Search Results

Search found 97855 results on 3915 pages for 'code performance'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 104/3915 | < Previous Page | 100 101 102 103 104 105 106 107 108 109 110 111  | Next Page >

  • Mechanics of reasoning during programming interviews

    - by user129506
    This is not the usual "I don't want to write code during an interview", in this question the assumption is that I need to write code during an interview (think about the level of rewriting the quicksort or mergesort from scratch) I know how the algorithm work or I have a basic idea of how I should start working from there, i.e. I don't remember the algorithm by heart I noticed that even on a whiteboard, I always end up writing bugged code or code that doesn't compile. If there's a typo, whatever I usually live with that.. but when there's a crash due to some uncaught particular case I end up losing confidence in my skills. I realize that perhaps interviewers might want to look at how I write code and/or how I solve problems rather than proof-compiling my whiteboard code, but I'd like to ask how should I approach the above problem in mental terms, i.e. what mental steps should I follow when writing code for an interview with the two bullet points above. There must be a unique and agreed series of steps I should follow to avoid getting stuck/caught into particular exception cases (limit cases) that might end up wasting my time and my energies rather than focusing on the overall algorithm for the general case. I hope I made my point clear

    Read the article

  • My first blog post…

    - by steveh99999
    I’ve been meaning to start a blog for a while now, (OK, for several years…..) - finally now, here it begins First post, something really simple but, a wise-man once told me about the best way to improve SQL server performance. Store Less Data. That's it.. that's all there is to it... Over the years, I've seen the following :- -  a 200Gb database which held 3 days data. Once business requirements changed, we were able to hold only 1 days data in this database. -  a table developed by DBAs to hold application table cardinality information - that information was collected at 2 hour intervals every day for 7 years ! After 7 years the DBA space-info table had become the largest table in the database - 60 million rows !  It was a simple change to remove alot of the historical intra-day data and change the schedule to run only once per evening. Suddenly that table held 6 million rows instead of 60 million.... - lots of backup and restore history held in msdb. See this post by Brent Ozar for more details on this issue. Imagine how much faster the backups, DBCC Checks and reindexes ran when the above 3 changes were implemented ?   How often do you review your big databases \ tables to see if you’re actually holding only data that is really required by the business ?

    Read the article

  • Why is quicksort better than other sorting algorithms in practice?

    - by Raphael
    This is a repost of a question on cs.SE by Janoma. Full credits and spoils to him or cs.SE. In a standard algorithms course we are taught that quicksort is O(n log n) on average and O(n²) in the worst case. At the same time, other sorting algorithms are studied which are O(n log n) in the worst case (like mergesort and heapsort), and even linear time in the best case (like bubblesort) but with some additional needs of memory. After a quick glance at some more running times it is natural to say that quicksort should not be as efficient as others. Also, consider that students learn in basic programming courses that recursion is not really good in general because it could use too much memory, etc. Therefore (and even though this is not a real argument), this gives the idea that quicksort might not be really good because it is a recursive algorithm. Why, then, does quicksort outperform other sorting algorithms in practice? Does it have to do with the structure of real-world data? Does it have to do with the way memory works in computers? I know that some memories are way faster than others, but I don't know if that's the real reason for this counter-intuitive performance (when compared to theoretical estimates).

    Read the article

  • Use a SQL Database for a Desktop Game

    - by sharethis
    Developing a Game Engine I am planning a computer game and its engine. There will be a 3 dimensional world with first person view and it will be single player for now. The programming language is C++ and it uses OpenGL. Data Centered Design Decision My design decision is to use a data centered architecture where there is a global event manager and a global data manager. There are many components like physics, input, sound, renderer, ai, ... Each component can trigger and listen to events. Moreover, each component can read, edit, create and remove data. The question is about the data manager. Whether to Use a Relational Database Should I use a SQL Database, e.g. SQLite or MySQL, to store the game data? This contains virtually all game content like items, characters, inventories, ... Except of meshes and textures which are even more performance related, so I will keep them in memory. Is a SQL database fast enough to use it for realtime reading and writing game informations, like the position of a moving character? I also need to care about cross-platform compatibility. Aside from keeping everything in memory, what alternatives do I have? Advantages Would Be The advantages of using a relational database like MySQL would be the data orientated structure which allows fast computation. I would not need objects for representing entities. I could easily query data of objects near the player needed for rendering. And I don't have to take care about data of objects far away. Moreover there would be no need for savegames since the hole game state is saved in the database. Last but not least, expanding the game to an online game would be relative easy because there already is a place where the hole game state is stored.

    Read the article

  • Java single Array best choice for accessing pixels for manipulation?

    - by Petrol
    I am just watching this tutorial https://www.youtube.com/watch?v=HwUnMy_pR6A and the guy (who seems to be pretty competent) is using a single array to store and access the pixels of his to-be-rendered image. I was wondering if this really is the best way to do this. The alternative of Multi-Array does have one pointer more, but Arrays do have an O(1) for accessing each index and calculating the index in a single array seems to take one addition and one multiplication operation per pixel. And if Multi-Arrays really are bad, can't you use something with Hashing to avoid those addition and multiplication operations? EDIT: here is his code... public class Screen { private int width, height; public int[] pixels; public Screen(int width, int height) { this.width = width; this.height = height; // creating array the size of one index/int for every pixel // single array has better performance than multi-array pixels = new int[width * height]; } public void render() { for (int y = 0; y < height; y++) { for (int x = 0; x < width; x++) { pixels[x + y * width] = 0xff00ff; } } } }

    Read the article

  • Invariant code contracts – using class-wide contracts

    - by DigiMortal
    It is possible to define invariant code contracts for classes. Invariant contracts should always hold true whatever member of class is called. In this posting I will show you how to use invariant code contracts so you understand how they work and how they should be tested. This is my randomizer class I am using to demonstrate code contracts. I added one method for invariant code contracts. Currently there is one contract that makes sure that random number generator is not null. public class Randomizer {     private IRandomGenerator _generator;       private Randomizer() { }       public Randomizer(IRandomGenerator generator)     {         _generator = generator;     }       public int GetRandomFromRangeContracted(int min, int max)     {         Contract.Requires<ArgumentOutOfRangeException>(             min < max,             "Min must be less than max"         );           Contract.Ensures(             Contract.Result<int>() >= min &&             Contract.Result<int>() <= max,             "Return value is out of range"         );           return _generator.Next(min, max);     }       [ContractInvariantMethod]     private void ObjectInvariant()     {         Contract.Invariant(_generator != null);     } } Invariant code contracts are define in methods that have ContractInvariantMethod attribute. Some notes: It is good idea to define invariant methods as private. Don’t call invariant methods from your code because code contracts system does not allow it. Invariant methods are defined only as place where you can keep invariant contracts. Invariant methods are called only when call to some class member is made! The last note means that having invariant method and creating Randomizer object with null as argument does not automatically generate exception. We have to call at least one method from Randomizer class. Here is the test for generator. You can find more about contracted code testing from my posting Code Contracts: Unit testing contracted code. There is also explained why the exception handling in test is like it is. [TestMethod] [ExpectedException(typeof(Exception))] public void Should_fail_if_generator_is_null() {     try     {         var randomizer = new Randomizer(null);         randomizer.GetRandomFromRangeContracted(1, 4);     }     catch (Exception ex)     {         throw new Exception(ex.Message, ex);     } } Try out this code – with unit tests or with test application to see that invariant contracts are checked as soon as you call some member of Randomizer class.

    Read the article

  • Advanced donut caching: using dynamically loaded controls

    - by DigiMortal
    Yesterday I solved one caching problem with local community portal. I enabled output cache on SharePoint Server 2007 to make site faster. Although caching works fine I needed to do some additional work because there are some controls that show different content to different users. In this example I will show you how to use “donut caching” with user controls – powerful way to drive some content around cache. About donut caching Donut caching means that although you are caching your content you have some holes in it so you can still affect the output that goes to user. By example you can cache front page on your site and still show welcome message that contains correct user name. To get better idea about donut caching I suggest you to read ScottGu posting Tip/Trick: Implement "Donut Caching" with the ASP.NET 2.0 Output Cache Substitution Feature. Basically donut caching uses ASP.NET substitution control. In output this control is replaced by string you return from static method bound to substitution control. Again, take a look at ScottGu blog posting I referred above. Problem If you look at Scott’s example it is pretty plain and easy by its output. All it does is it writes out current user name as string. Here are examples of my login area for anonymous and authenticated users:    It is clear that outputting mark-up for these views as string is pretty lame to implement in code at string level. Every little change in design will end up with new version of controls library because some parts of design “live” there. Solution: using user controls I worked out easy solution to my problem. I used cache substitution and user controls together. I have three user controls: LogInControl – this is the proxy control that checks which “real” control to load. AnonymousLogInControl – template and logic for anonymous users login area. AuthenticatedLogInControl – template and logic for authenticated users login area. This is the control we render for each user separately because it contains user name and user profile fill percent. Anonymous control is not very interesting because it is only about keeping mark-up in separate file. Interesting parts are LogInControl and AuthenticatedLogInControl. Creating proxy control The first thing was to create control that has substitution area where “real” control is loaded. This proxy control should also be available to decide which control to load. The definition of control is very primitive. <%@ Control EnableViewState="false" Inherits="MyPortal.Profiles.LogInControl" %> <asp:Substitution runat="server" MethodName="ShowLogInBox" /> But code is a little bit tricky. Based on current user instance we decide which login control to load. Then we create page instance and load our control through it. When control is loaded we will call DataBind() method. In this method we evaluate all fields in loaded control (it was best choice as Load and other events will not be fired). Take a look at the code. public static string ShowLogInBox(HttpContext context) {     var user = SPContext.Current.Web.CurrentUser;     string controlName;       if (user != null)         controlName = "AuthenticatedLogInControl.ascx";     else         controlName = "AnonymousLogInControl.ascx";       var path = "~/_controltemplates/" + controlName;     var output = new StringBuilder(10000);       using(var page = new Page())     using(var ctl = page.LoadControl(path))     using(var writer = new StringWriter(output))     using(var htmlWriter = new HtmlTextWriter(writer))     {         ctl.DataBind();         ctl.RenderControl(htmlWriter);     }     return output.ToString(); } When control is bound to data we ask to render it its contents to StringBuilder. Now we have the output of control as string and we can return it from our method. Of course, notice how correct I am with resources disposing. :) The method that returns contents for substitution control is static method that has no connection with control instance because hen page is read from cache there are no instances of controls available. Conclusion As you saw it was not very hard to use donut caching with user controls. Instead of writing mark-up of controls to static method that is bound to substitution control we can still use our user controls.

    Read the article

  • Ever any performance different between Java >> and >>> right shift operators?

    - by Sean Owen
    Is there ever reason to think the (signed) and (unsigned) right bit-shift operators in Java would perform differently? I can't detect any difference on my machine. This is purely an academic question; it's never going to be the bottleneck I'm sure. I know: it's best to write what you mean foremost; use for division by 2, for example. I assume it comes down to which architectures have which operations implemented as an instruction.

    Read the article

  • Will client side performance improve if images/scripts/styles on different subdomains?

    - by Andrey
    Hi, I have a domain specifically for static content, so cookies don't travel along with requests to images/scripts/css. Now, I think I've read somewhere that most browsers only open one download thread for each domain/subdomain, so different static content can't be downloaded in parallel if on the same domain. Will it make difference for browsers if i place scripts in script.mycdn.com, styles in css.mycdn.com and images in images.mycdn.com? Will it allow to let browser download images at the same time as scripts and styles? mycdn.com is of course a made up name :) Thanks! Andrey

    Read the article

  • How best to pre-install OR pre-load OR cache Java Script library to optimize performance.

    - by Kabeer
    Hello. I am working for an intranet application. Therefore I have some control on the client machines. The Java Script library I am using is somewhat big in size. I would like to pre-install OR pre-load OR cache the Java Script library on each machine (each browser as well) so that it does not travel for each request. I know that browsers do cache a Java Script library for subsequent requests but I would like the library to be cached once so all subsequent requests, sessions and users. What is the best mechanism to achieve this?

    Read the article

  • How best to pre-install OR pre-load OR cache JavaScript library to optimize performance?

    - by Kabeer
    Hello. I am working for an intranet application. Therefore I have some control on the client machines. The JavaScript library I am using is somewhat big in size. I would like to pre-install OR pre-load OR cache the JavaScript library on each machine (each browser as well) so that it does not travel for each request. I know that browsers do cache a JavaScript library for subsequent requests but I would like the library to be cached once for all subsequent requests, sessions and users. What is the best mechanism to achieve this?

    Read the article

  • Why does Microsoft Windows' performance appear to degrade over time?

    - by Ben Aston
    Windows XP/2k3 and earlier (can't attest to Vista, but suspect it's the same) all appear to become more sluggish over time as applications are installed and uninstalled. This is not a scientifically tested observation, but more of a learned-through-experience piece of wisdom. (I've always suspected the registry as being behind the issue.) Does anyone have any concrete evidence of this degradation occurring, or it just an invalid perception of mine?

    Read the article

  • How can I improve the performance of this double-for print?

    - by Florenc
    I have the following static method that prints the data imported from a 40.000 lines .xls spreadsheet. Now, it takes about 27 seconds to print the data in the console and the memory consumption is huge. import org.apache.poi.hssf.usermodel.*; import org.apache.poi.ss.usermodel.*; public static void printSheetData(List<List<HSSFCell>> sheetData) { for (int i = 0; i < sheetData.size(); i++) { List<HSSFCell> list = (List<HSSFCell>) sheetData.get(i); for (int j = 0; j < list.size(); j++) { HSSFCell cell = (HSSFCell) list.get(j); System.out.print(cell.toString()); if (j < list.size() - 1) { System.out.print(", "); } } System.out.println(""); } } Disclaimer: I know, I know large data belong to a database, don't print output in the console, premature optimization is the root of all evils...

    Read the article

  • Does clustered index on foreign key column increase join performance vs non-clustered ?

    - by alpav
    In many places it's recommended that clustered indexes are better utilized when used to select range of rows using BETWEEN statement. When I select joining by foreign key field in such a way that this clustered index is used, I guess, that clusterization should help too because range of rows is being selected even though they all have same clustered key value and BETWEEN is not used. Considering that I care only about that one select with join and nothing else, am I wrong with my guess ?

    Read the article

  • How can I Monitor the Performance of Individual Apps on Windows?

    My XP machine has become terribly slow and I want to identify the application at fault. It seems to be related to disk access rather than processor hogging. I can look at the task manager to get a good idea but it's not ideal. I was wondering if there was some application that can monitor all aspects of processes effectively. Is Process Explorer my only hope?

    Read the article

  • Performance, serve all CSS at once, or as its needed?

    - by yaya3
    As far as I know, these days there are two main techniques used for including CSS in a website. A) Provide all the CSS used by the website in one (compressed) file B) Provide the CSS for required by the elements on the page that is currently being viewed only Positives for A: The entire CSS used on the site is cached on first visit via 1 http request Negatives for A: if it's a big file, it will take a long time to load initially Positives for B: Faster initial load time Negatives for B: More HTTP requests, more files to cache Is there anything (fundamental) that I am missing here?

    Read the article

  • What performance indicators can I use to convince management that I need my development PC upgraded?

    - by Aaron Daniels
    At work, my PC is slow. I feel that I can be way more productive if I just wasn't waiting for Visual Studio and everything else to respond. My PC isn't bad (dual-core, 3GB of RAM), but there is a lot of corporate software and whatnot to slow everything down and sometimes lock it up. Now, some developers have begun getting Windows 7 machines with 8 GB of RAM. Of course, I start salivating at this. However, I was told that I "had to justify" why I should get a new machine. I can think of a lot of different things, but I am curious as to what every one else on SO would have to say. NOTE: Ideally, these reasons should be specifically related to .NET development in Visual Studio on a Windows machine. This isn't a "how can I make my machine faster" question.

    Read the article

  • Can I improve performance by refactoring SQL commands into classes?

    - by Matthew Jones
    Currently, my entire website does updating from SQL parameterized queries. It works, we've had no problems with it, but it can occasionally be very slow. I was wondering if it makes sense to refactor some of these SQL commands into classes so that we would not have to hit the database so often. I understand hitting the database is generally the slowest part of any web application For example, say we have a class structure like this: Project (comprised of) Tasks (comprised of) Assignments Where Project, Task, and Assignment are classes. At certain points in the site you are only working on one project at a time, and so creating a Project class and passing it among pages (using Session, Profile, something else) might make sense. I imagine this class would have a Save() method to save value changes. Does it make sense to invest the time into doing this? Under what conditions might it be worth it?

    Read the article

  • Can I improve performance by refactoring SQL commands into C# classes?

    - by Matthew Jones
    Currently, my entire website does updating from SQL parameterized queries. It works, we've had no problems with it, but it can occasionally be very slow. I was wondering if it makes sense to refactor some of these SQL commands into classes so that we would not have to hit the database so often. I understand hitting the database is generally the slowest part of any web application For example, say we have a class structure like this: Project (comprised of) Tasks (comprised of) Assignments Where Project, Task, and Assignment are classes. At certain points in the site you are only working on one project at a time, and so creating a Project class and passing it among pages (using Session, Profile, something else) might make sense. I imagine this class would have a Save() method to save value changes. Does it make sense to invest the time into doing this? Under what conditions might it be worth it?

    Read the article

  • Is there a performance gain from defining routes in app.yaml versus one large mapping in a WSGIAppli

    - by jgeewax
    Scenario 1 This involves using one "gateway" route in app.yaml and then choosing the RequestHandler in the WSGIApplication. app.yaml - url: /.* script: main.py main.py from google.appengine.ext import webapp class Page1(webapp.RequestHandler): def get(self): self.response.out.write("Page 1") class Page2(webapp.RequestHandler): def get(self): self.response.out.write("Page 2") application = webapp.WSGIApplication([ ('/page1/', Page1), ('/page2/', Page2), ], debug=True) def main(): wsgiref.handlers.CGIHandler().run(application) if __name__ == '__main__': main() Scenario 2: This involves defining two routes in app.yaml and then two separate scripts for each (page1.py and page2.py). app.yaml - url: /page1/ script: page1.py - url: /page2/ script: page2.py page1.py from google.appengine.ext import webapp class Page1(webapp.RequestHandler): def get(self): self.response.out.write("Page 1") application = webapp.WSGIApplication([ ('/page1/', Page1), ], debug=True) def main(): wsgiref.handlers.CGIHandler().run(application) if __name__ == '__main__': main() page2.py from google.appengine.ext import webapp class Page2(webapp.RequestHandler): def get(self): self.response.out.write("Page 2") application = webapp.WSGIApplication([ ('/page2/', Page2), ], debug=True) def main(): wsgiref.handlers.CGIHandler().run(application) if __name__ == '__main__': main() Question What are the benefits and drawbacks of each pattern? Is one much faster than the other?

    Read the article

  • Tips for improving performance of DB that is above size 40 GB (Sql Server 2005) and growing monthly

    - by HotTester
    The current DB or our project has crossed over 40 GB this month and on an average it is growing monthly by around 3 GB. Now all the tables are best normalized and proper indexing has been used. But still as the size is growing it is taking more time to fire even basic queries like 'select count(1) from table'. So can u share some more points that will help in this front. Database is Sql Server 2005. Further if we implement Partitioning wouldn't it create a overhead ? Thanks in advance.

    Read the article

  • Drawing performance in Java 6 updates 19,20 versus Java 6 update 3 ?

    - by Pesho
    I'm getting twice the frame rate with the earlier Java 6 u 3, than with the new ones. Very weird. Can anyone give some explanation? On Core 2 Duo 1.83ghz, integrated video (only one core is used) - 1500 (older java) vs 700 fps On Athlon 64 3500+, discrete video - 120 (older java) vs 55 fps The app is a simple game with a moving rectangle. I'm using Graphics2D to draw from a loop.

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 100 101 102 103 104 105 106 107 108 109 110 111  | Next Page >