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• Adding a minimum display time for Silverlight splash screen.

  - by David

  When hosting a silverlight application on a webpage it is possible to use the splashscreensource parameter to specify a simple Silverlight 1.0 (xaml+javascript) control to be displayed while the real xap file is downloaded, and which can receive notification of the downloads progress through onSourceDownloadProgressChanged. If the xap file is in cache, the splash screen is not shown (and if the download only takes 1 second, the splash screen will only be shown for 1 second). I know this is not best practice in general, but I am looking for a way to specify a minimum display time for the splash screen - even if the xap cached or the download is fast, the splash screen would remain up for at least, let's say, 5 seconds (for example to show a required legal disclaimer, corporate identity mark or other bug). I do want to do it in the splash screen exclusively (rather then in the main xap) as I want it to be clean and uninterupted (for example a sound bug) and shown to the user as soon as they open the page, rather then after the download (which could take anywhere from 1 to 20+ seconds). I'd prefer not to accomplish this with preloading - replacing the splash screen with a full Silverlight xap application (with it's own loading screen), which then programmably loads and displays the full xap after a minimum wait time.

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• Render an SSRS report with a Map as an image map without actually having a ReportViewer on the page

  - by Erica Merchant

  I have a report that has a Map with spatial data. Clicking an object on that map sends you to other pages on the site. I have tried a few different ways of displaying the report: If I put a ReportViewer on the actual page, the page sometimes takes 10+ seconds to load, but the report viewer creates a fully operable image map. If I create a ReportViewer in the code behind, I can use the Render method to to format the report as HTML4.0 and get the streamids from which I can extract the image (painfully). This is pretty fast (1-2 seconds), but only gives me an image, no image map. I can get a very similar functionality as the above example by using rendering extensions on the report URL to create an image and then set an image's source to this url. This is the fastest method, but still does not create an image map. So is there a way to create an image map from the report without having to use the ReportViewer? Or a way to substantially speed up the Report Viewer?

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• how to implement a really efficient bitvector sorting in python

  - by xiao

  Hello guys! Actually this is an interesting topic from programming pearls, sorting 10 digits telephone numbers in a limited memory with an efficient algorithm. You can find the whole story here What I am interested in is just how fast the implementation could be in python. I have done a naive implementation with the module bitvector. The code is as following: from BitVector import BitVector import timeit import random import time import sys def sort(input_li): return sorted(input_li) def vec_sort(input_li): bv = BitVector( size = len(input_li) ) for i in input_li: bv[i] = 1 res_li = [] for i in range(len(bv)): if bv[i]: res_li.append(i) return res_li if __name__ == "__main__": test_data = range(int(sys.argv[1])) print 'test_data size is:', sys.argv[1] random.shuffle(test_data) start = time.time() sort(test_data) elapsed = (time.time() - start) print "sort function takes " + str(elapsed) start = time.time() vec_sort(test_data) elapsed = (time.time() - start) print "sort function takes " + str(elapsed) start = time.time() vec_sort(test_data) elapsed = (time.time() - start) print "vec_sort function takes " + str(elapsed) I have tested from array size 100 to 10,000,000 in my macbook(2GHz Intel Core 2 Duo 2GB SDRAM), the result is as following: test_data size is: 1000 sort function takes 0.000274896621704 vec_sort function takes 0.00383687019348 test_data size is: 10000 sort function takes 0.00380706787109 vec_sort function takes 0.0371489524841 test_data size is: 100000 sort function takes 0.0520560741425 vec_sort function takes 0.374383926392 test_data size is: 1000000 sort function takes 0.867373943329 vec_sort function takes 3.80475401878 test_data size is: 10000000 sort function takes 12.9204008579 vec_sort function takes 38.8053860664 What disappoints me is that even when the test_data size is 100,000,000, the sort function is still faster than vec_sort. Is there any way to accelerate the vec_sort function?

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• Using java.util.regex in Android apps - are there issues with this?

  - by johnrock

  In an Android app I have a utility class that I use to parse strings for 2 regEx's. I compile the 2 patterns in a static initializer so they only get compiled once, then activities can use the parsing methods statically. This works fine except that the first time the class is accessed and loaded, and the static initializer compiles the pattern, the UI hangs for close to a MINUTE while it compiles the pattern! After the first time, it flies on all subsequent calls to parseString(). My regEx that I am using is rather large - 847 characters, but in a normal java webapp this is lightning fast. I am testing this so far only in the emulator with a 1.5 AVD. Could this just be an emulator issue or is there some other reason that this pattern is taking so long to compile? private static final String exp1 = "(insertratherlong---847character--regexhere)"; private static Pattern regex1 = null; private static final String newLineAndTagsExp = "[<>\\s]"; private static Pattern regexNewLineAndTags = null; static { regex1 = Pattern.compile(exp1, Pattern.CASE_INSENSITIVE); regexNewLineAndTags = Pattern.compile(newLineAndTagsExp); } public static String parseString(CharSequence inputStr) { String replacementStr = "replaceMentText"; String resultString = "none"; try { Matcher regexMatcher = regex1.matcher(inputStr); try { resultString = regexMatcher.replaceAll(replacementStr); } catch (IllegalArgumentException ex) { } catch (IndexOutOfBoundsException ex) { } } catch (PatternSyntaxException ex) { } return resultString; }

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• tips for fixing bad coding/dev habits ?

  - by dfafa

  i want to become a better coder....so i have decided to sign up for computing science program...maybe a formal education can assist me. i started working on smaller projects to learn but currently i have really bad coding/dev habits which is hindering my productivity as the codebase increases.... i have highlighted them and perhaps someone could make suggestions (or redirect to resources) or a more efficient method. most stuff that i made in the past were web apps. i usually develop with putty + nano...i just love the minimalist feel i use winscp and develop directly on my private web server...too lazy to do it on localhost and upload it later. i dont use subversion control...which one do i need ? sometimes ctrl +z doesn't work well. when i run out of ideas for naming variable, i use swear words instead. i swear a lot when i get stuck....how to deal with anger issue ? my codes look ugly with comments everywhere. would rather use procedural coding finds "thinking" in OO difficult and time consuming i "write first think later". refactors code only if i am getting paid for it. dislikes configuring linux distro, Apache, MySQL, scaling, designing graphics and layouts. does not like writing tests likes working alone. does not like sharing codes. has an econ degree dislikes reading other people's code would rather write it on my own it seems my only true desire is to translate my ideas to a working prototype as fast as possible....it seems like i am very uninterested in the other details...could it be that i am not cut out to be a coder after all ? is going back to study comp sci a bad idea ?

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• Getting a key in the ActionScript Dictionary

  - by Rudy

  Hello, I am using a Dictionary in ActionScript as a queue, sort of, still reading most of the time as an associative container, but I need one time to make a loop to run through the whole dictionary, such as for (var key:String in queue) . Inside this for loop I perform some actions on an element and then call delete on that key. My issue is that I would like to wait for an Event before fetching the next element in this queue. Basically my for loop runs too fast. I would like to fetch the next key all the time, but I know there is no built in method. A solution I thought is to add a break to the loop, as the for.. in will automatically fetch the next key, but it would be a loop which always executes one time, simply to fetch the next key. This sounds a bit counter intuitive. I hope my problem makes sense and I really look for some better ideas than what I currently have. Thanks for your help! Rudy

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• how do I insert an hidden token in my form to prevent double posts? (PHP)

  - by jpjp

  I want to prevent users from accidentally posting a comment twice. I use the PRG (post redirect get) method, so that I insert the data on another page then redirect the user back to the page which shows the comment. This allows users to refresh as many times as they want. However this doesn't work when the user goes back and clicks submit again or when they click submit 100 times really fast. I don't want 100 of the same comments. I looked at related questions on SO and found that a token is best. But I am having trouble using it. //makerandomtoken(20) returns a random 20 length char. <form method="post" ... > <input type="text" id="comments" name="comments" class="commentbox" /><br/> <input type="hidden" name="_token" value="<?php echo $token=makerandomtoken(20); ?>" /> <input type="submit" value="submit" name="submit" /> </form> if (isset($_POST['submit']) && !empty($comments)) { $comments= mysqli_real_escape_string($dbc,trim($_POST['comments'])); //how do I make the if-statment to check if the token has been already set once? if ( ____________){ //don't insert comment because already clicked submit } else{ //insert the comment into the database } } So I have the token as a hidden value, but how do I use that to prevent multiple clicking of submit.

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• How do I track down sporadic ASP.NET performance problems in a production environment?

  - by Steve Wortham

  I've had sporadic performance problems with my website for awhile now. 90% of the time the site is very fast. But occasionally it is just really, really slow. I mean like 5-10 seconds load time kind of slow. I thought I had narrowed it down to the server I was on so I migrated everything to a new dedicated server from a completely different web hosting company. But the problems continue. I guess what I'm looking for is a good tool that'll help me track down the problem, because it's clearly not the hardware. I'd like to be able to log certain events in my ASP.NET code and have that same logger also track server performance/resources at the time. If I can then look back at the logs then I can see what exactly my website was doing at the time of extreme slowness. Is there a .NET logging system that'll allow me to make calls into it with code while simultaneously tracking performance? What would you recommend?

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• Netty options for real-time distribution of small messages to a large number of clients?

  - by user439407

  I am designing a (near) real-time Netty server to distribute a large number of very small messages to a large number of clients across the internet. In internal, go as fast as you can testing, I found that I could do 10k clients no sweat, but now that we are trying to go across the internet, where the latency, bandwidth etc varies pretty wildly we are running into the dreaded outOfMemory issues, even with 2 gigs of RAM. I have tried various workarounds(setting the socket stack sizes smaller, setting high and low water marks, cancelling things that are too old), and they help a little, but they seem to only help a little bit. What would some good ways to optimize Netty for sending large #s of small messages without significant delays? Also, the bulk of the message only consists of one kind of message that I don't particularly care if it doesn't arrive. I would use UDP but because we don't control the client, thats not really a possibility. Is it possible to set a separate timeout solely for this kind of message without affecting the other messages? Any insight you could offer would be greatly appreciated.

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• Reducing moire when downsampling halftone comic images.

  - by drawnonward

  How can I reduce moire effects when downsampling halftone comic book images during live zoom on an iPhone or iPad? I am writing a comic book viewer. It would be nice to provide higher resolution images and allow the user to zoom in while reading the comic book. However, my client is averse to moire effects and will not allow this feature if there are noticeable moire artifacts while zooming, which of course there are. Modifying the images to be less susceptible to moire would only work if the modifications were not perceptible. Blur was specifically prohibited, as is anything that removes the beloved halftone dots. The images are black and white halftone and line art. The originals are 600 dpi but what we ship with the application will be half that at best, so probably 2500 pixels or less tall. So what are my options? If I write a custom downsampling algorithm would it be fast enough for real time on these devices? Are there other tricks I can do? Would it work to just avoid the size ratios that have the most visual moire effects? As you zoom in an out, there are definitely peaks where the moire effects are worst. Is there a way to calculate what those points are and just zoom to a nearby scale that is not as bad? Any suggestions are welcome. I have very little experience with image and signal processing, but am enjoying the opportunity to learn. I know nothing of wavelets and acutance and other jargon, so please be verbose.

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• Managing large binary files with git

  - by pi

  Hi there. I am looking for opinions of how to handle large binary files on which my source code (web application) is dependent. We are currently discussing several alternatives: Copy the binary files by hand. Pro: Not sure. Contra: I am strongly against this, as it increases the likelihood of errors when setting up a new site/migrating the old one. Builds up another hurdle to take. Manage them all with git. Pro: Removes the possibility to 'forget' to copy a important file Contra: Bloats the repository and decreases flexibility to manage the code-base and checkouts/clones/etc will take quite a while. Separate repositories. Pro: Checking out/cloning the source code is fast as ever, and the images are properly archived in their own repository. Contra: Removes the simpleness of having the one and only git repository on the project. Surely introduces some other things I haven't thought about. What are your experiences/thoughts regarding this? Also: Does anybody have experience with multiple git repositories and managing them in one project? Update: The files are images for a program which generates PDFs with those files in it. The files will not change very often(as in years) but are very relevant to a program. The program will not work without the files. Update2: I found a really nice screencast on using git-submodule at GitCasts.

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• Re-use of database object in sub-sonic

  - by cantabilesoftware

  Yet another newbie SubSonic/ActiveRecord question. Suppose I want to insert a couple of records, currently I'm doing this: using (var scope = new System.Transactions.TransactionScope()) { // Insert company company c = new company(); c.name = "ACME"; c.Save(); // Insert some options company_option o = new company_option(); o.name = "ColorScheme"; o.value = "Red"; o.company_id = c.company_id; o.Save(); o = new company_option(); o.name = "PreferredMode"; o.value = "Fast"; o.company_id = c.company_id; o.Save(); scope.Complete(); } Stepping through this code however, each of the company/company_option constructors go off and create a new myappDB object which just seems wasteful. Is this the recommended approach or should I be trying to re-use a single DB object - and if so, what's the easiest way to do this?

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• Python: slow read & write for millions of small files

  - by Jami

  I am building directory tree which has tons of subdirectories and files. The total directory count is somewhere along 256^32 subdirectories with 256 files in each end which are only a few bytes long. I did this so I would have fast access to these files (since i'm not searching and i'm just directly accessing then via a known file path) I have a python script that builds this filesystem and reads & writes those files. The problem is that when I reach more than 1Gb of total filesize, the read and write methods become extremely slow. Here's the function I have that reads the contents of a file (the file contains an integer string), adds a certain number to it, then writes it back to the original file. def addInFile(path, scoreToAdd): num = scoreToAdd try: shutil.copyfile(path, '/tmp/tmp.txt') fp = open('/tmp/tmp.txt', 'r') num += int(fp.readlines()[0]) fp.close() except: pass fp = open('/tmp/tmp.txt', 'w') fp.write(str(num)) fp.close() shutil.copyfile('/tmp/tmp.txt', path) I previously tried performing linux console commands but it was slower. I copy the file to a temporary file first then access/modify it then copy it back because i found this was faster than directly accessing the file. I think the cause of the slowdown is because there're tons of files. performing this function 1000 times sometimes reach 1 minute now, but before (when there were only a few files, 1000 calls was performed for only less than 1 second) How do you suggest I fix this?

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• Passing options in autospec with Cucumber in Ruby on Rails Development

  - by TK

  I always run autospec to run features and RSpec at the same time, but running all the features is often time-consuming on my local computer. I would run every feature before committing code. I would like to pass the argument in autospec command. autospec doesn't obviously doesn't accept the arguments directly. Here's the output of autospec -h: autotest [options] options: -h -help You're looking at it. -v Be verbose. Prints files that autotest doesn't know how to map to tests. -q Be more quiet. -f Fast start. Doesn't initially run tests at start. I do have a cucumber.yml in config directory. I also have rerun.txt in the Rails root directory. cucumber -h gives me a lot of information about arguments. How can I run autospec against features that are tagged as @wip? I think I can make use of config/cucumber.yml. There are profile definitions. I can run cucumber -p wip to run only @wip-tagged features, but I'd like to do this with autospec. I would appreciate any tips for working with many spec and feature files.

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• Can you recommend a full-text search engine?

  - by Jen

  Can you recommend a full-text search engine? (Preferably open source) I have a database of many (though relatively short) HTML documents. I want users to be able to search this database by entering one or more search words in my C++ desktop application. Hence, I’m looking for a fast full-text search solution to integrate with my app. Ideally, it should: Skip common words, such as the, of, and, etc. Support stemming, i.e. search for run also finds documents containing runner, running and ran. Be able to update its index in the background as new documents are added to the database. Be able to provide search word suggestions (like Google Suggest) Have a well-documented API To illustrate, assume the database has just two documents: Document 1: This is a test of text search. Document 2: Testing is fun. The following words should be in the index: fun, search, test, testing, text. If the user types t in the search box, I want the application to be able to suggest test, testing and text (Ideally, the application should be able to query the search engine for the 10 most common search words starting with t). A search for testing should return both documents. Other points: I don't need multi-user support I don't need support for complex queries The database resides on the user's computer, so the indexing should be performed locally. Can you suggest a C or C++ based solution? (I’ve briefly reviewed CLucene and Xapian, but I’m not sure if either will address my needs, especially querying the search word indexes for the suggest feature).

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• How to find if a branch is a locally tracked branch or user created local branch?

  - by Senthil A Kumar

  I have a remote tracking branch tracked locally in my local repository using 'git branch -b branch-name origin/branch-name'. My remote branch is test2/test2 (origin/branch-name) which is being tracked locally as test2. The origin is also named test2. I haven't checked-out my local tracking branch test2. When i do a 'git pull origin remote-branch:local-tracked-branch' i get this error [test2]$ git pull test2 test2:test2 From /gitvobs/git_bare/test2 ! [rejected] test2 - test2 (non fast forward) Whereas when i checkout my local tracking branch test2 and do pull 'git pull origin local-tracked-branch' i don't get the error and i do a pull using 'git pull test2 test2' From /gitvobs/git_bare/test2 * branch test2 - FETCH_HEAD Auto-merging a.txt Automatic merge failed; fix conflicts and then commit the result. i know that adding a + (git pull test2 +test2:test2) would help but it overwrites local changes. So how do i know which of my local branches are created by me locally using 'git branch new-branch-name' or tracked locally from remote branches using git branch -b branch-name origin/branch-name'?

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• Need guidelines for optimizing WebGL performance by minimizing shader changes

  - by brainjam

  I'm trying to get an idea of the practicality of WebGL for rendering large architectural interior scenes, consisting of 100K's of triangles. These triangles are distributed over many objects, and there are many materials in the scene. On the other hand, there are no moving parts. And the materials tend to be fairly simple, mostly based on texture maps. There is a lot of texture map sharing .. for example all the chairs in scene will share a common map. There is also some multitexturing - up to three textures overlaid in a material. I've been doing a little experimentation and reading, and gather that frequently switching materials during a rendering pass will slow things down. For example, a scene with 200K triangles will have significant performance differences, depending on whether there are 10 or 1000 objects, assuming that each time an object is displayed a new material is set up. So it seems that if performance is important the scene should be sorted by materials so as to minimize material switching. What I'm looking for is guidelines on how to think of the overhead of various state changes, and where do I get the biggest bang for the buck. For example, what are the relative performance costs of, say, gl.useProgram(), gl.uniformMatrix4fv(), gl.drawElements() should I try to write ubershaders to minimize shader switching? should I try to aggregate geometry to minimize the number of gl.drawElements() calls I realize that mileage may vary depending on browser, OS, and graphics hardware. And I'm also not looking for heroic measures. Just some guidelines from people who have already had some experience in making scenes fast. I'll add that while I've had some experience with fixed-pipeline OpenGL programming in the past, I'm rather new to the WebGL/OpenGL ES 2.0 way of doing things.

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• I can't figure out why this fps counter is inaccurate.

  - by rmetzger

  I'm trying to track frames per second in my game. I don't want the fps to show as an average. I want to see how the frame rate is affected when I push keys and add models etc. So I am using a variable to store the current time and previous time, and when they differ by 1 second, then I update the fps. My problem is that it is showing around 33fps but when I move the mouse around really fast, the fps jumps up to 49fps. Other times, if I change a simple line of code elsewhere not related to the frame counter, or close the project and open it later, the fps will be around 60. Vsync is on so I can't tell if the mouse is still effecting the fps. Here is my code which is in an update function that happens every frame: FrameCount++; currentTime = timeGetTime (); static unsigned long prevTime = currentTime; TimeDelta = (currentTime - prevTime) / 1000; if (TimeDelta > 1.0f) { fps = FrameCount / TimeDelta; prevTime = currentTime; FrameCount = 0; TimeDelta = 0; } Here are the variable declarations: int FrameCount; double fps, currentTime, prevTime, TimeDelta, TimeElapsed; Please let me know what is wrong here and how to fix it, or if you have a better way to count fps. Thanks!!!!!! I am using DirectX 9 btw but I doubt that is relevant, and I am using PeekMessage. Should I be using an if else statement instead? Here is my message processing loop: MSG msg; ZeroMemory (&msg, sizeof (MSG)); while (msg.message != WM_QUIT) { if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) { TranslateMessage (&msg); DispatchMessage (&msg); } Update (); RenderFrame (); }

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• How can I protect my .NET assemblies from decompilation?

  - by Holli

  One if the first things I learned when I started with C# was the most important one. You can decompile any .NET assembly with Reflector or other tools. Many developers are not aware of this fact and most of them are shocked when I show them their source code. Protection against decompilation is still a difficult task. I am still looking for a fast, easy and secure way to do it. I don't want to obfuscate my code so my method names will be a,b,c or so. Reflector or other tools should be unable to recognize my application as .NET assembly at all. I know about some tools already but they are very expensive. Is there any other way to protect my applications? EDIT: The reason for my question is not to prevent piracy. I only want to stop competitors from reading my code. I know they will and they already did. They even told me so. Maybe I am a bit paranoid but business rivals reading my code doesn't make me feel good.

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• Transitioning from FlexBuilder 3 to FlashBuilder 4 ... there and back again.

  - by Robusto

  It's growing pains time again. Some of our stuff requires FlashBuilder 4 and some still requires FlexBuilder 3. Both are installed OK, and no projects use both IDEs. The trouble is, when I go back to work on a FlexBuilder 3 project it takes freakin' forever to build and I get weird errors like these: This doesn't seem to cause any identifiable problems except to throw up a modal dialog at various points in the build process, forcing user interaction. But I do notice that memory fills up fast in FB3 and generally FB3 starts behaving strangely and ultimately quits once it gets up over 700MB. This is only a temporary bridge situation until we get all projects into FB4, but "temporary" could mean weeks if not months. Does anyone have any advice for how to get through this bridge period? Is there anything I can do to make these two IDEs work and play well together? Failing that, does anyone know what "java.lang.String" is the "reason" for the problem? Does Eclipse have a resource bundle somewhere that is getting corrupted when i go back and forth between the two?

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• Laggy interface with NSSearchField hooked up to an NSArrayController via bindings

  - by Simone Manganelli

  So I've got an NSSearchField hooked up directly to an NSArrayController via bindings, attached to the filterPredicate, so that without any code, the user can just type in the NSSearchField and filter the list of objects in the NSArrayController presented to him in the interface (an NSCollectionView, to be specific). The NSSearchField is hooked up to provide live searching, so that the NSCollectionView is filtered instantly as the user types, not after waiting for a short period for the user to stop typing. However, the problem is that this makes the interface really laggy. Typing is delayed significantly, by 0.5-1 seconds, and it seems like the NSCollectionView is trying to animate each and every rearrangement of items for each portion of the search string that the user enters. What I'd like is for the searching to be live, but the typing in the search field to be fluid, and the results to filter as fast as possible. Is there a way to do this via bindings, or will I need to put in some custom code that triggers the filterPredicate on a separate thread? (Note that I've got a custom sorting algorithm set up on the NSArrayController, and removing it seems to help a bit with the laggyness, but not completely.)

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• Is my method for avoiding dynamic_cast<> faster than dynamic_cast<> itself ?

  - by ereOn

  Hi, I was answering a question a few minutes ago and it raised to me another one: In one of my projects, I do some network message parsing. The messages are in the form of: [1 byte message type][2 bytes payload length][x bytes payload] The format and content of the payload are determined by the message type. I have a class hierarchy, based on a common class Message. To instanciate my messages, i have a static parsing method which gives back a Message* depending on the message type byte. Something like: Message* parse(const char* frame) { // This is sample code, in real life I obviously check that the buffer // is not NULL, and the size, and so on. switch(frame[0]) { case 0x01: return new FooMessage(); case 0x02: return new BarMessage(); } // Throw an exception here because the mesage type is unknown. } I sometimes need to access the methods of the subclasses. Since my network message handling must be fast, I decived to avoid dynamic_cast<> and I added a method to the base Message class that gives back the message type. Depending on this return value, I use a static_cast<> to the right child type instead. I did this mainly because I was told once that dynamic_cast<> was slow. However, I don't know exactly what it really does and how slow it is, thus, my method might be as just as slow (or slower) but far more complicated. What do you guys think of this design ? Is it common ? Is it really faster than using dynamic_cast<> ? Any detailed explanation of what happen under the hood when one use dynamic_cast<> is welcome !

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• Parallel version of loop not faster than serial version

  - by Il-Bhima

  I'm writing a program in C++ to perform a simulation of particular system. For each timestep, the biggest part of the execution is taking up by a single loop. Fortunately this is embarassingly parallel, so I decided to use Boost Threads to parallelize it (I'm running on a 2 core machine). I would expect at speedup close to 2 times the serial version, since there is no locking. However I am finding that there is no speedup at all. I implemented the parallel version of the loop as follows: Wake up the two threads (they are blocked on a barrier). Each thread then performs the following: Atomically fetch and increment a global counter. Retrieve the particle with that index. Perform the computation on that particle, storing the result in a separate array Wait on a job finished barrier The main thread waits on the job finished barrier. I used this approach since it should provide good load balancing (since each computation may take differing amounts of time). I am really curious as to what could possibly cause this slowdown. I always read that atomic variables are fast, but now I'm starting to wonder whether they have their performance costs. If anybody has some ideas what to look for or any hints I would really appreciate it. I've been bashing my head on it for a week, and profiling has not revealed much.

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• SQL Server becomes slow after restart

  - by Tobi DM

  We use SQL Server 2005 on an Windwos Server 2008. Ther Server has 48 GB RAM. SQL Server is configured to use 40 GB RAM. There is only one database hosted (About 70 GB). The only app beside SQL Server is our App-Server which connects the clients to the database. Now we encounter the following problem: After a restart of the server our the performance is great. The server grabs the 40 GB RAM wich it is allowed to and then runs fast as hell. But after about 4 weeks the system becomes slower and slower. The execution of statements (seen in the profiler) is raising slowly. But I cannot see that there is something going wrong on the server. CPU usage is at about 20% I/O also seems to be no Problem The process monitor does also not show that there are strange apps or something like that. Eventlog does also have no interessting messages No open transactions or blockings to see We tried already the following things without effect: Droped the cache by using the statements DBCC FreeProcCache DBCC FREESYSTEMCACHE('ALL') DBCC DropCleanbuffers Restarted the Appserver we are using. Restart the sql server service But nothing did help exept restarting the whole server. Any ideas?

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• How to manipulate *huge* amounts of data

  - by Alejandro

  Hi there! I'm having the following problem. I need to store huge amounts of information (~32 GB) and be able to manipulate it as fast as possible. I'm wondering what's the best way to do it (combinations of programming language + OS + whatever you think its important). The structure of the information I'm using is a 4D array (NxNxNxN) of double-precission floats (8 bytes). Right now my solution is to slice the 4D array into 2D arrays and store them in separate files in the HDD of my computer. This is really slow and the manipulation of the data is unbearable, so this is no solution at all! I'm thinking on moving into a Supercomputing facility in my country and store all the information in the RAM, but I'm not sure how to implement an application to take advantage of it (I'm not a professional programmer, so any book/reference will help me a lot). An alternative solution I'm thinking on is to buy a dedicated server with lots of RAM, but I don't know for sure if that will solve the problem. So right now my ignorance doesn't let me choose the best way to proceed. What would you do if you were in this situation? I'm open to any idea. Thanks in advance!

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