets_test.c:6: warning: `gets' is deprecated (declared at /usr/include/iso/stdio_iso.h:221) Warning is completely silenced with gcc -Wno-deprecated-declarations gcc 4.7.3 % /usr/gcc/4.7/bin/gcc gets_test.c gets_test.c: In function ‘main’: gets_test.c:6:5: warning: ‘gets’ is deprecated (declared at /usr/include/iso/stdio_iso.h:221) [-Wdeprecated-declarations] % /usr/gcc/4.7/bin/gcc -Werror=deprecated-declarations gets_test.c gets_test.c: In function ‘main’: gets_test.c:6:5: error: ‘gets’ is deprecated (declared at /usr/include/iso/stdio_iso.h:221) [-Werror=deprecated-declarations] cc1: some warnings being treated as errors Warning is completely silenced with gcc -Wno-deprecated-declarations gcc 4.8.2 % /usr/bin/gcc gets_test.c gets_test.c: In function ‘main’: gets_test.c:6:5: warning: ‘gets’ is deprecated (declared at /usr/include/iso/stdio_iso.h:221) [-Wdeprecated-declarations] while (gets(buf) != NULL) ^ % /usr/bin/gcc -Werror=deprecated-declarations gets_test.c gets_test.c: In function ‘main’: gets_test.c:6:5: error: ‘gets’ is deprecated (declared at /usr/include/iso/stdio_iso.h:221) [-Werror=deprecated-declarations] while (gets(buf) != NULL) ^ cc1: some warnings being treated as errors Warning is completely silenced with gcc -Wno-deprecated-declarations

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  • Best Practices - Dynamic Reconfiguration

    - by jsavit
    This post is one of a series of "best practices" notes for Oracle VM Server for SPARC (formerly named Logical Domains) Overview of dynamic Reconfiguration Oracle VM Server for SPARC supports Dynamic Reconfiguration (DR), making it possible to add or remove resources to or from a domain (virtual machine) while it is running. This is extremely useful because resources can be shifted to or from virtual machines in response to load conditions without having to reboot or interrupt running applications. For example, if an application requires more CPU capacity, you can add CPUs to improve performance, and remove them when they are no longer needed. You can use even use Dynamic Resource Management (DRM) policies that automatically add and remove CPUs to domains based on load. How it works (in broad general terms) Dynamic Reconfiguration is done in coordination with Solaris, which recognises a hypervisor request to change its virtual machine configuration and responds appropriately. In essence, Solaris receives a message saying "you now have 16 more CPUs numbered 16 to 31" or "8GB more RAM starting at address X" or "here's a new network or disk device - have fun with it". These actions take very little time. Solaris then can start using the new resource. In the case of added CPUs, that means dispatching processes and potentially binding interrupts to the new CPUs. For memory, Solaris adds the new memory pages to its "free" list and starts using them. Comparable actions occur with network and disk devices: they are recognised by Solaris and then used. Removing is the reverse process: after receiving the DR message to free specific CPUs, Solaris unbinds interrupts assigned to the CPUs and stops dispatching process threads. That takes very little time. primary # ldm list NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- SP 16 4G 1.0% 6d 22h 29m ldom1 active -n---- 5000 16 8G 0.9% 6h 59m primary # ldm set-core 5 ldom1 primary # ldm list NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- SP 16 4G 0.2% 6d 22h 29m ldom1 active -n---- 5000 40 8G 0.1% 6h 59m primary # ldm set-core 2 ldom1 primary # ldm list NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- SP 16 4G 1.0% 6d 22h 29m ldom1 active -n---- 5000 16 8G 0.9% 6h 59m Memory pages are vacated by copying their contents to other memory locations and wiping them clean. Solaris may have to swap memory contents to disk if the remaining RAM isn't enough to hold all the contents. For this reason, deallocating memory can take longer on a loaded system. Even on a lightly loaded system it took several 7 or 8 seconds to switch the domain below between 8GB and 24GB of RAM. primary # ldm set-mem 24g ldom1 primary # ldm list NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- SP 16 4G 0.1% 6d 22h 36m ldom1 active -n---- 5000 16 24G 0.2% 7h 6m primary # ldm set-mem 8g ldom1 primary # ldm list NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- SP 16 4G 0.7% 6d 22h 37m ldom1 active -n---- 5000 16 8G 0.3% 7h 7m What if the device is in use? (this is the anecdote that inspired this blog post) If CPU or memory is being removed, releasing it pretty straightforward, using the method described above. The resources are released, and Solaris continues with less capacity. It's not as simple with a network or I/O device: you don't want to yank a device out from underneath an application that might be using it. In the following example, I've added a virtual network device to ldom1 and want to take it away, even though it's been plumbed. primary # ldm rm-vnet vnet19 ldom1 Guest LDom returned the following reason for failing the operation: Resource Information ---------------------------------------------------------- ----------------------- /devices/virtual-devices@100/channel-devices@200/network@1 Network interface net1 VIO operation failed because device is being used in LDom ldom1 Failed to remove VNET instance That's what I call a helpful error message - telling me exactly what was wrong. In this case the problem is easily solved. I know this NIC is seen in the guest as net1 so: ldom1 # ifconfig net1 down unplumb Now I can dispose of it, and even the virtual switch I had created for it: primary # ldm rm-vnet vnet19 ldom1 primary # ldm rm-vsw primary-vsw9 If I had to take away the device disruptively, I could have used ldm rm-vnet -f but that could disrupt whoever was using it. It's better if that can be avoided. Summary Oracle VM Server for SPARC provides dynamic reconfiguration, which lets you modify a guest domain's CPU, memory and I/O configuration on the fly without reboot. You can add and remove resources as needed, and even automate this for CPUs by setting up resource policies. Taking things away can be more complicated than giving, especially for devices like disks and networks that may contain application and system state or be involved in a transaction. LDoms and Solaris cooperative work together to coordinate resource allocation and de-allocation in a safe and effective way. For best practices, use dynamic reconfiguration to make the best use of your system's resources.

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  • Visual Tree Enumeration

    - by codingbloke
    I feel compelled to post this blog because I find I’m repeatedly posting this same code in silverlight and windows-phone-7 answers in Stackoverflow. One common task that we feel we need to do is burrow into the visual tree in a Silverlight or Windows Phone 7 application (actually more recently I found myself doing this in WPF as well).  This allows access to details that aren’t exposed directly by some controls.  A good example of this sort of requirement is found in the “Restoring exact scroll position of a listbox in Windows Phone 7”  question on stackoverflow.  This required that the scroll position of the scroll viewer internal to a listbox be accessed. A caveat One caveat here is that we should seriously challenge the need for this burrowing since it may indicate that there is a design problem.  Burrowing into the visual tree or indeed burrowing out to containing ancestors could represent significant coupling between module boundaries and that generally isn’t a good idea. Why isn’t this idea just not cast aside as a no-no?  Well the whole concept of a “Templated Control”, which are in extensive use in these applications, opens the coupling between the content of the visual tree and the internal code of a control.   For example, I can completely change the appearance and positioning of elements that make up a ComboBox.  The ComboBox control relies on specific template parts having set names of a specified type being present in my template.  Rightly or wrongly this does kind of give license to writing code that has similar coupling. Hasn’t this been done already? Yes it has.  There are number of blogs already out there with similar solutions.  In fact if you are using Silverlight toolkit the VisualTreeExtensions class already provides this feature.  However I prefer my specific code because of the simplicity principle I hold to.  Only write the minimum code necessary to give all the features needed.  In this case I add just two extension methods Ancestors and Descendents, note I don’t bother with “Get” or “Visual” prefixes.  Also I haven’t added Parent or Children methods nor additional “AndSelf” methods because all but Children is achievable with the addition of some other Linq methods.  I decided to give Descendents an additional overload for depth hence a depth of 1 is equivalent to Children but this overload is a little more flexible than simply Children. So here is the code:- VisualTreeEnumeration public static class VisualTreeEnumeration {     public static IEnumerable<DependencyObject> Descendents(this DependencyObject root, int depth)     {         int count = VisualTreeHelper.GetChildrenCount(root);         for (int i = 0; i < count; i++)         {             var child = VisualTreeHelper.GetChild(root, i);             yield return child;             if (depth > 0)             {                 foreach (var descendent in Descendents(child, --depth))                     yield return descendent;             }         }     }     public static IEnumerable<DependencyObject> Descendents(this DependencyObject root)     {         return Descendents(root, Int32.MaxValue);     }     public static IEnumerable<DependencyObject> Ancestors(this DependencyObject root)     {         DependencyObject current = VisualTreeHelper.GetParent(root);         while (current != null)         {             yield return current;             current = VisualTreeHelper.GetParent(current);         }     } }   Usage examples The following are some examples of how to combine the above extension methods with Linq to generate the other axis scenarios that tree traversal code might require. Missing Axis Scenarios var parent = control.Ancestors().Take(1).FirstOrDefault(); var children = control.Descendents(1); var previousSiblings = control.Ancestors().Take(1)     .SelectMany(p => p.Descendents(1).TakeWhile(c => c != control)); var followingSiblings = control.Ancestors().Take(1)     .SelectMany(p => p.Descendents(1).SkipWhile(c => c != control).Skip(1)); var ancestorsAndSelf = Enumerable.Repeat((DependencyObject)control, 1)     .Concat(control.Ancestors()); var descendentsAndSelf = Enumerable.Repeat((DependencyObject)control, 1)     .Concat(control.Descendents()); You might ask why I don’t just include these in the VisualTreeEnumerator.  I don’t on the principle of only including code that is actually needed.  If you find that one or more of the above  is needed in your code then go ahead and create additional methods.  One of the downsides to Extension methods is that they can make finding the method you actually want in intellisense harder. Here are some real world usage scenarios for these methods:- Real World Scenarios //Gets the internal scrollviewer of a ListBox ScrollViewer sv = someListBox.Descendents().OfType<ScrollViewer>().FirstOrDefault(); // Get all text boxes in current UserControl:- var textBoxes = this.Descendents().OfType<TextBox>(); // All UIElement direct children of the layout root grid:- var topLevelElements = LayoutRoot.Descendents(0).OfType<UIElement>(); // Find the containing `ListBoxItem` for a UIElement:- var container = elem.Ancestors().OfType<ListBoxItem>().FirstOrDefault(); // Seek a button with the name "PinkElephants" even if outside of the current Namescope:- var pinkElephantsButton = this.Descendents()     .OfType<Button>()     .FirstOrDefault(b => b.Name == "PinkElephants"); //Clear all checkboxes with the name "Selector" in a Treeview foreach (CheckBox checkBox in elem.Descendents()     .OfType<CheckBox>().Where(c => c.Name == "Selector")) {     checkBox.IsChecked = false; }   The last couple of examples above demonstrate a common requirement of finding controls that have a specific name.  FindName will often not find these controls because they exist in a different namescope. Hope you find this useful, if not I’m just glad to be able to link to this blog in future stackoverflow answers.

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  • A Basic Thread

    - by Joe Mayo
    Most of the programs written are single-threaded, meaning that they run on the main execution thread. For various reasons such as performance, scalability, and/or responsiveness additional threads can be useful. .NET has extensive threading support, from the basic threads introduced in v1.0 to the Task Parallel Library (TPL) introduced in v4.0. To get started with threads, it's helpful to begin with the basics; starting a Thread. Why Do I Care? The scenario I'll use for needing to use a thread is writing to a file.  Sometimes, writing to a file takes a while and you don't want your user interface to lock up until the file write is done. In other words, you want the application to be responsive to the user. How Would I Go About It? The solution is to launch a new thread that performs the file write, allowing the main thread to return to the user right away.  Whenever the file writing thread completes, it will let the user know.  In the meantime, the user is free to interact with the program for other tasks. The following examples demonstrate how to do this. Show Me the Code? The code we'll use to work with threads is in the System.Threading namespace, so you'll need the following using directive at the top of the file: using System.Threading; When you run code on a thread, the code is specified via a method.  Here's the code that will execute on the thread: private static void WriteFile() { Thread.Sleep(1000); Console.WriteLine("File Written."); } The call to Thread.Sleep(1000) delays thread execution. The parameter is specified in milliseconds, and 1000 means that this will cause the program to sleep for approximately 1 second.  This method happens to be static, but that's just part of this example, which you'll see is launched from the static Main method.  A thread could be instance or static.  Notice that the method does not have parameters and does not have a return type. As you know, the way to refer to a method is via a delegate.  There is a delegate named ThreadStart in System.Threading that refers to a method without parameters or return type, shown below: ThreadStart fileWriterHandlerDelegate = new ThreadStart(WriteFile); I'll show you the whole program below, but the ThreadStart instance above goes in the Main method. The thread uses the ThreadStart instance, fileWriterHandlerDelegate, to specify the method to execute on the thread: Thread fileWriter = new Thread(fileWriterHandlerDelegate); As shown above, the argument type for the Thread constructor is the ThreadStart delegate type. The fileWriterHandlerDelegate argument is an instance of the ThreadStart delegate type. This creates an instance of a thread and what code will execute, but the new thread instance, fileWriter, isn't running yet. You have to explicitly start it, like this: fileWriter.Start(); Now, the code in the WriteFile method is executing on a separate thread. Meanwhile, the main thread that started the fileWriter thread continues on it's own.  You have two threads running at the same time. Okay, I'm Starting to Get Glassy Eyed. How Does it All Fit Together? The example below is the whole program, pulling all the previous bits together. It's followed by its output and an explanation. using System; using System.Threading; namespace BasicThread { class Program { static void Main() { ThreadStart fileWriterHandlerDelegate = new ThreadStart(WriteFile); Thread fileWriter = new Thread(fileWriterHandlerDelegate); Console.WriteLine("Starting FileWriter"); fileWriter.Start(); Console.WriteLine("Called FileWriter"); Console.ReadKey(); } private static void WriteFile() { Thread.Sleep(1000); Console.WriteLine("File Written"); } } } And here's the output: Starting FileWriter Called FileWriter File Written So, Why are the Printouts Backwards? The output above corresponds to Console.Writeline statements in the program, with the second and third seemingly reversed. In a single-threaded program, "File Written" would print before "Called FileWriter". However, this is a multi-threaded (2 or more threads) program.  In multi-threading, you can't make any assumptions about when a given thread will run.  In this case, I added the Sleep statement to the WriteFile method to greatly increase the chances that the message from the main thread will print first. Without the Thread.Sleep, you could run this on a system with multiple cores and/or multiple processors and potentially get different results each time. Interesting Tangent but What Should I Get Out of All This? Going back to the main point, launching the WriteFile method on a separate thread made the program more responsive.  The file writing logic ran for a while, but the main thread returned to the user, as demonstrated by the print out of "Called FileWriter".  When the file write finished, it let the user know via another print statement. This was a very efficient use of CPU resources that made for a more pleasant user experience. Joe

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  • Seizing the Moment with Mobility

    - by Divya Malik
    Empowering people to work where they want to work is becoming more critical now with the consumerisation of technology. Employees are bringing their own devices to the workplace and expecting to be productive wherever they are. Sales people welcome the ability to run their critical business applications where they can be most effective which is typically on the road and when they are still with the customer. Oracle has invested many years of research in understanding customer's Mobile requirements. “The keys to building the best user experience were building in a lot of flexibility in ways to support sales, and being useful,” said Arin Bhowmick, Director, CRM, for the Applications UX team. “We did that by talking to and analyzing the needs of a lot of people in different roles.” The team studied real-life sales teams. “We wanted to study salespeople in context with their work,” Bhowmick said. “We studied all user types in the CRM world because we wanted to build a user interface and user experience that would cater to sales representatives, marketing managers, sales managers, and more. Not only did we do studies in our labs, but also we did studies in the field and in mobile environments because salespeople are always on the go.” Here is a recent post from Hernan Capdevila, Vice President, Oracle Fusion Apps which was featured on the Oracle Applications Blog.  Mobile devices are forcing a paradigm shift in the workplace – they’re changing the way businesses can do business and the type of cultures they can nurture. As our customers talk about their mobile needs, we hear them saying they want instant-on access to enterprise data so workers can be more effective at their jobs anywhere, anytime. They also are interested in being more cost effective from an IT point of view. The mobile revolution – with the idea of BYOD (bring your own device) – has added an interesting dynamic because previously IT was driving the employee device strategy and ecosystem. That's been turned on its head with the consumerization of IT. Now employees are figuring out how to use their personal devices for work purposes and IT has to figure out how to adapt. Blurring the Lines between Work and Personal Life My vision of where businesses will be five years from now is that our work lives and personal lives will be more interwoven together. In turn, enterprises will have to determine how to make employees’ work lives fit more into the fabric of their personal lives. And personal devices like smartphones are going to drive significant business value because they let us accomplish things very incrementally. I can be sitting on a train or in a taxi and be productive. At the end of any meeting, I can capture ideas and tasks or follow up with people in real time. Mobile devices enable this notion of seizing the moment – capitalizing on opportunities that might otherwise have slipped away because we're not connected. For the industry shapers out there, this is game changing. The lean and agile workforce is definitely the future. This notion of the board sitting down with the executive team to lay out strategic objectives for a three- to five-year plan, bringing in HR to determine how they're going to staff the strategic activities, kicking off the execution, and then revisiting the plan in three to five years to create another three- to five-year plan is yesterday's model. Businesses that continue to approach innovating in that way are in the dinosaur age. Today it's about incremental planning and incremental execution, which requires a lot of cohesion and synthesis within the workforce. There needs to be this interweaving notion within the workforce about how ideas cascade down, how people engage, how they stay connected, and how insights are shared. How to Survive and Thrive in Today’s Marketplace The notion of Facebook isn’t new. We lived it pre-Internet days with America Online and Prodigy – Facebook is just the renaissance of these services in a more viral and pervasive way. And given the trajectory of the consumerization of IT with people bringing their personal tooling to work, the enterprise has no option but to adapt. The sooner that businesses realize this from a top-down point of view the sooner that they will be able to really drive significant innovation and adapt to the marketplace. There are a small number of companies right now (I think it's closer to 20% rather than 80%, but the number is expanding) that are able to really innovate in this incremental marketplace. So from a competitive point of view, there's no choice but to be social and stay connected. By far the majority of users on Facebook and LinkedIn are mobile users – people on iPhones, smartphones, Android phones, and tablets. It's not the couch people, right? It's the on-the-go people – those people at the coffee shops. Usually when you're sitting at your desk on a big desktop computer, typically you have better things to do than to be on Facebook. This is a topic I'm extremely passionate about because I think mobile devices are game changing. Mobility delivers significant value to businesses – it also brings dramatic simplification from a functional point of view and transforms our work life experience. Hernan Capdevila Vice President, Oracle Applications Development

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  • Existential CAML - does an item exist?

    - by PointsToShare
    © 2011 By: Dov Trietsch. All rights reserved More CAML and existence. In “SharePoint List Issues” and “Passing the CAML thru the EY of the NEEDL we saw how to use CAML to return a subset of a list and also how to check the existence of lists, fields, defaults, and values.   Here is a general function that may be used to get a subset of a list by comparing a “text” type field to a given value.  The function is pretty smart. It can be used to check existence or to return a collection of items that may be further processed. It handles non existing fields and replaces them with the ubiquitous “Title”, but only once!  /// Build an SPQuery that returns a selected set of columns from a List /// titleField must be a "Text" type field /// When the titleField parameter is empty ("") "Title" is assumed /// When the title parameter is empty ("") All is assumed /// When the columnNames parameter is null, the query returns all the fields /// When the rowLimit parameter is 0, the query return all the items. /// with a non-zero, the query returns at most rowLimits /// /// usage: to check if an item titled "Blah" exists in your list, do: /// colNames = {"Title"} /// col = GetListItemColumnByTitle(myList, "", "Blah", colNames, 1) /// Check the col.Count. if > 0 the item exists and is in the collection private static SPListItemCollection GetListItemColumnByTitle(SPList list, string titleField, string title, string[] columnNames, uint rowLimit) {   try   {     char QT = Convert.ToChar((int)34);     SPQuery query = new SPQuery();     if (title != "")     {       string tf = titleField;       if (titleField == "") tf = "Title";       tf = CAMLThisName(list, tf, "Title");        StringBuilder titleQuery = new StringBuilder  ("<Where><Eq><FieldRef Name=");       titleQuery.Append(QT);       titleQuery.Append(tf);       titleQuery.Append(QT);       titleQuery.Append("/><Value Type=");       titleQuery.Append(QT);       titleQuery.Append("Text");       titleQuery.Append(QT);       titleQuery.Append(">");       titleQuery.Append(title);       titleQuery.Append("</Value></Eq></Where>");       query.Query = titleQuery.ToString();     }     if (columnNames.Length != 0)     {       StringBuilder sb = new StringBuilder("");       bool TitleAlreadyIncluded = false;       foreach (string columnName in columnNames)       {         string tst = CAMLThisName(list, columnName, "Title");         //Allow Title only once         if (tst != "Title" || !TitleAlreadyIncluded)         {           sb.Append("<FieldRef Name=");           sb.Append(QT);           sb.Append(tst);           sb.Append(QT);           sb.Append("/>");           if (tst == "Title") TitleAlreadyIncluded = true;         }       }       query.ViewFields = sb.ToString();     }     if (rowLimit > 0)     {        query.RowLimit = rowLimit;     }     SPListItemCollection col = list.GetItems(query);     return col;   }   catch (Exception ex)   {     //Console.WriteLine("GetListItemColumnByTitle" + ex.ToString());     //sw.WriteLine("GetListItemColumnByTitle" + ex.ToString());     return null;   } } Here I called it for a list in which “Author” (it is the internal name for “Created”) and “Blah” do not exist. The list of column names is:  string[] columnNames = {"Test Column1", "Title", "Author", "Allow Multiple Ratings", "Blah"};  So if I use this call, I get all the items for which “01-STD MIL_some” has the value of 1. the fields returned are: “Test Column1”, “Title”, and “Allow Multiple Ratings”. Because “Title” was already included and the default for non exixsting is “Title”, it was not replicated for the 2 non-existing fields.  SPListItemCollection col = GetListItemColumnByTitle(masterList, "01-STD MIL_some", "1", columnNames, 0); The following call checks if there are any items where “01-STD MIL_some” has the value of “1”. Note that I limited the number of returned items to 1.  SPListItemCollection col = GetListItemColumnByTitle(masterList, "01-STD MIL_some", "1", columnNames, 1); The code also uses the CAMLThisName function that checks for an existence of a field and returns its InternalName. This is yet another useful function that I use again and again.  /// <summary> /// return a fields internal name (CAMLName)  /// or the "default" name that you passed. /// To check existence pass "" or some funny name like "mud in your eye" /// </summary> public static string CAMLThisName(SPList list, string name, string def) {   String CAMLName = def;   SPField fld = GetFieldByName(list, name);   if (fld != null)   {      CAMLName = fld.InternalName;   }   return CAMLName; } That’s all folks?!

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  • Namespaces are obsolete

    - by Bertrand Le Roy
    To those of us who have been around for a while, namespaces have been part of the landscape. One could even say that they have been defining the large-scale features of the landscape in question. However, something happened fairly recently that I think makes this venerable structure obsolete. Before I explain this development and why it’s a superior concept to namespaces, let me recapitulate what namespaces are and why they’ve been so good to us over the years… Namespaces are used for a few different things: Scope: a namespace delimits the portion of code where a name (for a class, sub-namespace, etc.) has the specified meaning. Namespaces are usually the highest-level scoping structures in a software package. Collision prevention: name collisions are a universal problem. Some systems, such as jQuery, wave it away, but the problem remains. Namespaces provide a reasonable approach to global uniqueness (and in some implementations such as XML, enforce it). In .NET, there are ways to relocate a namespace to avoid those rare collision cases. Hierarchy: programmers like neat little boxes, and especially boxes within boxes within boxes. For some reason. Regular human beings on the other hand, tend to think linearly, which is why the Windows explorer for example has tried in a few different ways to flatten the file system hierarchy for the user. 1 is clearly useful because we need to protect our code from bleeding effects from the rest of the application (and vice versa). A language with only global constructs may be what some of us started programming on, but it’s not desirable in any way today. 2 may not be always reasonably worth the trouble (jQuery is doing fine with its global plug-in namespace), but we still need it in many cases. One should note however that globally unique names are not the only possible implementation. In fact, they are a rather extreme solution. What we really care about is collision prevention within our application. What happens outside is irrelevant. 3 is, more than anything, an aesthetical choice. A common convention has been to encode the whole pedigree of the code into the namespace. Come to think about it, we never think we need to import “Microsoft.SqlServer.Management.Smo.Agent” and that would be very hard to remember. What we want to do is bring nHibernate into our app. And this is precisely what you’ll do with modern package managers and module loaders. I want to take the specific example of RequireJS, which is commonly used with Node. Here is how you import a module with RequireJS: var http = require("http"); .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 is of course importing a HTTP stack module into the code. There is no noise here. Let’s break this down. Scope (1) is provided by the one scoping mechanism in JavaScript: the closure surrounding the module’s code. Whatever scoping mechanism is provided by the language would be fine here. Collision prevention (2) is very elegantly handled. Whereas relocating is an afterthought, and an exceptional measure with namespaces, it is here on the frontline. You always relocate, using an extremely familiar pattern: variable assignment. We are very much used to managing our local variable names and any possible collision will get solved very easily by picking a different name. Wait a minute, I hear some of you say. This is only taking care of collisions on the client-side, on the left of that assignment. What if I have two libraries with the name “http”? Well, You can better qualify the path to the module, which is what the require parameter really is. As for hierarchical organization, you don’t really want that, do you? RequireJS’ module pattern does elegantly cover the bases that namespaces used to cover, but it also promotes additional good practices. First, it promotes usage of self-contained, single responsibility units of code through the closure-based, stricter scoping mechanism. Namespaces are somewhat more porous, as using/import statements can be used bi-directionally, which leads us to my second point… Sane dependency graphs are easier to achieve and sustain with such a structure. With namespaces, it is easy to construct dependency cycles (that’s bad, mmkay?). With this pattern, the equivalent would be to build mega-components, which are an easier problem to spot than a decay into inter-dependent namespaces, for which you need specialized tools. I really like this pattern very much, and I would like to see more environments implement it. One could argue that dependency injection has some commonalities with this for example. What do you think? This is the half-baked result of some morning shower reflections, and I’d love to read your thoughts about it. What am I missing?

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  • Upgrading to Code Based Migrations EF 4.3.1 with Connector/Net 6.6

    - by GABMARTINEZ
    Entity Framework 4.3.1 includes a new feature called code first migrations.  We are adding support for this feature in our upcoming 6.6 release of Connector/Net.  In this walk-through we'll see the workflow of code-based migrations when you have an existing application and you would like to upgrade to this EF 4.3.1 version and use this approach, so you can keep track of the changes that you do to your database.   The first thing we need to do is add the new Entity Framework 4.3.1 package to our application. This should via the NuGet package manager.  You can read more about why EF is not part of the .NET framework here. Adding EF 4.3.1 to our existing application  Inside VS 2010 go to Tools -> Library Package Manager -> Package Manager Console, this will open the Power Shell Host Window where we can work with all the EF commands. In order to install this library to your existing application you should type Install-Package EntityFramework This will make some changes to your application. So Let's check them. In your .config file you'll see a  <configSections> which contains the version you have from EntityFramework and also was added the <entityFramework> section as shown below. This section is by default configured to use SQL Express which won't be necesary for this case. So you can comment it out or leave it empty. Also please make sure you're using the Connector/Net 6.6.x version which is the one that has this support as is shown in the previous image. At this point we face one issue; in order to be able to work with Migrations we need the __MigrationHistory table that we don't have yet since our Database was created with an older version. This table is used to keep track of the changes in our model. So we need to get it in our existing Database. Getting a Migration-History table into an existing database First thing we need to do to enable migrations in our existing application is to create our configuration class which will set up the MySqlClient Provider as our SQL Generator. So we have to add it with the following code: using System.Data.Entity.Migrations;     //add this at the top of your cs file public class Configuration : DbMigrationsConfiguration<NameOfYourDbContext>  //Make sure to use the name of your existing DBContext { public Configuration() { this.AutomaticMigrationsEnabled = false; //Set Automatic migrations to false since we'll be applying the migrations manually for this case. SetSqlGenerator("MySql.Data.MySqlClient", new MySql.Data.Entity.MySqlMigrationSqlGenerator());     }   }  This code will set up our configuration that we'll be using when executing all the migrations for our application. Once we have done this we can Build our application so we can check that everything is fine. Creating our Initial Migration Now let's add our Initial Migration. In Package Manager Console, execute "add-migration InitialCreate", you can use any other name but I like to set this as our initial create for future reference. After we run this command, some changes were done in our application: A new Migrations Folder was created. A new class migration call InitialCreate which in most of the cases should have empty Up and Down methods as long as your database is up to date with your Model. Since all your entities already exists, delete all duplicated code to create any entity which exists already in your Database if there is any. I found this easier when you don't have any pending updates to do to your database. Now we have our empty migration that will make no changes in our database and represents how are all the things at the begining of our migrations.  Finally, let's create our MigrationsHistory table. Optionally you can add SQL code to delete the edmdata table which is not needed anymore. public override void Up() { // Just make sure that you used 4.1 or later version         Sql("DROP TABLE EdmMetadata"); } From our Package Manager Console let's type: Update-database; If you like to see the operations made on each Update-database command you can use the flag -verbose after the Update-database. This will make two important changes.  It will execute the Up method in the initial migration which has no changes in the database. And second, and very important,  it will create the __MigrationHistory table necessary to keep track of your changes. And next time you make a change to your database it will compare the current model to the one stored in the Model Column of this table. Conclusion The important thing of this walk through is that we must create our initial migration before we start doing any changes to our model. This way we'll be adding the necessary __MigrationsHistory table to our existing database, so we can keep our database up to date with all the changes we do in our context model using migrations. Hope you have found this information useful. Please let us know if you have any questions or comments, also please check our forums here where we keep answering questions in general for the community.  Happy MySQL/Net Coding!

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  • NDepend Evaluation: Part 3

    - by Anthony Trudeau
    NDepend is a Visual Studio add-in designed for intense code analysis with the goal of high code quality. NDepend uses a number of metrics and aggregates the data in pleasing static and active visual reports. My evaluation of NDepend will be broken up into several different parts. In the first part of the evaluation I looked at installing the add-in.  And in the last part I went over my first impressions including an overview of the features.  In this installment I provide a little more detail on a few of the features that I really like. Dependency Matrix The dependency matrix is one of the rich visual components provided with NDepend.  At a glance it lets you know where you have coupling problems including cycles.  It does this with number indicating the weight of the dependency and a color-coding that indicates the nature of the dependency. Green and blue cells are direct dependencies (with the difference being whether the relationship is from row-to-column or column-to-row).  Black cells are the ones that you really want to know about.  These indicate that you have a cycle.  That is, type A refers to type B and type B also refers to Type A. But, that’s not the end of the story.  A handy pop-up appears when you hover over the cell in question.  It explains the color, the dependency, and provides several interesting links that will teach you more than you want to know about the dependency. You can double-click the problem cells to explode the dependency.  That will show the dependencies on a method-by-method basis allowing you to more easily target and fix the problem.  When you’re done you can click the back button on the toolbar. Dependency Graph The dependency graph is another component provided.  It’s complementary to the dependency matrix, but it isn’t as easy to identify dependency issues using the window. On a positive note, it does provide more information than the matrix. My biggest issue with the dependency graph is determining what is shown.  This was not readily obvious.  I ended up using the navigation buttons to get an acceptable view.  I would have liked to choose what I see. Once you see the types you want you can get a decent idea of coupling strength based on the width of the dependency lines.  Double-arrowed lines are problematic and are shown in red.  The size of the boxes will be related to the metric being displayed.  This is controlled using the Box Size drop-down in the toolbar.  Personally, I don’t find the size of the box to be helpful, so I change it to Constant Font. One nice thing about the display is that you can see the entire path of dependencies when you hover over a type.  This is done by color-coding the dependencies and dependants.  It would be nice if selecting the box for the type would lock the highlighting in place. I did find a perhaps unintended work-around to the color-coding.  You can lock the color-coding in by hovering over the type, right-clicking, and then clicking on the canvas area to clear the pop-up menu.  You can then do whatever with it including saving it to an image file with the color-coding. CQL NDepend uses a code query language (CQL) to work with your code just like it was a database.  CQL cannot be confused with the robustness of T-SQL or even LINQ, but it represents an impressive attempt at providing an expressive way to enumerate and interrogate your code. There are two main windows you’ll use when working with CQL.  The CQL Query Explorer allows you to define what queries (rules) are run as part of a report – I immediately unselected rules that I don’t want in my results.  The CQL Query Edit window is where you can view or author your own rules.  The explorer window is pretty self-explanatory, so I won’t mention it further other than to say that any queries you author will appear in the custom group. Authoring your own queries is really hard to screw-up.  The Intellisense-like pop-ups tell you what you can do while making composition easy.  I was able to create a query within two minutes of playing with the editor.  My query warns if any types that are interfaces don’t start with an “I”. WARN IF Count > 0 IN SELECT TYPES WHERE IsInterface AND !NameLike “I” The results from the CQL Query Edit window are immediate. That fact makes it useful for ad hoc querying.  It’s worth mentioning two things that could make the experience smoother.  First, out of habit from using Visual Studio I expect to be able to scroll and press Tab to select an item in the list (like Intellisense).  You have to press Enter when you scroll to the item you want.  Second, the commands are case-sensitive.  I don’t see a really good reason to enforce that. CQL has a lot of potential not just in enforcing code quality, but also enforcing architectural constraints that your enterprise has defined. Up Next My next update will be the final part of the evaluation.  I will summarize my experience and provide my conclusions on the NDepend add-in. ** View Part 1 of the Evaluation ** ** View Part 2 of the Evaluation ** Disclaimer: Patrick Smacchia contacted me about reviewing NDepend. I received a free license in return for sharing my experiences and talking about the capabilities of the add-in on this site. There is no expectation of a positive review elicited from the author of NDepend.

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