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• MSSQL 2008 - Bit Param Evaluation alters Execution Plan

  - by Nathanial Woolls

  I have been working on migrating some of our data from Microsoft SQL Server 2000 to 2008. Among the usual hiccups and whatnot, I’ve run across something strange. Linked below is a SQL query that returns very quickly under 2000, but takes 20 minutes under 2008. I have read quite a bit on upgrading SQL server and went down the usual paths of checking indexes, statistics, etc. before coming to the conclusion that the following statement, found in the WHERE clause, causes the execution plan for the steps that follow this statement to change dramatically: And ( @bOnlyUnmatched = 0 -- offending line Or Not Exists( The SQL statements and execution plans are linked below. A coworker was able to rewrite a portion of the WHERE clause using a CASE statement, which seems to “trick” the optimizer into using a better execution plan. The version with the CASE statement is also contained in the linked archive. I’d like to see if someone has an explanation as to why this is happening and if there may be a more elegant solution than using a CASE statement. While we can work around this specific issue, I’d like to have a broader understanding of what is happening to ensure the rest of the migration is as painless as possible. Zip file with SQL statements and XML execution plans Thanks in advance!

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• Memory Management with returning char* function

  - by RageD

  Hello all, Today, without much thought, I wrote a simple function return to a char* based on a switch statement of given enum values. This, however, made me wonder how I could release that memory. What I did was something like this: char* func() { char* retval = new char; // Switch blah blah - will always return some value other than NULL since default: return retval; } I apologize if this is a naive question, but what is the best way to release the memory seeing as I cannot delete the memory after the return and, obviously, if I delete it before, I won't have a returned value. What I was thinking as a viable solution was something like this void func(char*& in) { // blah blah switch make it do something } int main() { char* val = new char; func(val); // Do whatever with func (normally func within a data structure with specific enum set so could run multiple times to change output) val = NULL; delete val; val = NULL; return 0; } Would anyone have anymore insight on this and/or explanation on which to use? Regards, Dennis M.

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• Criteria for triggering garbage collection in .Net

  - by Kennet Belenky

  I've come across some curious behavior with regard to garbage collection in .Net. The following program will throw an OutOfMemoryException very quickly (after less than a second on a 32-bit, 2GB machine). The Foo finalizer is never called. class Foo { static Dictionary<Guid, WeakReference> allFoos = new Dictionary<Guid, WeakReference>(); Guid guid = Guid.NewGuid(); byte[] buffer = new byte[1000000]; static Random rand = new Random(); public Foo() { // Uncomment the following line and the program will run forever. // rand.NextBytes(buffer); allFoos[guid] = new WeakReference(this); } ~Foo() { allFoos.Remove(guid); } static public void Main(string args[]) { for (; ; ) { new Foo(); } } } If the rand.nextBytes line is uncommented, it will run ad infinitum, and the Foo finalizer is regularly invoked. Why is that? My best guess is that in the former case, either the CLR or the Windows VMM is lazy about allocating physical memory. The buffer never gets written to, so the physical memory is never used. When the address space runs out, the system crashes. In the latter case, the system runs out of physical memory before it runs out of address space, the GC is triggered and the objects are collected. However, here's the part I don't get. Assuming my theory is correct, why doesn't the GC trigger when the address space runs low? If my theory is incorrect, then what's the real explanation?

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• LINQ to SQL Queries odd Materialization

  - by ptoinson

  I ran across an interesting Linq to SQL, uh, feature, the other day. Perhaps someone can give me a logical explanation for the reasoning behind the results. Take the code below as my example which utilizes the AdventureWorks database setup in a Linq to SQL DataContext. This is a clip from my unit test. The resulting customer returned from a call to both CustomerQuery_Test_01() and CustomerQuery_Test_02() is the same. However, the query executed on the SQLServer are different is a major way. The method CustomerQuery_Test_01 us causing the entire Customer table to be materialized, which the call to CustomerQuery_Test_02 is only causing the single customer to be materialized. The resulting SQL Queries are at the bottom of this post. Anyone have a good reason for this? To me, it was highly non-intuitive. protected virtual Customer GetByPrimaryKey(Func<Customer, bool> keySelection) { AdventureWorksDataContext context = new AdventureWorksDataContext(); return (from r in context.Customers select r).SingleOrDefault(keySelection); } [TestMethod] public void CustomerQuery_Test_01() { Customer customer = GetByPrimaryKey(c => c.CustomerID == 2); } [TestMethod] public void CustomerQuery_Test_02() { AdventureWorksDataContext context = new AdventureWorksDataContext(); Customer customer = (from r in context.Customers select r).SingleOrDefault(c => c.CustomerID == 2); } Query for CustomerQuery_Test_01 (notice the lack of a where clause) SELECT [t0].[CustomerID], [t0].[NameStyle], [t0].[Title], [t0].[FirstName], [t0].[MiddleName], [t0].[LastName], [t0].[Suffix], [t0].[CompanyName], [t0].[SalesPerson], [t0].[EmailAddress], [t0].[Phone], [t0].[PasswordHash], [t0].[PasswordSalt], [t0].[rowguid], [t0].[ModifiedDate] FROM [SalesLT].[Customer] AS [t0] Query for CustomerQuery_Test_02 (notice the where clause) SELECT [t0].[CustomerID], [t0].[NameStyle], [t0].[Title], [t0].[FirstName], [t0].[MiddleName], [t0].[LastName], [t0].[Suffix], [t0].[CompanyName], [t0].[SalesPerson], [t0].[EmailAddress], [t0].[Phone], [t0].[PasswordHash], [t0].[PasswordSalt], [t0].[rowguid], [t0].[ModifiedDate] FROM [SalesLT].[Customer] AS [t0] WHERE [t0].[CustomerID] = @p0

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• Aliasing `T*` with `char*` is allowed. Is it also allowed the other way around?

  - by StackedCrooked

  Note: This question has been renamed and reduced to make it more focused and readable. Most of the comments refer to the old text. According to the standard objects of different type may not share the same memory location. So this would not be legal: int i = 0; short * s = reinterpret_cast<short*>(&i); // BAD! The standard however allows an exception to this rule: any object may be accessed through a pointer to char or unsigned char: int i = 0; char * c = reinterpret_cast<char*>(&i); // OK However, it is not clear to me if this is also allowed the other way around. For example: char * c = read_socket(...); unsigned * u = reinterpret_cast<unsigned*>(c); // huh? Summary of the answers The answer is NO for two reasons: You an only access an existing object as char*. There is no object in my sample code, only a byte buffer. The pointer address may not have the right alignment for the target object. In that case dereferencing it would result in undefined behavior. On the Intel and AMD platforms it will result performance overhead. On ARM it will trigger a CPU trap and your program will be terminated! This is a simplified explanation. For more detailed information see answers by @Luc Danton, @Cheers and hth. - Alf and @David Rodríguez.

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• How to make buttons in python/pygame?

  - by user1334014

  I'm making a game in pygame and on the first screen I want there to be buttons that you can press to (i) start the game, (ii) load a new screen with instructions, and (iii) exit the program. I've found this code online for button making, but I don't really understand it (I'm not that good at object oriented programming). If I could get some explanation as to what it's doing that would be great. Also, when I use it and try to open a file on my computer using the file path, I get the error sh: filepath :Permission denied, which I don't know how to solve. #load_image is used in most pygame programs for loading images def load_image(name, colorkey=None): fullname = os.path.join('data', name) try: image = pygame.image.load(fullname) except pygame.error, message: print 'Cannot load image:', fullname raise SystemExit, message image = image.convert() if colorkey is not None: if colorkey is -1: colorkey = image.get_at((0,0)) image.set_colorkey(colorkey, RLEACCEL) return image, image.get_rect() class Button(pygame.sprite.Sprite): """Class used to create a button, use setCords to set position of topleft corner. Method pressed() returns a boolean and should be called inside the input loop.""" def __init__(self): pygame.sprite.Sprite.__init__(self) self.image, self.rect = load_image('button.png', -1) def setCords(self,x,y): self.rect.topleft = x,y def pressed(self,mouse): if mouse[0] > self.rect.topleft[0]: if mouse[1] > self.rect.topleft[1]: if mouse[0] < self.rect.bottomright[0]: if mouse[1] < self.rect.bottomright[1]: return True else: return False else: return False else: return False else: return False def main(): button = Button() #Button class is created button.setCords(200,200) #Button is displayed at 200,200 while 1: for event in pygame.event.get(): if event.type == MOUSEBUTTONDOWN: mouse = pygame.mouse.get_pos() if button.pressed(mouse): #Button's pressed method is called print ('button hit') if __name__ == '__main__': main() Thank you to anyone who can help me.

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• how to create an object using self?

  - by Nick

  I thought I understood the use of self while referring to anything in the current class. After encountering this warning and subsequent run failure, I have googled many variants of "define self" or "usage of self" and gotten nowhere. This problem is how to create an object without the warning, and understand why. #import <Cocoa/Cocoa.h> @interface Foo : NSObject { Foo *obj; } -(void)beta; @end #import "Foo.h" @implementation Foo -(void)beta{ obj = [self new]; // 'Foo' may not respond to '-new' } @end Note, if I substitute Foo for self, there's no problem. I thought the class name and self were equivalent, but obviously the compiler doesn't think so. Perhaps an explanation of what's wrong here will not only solve my problem but also enlighten my understanding of the usage of self. Are there any tutorials about proper usage of self? I couldn't find anything beyond something like "self is the receiver of the message," which I didn't help me at all.

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• Memory usage of strings (or any other objects) in .Net

  - by ava

  I wrote this little test program: using System; namespace GCMemTest { class Program { static void Main(string[] args) { System.GC.Collect(); System.Diagnostics.Process pmCurrentProcess = System.Diagnostics.Process.GetCurrentProcess(); long startBytes = pmCurrentProcess.PrivateMemorySize64; double kbStart = (double)(startBytes) / 1024.0; System.Console.WriteLine("Currently using " + kbStart + "KB."); { int size = 2000000; string[] strings = new string[size]; for(int i = 0; i < size; i++) { strings[i] = "blabla" + i; } } System.GC.Collect(); pmCurrentProcess = System.Diagnostics.Process.GetCurrentProcess(); long endBytes = pmCurrentProcess.PrivateMemorySize64; double kbEnd = (double)(endBytes) / 1024.0; System.Console.WriteLine("Currently using " + kbEnd + "KB."); System.Console.WriteLine("Leaked " + (kbEnd - kbStart) + "KB."); System.Console.ReadKey(); } } } The output in Release build is: Currently using 18800KB. Currently using 118664KB. Leaked 99864KB. I assume that the GC.collect call will remove the allocated strings since they go out of scope, but it appears it does not. I do not understand nor can I find an explanation for it. Maybe anyone here? Thanks, Alex

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• XCode Obj-C: Make new NSArray from one key each out of an Array of Dictionaries

  - by user323772

  This actually could be a multipart question. But here's the first part ... I have an array (actually in a plist) of dictionaries. Each dictionary has 3 keys in it: (title), (points), and (description). I am trying to make a NEW array with the values of the key "title" from each dictionary in that first array. Let me explain WHY I am doing this and maybe that will provide a better all around explanation. I am trying to let people pick from a pre-determined list. Heck, if this was a web page it would be very simple since all I really care about are the "points" and the "Title". On a web site I could simply do a drop down combo-box with the "points" being the value and the title being the text for each row. But this is not a web page. So what I am trying to do here is pop out a modal picker when they click the text field. The modal picker shows the alphabetical ordered "titles" from our new array. And whichever one they select, it closes the modal view and assigns that "title" text to the UITextField which cannot be edited by the user. I have some code to get my modal picker to pop out. But I need to feed it an array of just the "titles" of each dictionary in my real array. Thanks in advance (and yes I am a newbie)

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• Detecting what the target object is when NullReferenceException is thrown.

  - by StingyJack

  I'm sure we all have received the wonderfully vague "Object reference not set to instance of an Object" exception at some time or another. Identifying the object that is the problem is often a tedious task of setting breakpoints and inspecting all members in each statement. Does anyone have any tricks to easily and efficiently identify the object that causes the exception, either via programmatical means or otherwise? --edit It seems I was vague like the exception =). The point is to _not have to debug the app to find the errant object. The compiler/runtime does know that the object has been allocated, and that the object has not yet been instantiated. Is there a way to extract / identify those details in a caught exception @ W. Craig Trader Your explanation that it is a result of a design problem is probably the best answer I could get. I am fairly compulsive with defensive coding and have managed to get rid of most of these errors after fixing my habits over time. The remaining ones just tweak me to no end, and lead me to posting this question to the community. Thanks for everyone's suggestions.

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• How to change the picture of CustomButtonField on click event?

  - by Ujjal boruah Vinod

  I have posted this question previously but the answer is not appropiate. The solution provided just change the picture when the custombutton has focus and unfocus. Suppose in my application I need to change the picture if the user clicks on the customButton, n i m doing this by calling the same screen (ie UiApplication.getUiApplication().pushScreen(new Screen2(b));) . Screen2 is the screen which holds the customButton. On the click evevt i m pushing the same screen by passing aint variable pic_status that determines which picture to be drawn in the CustomButton in the new screen. Is there any way to update the picture in the CustomButtonField on click event without pushing the same Screen again and again. //code in Screen2 public void fieldChanged(Field field, int context) { if(field == bf1) { if(pic_status == 0) { pic_status=1; } UiApplication.getUiApplication().pushScreen(new Screen2(pic_status)); } //code in CustomButtonField CustomButtonField(String label,int pic_status,long style) { super(style); this.label = label; this.labelHeight = getFont().getHeight(); this.labelWidth = getFont().getAdvance(label); this.notice = s; if(pic_status ==0) { currentPicture1 = onPicture; currentPicture2 = onPicture; } if(pic_status ==1) { currentPicture1 = clickPicture; currentPicture2 = onPicture; } if( pic_status==2 ) { currentPicture1 = onPicture; currentPicture2 = clickPicture; } } I need a way to update the customButtonField text and picture on the buttonClick event not on focus/unfocus event without pushing the same Screen again and again. If my above description of problem is not satisfactory, plz add a comment n i can give more details explanation of my problem?

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• How to enforce that HTTP client uses conditional requests for updates?

  - by Day

  In a (proper RMM level 3) RESTful HTTP API, I want to enforce the fact that clients should make conditional requests when updating resources, in order to avoid the lost update problem. What would be an appropriate response to return to clients that incorrectly attempt unconditional PUT requests? I note that the (abandoned?) mod_atom returns a 405 Method Not Allowed with an Allow header set to GET, HEAD (view source) when an unconditional update is attempted. This seems slightly misleading - to me this implies that PUT is never a valid method to attempt on the resource. Perhaps the response just needs to have an entity body explaining that If-Match or If-Unmodified-Since must be used to make the PUT request conditional in which case it would be allowed? Or perhaps a 400 Bad Request with a suitable explanation in the entity body would be a better solution? But again, this doesn't feel quite right because it's using a 400 response for a violation of application specific semantics when RFC 2616 says (my emphasis): The request could not be understood by the server due to malformed syntax. But than again, I think that using 400 Bad Request for application specific semantics is becoming a widely accepted pragmatic solution (citation needed!), and I'm just being overly pedantic.

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• What is the worst gotcha in WPF?

  - by David

  Hi, I've started to make myself a list of "WPF gotchas": things that bug me and that I had to write down to remember because I fall for them every time.... Now, I'm pretty sure you all stumbled upon similar situations at one point, and I would like you to share your experience on the subject: What is the gotcha that gets you all the time? the one you find the most annoying? (I have a few issues that seem to be without explanation, maybe your submissions will explain them) Here are a few of my "personnal" gotchas (randomly presented): For a MouseEvent to be fired even when the click is on the "transparent" background of a control (e.g. a label) and not just on the content (the Text in this case), the control's Background has to be set to "Brushes.Transparent" and not just "null" (default value for a label) A WPF DataGridCell's DataContext is the RowView to whom the cell belong, not the CellView When inside a ScrollViewer, a Scrollbar is managed by the scrollviewer itself (i.e. setting properties such as ScrollBar.Value is without effect) Key.F10 is not fired when you press "F10", instead you get Key.System and you have to go look for e.SystemKey to get the Key.F10 ... and now you're on.

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• Weird behaviour with Scanner#nextFloat

  - by James P.

  Running the following in Eclipse initially caused Scanner to not recognize carriage returns in the console effectively blocking further input: price = sc.nextFloat(); Adding this line before the code causes Scanner to accept 0,23 (french notation) as a float: Locale.setDefault(Locale.US); This is most probably due to regional settings in Windows XP Pro. When the code is run again 0,23 is still accepted and entering 0.23 causes it to throw a java.util.InputMismatchException. Any explanation as to why this is happening? Also is there a workaround or should I just use Float#parseFloat? Edit: import java.util.Locale; import java.util.Scanner; public class NexFloatTest { public static void main(String[] args) { //Locale.setDefault(Locale.US); //Locale.setDefault(Locale.FRANCE); // Gives fr_BE on this system System.out.println(Locale.getDefault()); float price; String uSDecimal = "0.23"; String frenchDecimal = "0,23"; Scanner sc = new Scanner(uSDecimal); try{ price = sc.nextFloat(); System.out.println(price); } catch (java.util.InputMismatchException e){ e.printStackTrace(); } try{ sc = new Scanner(frenchDecimal); price = sc.nextFloat(); System.out.println(price); } catch (java.util.InputMismatchException e){ e.printStackTrace(); } String title = null; System.out.print("Enter title:"); try{ title = sc.nextLine(); // This line is skippe } catch(java.util.NoSuchElementException e ){ e.printStackTrace(); } System.out.print(title); } }

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• Suitable web framework for the following scenario

  - by Paralife

  I have the following scenario: I have a view in an Oracle server and all Iwant is to show that view in a web browser, along with an input field or two for basic filtering. No users, no authentication, just this view maybe with a column or two linking to a second page for master detail viewing. The children are just string descriptions of the columns of the master that contain IDs. No inserts or updates. The question is which is the JAVA based web framework of choice that can accomplish the above in the minimum amount of code lines code time(subjective but also kind of objective if someone has expirience with more than one or two frameworks) configuration effort deployment effort and requirements. dependencies and mem footprint Also: 6. Oracle APEX is not an option. 3,4 and 5 are maybe the same in the sense that they are everything except the functionality coding. I want something that I can compile, deploy by just FTPing to the database host, run and forget. (e.g. For the deployment aspect, Hudson way comes in mind (java -jar hudson.war and that's all)). Also: 3,4 have priority over 1 and 2. (Explanation with a rant: I dont mind coding a lot as long as it is application code and not "why the fuck do we still use javascript over http for everything" code) Thanks.

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• What is the n in O(n) when comparing sorting algorithms?

  - by Mumfi

  The question is rather simple, but I just can't find a good enough answer. I've taken a look at the most upvoted question regarding the Big-Oh notation, namely this: Plain English explanation of Big O It says there that: For example, sorting algorithms are typically compared based on comparison operations (comparing two nodes to determine their relative ordering). Now let's consider the simple bubble sort algorithm: for (int i = arr.length - 1; i > 0 ; i--) { for (int j = 0; j<i; j++) { if (arr[j] > arr[j+1]) { switchPlaces(...) } } } I know that worst case is O(n^2) and best case is O(n), but what is n exactly? If we attempt to sort an already sorted algorithm (best case), we would end up doing nothing, so why is it still O(n)? We are looping through 2 for-loops still, so if anything it should be O(n^2). n can't be the number of comparison operations, because we still compare all the elements, right? This confuses me, and I appreciate if someone could help me.

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• Can anyone give me a sample java socket programming for doing a peer to peer for 3 systems?

  - by Sadesh Kumar N

  I am doing an university project. I need some sample programs on peer to peer programs in java socket programming. Every where people are telling to add a server socket in the client program. I am in a confusion. Can a single program having server socket and client socket will do or i have to create two programs of one initiating a system and another peer program running thrice to solve the problem. or i need to create three programs for three peer systems. I am not clear on the architecture of building peer to peer programs using java sockets. Can some one help me giving a simple program on how to create a peer to peer connection between three systems. I know how to do a socket program for client server model and clear on the concept. But creating a peer to peer architecture sounds complex for me to understand. I also referred this thread. developing peer to peer in java The person commented second says" To make peer2peer app each client opens server socket too. When client A wishes to connect to client B it just connects to its socket. " Need some more sample and an explanation on how peer to peer java socket program works I dont want any external api like jxta to do this task. I need a clear picture on how it works alone with an example.

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• Adding validations without knowing the fields

  - by Frexuz

  My example form <% form_for @ad do |f| %> <%= f.error_messages %> <p> <%= f.label :ad_type_id %><br /> <%= f.collection_select(:ad_type_id, AdType.all, :id, :name) %> </p> <p> <% @ad.ad_properties.each do |property| %> <%= property.name %>: <% f.fields_for :ad_values do |value_field| %> <%= value_field.text_field :ad_id, :value => @ad.id %> <%= value_field.text_field :ad_property_id, :value => property.id %> <%= value_field.text_field :value %> <% end %><br /><br /> <% end %> </p> <p> <%= f.label :description %><br /> <%= f.text_area :description %> </p> <p><%= f.submit %></p> <% end %> Explanation: Ad has many properties. I can add new properties at any time (it's a normal model). Lets say the Ad is of the type 'hotel'. Then I would add properties like 'stars' and 'breakfast_included' Then I store each of these properties' values in a separate model. And all this works fine with my form above. My problem: These fields are not validated because I can't know what their names are. I need to add validations dynamically somehow. My thought: #Before the normal validations kick in def add_validations self.properties.each do |property| property.add_validation :whatever #somehow :) end end How could I do this?

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• Ruby on Rails or PHP... Somehow uncertain

  - by Clamm

  Hi everybody... I've been thinking about this a long time now but i wanna hear your opinion because i always received the ebst answers here. So in advance... thank you guys. Right now i have to make this decision: Shift a prototype webservice to production quality. Choose either Ruby or PHP... (Background: A friend of mine is joining the project and prefers rails) I've already played around a bit with RoR (only basic stuff) but i am really disappointed about the documentation of Rails and Ruby. In relation to PHP i find only fragments or hard to use references. At the end i am a bit scared. I dont wanna waste my time realizing that i am not capable of doing s.th in Ruby what i could with PHP. Maybe only because i am too stupid and don't find a proper explanation ;-) Did anyone experience this shift and can tell me how easy/hard it was to switch from PHP to Ruby? E.G. would you recommend programming it in PHP and using MVC as a base pattern? Thanks for your opinion!!!

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• Strange bug with PHP on Windows 7

  - by chessweb

  This is the configuration: Windows 7 Home Premium, XAMPP 1.7.3 (Apache 2.2.14 , PHP 5.3.1), Firefox 3.6 This is the PHP-code in a file named 'test.php' in htdocs: <?php echo('04556-8978765'); ?> On http://localhost/test.php I would expect to see the string 04556-8978765 in the browser. This is not what happens, though. The string appears for a short time and then it disappears altogether. Firebug shows an empty body-tag. However, when I look at page source, the string is there alright. When I change the string in the echo-statement to e.g. 4556-8978765, everything is fine. Internet Explorer 8 does not show this strange behavior. I could not reproduce this with the same Apache/PHP/Firefox configuration on Windows XP. '04556-8978765' is by no means unique. The couple '02065-96047' and '02065-9604' behave exactly the same. Can anybody reproduce this and offer an explanation as to what is going on? PS: If you can not see the string '04556-8978765' in the echo-statement above, look at this post with IE8.

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• Nested Lambdas in wxHaskell Library

  - by kunkelwe

  I've been trying to figure out how I can make staticText elements resize to fit their contents with wxHaskell. From what I can tell, this is the default behavior in wxWidgets, but the wxHaskell wrapper specifically disables this behavior. However, the library code that creates new elements has me very confused. Can anyone provide an explanation for what this code does? staticText :: Window a -> [Prop (StaticText ())] -> IO (StaticText ()) staticText parent props = feed2 props 0 $ initialWindow $ \id rect -> initialText $ \txt -> \props flags -> do t <- staticTextCreate parent id txt rect flags {- (wxALIGN_LEFT + wxST_NO_AUTORESIZE) -} set t props return t I know that feed2 x y f = f x y, and that the type signature of initialWindow is initialWindow :: (Id -> Rect -> [Prop (Window w)] -> Style -> a) -> [Prop (Window w)] -> Style -> a and the signature of initialText is initialText :: Textual w => (String -> [Prop w] -> a) -> [Prop w] -> a but I just can't wrap my head around all the lambdas.

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• PHP include taking too long

  - by wxiiir

  I have a php file with around 100mb which is full of arrays (only arrays). I've made a script that includes this file (for processing), first it exhausted the default Xampp 128mb memory limit, i've raised it to 1024mb but it just takes forever and doesn't do anything. I'm sure the problem is being created by the sheer size of the file because i've tried removing all lines of code and just leaving the include and an echo for me to know when it finishes executing, and it does the same thing (which is taking forever), i've also tried to run the 100mb file in separate and same thing again. A 10mb file is taking forever as well but a similar 1mb file is almost instantly read and executed so the problem must be more than just the file size. I was avoiding using c++ for a simple project as this and would rather not to as php is easier for me and the task that will be executed doesn't need to benefit from the added speed that it would have if it had been done in c++ but if i have no luck in solving this problem i guess i'll have to. EDIT Reasons for not using a database: 1-Whoever made it didn't used a database and it will be pretty hard to store this in an organized database if i'm not able to do something with it first, like just reading it, copying parts from it or putting in memory or something. 2-I don't have experience working with databases as pretty much all stuff i've ever done in php didn't needed large amounts of stored data, 50kb at best, if i was thinking about a big project or huge chunks of data as this one, i definitely would, but i didn't made this mess to start with and now i have to undo it. 3-The logic for having to store a small portion of data like 10mb in hard drive when now every computer has pretty much enough ram to fit the whole OS in it is pretty much incomprehensible unless someone gives a good explanation about it, if i had to access a lot of said files simultaneously i would understand but like i said, this is a simple project, this is the only file that will be accessed at a given time this isn't even to make some kind of website, it's to run a few times and be done with it.

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• Javascript object properties access functions in parent constructor?

  - by Bob Spryn

  So I'm using this pretty standard jquery plugin pattern whereby you can grab an api after applying the jquery function to a specific instance. This API is essentially a javascript object with a bunch of methods and data. So I wanted to essentially create some private internal methods for the object only to manipulate data etc, which just doesn't need to be available as part of the API. So I tried this: // API returned with new $.TranslationUI(options, container) $.TranslationUI = function (options, container) { // private function? function monkey(){ console.log("blah blah blah"); } // extend the default settings with the options object passed this.settings = $.extend({},$.TranslationUI.defaultSettings,options); // set a reference for the container dom element this.container = container; // call the init function this.init(); }; The problem I'm running into is that init can't call that function "monkey". I'm not understanding the explanation behind why it can't. Is it because init is a prototype method?($.TranslationUI's prototype is extended with a bunch of methods including init elsewhere in the code) $.extend($.TranslationUI, { prototype: { init : function(){ // doesn't work monkey(); // editing flag this.editing = false; // init event delegates here for // languagepicker $(this.settings.languageSelector, this.container).bind("click", {self: this}, this.selectLanguage); } } }); Any explanations would be helpful. Would love other thoughts on creating private methods with this model too. These particular functions don't HAVE to be in prototype, and I don't NEED private methods protected from being used externally, but I want to know how should I have that requirement in the future.

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• Oracle Query Optimization: Why is My Second Query Faster?

  - by Patrick Cuff

  I was having some performance issues with an Oracle query, so I downloaded a trial of the Quest SQL Optimizer for Oracle, which made some changes that dramatically improved the query's performance. I'm not exactly sure why the recommended query had such an improvement; can anyone provide an explanation? Before: SELECT t1.version_id, t1.id, t2.field1, t3.person_id, t2.id FROM table1 t1, table2 t2, table3 t3 WHERE t1.id = t2.id AND t1.version_id = t2.version_id AND t2.id = 123 AND t1.version_id = t3.version_id AND t1.VERSION_NAME <> 'AA' order by t1.id Plan Cost: 831 Elapsed Time: 00:00:21.40 Number of Records: 40,717 After: SELECT /*+ USE_NL_WITH_INDEX(t1) */ t1.version_id, t1.id, t2.field1, t3.person_id, t2.id FROM table2 t2, table3 t3, table1 t1 WHERE t1.id = t2.id + 0 AND t1.version_id = t2.version_id + 0 AND t2.id = 123 AND t1.version_id = t3.version_id + 0 AND t1.VERSION_NAME || '' <> 'AA' AND t3.version_id = t2.version_id + 0 order by t1.id Plan Cost: 686 Elapsed Time: 00:00:00.95 Number of Records: 40,717 Questions: Why does re-arranging the order of the tables in the FROM clause help? Why does adding + 0 to the WHERE clause comparisons help? Why does || '' <> 'AA' in the WHERE clause VERSION_NAME comparison help? Is this a more efficient way of handling possible nulls on this column?

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• SQL query select from table and group on other column...

  - by scaryjones

  I'm phrasing the question title poorly as I'm not sure what to call what I'm trying to do but it really should be simple. I've a link / join table with two ID columns. I want to run a check before saving new rows to the table. The user can save attributes through a webpage but I need to check that the same combination doesn't exist before saving it. With one record it's easy as obviously you just check if that attributeId is already in the table, if it is don't allow them to save it again. However, if the user chooses a combination of that attribute and another one then they should be allowed to save it. Here's an image of what I mean: So if a user now tried to save an attribute with ID of 1 it will stop them, but I need it to also stop them if they tried ID's of 1, 10 so long as both 1 and 10 had the same productAttributeId. I'm confusing this in my explanation but I'm hoping the image will clarify what I need to do. This should be simple so I presume I'm missing something.

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