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• Grub2 : Windows 7 can't boot installing with Ubuntu 10.04 on different hard drive

  - by dellphi

  I use a dual boot with two hard disks and two OS is Ubuntu 10.04 and Windows 7. Windows 7 installed on the first disk, first partition. Grub is installed on a second hard disk MBR, and Ubuntu installed on an extended partition on a second hard drive. When I select Windows 7 on the Grub menu, the HDD lamp lights up briefly and then black screen on the monitor, with the status of the keyboard is still functioning. Until now (with the default boot from first HDD), I have to press F12 to get into the Grub to run Linux on a second HDD. ================ fdisk -l ================================ dellph1@dellph1-desktop:~$ fdisk -l omitting empty partition (5) Disk /dev/sda: 1000.2 GB, 1000204886016 bytes 255 heads, 63 sectors/track, 121601 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00087dec Device Boot Start End Blocks Id System /dev/sda1 * 1 23104 185582848+ 7 HPFS/NTFS /dev/sda2 23105 121601 791177122 5 Extended /dev/sda5 36107 74408 307660783+ 7 HPFS/NTFS /dev/sda6 74409 100081 206218341 7 HPFS/NTFS /dev/sda7 100082 121601 172859368+ 7 HPFS/NTFS Disk /dev/sdb: 160.0 GB, 160041885696 bytes 255 heads, 63 sectors/track, 19457 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x6d43dfb2 Device Boot Start End Blocks Id System /dev/sdb1 1 10030 80560066 5 Extended /dev/sdb5 * 1 5560 44657601 83 Linux /dev/sdb6 5560 9387 30736384 83 Linux /dev/sdb7 9387 10030 5164032 82 Linux swap / Solaris dellph1@dellph1-desktop:~$ ================= grub.cfg ================== # DO NOT EDIT THIS FILE # It is automatically generated by /usr/sbin/grub-mkconfig using templates from /etc/grub.d and settings from /etc/default/grub # BEGIN /etc/grub.d/00_header if [ -s $prefix/grubenv ]; then load_env fi set default="0" if [ ${prev_saved_entry} ]; then set saved_entry=${prev_saved_entry} save_env saved_entry set prev_saved_entry= save_env prev_saved_entry set boot_once=true fi function savedefault { if [ -z ${boot_once} ]; then saved_entry=${chosen} save_env saved_entry fi } function recordfail { set recordfail=1 if [ -n ${have_grubenv} ]; then if [ -z ${boot_once} ]; then save_env recordfail; fi; fi } insmod ext2 set root='(hd1,5)' search --no-floppy --fs-uuid --set 2f014a3a-35f3-4d05-87aa-34ca677160b7 if loadfont /usr/share/grub/unicode.pf2 ; then set gfxmode=1024x768 insmod gfxterm insmod vbe if terminal_output gfxterm ; then true ; else # For backward compatibility with versions of terminal.mod that don't # understand terminal_output terminal gfxterm fi fi insmod ext2 set root='(hd1,5)' search --no-floppy --fs-uuid --set 2f014a3a-35f3-4d05-87aa-34ca677160b7 set locale_dir=($root)/boot/grub/locale set lang=en insmod gettext if [ ${recordfail} = 1 ]; then set timeout=-1 else set timeout=5 fi END /etc/grub.d/00_header BEGIN /etc/grub.d/05_debian_theme insmod ext2 set root='(hd1,5)' search --no-floppy --fs-uuid --set 2f014a3a-35f3-4d05-87aa-34ca677160b7 insmod jpeg if background_image /usr/share/backgrounds/CurlsbyCandy.jpg ; then set color_normal=white/black set color_highlight=black/light-gray else set menu_color_normal=white/black set menu_color_highlight=black/light-gray fi END /etc/grub.d/05_debian_theme BEGIN /etc/grub.d/10_linux menuentry 'Ubuntu, with Linux 2.6.32-24-generic' --class ubuntu --class gnu-linux --class gnu --class os { recordfail insmod ext2 set root='(hd1,5)' search --no-floppy --fs-uuid --set 2f014a3a-35f3-4d05-87aa-34ca677160b7 linux /boot/vmlinuz-2.6.32-24-generic root=UUID=2f014a3a-35f3-4d05-87aa-34ca677160b7 ro splash vga=795 quiet splash nomodeset video=uvesafb:mode_option=1280x1024-24,mtrr=3,scroll=ywrap initrd /boot/initrd.img-2.6.32-24-generic } menuentry 'Ubuntu, with Linux 2.6.32-24-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os { recordfail insmod ext2 set root='(hd1,5)' search --no-floppy --fs-uuid --set 2f014a3a-35f3-4d05-87aa-34ca677160b7 echo 'Loading Linux 2.6.32-24-generic ...' linux /boot/vmlinuz-2.6.32-24-generic root=UUID=2f014a3a-35f3-4d05-87aa-34ca677160b7 ro single splash vga=795 echo 'Loading initial ramdisk ...' initrd /boot/initrd.img-2.6.32-24-generic } END /etc/grub.d/10_linux BEGIN /etc/grub.d/30_os-prober menuentry "Windows 7 (loader) (on /dev/sda1)" { insmod ntfs set root='(hd0,1)' search --no-floppy --fs-uuid --set 5cac2139ac210f58 chainloader +1 } END /etc/grub.d/30_os-prober BEGIN /etc/grub.d/40_multisystem Ajout de MultiSystem MULTISYSTEM MENU menuentry "PLoP Boot Manager" { linux16 /boot/plpbt } menuentry "Smart Boot Manager" { search --set -f /boot/sbootmgr.dsk linux16 /boot/memdisk initrd16 /boot/sbootmgr.dsk } FIN MULTISYSTEM MENU END /etc/grub.d/40_multisystem ================================================ I want to keep the Grub on the second HDD. I have been using the Startup Manager, Boot Manager and Grub Customizer, and this problem still unsolved. The easiest thing that I can possibly do is to install Grub on first HDD, but I was curious and maybe someone can help.

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• Get Fanatical About Your Followers

  - by Mike Stiles

  In the fourth of our series of discussions with Aberdeen’s Trip Kucera, we touch on what fans of your brand have come to expect in exchange for their fandom. Spotlight: Around the Oracle Social office, we live for football. So when we think of a true “fan” of a brand, something on the level of a football fan is what comes to mind. But are brands trying to invest fans on that same level? Trip: Yeah, if you’re a football fan, this is definitely your time of year. And if you’ve been to any NFL games recently, especially if you hadn’t been for a few years previously, you may have noticed that from the cup holders to in-stadium Wi-Fi, there’s an increasing emphasis being placed on “fan-focused” accommodations. That’s what they’re known as in the stadium business. Spotlight: How are brands doing in that fan-focused arena? Trip: Remember fan is short for “fanatical.” Brands can definitely learn from the way teams have become fanatical about their fans, or in the social media world, their followers. Many companies consider a segment of their addressable social audience as true fans; I’ve even heard the term “super-fans” used. So just as fans know and can tell you nearly everything about their favorite team, our research shows that there’s a lot value from getting to know your social audience—your followers—at a deeper level. Spotlight: So did your research show there’s a lot to be gained by making fandom a two-way street? Trip: Aberdeen’s new social relationship management research suggests that companies should develop capabilities to better analyze their social audience at a more granular level. Countless “ripped from the headlines” examples, from “United Breaks Guitars” to the most recent British Airways social fiasco we talked about a few weeks ago show how social can magnify the impact of a single customer voice. Spotlight: So how do the companies who are executing social most successfully do that? Trip: Leaders, which are the top-performing companies in Aberdeen’s study, are showing the value of identifying and categorizing your social audience. You should certainly treat every customer as if they have 10,000 followers, because they just might, but you can also proactively engage with high-value customer and high-value influencers. Getting back to the football analogy, it’s like how teams strive to give every guest a great experience, but they really roll out the red carpet for those season ticket and luxury box holders. Spotlight: I’m not allowed in luxury boxes, so you’ll have to tell me what that’s like. But what is the brand equivalent of rolling out the red carpet? Trip: Leaders are nearly three times more likely than Followers to have a process in place that identifies key social influencers for engagement, and more than twice as likely to identify customer advocates for social outreach. This is the kind of knowledge that gives companies the ability to better target social messaging and promotions like we talked about in our last discussion, as well as a basis for understanding how to measure the impact of their social media programs. I’ll give you an example. I hosted an event at one of my favorite restaurants recently. I had mentioned them in a Tweet several weeks before the event, and on the day of the event, they Tweeted out that they were looking forward to seeing me that evening for the event. It’s a small thing, but it had a big impact and I’d certainly go back as a result. Spotlight: So what specifically can brands use and look at to determine where their potential super-fans are? Trip: Social graph analysis, which looks at both the demographic/psychographic trends as well as the behavioral connections, can surface important brand value. Aberdeen’s PR and Brand Management research indicated that top-performing companies are more than three times more likely than Followers to both determine demographic trends through social listening (44% vs. 13%), and to identify meaningful customer segments through social (44% vs. 12%). This kind of brand-level insight can complement and enrich traditional market research. But perhaps even more importantly, it can serve as an early warning system for customer experience failures. @mikestilesPhoto: freedigitalphotos.net

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• Running Powershell from within SharePoint

  - by Norgean

  Just because something is a daft idea, doesn't mean it can't be done. We sometimes need to do some housekeeping - like delete old files or list items or… yes, well, whatever you use Powershell for in a SharePoint world. Or it could be that your solution has "issues" for which you have Powershell solutions, but not the budget to transform into proper bug fixes. So you create a "how to" for the ITPro guys. Idea: What if we keep the scripts in a list, and have SharePoint execute the scripts on demand? An announcements list (because of the multiline body field). Warning! Let us be clear. This list needs to be locked down; if somebody creates a malicious script and you run it, I cannot help you. First; we need to figure out how to start Powershell scripts from C#. Hit teh interwebs and the Googlie, and you may find jpmik's post: http://www.codeproject.com/Articles/18229/How-to-run-PowerShell-scripts-from-C. (Or MS' official answer at http://msdn.microsoft.com/en-us/library/ee706563(v=vs.85).aspx) public string RunPowershell(string powershellText, SPWeb web, string param1, string param2) { // Powershell ~= RunspaceFactory - i.e. Create a powershell context var runspace = RunspaceFactory.CreateRunspace(); var resultString = new StringBuilder(); try { // load the SharePoint snapin - Note: you cannot do this in the script itself (i.e. add-pssnapin etc does not work) PSSnapInException snapInError; runspace.RunspaceConfiguration.AddPSSnapIn("Microsoft.SharePoint.PowerShell", out snapInError); runspace.Open(); // set a web variable. runspace.SessionStateProxy.SetVariable("webContext", web); // and some user defined parameters runspace.SessionStateProxy.SetVariable("param1", param1); runspace.SessionStateProxy.SetVariable("param2", param2); var pipeline = runspace.CreatePipeline(); pipeline.Commands.AddScript(powershellText); // add a "return" variable pipeline.Commands.Add("Out-String"); // execute! var results = pipeline.Invoke(); // convert the script result into a single string foreach (PSObject obj in results) { resultString.AppendLine(obj.ToString()); } } finally { // close the runspace runspace.Close(); } // consider logging the result. Or something. return resultString.ToString(); } Ok. We've written some code. Let us test it. var runner = new PowershellRunner(); runner.RunPowershellScript(@" $web = Get-SPWeb 'http://server/web' # or $webContext $web.Title = $param1 $web.Update() $web.Dispose() ", null, "New title", "not used"); Next step: Connect the code to the list, or more specifically, have the code execute on one (or several) list items. As there are more options than readers, I'll leave this as an exercise for the reader. Some alternatives: Create a ribbon button that calls RunPowershell with the body of the selected itemsAdd a layout pageSpecify list item from query string (possibly coupled with content editor webpart with html that links directly to this page with querystring)WebpartListing with an "execute" columnList with multiselect and an execute button Etc!Now that you have the code for executing powershell scripts, you can easily expand this into a timer job, which executes scripts at regular intervals. But if the previous solution was dangerous, this is even worse - the scripts will usually be run with one of the admin accounts, and can do pretty much anything...One more thing... Note that as this is running "consoleless" calls to Write-Host will fail. Two solutions; remove all output, or check if the script is run in a console-window or not.  if ($host.Name -eq "ConsoleHost") { Write-Host 'If I agreed with you we'd both be wrong' }

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• Strings in .NET are Enumerable

  - by Scott Dorman

  It seems like there is always some confusion concerning strings in .NET. This is both from developers who are new to the Framework and those that have been working with it for quite some time. Strings in the .NET Framework are represented by the System.String class, which encapsulates the data manipulation, sorting, and searching methods you most commonly perform on string data. In the .NET Framework, you can use System.String (which is the actual type name or the language alias (for C#, string). They are equivalent so use whichever naming convention you prefer but be consistent. Common usage (and my preference) is to use the language alias (string) when referring to the data type and String (the actual type name) when accessing the static members of the class. Many mainstream programming languages (like C and C++) treat strings as a null terminated array of characters. The .NET Framework, however, treats strings as an immutable sequence of Unicode characters which cannot be modified after it has been created. Because strings are immutable, all operations which modify the string contents are actually creating new string instances and returning those. They never modify the original string data. There is one important word in the preceding paragraph which many people tend to miss: sequence. In .NET, strings are treated as a sequence…in fact, they are treated as an enumerable sequence. This can be verified if you look at the class declaration for System.String, as seen below: // Summary:// Represents text as a series of Unicode characters.public sealed class String : IEnumerable, IComparable, IComparable<string>, IEquatable<string> The first interface that String implements is IEnumerable, which has the following definition: // Summary:// Exposes the enumerator, which supports a simple iteration over a non-generic// collection.public interface IEnumerable{ // Summary: // Returns an enumerator that iterates through a collection. // // Returns: // An System.Collections.IEnumerator object that can be used to iterate through // the collection. IEnumerator GetEnumerator();} As a side note, System.Array also implements IEnumerable. Why is that important to know? Simply put, it means that any operation you can perform on an array can also be performed on a string. This allows you to write code such as the following: string s = "The quick brown fox";foreach (var c in s){ System.Diagnostics.Debug.WriteLine(c);}for (int i = 0; i < s.Length; i++){ System.Diagnostics.Debug.WriteLine(s[i]);} If you executed those lines of code in a running application, you would see the following output in the Visual Studio Output window: In the case of a string, these enumerable or array operations return a char (System.Char) rather than a string. That might lead you to believe that you can get around the string immutability restriction by simply treating strings as an array and assigning a new character to a specific index location inside the string, like this: string s = "The quick brown fox";s[2] = 'a';   However, if you were to write such code, the compiler will promptly tell you that you can’t do it: This preserves the notion that strings are immutable and cannot be changed once they are created. (Incidentally, there is no built in way to replace a single character like this. It can be done but it would require converting the string to a character array, changing the appropriate indexed location, and then creating a new string.)

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• Rotation of viewplatform in Java3D

  - by user29163

  I have just started with Java3D programming. I thought I had built up some basic intuition about how the scene graph works, but something that should work, does not work. I made a simple program for rotating a pyramid around the y-axis. This was done just by adding a RotationInterpolator R to the TransformGroup above the pyramid. Then I thought hey, can I now remove the RotationInterpolator from this TransformGroup, then add it to the TransformGroup above my ViewPlatform leaf. This should work if I have understood how things work. Adding the RotationInterpolator to this TransformGroup, should make the children of this TransformGroup rotate, and the ViewingPlatform is a child of the TransformGroup. Any ideas on where my reasoning is flawed? Here is the code for setting up the universe, and the view branchgroup. import java.awt.*; import java.awt.event.*; import javax.media.j3d.*; import javax.vecmath.*; public class UniverseBuilder { // User-specified canvas Canvas3D canvas; // Scene graph elements to which the user may want access VirtualUniverse universe; Locale locale; TransformGroup vpTrans; View view; public UniverseBuilder(Canvas3D c) { this.canvas = c; // Establish a virtual universe that has a single // hi-res Locale universe = new VirtualUniverse(); locale = new Locale(universe); // Create a PhysicalBody and PhysicalEnvironment object PhysicalBody body = new PhysicalBody(); PhysicalEnvironment environment = new PhysicalEnvironment(); // Create a View and attach the Canvas3D and the physical // body and environment to the view. view = new View(); view.addCanvas3D(c); view.setPhysicalBody(body); view.setPhysicalEnvironment(environment); // Create a BranchGroup node for the view platform BranchGroup vpRoot = new BranchGroup(); // Create a ViewPlatform object, and its associated // TransformGroup object, and attach it to the root of the // subgraph. Attach the view to the view platform. Transform3D t = new Transform3D(); Transform3D s = new Transform3D(); t.set(new Vector3f(0.0f, 0.0f, 10.0f)); t.rotX(-Math.PI/4); s.set(new Vector3f(0.0f, 0.0f, 10.0f)); //forandre verdier her for å endre viewing position t.mul(s); ViewPlatform vp = new ViewPlatform(); vpTrans = new TransformGroup(t); vpTrans.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE); // Rotator stuff Transform3D yAxis = new Transform3D(); //yAxis.rotY(Math.PI/2); Alpha rotationAlpha = new Alpha( -1, Alpha.INCREASING_ENABLE, 0, 0,4000, 0, 0, 0, 0, 0); RotationInterpolator rotator = new RotationInterpolator( rotationAlpha, vpTrans, yAxis, 0.0f, (float) Math.PI*2.0f); RotationInterpolator rotator2 = new RotationInterpolator( rotationAlpha, vpTrans); BoundingSphere bounds = new BoundingSphere(new Point3d(0.0,0.0,0.0), 1000.0); rotator.setSchedulingBounds(bounds); vpTrans.addChild(rotator); vpTrans.addChild(vp); vpRoot.addChild(vpTrans); view.attachViewPlatform(vp); // Attach the branch graph to the universe, via the // Locale. The scene graph is now live! locale.addBranchGraph(vpRoot); } public void addBranchGraph(BranchGroup bg) { locale.addBranchGraph(bg); } }

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• Dont Throw Duplicate Exceptions

  In your code, youll sometimes have write code that validates input using a variety of checks.  Assuming you havent embraced AOP and done everything with attributes, its likely that your defensive coding is going to look something like this: public void Foo(SomeClass someArgument) { if(someArgument == null) { throw new InvalidArgumentException("someArgument"); } if(!someArgument.IsValid()) { throw new InvalidArgumentException("someArgument"); }   // Do Real Work } Do you see a problem here?  Heres the deal Exceptions should be meaningful.  They have value at a number of levels: In the code, throwing an exception lets the develop know that there is an unsupported condition here In calling code, different types of exceptions may be handled differently At runtime, logging of exceptions provides a valuable diagnostic tool Its this last reason I want to focus on.  If you find yourself literally throwing the exact exception in more than one location within a given method, stop.  The stack trace for such an exception is likely going to be identical regardless of which path of execution led to the exception being thrown.  When that happens, you or whomever is debugging the problem will have to guess which exception was thrown.  Guessing is a great way to introduce additional problems and/or greatly increase the amount of time require to properly diagnose and correct any bugs related to this behavior. Dont Guess Be Specific When throwing an exception from multiple code paths within the code, be specific.  Virtually ever exception allows a custom message use it and ensure each case is unique.  If the exception might be handled differently by the caller, than consider implementing a new custom exception type.  Also, dont automatically think that you can improve the code by collapsing the if-then logic into a single call with short-circuiting (e.g. if(x == null || !x.IsValid()) ) that will guarantee that you cant easily throw different information into the message as easily as constructing the exception separately in each case. The code above might be refactored like so:   public void Foo(SomeClass someArgument) { if(someArgument == null) { throw new ArgumentNullException("someArgument"); } if(!someArgument.IsValid()) { throw new InvalidArgumentException("someArgument"); }   // Do Real Work } In this case its taking advantage of the fact that there is already an ArgumentNullException in the framework, but if you didnt have an IsValid() method and were doing validation on your own, it might look like this: public void Foo(SomeClass someArgument) { if(someArgument.Quantity < 0) { throw new InvalidArgumentException("someArgument", "Quantity cannot be less than 0. Quantity: " + someArgument.Quantity); } if(someArgument.Quantity > 100) { throw new InvalidArgumentException("someArgument", "SomeArgument.Quantity cannot exceed 100. Quantity: " + someArgument.Quantity); }   // Do Real Work }   Note that in this last example, Im throwing the same exception type in each case, but with different Message values.  Im also making sure to include the value that resulted in the exception, as this can be extremely useful for debugging.  (How many times have you wished NullReferenceException would tell you the name of the variable it was trying to reference?) Dont add work to those who will follow after you to maintain your application (especially since its likely to be you).  Be specific with your exception messages follow DRY when throwing exceptions within a given method by throwing unique exceptions for each interesting case of invalid state. Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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• Best triple head display setup

  - by dgel

  I'm currently running Ubuntu 12.04 with a darn good triple head display setup. I've got a VisionTek 900530 Radeon HD 5450 512MB DDR3 PCI Express video card that has two DVI outputs and one Mini DisplayPort that I have connected to a HDMI adapter. I'm running three identical Asus 1920x1080 monitors that each have a DVI, VGA, and HDMI input. I'm using the xorg-edgers ppa, so I'm using the open source radeon driver version 6.99.99. I tried using the ATI binary fglrx driver, but I wasn't able to get the three monitors working properly- the monitor connected via HDMI / DisplayPort wouldn't run at full resolution. The setup is almost perfect: Compiz runs fine and is quite snappy. I'm not able to use that great compiz feature where you can drag a window to the side of a display and it will half maximize. I occasionally experience display corruption weirdness with Unity and need to restart it. When I use a dropdown menu in LibreOffice it often pops the menu down in another window. For example, if I'm using the center monitor and click the Insert menu, the menu pulls down on the monitor to my right, forcing me to chase it. If I chase down the menu and choose Manual Break, the dialog appears over on my left monitor. This absurdity is mildly entertaining but has lost its novelty. I've decided to build a new system and have spared no expense- latest i7 processor, SSD, etc. I really like the performance of the Nvidia binary drivers, so I put two ZOTAC ZT-40707-10L GeForce GT 440 in the system, figuring I'd have four DVI outputs and an awesome triple (or even eventually quad) head setup. Unfortunately it appears that I didn't do sufficient research before my purchase. It seems that Nvidia TwinView only supports two monitors on one card (I guess that's why they call it TwinView...). I messed around with running two X servers, but I really don't want that- being able to drag windows to any monitor is critical. It doesn't sound like Xinerama is an option because from what I understand it simply doesn't support Compiz. I've seen a BaseMosaic option that can be used with the Nvidia drivers that appears to support an almost unlimited number of heads- unfortunately me cheap little cards don't support it. I'm also not sure whether you'll still have all nice maximizing and snapping that TwinView provides, or whether Ubuntu will only see it as one massive display. I put my old trusty ATI card into my new system and installed 12.10. I'm using the opensource radeon drivers again because even in 12.10 I can't get the fglrx binary drivers to do triple head. Unfortunately, even with an unbelievably powerful system the experience is extremely sluggish (much more so than my experience in 12.04). The menu scattering problem appears to be fixed, but I get a lot of nasty Unity display corruption. So finally, my question is this: What hardware / drivers should I use? I'm willing to buy (almost) any video card(s). I have two PCI-Express 3.0 slots on my motherboard (which has an integrated Intel HD card). I'm willing to use ATI or Nvidia cards and willing to run Ubuntu 12.04.1 or 12.10. I'm not a gamer, but do want beautiful and snappy Compiz effects. Does anyone out there have the perfect triple head setup in 12.04 or 12.10? What hardware / drivers are you using? I have those two Nvidia cards but will probably be returning them unless someone knows a way to use them together for a triple head setup. Since I'm having pretty good luck with a single ATI card providing three displays, should I just buy a beefier one with the hopes that it will fix the horrible sluggishness I'm experiencing in 12.10?

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• E-Business Suite : Role of CHUNK_SIZE in Oracle Payroll

  - by Giri Mandalika

  Different batch processes in Oracle Payroll flow have the ability to spawn multiple child processes (or threads) to complete the work in hand. The number of child processes to fork is controlled by the THREADS parameter in APPS.PAY_ACTION_PARAMETERS view. THREADS parameter The default value for THREADS parameter is 1, which is fine for a single-processor system but not optimal for the modern multi-core multi-processor systems. Setting the THREADS parameter to a value equal to or less than the total number of [virtual] processors available on the system may improve the performance of payroll processing. However on the down side, since multiple child processes operate against the same set of payroll tables in HR schema, database may experience undesired consequences such as buffer busy waits and index contention, which results in giving up some of the gains achieved by using multiple child processes/threads to process the work. Couple of other action parameters, CHUNK_SIZE and CHUNK_SHUFFLE, help alleviate the database contention. eg., Set a value for THREADS parameter as shown below. CONNECT APPS/APPS_PASSWORD UPDATE PAY_ACTION_PARAMETERS SET PARAMETER_VALUE = DESIRED_VALUE WHERE PARAMETER_NAME = 'THREADS'; COMMIT; (I am not aware of any maximum value for THREADS parameter) CHUNK_SIZE parameter The size of each commit unit for the batch process is controlled by the CHUNK_SIZE action parameter. In other words, chunking is the act of splitting the assignment actions into commit groups of desired size represented by the CHUNK_SIZE parameter. The default value is 20, and each thread processes one chunk at a time -- which means each child process inserts or processes 20 assignment actions at any time. When multiple threads are configured, each thread picks up a chunk to process, completes the assignment actions and then picks up another chunk. This is repeated until all the chunks are exhausted. It is possible to use different chunk sizes in different batch processes. During the initial phase of processing, CHUNK_SIZE number of assignment actions are inserted into relevant table(s). When multiple child processes are inserting data at the same time into the same set of tables, as explained earlier, database may experience contention. The default value of 20 is mostly optimal in such a case. Experiment with different values for the initial phase by +/-10 for CHUNK_SIZE parameter and observe the performance impact. A larger value may make sense during the main processing phase. Again experimentation is the key in finding the suitable value for your environment. Start with a large value such as 2000 for the chunk size, then increment or decrement the size by 500 at a time until an optimal value is found. eg., Set a value for CHUNK_SIZE parameter as shown below. CONNECT APPS/APPS_PASSWORD UPDATE PAY_ACTION_PARAMETERS SET PARAMETER_VALUE = DESIRED_VALUE WHERE PARAMETER_NAME = 'CHUNK_SIZE'; COMMIT; CHUNK_SIZE action parameter accepts a value that is as low as 1 or as high as 16000. CHUNK SHUFFLE parameter By default, chunks of assignment actions are processed sequentially by all threads - which may not be a good thing especially given that all child processes/threads performing similar actions against the same set of tables almost at the same time. By saying not a good thing, I mean to say that the default behavior leads to contention in the database (in data blocks, for example). It is possible to relieve some of that database contention by randomizing the processing order of chunks of assignment actions. This behavior is controlled by the CHUNK SHUFFLE action parameter. Chunk processing is not randomized unless explicitly configured. eg., Set chunk shuffling as shown below. CONNECT APPS/APPS_PASSWORD UPDATE PAY_ACTION_PARAMETERS SET PARAMETER_VALUE = 'Y' WHERE PARAMETER_NAME = 'CHUNK SHUFFLE'; COMMIT; Finally I recommend checking the following document out for additional details and additional pay action tunable parameters that may speed up the processing of Oracle Payroll.     My Oracle Support Doc ID: 226987.1 Oracle 11i & R12 Human Resources (HRMS) & Benefits (BEN) Tuning & System Health Checks Also experiment with different combinations of parameters and values until the right set of action parameters and values are found for your deployment.

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• What is a good design pattern / lib for iOS 5 to synchronize with a web service?

  - by Junto

  We are developing an iOS application that needs to synchronize with a remote server using web services. The existing web services have an "operations" style rather than REST (implemented in WCF but exposing JSON HTTP endpoints). We are unsure of how to structure the web services to best fit with iOS and would love some advice. We are also interested in how to manage the synchronization process within iOS. Without going into detailed specifics, the application allows the user to estimate repair costs at a remote site. These costs are broken down by room and item. If the user has an internet connection this data can be sent back to the server. Multiple photographs can be taken of each item, but they will be held in a separate queue, which sends when the connection is optimal (ideally wifi). Our backend application controls the unique ids for each room and item. Thus, each time we send these costs to the server, the server echoes the central database ids back, thus, that they can be synchronized in the mobile app. I have simplified this a little, since the operations contract is actually much larger, but I just want to illustrate the basic requirements without complicating matters. Firstly, the web service architecture: We currently have two operations: GetCosts and UpdateCosts. My assumption is that if we used a strict REST architecture we would need to break our single web service operations into multiple smaller services. This would make the services much more chatty and we would also have to guarantee a delivery order from the app. For example, we need to make sure that containing rooms are added before the item. Although this seems much more RESTful, our perception is that these extra calls are expensive connections (security checks, database calls, etc). Does the type of web api (operation over service focus) determine chunky vs chatty? Since this is mobile (3G), are we better handling lots of smaller messages, or a few large ones? Secondly, the iOS side. What is the current advice on how to manage data synchronization within the iOS (5) app itself. We need multiple queues and we need to guarantee delivery order in each queue (and technically, ordering between queues). The server needs to control unique ids and other properties and echo them back to the application. The application then needs to update an internal database and when re-updating, make sure the correct ids are available in the update message (essentially multiple inserts and updates in one call). Our backend has a ton of business logic operating on these cost estimates. We don't want any of this in the app itself. Currently the iOS app sends the cost data, and then the server echoes that data back with populated ids (and other data). The existing cost data is deleted and the echoed response data is added to the client database on the device. This is causing us problems, because any photos might not have been sent, but the original entity tree has been removed and replaced. Obviously updating the costs tree rather than replacing it would remove this problem, but I'm not sure if there are any nice xcode libraries out there to do such things. I welcome any advice you might have.

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• Omni-directional light shadow mapping with cubemaps in WebGL

  - by Winged

  First of all I must say, that I have read a lot of posts describing an usage of cubemaps, but I'm still confused about how to use them. My goal is to achieve a simple omni-directional (point) light type shading in my WebGL application. I know that there is a lot more techniques (like using Two-Hemispheres or Camera Space Shadow Mapping) which are way more efficient, but for an educational purpose cubemaps are my primary goal. Till now, I have adapted a simple shadow mapping which works with spotlights (with one exception: I don't know how to cut off the glitchy part beyond the reach of a single shadow map texture): glitchy shadow mapping<<< So for now, this is how I understand the usage of cubemaps in shadow mapping: Setup a framebuffer (in case of cubemaps - 6 framebuffers; 6 instead of 1 because every usage of framebufferTexture2D slows down an execution which is nicely described here <<<) and a texture cubemap. Also in WebGL depth components are not well supported, so I need to render it to RGBA first. this.texture = gl.createTexture(); gl.bindTexture(gl.TEXTURE_CUBE_MAP, this.texture); gl.texParameteri(gl.TEXTURE_CUBE_MAP, gl.TEXTURE_MIN_FILTER, gl.LINEAR); gl.texParameteri(gl.TEXTURE_CUBE_MAP, gl.TEXTURE_MAG_FILTER, gl.LINEAR); for (var face = 0; face < 6; face++) gl.texImage2D(gl.TEXTURE_CUBE_MAP_POSITIVE_X + face, 0, gl.RGBA, this.size, this.size, 0, gl.RGBA, gl.UNSIGNED_BYTE, null); gl.bindTexture(gl.TEXTURE_CUBE_MAP, null); this.framebuffer = []; for (face = 0; face < 6; face++) { this.framebuffer[face] = gl.createFramebuffer(); gl.bindFramebuffer(gl.FRAMEBUFFER, this.framebuffer[face]); gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_CUBE_MAP_POSITIVE_X + face, this.texture, 0); gl.framebufferRenderbuffer(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.RENDERBUFFER, this.depthbuffer); var e = gl.checkFramebufferStatus(gl.FRAMEBUFFER); // Check for errors if (e !== gl.FRAMEBUFFER_COMPLETE) throw "Cubemap framebuffer object is incomplete: " + e.toString(); } Setup the light and the camera (I'm not sure if should I store all of 6 view matrices and send them to shaders later, or is there a way to do it with just one view matrix). Render the scene 6 times from the light's position, each time in another direction (X, -X, Y, -Y, Z, -Z) for (var face = 0; face < 6; face++) { gl.bindFramebuffer(gl.FRAMEBUFFER, shadow.buffer.framebuffer[face]); gl.viewport(0, 0, shadow.buffer.size, shadow.buffer.size); gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT); camera.lookAt( light.position.add( cubeMapDirections[face] ) ); scene.draw(shadow.program); } In a second pass, calculate the projection a a current vertex using light's projection and view matrix. Now I don't know If should I calculate 6 of them, because of 6 faces of a cubemap. ScaleMatrix pushes the projected vertex into the 0.0 - 1.0 region. vDepthPosition = ScaleMatrix * uPMatrixFromLight * uVMatrixFromLight * vWorldVertex; In a fragment shader calculate the distance between the current vertex and the light position and check if it's deeper then the depth information read from earlier rendered shadow map. I know how to do it with a 2D Texture, but I have no idea how should I use cubemap texture here. I have read that texture lookups into cubemaps are performed by a normal vector instead of a UV coordinate. What vector should I use? Just a normalized vector pointing to the current vertex? For now, my code for this part looks like this (not working yet): float shadow = 1.0; vec3 depth = vDepthPosition.xyz / vDepthPosition.w; depth.z = length(vWorldVertex.xyz - uLightPosition) * linearDepthConstant; float shadowDepth = unpack(textureCube(uDepthMapSampler, vWorldVertex.xyz)); if (depth.z > shadowDepth) shadow = 0.5; Could you give me some hints or examples (preferably in WebGL code) how I should build it?

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• Web Services Example - Part 1: Declarative

  - by Denis T

  In this edition of the ADF Mobile blog we'll tackle part 1 of our Web Service examples. In this posting we'll take a look at using a declarative SOAP Web Service. Getting the sample code: Just click here to download a zip of the entire project. You can unzip it and load it into JDeveloper and deploy it either to iOS or Android. Please follow the previous blog posts if you need help getting JDeveloper or ADF Mobile installed. Defining our Web Service: First off, we should mention that this sample code is using a public web service provided free by CDYNE Corporation that provides weather forecasts by zipcode. Sometimes this service goes down so please ensure you know it's up before reporting this example isn't working. Let's take a look at the web service.  We created this by using the "Web Service Data Control" from the New Gallery and using this link to this wsdl:  "http://wsf.cdyne.com/WeatherWS/Weather.asmx?WSDL"   This web service has several methods but we're interested in GetCityForecastByZIP which takes a single string parameter for the zipcode and the second method, GetWeatherInformation that enumerates all possible forecast descriptions and associated image URLs.  The latter we'll use in the next edition but we included it here for completeness. Defing the Application: After adding a feature to the adfmf-feature.xml file, we added a taskflow to host the application flow.  This comprises of a home screen with a list with items for each method in the web service, "Forecast by Zip" and "Weather Info".  In this application we've also decided to hide the navigation bar since there is only one feature in the application. Forecast by Zip: The "Forecast By ZIP" option first presents the user with a screen where they can enter a zipcode and when the "Search" button is tapped, it executes the GetCityForecastByZIP method.  This is done by binding an Action binding to that method. The easiest way to accomplish this is to just drag & drop the method from the Data Control palette to the AMX page and drop it as a button and let the framework hook it up for you.  There is an inputText component on the page that is bound to a pageFlowScope variable called "zip".  This is used as the parameter to the Action binding when it is executed.  Because the actionListener attribute of the commandButton executes the Web Service each time, we ensure that the method is invoked every time the button is clicked. Weather Info: Unlike the previous method, this time instead of explictly executing the web service method we are using deferred invocation.  What this means is that we will bind to the results of the method and the framework will execute the method when it the data is required to be rendered.  We do this by simply doing a drag & drop of the results of the GetWeatherInformation to the AMX page.  When the page is rendered and the bindings are resolved the framework invokes the method.  This executes the method only when it is needed and fills the Data Control provider.  Because we never re-execute the method, you can click from Home to Weather Info and back many times and the web service is only ever invoked once. Issues and Possible Improvements: One thing you will quickly realize with this example is that the error handling is done by the framework for you. For simple examples this is fine but for real applications you'll want to customize these error messages.  With the declarative invocation of web services, this is difficult.  This is one aspect we'll address in the second installment of the web service examples where we will show you how to do programmatic invocation which allows you better error handling. Another issue you will notice with this example is that we can enumerate the weather information but there isn't an easy way to use that information to show the corresponding description and image as part of the forecast results.  We'll show you how to do this in the next example.

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• Multithreading 2D gravity calculations

  - by Postman

  I'm building a space exploration game and I've currently started working on gravity ( In C# with XNA). The gravity still needs tweaking, but before I can do that, I need to address some performance issues with my physics calculations. This is using 100 objects, normally rendering 1000 of them with no physics calculations gets well over 300 FPS (which is my FPS cap), but any more than 10 or so objects brings the game (and the single thread it runs on) to its knees when doing physics calculations. I checked my thread usage and the first thread was killing itself from all the work, so I figured I just needed to do the physics calculation on another thread. However when I try to run the Gravity.cs class's Update method on another thread, even if Gravity's Update method has nothing in it, the game is still down to 2 FPS. Gravity.cs public void Update() { foreach (KeyValuePair<string, Entity> e in entityEngine.Entities) { Vector2 Force = new Vector2(); foreach (KeyValuePair<string, Entity> e2 in entityEngine.Entities) { if (e2.Key != e.Key) { float distance = Vector2.Distance(entityEngine.Entities[e.Key].Position, entityEngine.Entities[e2.Key].Position); if (distance > (entityEngine.Entities[e.Key].Texture.Width / 2 + entityEngine.Entities[e2.Key].Texture.Width / 2)) { double angle = Math.Atan2(entityEngine.Entities[e2.Key].Position.Y - entityEngine.Entities[e.Key].Position.Y, entityEngine.Entities[e2.Key].Position.X - entityEngine.Entities[e.Key].Position.X); float mult = 0.1f * (entityEngine.Entities[e.Key].Mass * entityEngine.Entities[e2.Key].Mass) / distance * distance; Vector2 VecForce = new Vector2((float)Math.Cos(angle), (float)Math.Sin(angle)); VecForce.Normalize(); Force = Vector2.Add(Force, VecForce * mult); } } } entityEngine.Entities[e.Key].Position += Force; } } Yeah, I know. It's a nested foreach loop, but I don't know how else to do the gravity calculation, and this seems to work, it's just so intensive that it needs its own thread. (Even if someone knows a super efficient way to do these calculations, I'd still like to know how I COULD do it on multiple threads instead) EntityEngine.cs (manages an instance of Gravity.cs) public class EntityEngine { public Dictionary<string, Entity> Entities = new Dictionary<string, Entity>(); public Gravity gravity; private Thread T; public EntityEngine() { gravity = new Gravity(this); } public void Update() { foreach (KeyValuePair<string, Entity> e in Entities) { Entities[e.Key].Update(); } T = new Thread(new ThreadStart(gravity.Update)); T.IsBackground = true; T.Start(); } } EntityEngine is created in Game1.cs, and its Update() method is called within Game1.cs. I need my physics calculation in Gravity.cs to run every time the game updates, in a separate thread so that the calculation doesn't slow the game down to horribly low (0-2) FPS. How would I go about making this threading work? (any suggestions for an improved Planetary Gravity system are welcome if anyone has them) I'm also not looking for a lesson in why I shouldn't use threading or the dangers of using it incorrectly, I'm looking for a straight answer on how to do it. I've already spent an hour googling this very question with little results that I understood or were helpful. I don't mean to come off rude, but it always seems hard as a programming noob to get a straight meaningful answer, I usually rather get an answer so complex I'd easily be able to solve my issue if I understood it, or someone saying why I shouldn't do what I want to do and offering no alternatives (that are helpful). Thank you for the help!

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• About the K computer

  - by nospam(at)example.com (Joerg Moellenkamp)

  Okay ? after getting yet another mail because of the new #1 on the Top500 list, I want to add some comments from my side: Yes, the system is using SPARC processor. And that is great news for a SPARC fan like me. It is using the SPARC VIIIfx processor from Fujitsu clocked at 2 GHz. No, it isn't the only one. Most people are saying there are two in the Top500 list using SPARC (#77 JAXA and #1 K) but in fact there are three. The Tianhe-1 (#2 on the Top500 list) super computer contains 2048 Galaxy "FT-1000" 1 GHz 8-core processors. Don't know it? The FeiTeng-1000 ? this proc is a 8 core, 8 threads per core, 1 ghz processor made in China. And it's SPARC based. By the way ? this sounds really familiar to me ? perhaps the people just took the opensourced UltraSPARC-T2 design, because some of the parameters sound just to similar. However it looks like that Tianhe-1 is using the SPARCs as input nodes and not as compute notes. No, I don't see it as the next M-series processor. Simple reason: You can't create SMP systems out of them ? it simply hasn't the functionality to do so. Even when there are multiple CPUs on a single board, they are not connected like an SMP/NUMA machine to a shared memory machine ? they are connected with the cluster interconnect (in this case the Tofu interconnect) and work like a large cluster. Yes, it has a lot of oomph in Linpack ? however I assume a lot came from the extensions to the SPARCv9 standard. No, Linpack has no relevance for any commercial workload ? Linpack is such a special load, that even some HPC people are arguing that it isn't really a good benchmark for HPC. It's embarrassingly parallel, it can work with relatively small interconnects compared to the interconnects in SMP systems (however we get in spheres SMP interconnects where a few years ago). Amdahl isn't hitting that hard when running Linpack. Yes, it's a good move to use SPARC. At some time in the last 10 years, there was an interesting twist in perception: SPARC was considered as proprietary architecture and x86 was the open architecture. However it's vice versa ? try to create a x86 clone and you have a lot of intellectual property problems, create a SPARC clone and you have to spend 100 bucks or so to get the specification from the SPARC Foundation and develop your own SPARC processor. Fujitsu is doing this for a long time now. So they had their own processor, their own know-how. So why was SPARC a good choice? Well ? essentially Fujitsu can do what they want with their core as it is their core, for example adding the extensions to the SPARCv9 chipset ? getting Intel to create extensions to x86 to help you with your product is a little bit harder. So Fujitsu could do they needed to do with their processor in order to create such a supercomputer. No, the K is really using no FPGA or GPU as accelerators. The K is really using the CPU at doing this job. Yes, it has a significantly enhanced FPU capable to execute 8 instructions in parallel. No, it doesn't run Solaris. Yes, it uses Linux. No, it doesn't hurt me ... as my colleague Roland Rambau (he knows a lot about HPC) said once to me ... it doesn't matter which OS is staying out of the way of the workload in HPC.

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• Fast Data - Big Data's achilles heel

  - by thegreeneman

  At OOW 2013 in Mark Hurd and Thomas Kurian's keynote, they discussed Oracle's Fast Data software solution stack and discussed a number of customers deploying Oracle's Big Data / Fast Data solutions and in particular Oracle's NoSQL Database.  Since that time, there have been a large number of request seeking clarification on how the Fast Data software stack works together to deliver on the promise of real-time Big Data solutions.   Fast Data is a software solution stack that deals with one aspect of Big Data, high velocity.   The software in the Fast Data solution stack involves 3 key pieces and their integration:  Oracle Event Processing, Oracle Coherence, Oracle NoSQL Database.   All three of these technologies address a high throughput, low latency data management requirement.   Oracle Event Processing enables continuous query to filter the Big Data fire hose, enable intelligent chained events to real-time service invocation and augments the data stream to provide Big Data enrichment. Extended SQL syntax allows the definition of sliding windows of time to allow SQL statements to look for triggers on events like breach of weighted moving average on a real-time data stream.    Oracle Coherence is a distributed, grid caching solution which is used to provide very low latency access to cached data when the data is too big to fit into a single process, so it is spread around in a grid architecture to provide memory latency speed access.  It also has some special capabilities to deploy remote behavioral execution for "near data" processing.   The Oracle NoSQL Database is designed to ingest simple key-value data at a controlled throughput rate while providing data redundancy in a cluster to facilitate highly concurrent low latency reads.  For example, when large sensor networks are generating data that need to be captured while analysts are simultaneously extracting the data using range based queries for upstream analytics.  Another example might be storing cookies from user web sessions for ultra low latency user profile management, also leveraging that data using holistic MapReduce operations with your Hadoop cluster to do segmented site analysis.  Understand how NoSQL plays a critical role in Big Data capture and enrichment while simultaneously providing a low latency and scalable data management infrastructure thru clustered, always on, parallel processing in a shared nothing architecture. Learn how easily a NoSQL cluster can be deployed to provide essential services in industry specific Fast Data solutions. See these technologies work together in a demonstration highlighting the salient features of these Fast Data enabling technologies in a location based personalization service. The question then becomes how do these things work together to deliver an end to end Fast Data solution.  The answer is that while different applications will exhibit unique requirements that may drive the need for one or the other of these technologies, often when it comes to Big Data you may need to use them together.   You may have the need for the memory latencies of the Coherence cache, but just have too much data to cache, so you use a combination of Coherence and Oracle NoSQL to handle extreme speed cache overflow and retrieval.   Here is a great reference to how these two technologies are integrated and work together.  Coherence & Oracle NoSQL Database.   On the stream processing side, it is similar as with the Coherence case.  As your sliding windows get larger, holding all the data in the stream can become difficult and out of band data may need to be offloaded into persistent storage.  OEP needs an extreme speed database like Oracle NoSQL Database to help it continue to perform for the real time loop while dealing with persistent spill in the data stream.  Here is a great resource to learn more about how OEP and Oracle NoSQL Database are integrated and work together.  OEP & Oracle NoSQL Database.

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• SQL to select random mix of rows fairly [migrated]

  - by Matt Sieker

  Here's my problem: I have a set of tables in a database populated with data from a client that contains product information. In addition to the basic product information, there is also information about the manufacturer, and categories for those products (a product can be in one or more categories). These categories are then referred to as "Product Categories", and which stores these products are available at. These tables are updated once a week from a feed from the customer. Since for our purposes, some of the product categories are the same, or closely related for our purposes, there is another level of categories called "General Categories", a general category can have one or more product categories. For the scope of these tables, here's some rough numbers: Data Tables: Products: 475,000 Manufacturers: 1300 Stores: 150 General Categories: 245 Product Categories: 500 Mapping Tables: Product Category -> Product: 655,000 Stores -> Products: 50,000,000 Now, for the actual problem: As part of our software, we need to select n random products, given a store and a general category. However, we also need to ensure a good mix of manufacturers, as in some categories, a single manufacturer dominates the results, and selecting rows at random causes the results to strongly favor that manufacturer. The solution that is currently in place, works for most cases, involves selecting all of the rows that match the store and category criteria, partition them on manufacturer, and include their row number from within their partition, then select from that where the row number for that manufacturer is less than n, and use ROWCOUNT to clamp the total rows returned to n. This query looks something like this: SET ROWCOUNT 6 select p.Id, GeneralCategory_Id, Product_Id, ISNULL(m.DisplayName, m.Name) AS Vendor, MSRP, MemberPrice, FamilyImageName from (select p.Id, gc.Id GeneralCategory_Id, p.Id Product_Id, ctp.Store_id, Manufacturer_id, ROW_NUMBER() OVER (PARTITION BY Manufacturer_id ORDER BY NEWID()) AS 'VendorOrder', MSRP, MemberPrice, FamilyImageName from GeneralCategory gc inner join GeneralCategoriesToProductCategories gctpc ON gc.Id=gctpc.GeneralCategory_Id inner join ProductCategoryToProduct pctp on gctpc.ProductCategory_Id = pctp.ProductCategory_Id inner join Product p on p.Id = pctp.Product_Id inner join StoreToProduct ctp on p.Id = ctp.Product_id where gc.Id = @GeneralCategory and ctp.Store_id=@StoreId and p.Active=1 and p.MemberPrice >0) p inner join Manufacturer m on m.Id = p.Manufacturer_id where VendorOrder <=6 order by NEWID() SET ROWCOUNT 0 (I've tried to somewhat format it to make it cleaner, but I don't think it really helps) Running this query with an execution plan shows that for the majority of these tables, it's doing a Clustered Index Seek. There are two operations that take up roughly 90% of the time: Index Seek (Nonclustered) on StoreToProduct: 17%. This table just contains the key of the store, and the key of the product. It seems that NHibernate decided not to make a composite key when making this table, but I'm not concerned about this at this point, as compared to the other seek... Clustered Index Seek on Product: 69%. I really have no clue how I could make this one more performant. On categories without a lot of products, performance is acceptable (<50ms), however larger categories can take a few hundred ms, with the largest category taking 3s (which has about 170k products). It seems I have two ways to go from this point: Somehow optimize the existing query and table indices to lower the query time. As almost every expensive operation is already a clustered index scan, I don't know what could be done there. The inner query could be tuned to not return all of the possible rows for that category, but I am unsure how to do this, and maintain the requirements (random products, with a good mix of manufacturers) Denormalize this data for the purpose of this query when doing the once a week import. However, I am unsure how to do this and maintain the requirements. Does anyone have any input on either of these items?

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• Creating a Corporate Data Hub

  - by BuckWoody

  The Windows Azure Marketplace has a rich assortment of data and software offerings for you to use – a type of Software as a Service (SaaS) for IT workers, not necessarily for end-users. Among those offerings is the “Data Hub” – a  codename for a project that ironically actually does what the codename says. In many of our organizations, we have multiple data quality issues. Finding data is one problem, but finding it just once is often a bigger problem. Lots of departments and even individuals have stored the same data more than once, and in some cases, made changes to one of the copies. It’s difficult to know which location or version of the data is authoritative. Then there’s the problem of accessing the data. It’s fairly straightforward to publish a database, share or other location internally to store the data. But then you have to figure out who owns it, how it is controlled, and pass out the various connection strings to those who want to use it. And then you need to figure out how to let folks access the internal data externally – bringing up all kinds of security issues. Finally, in many cases our user community wants us to combine data from the internally sources with external data, bringing up the security, strings, and exploration features up all over again. Enter the Data Hub. This is an online offering, where you assign an administrator and data stewards. You import the data into the service, and it’s available to you - and only you and your organization if you wish. The basic steps for this service are to set up the portal for your company, assign administrators and permissions, and then you assign data areas and import data into them. From there you make them discoverable, and then you have multiple options that you or your users can access that data. You’re then able, if you wish, to combine that data with other data in one location. So how does all that work? What about security? Is it really that easy? And can you really move the data definition off to the Subject Matter Experts (SME’s) that know the particular data stack better than the IT team does? Well, nothing good is easy – but using the Data Hub is actually pretty simple. I’ll give you a link in a moment where you can sign up and try this yourself. Once you sign up, you assign an administrator. From there you’ll create data areas, and then use a simple interface to bring the data in. All of this is done in a portal interface – nothing to install, configure, update or manage. After the data is entered in, and you’ve assigned meta-data to describe it, your users have multiple options to access it. They can simply use the portal – which actually has powerful visualizations you can use on any platform, even mobile phones or tablets.     Your users can also hit the data with Excel – which gives them ultimate flexibility for display, all while using an authoritative, single reference for the data. Since the service is online, they can do this wherever they are – given the proper authentication and permissions. You can also hit the service with simple API calls, like this one from C#: http://msdn.microsoft.com/en-us/library/hh921924  You can make HTTP calls instead of code, and the data can even be exposed as an OData Feed. As you can see, there are a lot of options. You can check out the offering here: http://www.microsoft.com/en-us/sqlazurelabs/labs/data-hub.aspx and you can read the documentation here: http://msdn.microsoft.com/en-us/library/hh921938

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• Oracle at ARM TechCon

  - by Tori Wieldt

  ARM TechCon is a technical conference for hardware and software engineers, Oct. 30-Nov 1 in Santa Clara, California. Days two and three of the conference will be geared towards systems designers and software developers, those interested in building ARM processor-based modules, boards, and systems. It will cover all of the hardware and software, tools, ranging from low-power design, networking and connectivity, open source software, and security. Oracle is a sponsor of ARM TechCon, and will present three Java sessions and a hands-on-lab:  "Do You Like Coffee with Your Dessert? Java and the Raspberry Pi" - The Raspberry Pi, an ARM-powered single board computer running a full Linux distro off an SD card has caused a huge wave of interest among developers. This session looks at how Java can be used on a device such as this. Using Java SE for embedded devices and a port of JavaFX, the presentation includes a variety of demonstrations of what the Raspberry Pi is capable of. The Raspberry Pi also provides GPIO line access, and the session covers how this can be used from Java applications. Prepare to be amazed at what this tiny board can do. (Angela Caicedo, Java Evangelist) "Modernizing the Explosion of Advanced Microcontrollers with Embedded Java" - This session explains why Oracle Java ME Embedded is the right choice for building small, connected, and intelligent embedded solutions, such as industrial control applications, smart sensing, wireless connectivity, e-health, or general machine-to-machine (M2M) functionality---extending your business to new areas, driving efficiency, and reducing cost. The new Oracle Java ME Embedded product brings the benefits of Java technology to microcontroller platforms. It is a full-featured, complete, compliant software runtime with value-add features targeted to the embedded space and has the ability to interface with additional hardware components, remote manageability, and over-the-air software updates. It is accompanied by a feature-rich set of tools free of charge. (Fareed Suliman, Java Product Manager) "Embedded Java in Smart Energy and Healthcare" - This session covers embedded Java products and technologies that enable smart and connect devices in the Smart Energy and Healthcare/Medical industries. (speaker Kevin Lee) "Java SE Embedded Development on ARM Made Easy" - This Hands-on Lab aims to show that developers already familiar with the Java develop/debug/deploy lifecycle can apply those same skills to develop Java applications, using Java SE Embedded, on embedded devices. (speaker Jim Connors) In the Oracle booth #603, you can see the following demos: Industry Solutions with JavaThis exhibit consists of a number of industry solutions and how they can be powered by Java technology deployed on embedded systems.  Examples in consumer devices, home gateways, mobile health, smart energy, industrial control, and tablets all powered by applications running on the Java platform are shown.  Some of the solutions demonstrate the ability of Java to connect intelligent devices at the edge of the network to the datacenter or the cloud as a total end-to-end platform.Java in M2M with QualcommThis station will exhibit a new M2M solutions platform co-developed by Oracle and Qualcomm that enables wireless communications for embedded smart devices powered by Java, and share the types of industry solutions that are possible.  In addition, a new platform for wearable devices based on the ARM Cortex M3 platform is exhibited.Why Java for Embedded?Demonstration platforms will show how traditional development environments, tools, and Java programming skills can be used to create applications for embedded devices.  The advantages that Java provides because of  the runtime's abstraction of software from hardware, modularity and scalability, security, and application portability and manageability are shared with attendees. Drop by and see why Java is an optimal applications platform for embedded systems.

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• Free hosting solution for a very low-traffic website [duplicate]

  - by user966939

  This question already has an answer here: How to find web hosting that meets my requirements? 4 answers I run a very low-traffic website (about 40 users, basically all of which are daily active on the site). I don't see it changing anytime soon either, as there is no way to sign up on the site right now. Until now I have just been using a sub-directory on a friend's host (shared), to host the web site. But in only a few weeks from now, his subscription will end, and he has no plans on renewing it. So of course this means I'll have to move on to something else. But I don't think I'll find someone who'd be willing to share a... shared host with me again. And besides, the software used on that server is ancient (PHP 4.4.9 + MySQL 4.1.22). There's one obvious solution that comes to mind, I guess: choose a better host and pay for it myself. The problem here is that I have no real fixed income, as I'm only a student. So even if the pricing is dirt cheap, I just can't be certain I will be able to afford it, every single month, for... at least 2 years maybe? So I've looked at free hosting solutions instead. The least requirement I had was that it was completely free of ads. But no matter where I look, I always find something in a corner or two ("what can you expect from a free host?" - yeah I know, but I guess it was worth a shot). For example, on Byethost (one of the free hosts I tried), if you trigger a PHP error while error reporting is set to E_ALL, you will spawn some hidden ad... Besides Byethost, I've tried 000Webhost, x10Hosting, 2Freehosting/1Freehosting, Wink.ws, and they are only worse. Okay, I'm running low on ideas. But! What if I just hosted the site myself, on my own computer? That could work. I actually do have my computer on practically 24/7. But not really. Sometimes I need to reboot it, and sometimes we even have power outages. And what if the hardware needs an upgrade? It's not such a big deal for me if the site went down, because I know what's going on; but what about the users? If I do decide to host it myself, is there some way to show users an alternate page instead of them just seeing a generic "server not found" page in the browser when the site is not accessible? Or is there something I have been missing out on? Is there a different kind of "web hosting" solution out there that I haven't heard of? Here is what I'm really looking for: Free (as in, no costs) NO ads Bandwidth enough for a low-traffic forum with roughly 40 users (Semi-)Up-to-date PHP and MySQL (at least not older than a year) No standard (non-extension) PHP functions turned off - such as sleep() The mbstring extension is enabled Disk space: at least 5 MB At least one MySQL database Some bonus points would be: Max execution time of PHP scripts can be set Remote access to MySQL database What would be the best solution for me? Is there one?

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• BI&EPM in Focus November 2012

  - by Mike.Hallett(at)Oracle-BI&EPM

  Customers ·       San Diego Unified School District Harnesses Attendance, Procurement, and Operational Data with Oracle Exalytics, Generating $4.4 Million in Savings ·       NilsonGroup chooses Oracle Exalytics In-Memory Machine as their solution to access critical data to keep its stores competitive with real-time Mobile BI:  Video ·       Nykredit, in the Danish Financial Sector, describes their experiences from testing the Exalytics Business Intelligence Machine: Video  ·       Sodexo chose Oracle Exalytics as their business analytics platform:  Video ·       AstraZeneca (US, Canada, MedImmune) Improves Insight, Analytics, and Reporting, Enterprisewide with Unified Planning on a Single Platform ·       Experian Consolidates Reporting Systems for One, Global View of Financial Data and Improves Planning for Continued Growth ·       Munchkin Gives its Line of Children’s Products Plenty of Room to Grow in an Upgraded Enterprise Application Environment ·       Top 20 EPM Customer Snapshots, in One Handy Booklet (link) ·       Customer and Partner Successes: Link to Complete Archive Enterprise Performance Management ·       Nov 15: Is Hope and Email the Core of your Reconciliation Process? (link) ·       Replay: Integrated Business Planning, Featuring Leggett & Platt (link) ·       Whitepaper: The New Competitive Advantage - Strategic CIO's Embrace the Cloud (link) ·       Press: Oracle Enterprise Performance Management Driving Significant Improvements in Budget Management and Reporting for Public Sector Organizations (link) ·       Enterprise Performance Management Video Feature Overviews, Now Available on YouTube (link) ·       NEW Solution Brief - Oracle Hyperion Planning on the Oracle Exalytics In-Memory Machine (link) ·       For Insurance sector: Datasheet for new release V2.0 - Oracle Quantitative Management and Reporting for Solvency II (link) ·       Whitepaper FSN 2012: Managing Risk and Uncertainty, an Executive's Guide to Integrated Business Planning (link) ·       NEW Datasheet for Oracle Planning and Budgeting Cloud Service (link) ·       Blog: Planning in the Cloud - For Real Business Intelligence ·       Press: Latest Release of Oracle Exalytics In-Memory Machine Software Enables Customers to View and Analyze Data at the Speed of Business (link) ·       Press: New Release (11.1.1.6.2BP1) of Oracle Business Intelligence Enables Users to Quickly Access and Analyze Key Business Information, Anytime, Anywhere (link) ·       Mark Hurd Interviewed on USA Today about Big Data & Analytics (link) ·       Whitepaper: Mastering Big Data - CFO Strategies to Transform Insight into Opportunity (link) ·       Nov 15: Improve Asset Utilization. Achieve Greater Profitability: Oracle Enterprise Asset Management Analytics (link) ·       Replay: Oracle Enterprise Asset Mgmt Analytics and Oracle Manufacturing Analytics (link) ·       Overload to Impact: An Industry Scorecard on Big Data Business Challenges (link) ·       Webcast Replay: Overview of Oracle Endeca Informational Discovery (link) ·       OBIEE 11g: Required and Recommended Patches and Patch Sets (link)

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• How can I best implement 'cache until further notice' with memcache in multiple tiers?

  - by ajreal

  the term "client" used here is not referring to client's browser, but client server Before cache workflow 1. client make a HTTP request --> 2. server process --> 3. store parsed results into memcache for next use (cache indefinitely) --> 4. return results to client --> 5. client get the result, store into client's local memcache with TTL After cache workflow 1. another client make a HTTP request --> 2. memcache found return memcache results to client --> 3. client get the result, store into client's local memcache with TTL TTL = time to live Is possible for me to know when the data was updated, and to expire relevant memcache(s) accordingly. However, the pitfalls on client site cache TTL Any data update before the TTL is not pick-up by client memcache. In reverse manner, where there is no update, client memcache still expire after the TTL First request (or concurrent requests) after cache TTL will get throttle as it need to repeat the "Before cache workflow" In the event where client require several HTTP requests on a single web page, it could be very bad in performance. Ideal solution should be client to cache indefinitely until further notice. Here are the three proposals about futher notice Proposal 1 : Make use on HTTP header (current implementation) 1. client sent HTTP request last modified time header 2. server check if last data modified time=last cache time return status 304 3. client based on header to decide further processing GOOD? ---- - save some parsing for client - lesser data transfer BAD? ---- - fire a HTTP request is still slow - server end still need to process lots of requests Proposal 2 : Consistently issue a HTTP request to check all data group last modified time 1. client fire a HTTP request 2. server to return last modified time for all data group 3. client compare local last cache time with the result 4. if data group last cache time < server last modified time then request again for that data group only GOOD? ---- - only fetch what is no up-to-date - less requests for server BAD? ---- - every web page require a HTTP request Proposal 3 : Tell client when new data is available (Push) 1. when server end notice there is a change on a data group 2. notify clients on the changes 3. help clients to fetch again data 4. then reset client local memcache after data is parsed GOOD? ---- - let the cache act/behave like a true cache BAD? ---- - encourage race condition My preference is on proposal 3, and something like Gearman could be ideal Where there is a change, Gearman server to sent the task to multiple clients (workers). Am I crazy? (I know my first question is a bit crazy)

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• Trouble rotating viewplatform in Java3D [closed]

  - by user29163

  I have just started with Java3D programming. I thought I had built up some basic intuition about how the scene graph works, but something that should work, does not work. I made a simple program for rotating a pyramid around the y-axis. This was done just by adding a RotationInterpolator R to the TransformGroup above the pyramid. Then I thought hey, can I now remove the RotationInterpolator from this TransformGroup, then add it to the TransformGroup above my ViewPlatform leaf. This should work if I have understood how things work. Adding the RotationInterpolator to this TransformGroup, should make the children of this TransformGroup rotate, and the ViewingPlatform is a child of the TransformGroup. Any ideas on where my reasoning is flawed? Here is the code for setting up the universe, and the view branchgroup. import java.awt.*; import java.awt.event.*; import javax.media.j3d.*; import javax.vecmath.*; public class UniverseBuilder { // User-specified canvas Canvas3D canvas; // Scene graph elements to which the user may want access VirtualUniverse universe; Locale locale; TransformGroup vpTrans; View view; public UniverseBuilder(Canvas3D c) { this.canvas = c; // Establish a virtual universe that has a single // hi-res Locale universe = new VirtualUniverse(); locale = new Locale(universe); // Create a PhysicalBody and PhysicalEnvironment object PhysicalBody body = new PhysicalBody(); PhysicalEnvironment environment = new PhysicalEnvironment(); // Create a View and attach the Canvas3D and the physical // body and environment to the view. view = new View(); view.addCanvas3D(c); view.setPhysicalBody(body); view.setPhysicalEnvironment(environment); // Create a BranchGroup node for the view platform BranchGroup vpRoot = new BranchGroup(); // Create a ViewPlatform object, and its associated // TransformGroup object, and attach it to the root of the // subgraph. Attach the view to the view platform. Transform3D t = new Transform3D(); Transform3D s = new Transform3D(); t.set(new Vector3f(0.0f, 0.0f, 10.0f)); t.rotX(-Math.PI/4); s.set(new Vector3f(0.0f, 0.0f, 10.0f)); //forandre verdier her for å endre viewing position t.mul(s); ViewPlatform vp = new ViewPlatform(); vpTrans = new TransformGroup(t); vpTrans.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE); // Rotator stuff Transform3D yAxis = new Transform3D(); //yAxis.rotY(Math.PI/2); Alpha rotationAlpha = new Alpha( -1, Alpha.INCREASING_ENABLE, 0, 0,4000, 0, 0, 0, 0, 0); RotationInterpolator rotator = new RotationInterpolator( rotationAlpha, vpTrans, yAxis, 0.0f, (float) Math.PI*2.0f); RotationInterpolator rotator2 = new RotationInterpolator( rotationAlpha, vpTrans); BoundingSphere bounds = new BoundingSphere(new Point3d(0.0,0.0,0.0), 1000.0); rotator.setSchedulingBounds(bounds); vpTrans.addChild(rotator); vpTrans.addChild(vp); vpRoot.addChild(vpTrans); view.attachViewPlatform(vp); // Attach the branch graph to the universe, via the // Locale. The scene graph is now live! locale.addBranchGraph(vpRoot); } public void addBranchGraph(BranchGroup bg) { locale.addBranchGraph(bg); } }

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• A .NET Developers day with the iPad.

  - by mbcrump

  The Apple iPad is currently getting a lot of buzz because of the app store, the book store and of course iTunes. I had the chance to play with one and this is what I have learned about the device. Let’s get this out of the way first, the iPad is awesome. It is the device for media consumption and casual web browsing. But how does it measure up to those of us with .NET on our brains all days. Let’s find out… Main Screen – you can customize everything on this page. I guess I should replace that image with a C# or VS logo. Its pretty standard stuff if you have an iPhone.   Programming Books If you have a subscription to Safari Books Online, then you are in luck, its very easy to read the books on the iPad. Just fire up Safari web browser and goto the Safari Books Online. The biggest benefit that I can see with the iPad is the ability to read books wherever and not have to worry about purchasing books that I already have the .PDF for. Below is a sample from Code Complete 2nd Edition. Below is a PDF of the ECMA-334 C# Language Specification. As you can see its very readable and you should have no problem reading actual code.   Example of Code shown below: It is however easier to read the PDF and store them with a 3rd party PDF reader. I have seen several for .99 cents or less. You can however switch the screen to vertical to get more viewing space as shown below: I was disappointed with the iBooks application. I could not find a single .NET programming book anywhere. I was able to download the excellent sci-fi book “A memory of Wind” for free though. If I just overlooked them, then please email me with the names and titles. I couldn’t even find a technology category in the categories list. Web Surfing – Technical Sites Below is an example of my site in Safari. The code is very readable and the experience was identical to viewing it in Firefox. I tried multiple programming site and the pages looked great except those that used flash and of course it did not display on those pages.   News Apps - Technical Content The standard NY Times and USA Today looked great, but the Technical Content was lacking. It would probably be better to use Google Reader for online technical news.     YouTube Videos – Technical Content  Since its YouTube, we already know that a lot of technical content exist and it plays great on the iPad. I watched several programming videos and could clearly see the code being written. Taking Technical Notes The iPad comes with a great notepad for taking notes. I found that it was easy to take notes regarding projects that I am currently working on.   Calendar The calendar that ships with the iPad is great for organizing. You can setup exchange server or manually enter the information. Pretty standard stuff.    Random Applications that I like: TweetDeck.   and Adobe Ideas. Adobe Ideas is kinda like SketchFlow except you use your finger to mock up the sketches.  Don’t forget that the iPad is great for any type of podcasting. That pretty much sums it up, I would definitely recommend this device as it will only get better. I believe the iOS4 comes out on the 24th and the iPad will only get more and more apps. You could save a few bucks by waiting for the 2nd generation, but that’s a call that only you can make.

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• Is this Hybrid of Interface / Composition kosher?

  - by paul

  I'm working on a project in which I'm considering using a hybrid of interfaces and composition as a single thing. What I mean by this is having a contain*ee* class be used as a front for functionality implemented in a contain*er* class, where the container exposes the containee as a public property. Example (pseudocode): class Visibility(lambda doShow, lambda doHide, lambda isVisible) public method Show() {...} public method Hide() {...} public property IsVisible public event Shown public event Hidden class SomeClassWithVisibility private member visibility = new Visibility(doShow, doHide, isVisible) public property Visibility with get() = visibility private method doShow() {...} private method doHide() {...} private method isVisible() {...} There are three reasons I'm considering this: The language in which I'm working (F#) has some annoyances w.r.t. implementing interfaces the way I need to (unless I'm missing something) and this will help avoid a lot of boilerplate code. The containee classes could really be considered properties of the container class(es); i.e. there seems to be a fairly strong has-a relationship. The containee classes will likely implement code which would have been pretty much the same when implemented in all the container classes, so why not do it once in one place? In the above example, this would include managing and emitting the Shown/Hidden events. Does anyone see any isseus with this Composiface/Intersition method, or know of a better way? EDIT 2012.07.26 - It seems a little background information is warranted: Where I work, we have a bunch of application front-ends that have limited access to system resources -- they need access to these resources to fully function. To remedy this we have a back-end application that can access the needed resources, with which the front-ends can communicate. (There is an API written for the front-ends for accessing back-end functionality as though it were part of the front-end.) The back-end program is out of date and its functionality is incomplete. It has made the transition from company to company a couple of times and we can't even compile it anymore. So I'm trying to rewrite it in my spare time. I'm trying to update things to make a nice(r) interface/API for the front-ends (while allowing for backwards compatibility with older front-ends), hopefully something full of OOPy goodness. The thing is, I don't want to write the front-end API after I've written pretty much the same code in F# for implementing the back-end; so, what I'm planning on doing is applying attributes to classes/methods/properties that I would like to have code for in the API then generate this code from the F# assembly using reflection. The method outlined in this question is a possible alternative I'm considering instead of implementing straight interfaces on the classes in F# because they're kind of a bear: In order to access something of an interface that has been implemented in a class, you have to explicitly cast an instance of that class to the interface type. This would make things painful when getting calls from the front-ends. If you don't want to have to do this, you have to call out all of the interface's methods/properties again in the class, outside of the interface implementation (which is separate from regular class members), and call the implementation's members. This is basically repeating the same code, which is what I'm trying to avoid!

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• SharePoint Content and Site Editing Tips

  - by Bil Simser

  A few content management and site editing tips for power users on this bacon flavoured unicorn morning. The theme here is keep it clean!Write "friendly" email addressesRemember it's human beings reading your content. So seeing something like "If you have questions please send an email to [email protected]" breaks up the readiblity. Instead just do the simple steps of writing the content in plain English and going back, highlighting the name and insert a link (note: you might have to prefix the link with mailto:[email protected]). It makes for a friendlier looking page and hides the ugliness that are sometimes in email addresses.Use friendly column and list namesThis is a big pet peeve of mine. When you first create a column or list with spaces the internal name is changed. The display name might be "My Amazing List of Animals with Large Testicles" but the internal (and link) name becomes "My_x00x20_Amazing_x00x20_List_x00x20_of_x00x20_Animals_x00x20_with_x00x20_Large_x00x20_Testicles". What's worse is if you create a publishing page named "This Website is Fueled By a Dolphin's Spleen". Not only is it incorrect grammar, but the apostrophe wreaks havoc on both the internal name for the list (with lots of crazy hex codes) as well as the hyperlink (where everything is uuencoded). Instead create the list with a distinct and compact name then go back and change it to whatever you want. The end result is a better formed name that you can both script and access in code easier.Keep your Views CleanWhen you add a column to a list or create a new list the default is to add it to the default view. Do everyone a favour and don't check this box! The default view of a list should be something similar to the Title field and nothing else. Keep it clean. If you want to set a defalt view that's different, go back and create one with all the fields and filtering and sorting columns you want and set it as default. It's a good idea to keep the original AllItems.aspx (note the lack of space in the filename!) easy and unfiltered. It's also a good idea to keep your column count down in views. Don't let every column be added by default and don't add every column just because you can. Create separate views for distinct responsibilities and try to keep the number of columns down to a single screen to prevent horizontal scrolling.Simple NavigationThe Quick Launch is a great tool for navigating around your site but don't use the default of adding all lists to it. Uncheck that box and keep navigation simple. Create custom groupings that make sense so if you don't have a site with "Documents and Lists" but "Reports and Notices" makes more sense then do it. Also hide internal lists from the Quick Launch. For example, if most users don't need to see all the lookup tables you might have on a site don't show them. You can use audience filtering on the Quick Launch if you want to hide admin items from non-admin users so consider that as an option.Enjoy!

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• C#&ndash;Using a delegate to raise an event from one class to another

  - by Bill Osuch

  Even though this may be a relatively common task for many people, I’ve had to show it to enough new developers that I figured I’d immortalize it… MSDN says “Events enable a class or object to notify other classes or objects when something of interest occurs. The class that sends (or raises) the event is called the publisher and the classes that receive (or handle) the event are called subscribers.” Any time you add a button to a Windows Form or Web app, you can subscribe to the OnClick event, and you can also create your own event handlers to pass events between classes. Here I’ll show you how to raise an event from a separate class to a console application (or Windows Form). First, create a console app project (you could create a Windows Form, but this is easier for this demo). Add a class file called MyEvent.cs (it doesn’t really need to be a separate file, this is just for clarity) with the following code: public delegate void MyHandler1(object sender, MyEvent e); public class MyEvent : EventArgs {     public string message; } Your event can have whatever public properties you like; here we’re just got a single string. Next, add a class file called WorkerDLL.cs; this will simulate the class that would be doing all the work in the project. Add the following code: class WorkerDLL {     public event MyHandler1 Event1;     public WorkerDLL()     {     }     public void DoWork()     {         FireEvent("From Worker: Step 1");         FireEvent("From Worker: Step 5");         FireEvent("From Worker: Step 10");     }     private void FireEvent(string message)     {         MyEvent e1 = new MyEvent();         e1.message = message;         if (Event1 != null)         {             Event1(this, e1);         }         e1 = null;     } } Notice that the FireEvent method creates an instance of the MyEvent class and passes it to the Event1 handler (which we’ll create in just a second). Finally, add the following code to Program.cs: static void Main(string[] args) {     Program p = new Program(args); } public Program(string[] args) {     Console.WriteLine("From Console: Creating DLL");     WorkerDLL wd = new WorkerDLL();     Console.WriteLine("From Console: Wiring up event handler");     WireEventHandlers(wd);     Console.WriteLine("From Console: Doing the work");     wd.DoWork();     Console.WriteLine("From Console: Done - press any key to finish.");     Console.ReadLine(); } private void WireEventHandlers(WorkerDLL wd) {     MyHandler1 handler = new MyHandler1(OnHandler1);     wd.Event1 += handler; } public void OnHandler1(object sender, MyEvent e) {     Console.WriteLine(e.message); } The OnHandler1 method is called any time the event handler “hears” an event matching the specified signature – you could have it log to a file, write to a database, etc. Run the app in debug mode and you should see output like this: You can distinctly see which lines were written by the console application itself (Program.cs) and which were written by the worker class (WorkerDLL.cs). Technorati Tags: Csharp

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