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• How to force oracle to use index range scan?

  - by wsb3383

  Hi, all. I have a series of extremely similar queries that I run against a table of 1.4 billion records (with indexes), the only problem is that at least 10% of those queries take 100x more time to execute than others. I ran an explain plan and noticed that the for the fast queries (roughly 90%) Oracle is using an index range scan (on my created), while on the slow one, it's using a full index scan. Is there a way to force Oracle to do a an index range scan? Thanks!

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• How do chains work in Rainbow tables?

  - by James Moore

  Hello, I was wondering if should one could explain in detail how chains work in rainbow tables as though you would a complete novice but with relevance to programming. I understand that a chain is 16 bytes long. 8 bytes mark the starting point and 8 mark the end. I also understand that in the filename we have the chain length i.e. 2400. Which means that between our starting point and end point in just 16 bytes we have 2400 possible clear texts? What? How does that work? in those 16 bytes how do i get my 2400 hashes and clear texts or am i miss understanding this? Your help is greatly appreciated. Thanks P.s. I have read the related papers and googled this topic a fair bit. I think im just missing something important to make these gears turn.

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• Git pre-receive hook

  - by Ralphz

  Hi When you enable pre-receive hook for git repository: It takes no arguments, but for each ref to be updated it receives on standard input a line of the format: < old-value SP < new-value SP < ref-name LF where < old-value is the old object name stored in the ref, < new-value is the new object name to be stored in the ref and is the full name of the ref. When creating a new ref, < old-value is 40 0. Does anyone can explain me how do I examine all the files that will be changed in the repository if i allow this commit? I'd like to run that files through some scripts to check syntax and so on. Thanks.

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• Why would I do an inner join on a non-distinct field?

  - by froadie

  I just came across a query that does an inner join on a non-distinct field. I've never seen this before and I'm a little confused about this usage. Something like: SELECT distinct all, my, stuff FROM myTable INNER JOIN myOtherTable ON myTable.nonDistinctField = myOtherTable.nonDistinctField (WHERE some filters here...) I'm not quite sure what my question is or how to phrase it, or why exactly this confuses me, but I was wondering if anyone could explain why someone would need to do an inner join on a non-distinct field and then select only distinct values...? Is there ever a legitimate use of an inner join on a non-distinct field? What would be the purpose? And if there's is a legitimate reason for such a query, can you give examples of where it would be used?

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• Check if hydrated doctrine result is NULL

  - by iggnition

  Hi, I'm trying to check if a result in my DQL is NULL. I got the following DQL query: $q = self::createQuery("l") ->select('i.*, s.aantal, m.naam, c.cat_naam, a.app_id') ->from('InstalledBase i, i.Spare s, i.Apparaat a, a.Categorie c, a.Merk m') ->execute(); return $q; Now i want to check if the s.aantal is NULL so i do: if(is_null($installedbase->Spare->spare_id)) when the variable is NOT null everything works, but when it is actually NULL i get a E notice message: Notice: Trying to get property of non-object in \installedbase\templates\_index.php on line 29 It does see that it is null though because the if condition is executed. Weird thing is i'm doing the exact same thing on another page where it works no problem. But i must be doing something wrong or stupid since those messages generally don't show for nothing. So can anybody explain this to me? :)

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• free switch : what is tls_port ?

  - by kiruthika

  Hi all, I am beginner to free switch.I have gone through the configuration file vars.xml in free switch. In this I have seen the following configurations. <X-PRE-PROCESS cmd="set" data="internal_auth_calls=true"/> <X-PRE-PROCESS cmd="set" data="internal_sip_port=5070"/> <X-PRE-PROCESS cmd="set" data="internal_tls_port=5071"/> <X-PRE-PROCESS cmd="set" data="internal_ssl_enable=false"/> <X-PRE-PROCESS cmd="set" data="internal_ssl_dir=$${base_dir}/conf/ssl"/> In the above I am having the doubt with tls_port. What is the use of tls_port .I have searched about this in net and I have read that tls protocol is used for secure data transfer in network. So please explain me about the communication in freeswitch. Thanks in advance.

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• Error while installing dependencies for PyGTK on Mac OS 10.6.3

  - by Winston C. Yang

  I tried to install the following dependencies for PyGTK 2.16.0 (the Python GIMP Tool Kit) on Mac OS 10.6.3: glib 2.25.5 gettext-0.18 libiconv-1.13.1 When I tried to install glib, I got the following error message: gconvert.c:55:2: error: #error GNU libiconv not in use but included iconv.h is from libiconv The libiconv web page talks about a circular dependency between gettext and libiconv---build one, then build the other, then build the first again. I tried to do this, though possibly incorrectly. (Will the following work: make distclean; ./configure; make; sudo make install?) The author of a posting had the same problem, and he solved it by installing libiconv-1.13.1. Could anyone explain the error in more detail, and how to correct it?

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• Python: split a list based on a condition?

  - by Parand

  What's the best way, both aesthetically and from a performance perspective, to split a list of items into multiple lists based on a conditional? The equivalent of: good = [x for x in mylist if x in goodvals] bad = [x for x in mylist if x not in goodvals] is there a more elegant way to do this? Update: here's the actual use case, to better explain what I'm trying to do: # files looks like: [ ('file1.jpg', 33L, '.jpg'), ('file2.avi', 999L, '.avi'), ... ] IMAGE_TYPES = ('.jpg','.jpeg','.gif','.bmp','.png') images = [f for f in files if f[2].lower() in IMAGE_TYPES] anims = [f for f in files if f[2].lower() not in IMAGE_TYPES]

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• Fixing warning from git

  - by japancheese

  I've been doing a workflow of making a git repository on a remote central repository, cloning that repo on my local dev machine, doing some work, and then pushing the changes back to the same repo on the remote server. However, and I believe this was after an update I did to git recently, after pushing up a change, I'm getting the following warning: Counting objects: 2724, done. Delta compression using up to 2 threads. Compressing objects: 100% (2666/2666), done. Writing objects: 100% (2723/2723), 5.90 MiB | 313 KiB/s, done. Total 2723 (delta 219), reused 0 (delta 0) warning: updating the currently checked out branch; this may cause confusion, as the index and working tree do not reflect changes that are now in HEAD. Can someone explain to me exactly what this warning means, and what I'm doing wrong in my workflow to not receive this warning?

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• Can I set a property on an object that is only declared on the instance type, when I don't know the

  - by WilberBeast

  Let me explain. I have a List into which I am adding various ASP.NET controls. I then wish to loop through the list and set a CssClass, however not every Control supports the property CssClass. What I would like to do is test if the underlying instance type supports the CssClass property and set it, but I'm not sure how to do the conversion prior to setting the property since I don't know the type of each Control object. I know that I can use typeof or x.GetType(), but I'm not sure how to use these to convert the controls back to the instance type in order to test for and then set the property. Actually I seem to have solved this, so I thought that I would post the code here for others. foreach (Control c in controlList) { PropertyInfo pi = c.GetType().GetProperty("CssClass"); if (pi != null) pi.SetValue(c, "desired_css_class", null); } I hope that this helps someone else as I has taken me hours to research these 2 lines of code. Cheers Steve

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• Why doesnt R.raw.'songname' not work on android devices?

  - by James Rattray

  I have some media (Audio tracks) on an app... With file path 'R.raw.test' I use some code to get it into a mediaplayer... MediaPlayer.create(Textbox.this, R.raw.fly); And it works PERFECTLY on the Android Emulator... (Plays track on click of button) Can someone explain why, when I put it on my Archos (5 IT) it doesnt work at all? -As soon as the button is clicked, it crashes... Do you have to do something to file paths or what? Please help... Thanks alot... James

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• How to use a DHT for a social trading environment

  - by Lirik

  I'm trying to understand if a DHT can be used to solve a problem I'm working on: I have a trading environment where professional option traders can get an increase in their risk limit by requesting that fellow traders lend them some of their risk limit. The lending trader will can either search for traders with certain risk parameters which are part of every trader's profile, i.e. Greeks, or the lending trader can subscribe to requests from certain traders. I want this environment to be scalable and decentralized, but I don't know how traders can search for specific profile parameters when the data is contained in a DHT. Could anybody explain how this can be done?

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• How do I use a shared library (in this case JsonCpp) in my C++ program on Linux?

  - by Not Joe Bloggs

  I'm a new-ish C++ programmer, and I'm doing my first program on my own using C++. I decided I would like to use JSON to store some of the data I'm going to be using, and I've found a library to handle JSON, JsonCpp. I've installed the library using my Linux system's package manager, and in my C++ code, I've used in my source code file #include <json> and compiled it using g++ and it's -ljson and -L/usr/lib options (libjson.so is located in /usr/lib). However, the first usage of Json::Value, an object provided by the library, gives a compilation error of "Json has not declared". I'm sure my mistake is something simple, so could someone explain what I'm doing wrong? None of the books I had mention how to use shared libraries, so I've had to google to find this much.

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• CSS button not styling

  - by o-logn

  Hey, I must be missing something obvious, but can someone explain what I'm doing wrong with my CSS? I would like all buttons to have a certain format, except a few. I was expecting to use CssClass in order to override the few that should be different, but they all seem to use the standard one. My CSS: .btn { border:none; background-color:red; } input[type="submit"] { border: 2px solid black; background-color:green; } All the buttons take the second value (green background, with a border). However, I have this button: <asp:Button ID="btnAdd" CssClass="btn" runat="server" Text="Add" /> I was expecting this to have no border, and a red background, but it's the same as every other button. Any ideas what I'm doing wrong? Thanks

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• .NET: What is the purpose of the ProhibitDtd property in XmlReaderSettings? Why is DTD a security i

  - by Cheeso

  The documentation says: When set to true, the XmlReader throws an XmlException when any DTD content is encountered. Do not enable DTD processing if you are concerned about Denial of Service issues or if you are dealing with untrusted sources. If you have DTD processing enabled, you can use the XmlSecureResolver to restrict the resources that the XmlReader can access. You can also design your application so that the XML processing is memory and time constrained. For example, configure time-out limits in your ASP.NET application. Can someone please explain the issue? Why would a reader application want to prohibit the retrieval of a DTD? Where is the denial-of-service issue, if it is a reading application? What is the "trust" issue that is mentioned? Thanks

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• How to write a virtual conditional breakpoint in java

  - by Phuong Nguyen de ManCity fan

  I'm sorry if the question title may mis-inform you, but I cannot find a proper word to explain that. If you ever working with .NET, you would know that there is Assert class that will automatically wake up and attach debugger if necessary and then have debugger (Visual Studio) pausing at the Assert command, given the Assert command failed. Given I'm running a java program and having debugger connected, then how can I have debugger to break on certain condition without manually setup a break point? I'm expecting something like that: void doSomeThing(String x){ if (x==null) breakDebuggerNow(); }

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• How to add data manually in core data entity

  - by pankaj

  Hi I am working on core data for the first time. I have just created an entity and attributes for that entity. I want to add some data inside the entity(u can say i want to add data in a table), earlier i when i was using sqlite, i would add data using terminal. But here in core data i am not able to find a place where i can manually add data. I just want to add data in entity and display it in a UITableView. I have gone through the the documentation of core data but it does not explain how to add data manually although it explains how i can add it programmiticaly but i dont need to do it programically. I want to do it manually. Thanks in advance

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• css absolute position won't work with margin-left:auto margin-right: auto

  - by user1118019

  Say you have the following css applied to a div tag .divtagABS { position: absolute; margin-left: auto; margin-right:auto; } the margin-left and margin-right does not take effect but if you have relative, it works fine i.e. ,divtagREL { position: relative; margin-left: auto; margin-right:auto; } why is that? i just want to center an element can someone explain why setting margins to auto in absolute position does not work?

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• C++ Static array vs. Dynamic array?

  - by user69514

  What is the difference between a static array and a dynamic array in C++? I have to do an assignment for my class and it says not to use static arrays, only dynamic arrays. I've looked in the book and online, but I don't seem to understand. I thought static was created at compile time and dynamic at runtime, but I might be mistaken this with memory allocation. Can you explain to me the difference between static array and dynamic array in C++? Thnaks.

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• WPF MVVM Pattern - References

  - by KroaX

  Hi everyone I wanted to know if some of you guys can post some articles, blog posts etc. that explain the MVVM Pattern in detail. There are not much explainations out there I think ( except Tutorials). I'm going to write my exam about WPF and also want to build in the MVVM Pattern. So I need some good references that are also digging a little deeper. I think I already have read a lot of texts about MVVM, but maybe you guys got some I didn't read yet. Would really appreciate if you would share your links to good and worth reading articles and explanations

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• Difference between mutableArrayValueForKey and calling insertObject:inEmployeesAtIndex: directly

  - by jasonbogd

  I have a question regarding using KVO-compliant methods to insert/remove objects from an array. I'm working through Aaron Hillegass' Cocoa Programming for Mac OS X and I saw the following line of code (in the insertObject:inEmployeesAtIndex: method: [[undoManager prepareWithInvocationTarget:self] removeObjectFromEmployeesAtIndex:index]; Correct me if I'm wrong, but I always thought it was better to call mutableArrayValueForKey: and then removeObjectAtIndex:...so I tried changing the above line to this: [[undoManager prepareWithInvocationTarget:[self mutableArrayValueForKey:@"employees"]] removeObjectAtIndex:index]; And it didn't work. Can someone explain the difference and why the first line works but the second line doesn't?

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• Why are alloc and init called separately in Objective-C?

  - by André Hoffmann

  Note: I'm relatively new to Objective-C and am coming from Java and PHP. Could someone explain to me why I always have to first allocate and then initialize an instance? Couldn't this be done in the init methods like this: + (MyClass*)init { MyClass *instance = [MyClass alloc]; [instance setFoo:@"bla"]; return instance; } + (MyClass*)initWithString:(NSString*)text { MyClass *instance = [MyClass init]; [instance setFoo:text]; return instance; } ... Is this just a relict from the old C days or is there something that I'm not seeing? I know this isn't a problem as I could as well always call alloc and init, but since it's a bit tedious I'd like to at least know why I'm doing it. I'm liking the expressiveness of the language so far, but this is something that I want to fully understand in order to think the Objective-C way. Thank you!

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• (fluxus) learning curve

  - by Inaimathi

  I'm trying to have some fun with fluxus, but its manual and online docs all seem to assume that the reader is already an expert network programmer who's never heard of Scheme before. Consequently, you get passages that try to explain the very basics of prefix notation, but assume that you know how to pipe sound-card data into the program, or setup and connect to an OSC process. Is there any tutorial out there that goes the opposite way? IE, assumes that you already have a handle on the Lisp/Scheme thing, but need some pointers before you can properly set up sound sources or an OSC server? Barring that, does anyone know how to get (for example) the system microphone to connect to (fluxus), or how to get it to play a sound file from disk?

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• How to check for empty values on two fields then prompt user of error using javascript

  - by Matthew

  Hello guys, I hope I can explain this right I have two input fields that require a price to be entered into them in order for donation to go through and submit. The problem that I am having is that I would like the validation process check to see if one of the two fields has a value if so then proceed to submit. If both fields are empty then alert. This is what I have in place now: function validate_required(field,alerttxt) { with (field) { if (value==null||value=="") {alert(alerttxt);return false;} else {return true} } } function validate_form(thisform) { with (thisform) { if (validate_required(input1,"Need a donation amount to continue")==false) {input1.focus();return false;} else if (validate_required(input2,"Need a donation amount to continue")==false) {input2.focus();return false;} } } I would like to ultimately like to get this over to Jquery as well Thanks guys any help would do Matt

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• Using Dijkstra's algorithm with negative edges?

  - by Riddler

  Most books explain the reason the algorithm doesn't work with negative edges as nodes are deleted from the priority queue after the node is arrived at since the algorithm assumes the shortest distance has been found. However since negative edges can reduce the distance, a future shorter distance might be found; but since the node is deleted it cannot be updated. Wouldn't an obvious solution to this be to not delete the node? Why not keep the node in the queue, so if a future shorter distance is found, it can be updated? If I am misunderstanding the problem, what is preventing the algorithm from being used with negative edges?

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