Search Results

Search found 10033 results on 402 pages for 'execution speed'.

Page 261/402 | < Previous Page | 257 258 259 260 261 262 263 264 265 266 267 268  | Next Page >

• Returning IEnumerable<T> vs IQueryable<T>

  - by stackoverflowuser

  what is the difference between returning iqueryable vs ienumerable. IQueryable<Customer> custs = from c in db.Customers where c.City == "<City>" select c; IEnumerable<Customer> custs = from c in db.Customers where c.City == "<City>" select c; Will both be deferred execution? When should one be preferred over the other?

  Read the article

• Are Scala "continuations" just a funky syntax for defining and using Callback Functions?

  - by Alex R

  And I mean that in the same sense that a C/Java for is just a funky syntax for a while loop. I still remember when first learning about the for loop in C, the mental effort that had to go into understanding the execution sequence of the three control expressions relative to the loop statement. Seems to me the same sort of effort has to be applied to understand Continuations (in Scala and I guess probably other languages). And then there's the obvious follow-up question... if so, then what's the point? It seems like a lot of pain (language complexity, programmer errors, unreadable programs, etc) for no gain.

  Read the article

• How to implement arrays in an interpreter?

  - by Ray

  I have managed to write several interpreters including Tokenizing Parsing, including more complicated expressions such as ((x+y)*z)/2 Building bytecode from syntax trees Actual bytecode execution What I didn't manage: Implementation of dictionaries/lists/arrays. I always got stuck with getting multiple values into one variable. My value structure (used for all values passed around, including variables) looks like this, for example: class Value { public: ValueType type; int integerValue; string stringValue; } Works fine with integers and strings, but how could I implement arrays? (From now on with array I mean arrays in my experimental language, not in C++) How can I fit the array concept into the Value class above? Is it possible? How should I make arrays able to be passed around just as you could pass around integers and strings in my language, using the class above? Accessing array elements or memory allocation wouldn't be the problem, I just don't know how to store them.

  Read the article

• Why is .NET faster than C++ in this case?

  - by acidzombie24

  -edit- I LOVE SLaks comment. "The amount of misinformation in these answers is staggering." :D Calm down guys. Pretty much all of you were wrong. I DID make optimizations. It turns out whatever optimizations I made wasn't good enough. I ran the code in GCC using gettimeofday (I'll paste code below) and used g++ -O2 file.cpp and got slightly faster results then C#. Maybe MS didn't create the optimizations needed in this specific case but after downloading and installing mingw I was tested and found the speed to be near identical. Justicle Seems to be right. I could have sworn I use clock on my PC and used that to count and found it was slower but problem solved. C++ speed isn't almost twice as slower in the MS compiler. When my friend informed me of this I couldn't believe it. So I took his code and put some timers onto it. Instead of Boo I used C#. I constantly got faster results in C#. Why? The .NET version was nearly half the time no matter what number I used. C++ version: #include <iostream> #include <stdio.h> #include <intrin.h> #include <windows.h> using namespace std; int fib(int n) { if (n < 2) return n; return fib(n - 1) + fib(n - 2); } int main() { __int64 time = 0xFFFFFFFF; while (1) { int n; //cin >> n; n = 41; if (n < 0) break; __int64 start = __rdtsc(); int res = fib(n); __int64 end = __rdtsc(); cout << res << endl; cout << (float)(end-start)/1000000<<endl; break; } return 0; } C# version: using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Runtime.InteropServices; using System.ComponentModel; using System.Threading; using System.IO; using System.Diagnostics; namespace fibCSTest { class Program { static int fib(int n) { if (n < 2)return n; return fib(n - 1) + fib(n - 2); } static void Main(string[] args) { //var sw = new Stopwatch(); //var timer = new PAB.HiPerfTimer(); var timer = new Stopwatch(); while (true) { int n; //cin >> n; n = 41; if (n < 0) break; timer.Start(); int res = fib(n); timer.Stop(); Console.WriteLine(res); Console.WriteLine(timer.ElapsedMilliseconds); break; } } } } GCC version: #include <iostream> #include <stdio.h> #include <sys/time.h> using namespace std; int fib(int n) { if (n < 2) return n; return fib(n - 1) + fib(n - 2); } int main() { timeval start, end; while (1) { int n; //cin >> n; n = 41; if (n < 0) break; gettimeofday(&start, 0); int res = fib(n); gettimeofday(&end, 0); int sec = end.tv_sec - start.tv_sec; int usec = end.tv_usec - start.tv_usec; cout << res << endl; cout << sec << " " << usec <<endl; break; } return 0; }

  Read the article

• High performance querying - Suggestions please

  - by Alex Takitani

  Supposing that I have millions of user profiles, with hundreds of fields (name, gender, preferred pet and so on...). You want to make searches on profiles. Ex.:All profiles that has age between x and y, loves butterflies, hates chocolate.... With database would you choose? Suppose that You have a Facebook like load. Speed is a must. Open Source preferred. I've read a lot about Cassandra, HBase, Mongo, Mysql... I just can't decide.....

  Read the article

• How can one use the "Add view" dialog in Visual Studio efficiently when working with ASP.NET MVC?

  - by Marek

  Does anyone else think that the add view dialog in VS is useless or is it just me? Why is there no search/filtering in there? I can not even paste the type name (without namespace) there to speed up the view creation. Plus, there are a lot of irrelevant classes there, including classes from all referenced libraries. Am I missing something or Microsoft never did any usability testing with that?? Is it possible to filter out types/assemblies in the dialog and/or better navigation compared to manually scrolling the combobox with all the types listed? Is it possible to include only types from a particular directory/assembly/namespace? (the ViewModels namespace for example) EDIT: As it seems from the answers that there is no usable workaround for this, I have filed a suggestion at Connect: https://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=507784 Please vote for the suggestion if you find this is an important issue.

  Read the article

• Can anyone telme whats wrong in this part of code

  - by Mobin

  string name = ((DateTimePicker)sender).Name.ToString(); name = name.Substring(0, name.Length - 1); name = name + "4"; TimeSpan duration = new TimeSpan(); duration = ((DateTimePicker)sender).Value - ((DateTimePicker)panel2.Controls[name]).Value; name = name.Substring(0, name.Length - 1); name = name + "6"; ((MaskedTextBox)panel2.Controls[name]).Text = duration.ToString(); on execution it gives me Object reference not set to instance of an object similar functionality is used on other places but can't find out what i have to reinitialize here :$

  Read the article

• Division to the nearest 1 decimal place without floating point math?

  - by John Sheares

  I am having some speed issues with my C# program and identified that this percentage calculation is causing a slow down. The calculation is simply n/d * 100. Both the numerator and denominator can be any integer number. The numerator can never be greater than the denominator and is never negative. Therefore, the result is always from 0-100. Right now, this is done by simply using floating point math and is somewhat slow, since it's being calculated tens of millions of times. I really don't need anything more accurate than to the nearest 0.1 percent. And, I just use this calculated value to see if it's bigger than a fixed constant value. I am thinking that everything should be kept as an integer, so the range with 0.1 accuracy would be 0-1000. Is there some way to calculate this percentage without floating point math?

  Read the article

• Shared Variable Among Ruby Processes

  - by Jesse J

  I have a Ruby program that loads up two very large yaml files, so I can get some speed-up by taking advantage of the multiple cores by forking off some processes. I've tried looking, but I'm having trouble figuring how, or even if, I can share variables in different processes. The following code is what I currently have: @proteins = "" @decoyProteins = "" fork do @proteins = YAML.load_file(database) exit end fork do @decoyProteins = YAML.load_file(database) exit end p @proteins["LVDK"] P displays nil though because of the fork. So is it possible to have the forked processes share the variables? And if so, how?

  Read the article

• Is being a programmer a younger person's job?

  - by Saobi

  After you get old, say past 30 or 40. Can you still keep up with the young coders from your company, those fresh out of school, who can code for 15+ hours on 10 cans of redbulls (most people in Google, Facebook, etc) ? And given the lightning speed with which today's programming frameworks and architectures evolve, can you keep up with the most up to date stuff and be as proficient at them as the next college grad? I know for jobs like unix/c/embedded programming, it might be that the older the better. But for programming jobs in say web development, social media, search engine technology, etc. Do you become less and less competitive career-wise versus youngsters? For example, most coders in Google and Facebook, I believe are under 25 years old. In other words, once you reach a certain age, would it be unwise to continue to be a coder, and is it better to try becoming a project manager or architect?

  Read the article

• How can I get read-ahead bytes?

  - by Bruno Martinez

  Operating systems read from disk more than what a program actually requests, because a program is likely to need nearby information in the future. In my application, when I fetch an item from disk, I would like to show an interval of information around the element. There's a trade off between how much information I request and show, and speed. However, since the OS already reads more than what I requested, accessing these bytes already in memory is free. What API can I use to find out what's in the OS caches? Alternatively, I could use memory mapped files. In that case, the problem reduces to finding out whether a page is swapped to disk or not. Can this be done in any common OS?

  Read the article

• Express any number as the sum of 4 prime numbers [Doubts]

  - by WarDoGG

  I was give a problem to express any number as sum of 4 prime numbers. Conditions: Not allowed to use any kind of database. Maximum execution time : 3 seconds Numbers only till 100,000 If the splitting is NOT possible, then return -1 What i did : using the sieve of eratosthenes, i calculated all prime numbers till the specified number. looked up a concept called goldbach conjecture which expresses an even number as the summation of 2 primes. However, i am stuck beyond that. Can anyone help me on this one as to what approach u might take ? The sieve of eratosthenes is taking 2 seconds to count primes till 100,000 :(((

  Read the article

• Unable upload large file size on Google Docs

  - by Preeti

  Hi, I am uploading document on Google Docs as: DocumentsService myService = new DocumentsService(""); myService.setUserCredentials("[email protected]", password ); DocumentEntry newEntry = myService.UploadDocument(@"C:\Sample.txt", "Sample.txt"); But when i try to upload a file of 3 MB it result into exception: An unhandled exception of type 'Google.GData.Client.GDataRequestException' occurred in Google.GData.Client.dll Additional information: Execution of request failed: http://docs.google.com/feeds/documents/private/full How can i upload large size file on Google Docs? I am using Google API ver 2. Thanx

  Read the article

• Limit the number of cron jobs runnging a PHP script

  - by ed209

  I have a daily cron job that grabs 10 users at a time and does a bunch of stuff with them. There are 1000's of users that are part of that process every day. I don't want the cron jobs to overlap as they are heavy on server load. They call stuff from various APIs so I have timeouts and slow data fetching to contend with. I've tried using a flag to mark a cron job as running, but it's not reliable enough as some PHP scripts may time out or fail in various ways. Is there a good way to stop a cron job from calling the PHP script multiple times, or controlling the number of times it is called, so there are only 3 instances for example? I'd prefer a solution in the PHP if possible. Any ideas? At the moment I'm storing the flag as a value in a database, is using a lock type file any better as in here http://stackoverflow.com/questions/851872/does-a-cron-job-kill-last-cron-execution ?

  Read the article

• How to get generate WSDL using GroovyWS

  - by James Black

  I am implementing SOAP web services for a commercial application, and I am using GroovyWS to speed up the development. But, when I deploy it on Tomcat, I am not using Grails, as the software has it's own J2EE framework, so how I do I get it to react to wsdl requests? Do I need to write a groovy-based servlet? Ideally I would like the WSDL generated upon request, so I can easily change the interface and see the change. It seems I will miss the annotations that JAX-WS provides for, though, to help fine-tune the WSDL.

  Read the article

• Speeding up inner joins between a large table and a small table

  - by Zaid

  This may be a silly question, but it may shed some light on how joins work internally. Let's say I have a large table L and a small table S (100K rows vs. 100 rows). Would there be any difference in terms of speed between the following two options?: OPTION 1: OPTION 2: --------- --------- SELECT * SELECT * FROM L INNER JOIN S FROM S INNER JOIN L ON L.id = S.id; ON L.id = S.id; Notice that the only difference is the order in which the tables are joined. I realize performance may vary between different SQL languages. If so, how would MySQL compare to Access?

  Read the article

• PyPy -- How can it possibly beat CPython?

  - by Vulcan Eager

  From the Google Open Source Blog: PyPy is a reimplementation of Python in Python, using advanced techniques to try to attain better performance than CPython. Many years of hard work have finally paid off. Our speed results often beat CPython, ranging from being slightly slower, to speedups of up to 2x on real application code, to speedups of up to 10x on small benchmarks. How is this possible? Which Python implementation was used to implement PyPy? CPython? And what are the chances of a PyPyPy or PyPyPyPy beating their score? (On a related note... why would anyone try something like this?)

  Read the article

• Timestamp as int field, query performance

  - by Kirzilla

  Hello, I'm storing timestamp as int field. And on large table it takes too long to get rows inserted at date because I'm using mysql function FROM_UNIXTIME. SELECT * FROM table WHERE FROM_UNIXTIME(timestamp_field, '%Y-%m-%d') = '2010-04-04' Is there any ways to speed this query? Maybe I should use query for rows using timestamp_field >= x AND timestamp_field < y? Thank you I've just tried this query... SELECT * FROM table WHERE timestamp_field >= UNIX_TIMESTAMP('2010-04-14 00:00:00') AND timestamp_field <= UNIX_TIMESTAMP('2010-04-14 23:59:59') but there is no any performance bonuses. :(

  Read the article

• php java in memory database

  - by msaif

  i need to load data as array to memory in PHP.but in PHP if i write $array= array("1","2"); in test.php then this $array variable is initialized every time user requests.if we request test.php 100 times by clicking 100 times browser refresh button then this $array variable will be executed 100 times. but i need to execute the $array variable only one time for first time request and subsequent request of test.php must not execute the $array variable.but only use that memory location.how can i do that in PHP. but in JAVA SEVRVLET it is easy to execute,just write the $array variable in one time execution of init() method of servlet lifecycle method and subsequent request of that servlet dont execute init() method but service() method but service() method always uses that $array memeory location. all i want to initilize $array variable once but use that memory loc from subsequent request in PHP.is there any possiblity in PHP?

  Read the article

• Which jsPerf-test should I consider as standard for checking the performance of javascript template-engines

  - by bhargav

  I am on a search for a javascript template engine that has good performance when used in large js applications and is also very suitable for mobile applications. So I have gone through the various jsPerf-tests for these. There seems to be a lot which show different results and it is confusing to find out which is the standard test. Can some one guide me a standard jsPerf that I can refer to and that should also include following templates dust, underscore, hogan, mustache, handlebars. From what I have observed dot.js is a constant performer with good rendering speed, but is it mature enough for larger applications ? What is this "with" and "no with" that is shown in the jspref tests? Can some one explain. In all the tests I have seen popular templates like mustache, handlebars, dust, hogan,etc seems to be behind performance than other templates, so why people are using them leaving out the top performers,is it because of maturity of these template engines? Thanks in advance

  Read the article

• Are concurrency issues possible when using the WCF Service Behavoir attribute set to ConcurrencyMode

  - by Brandon Linton

  We have a WCF service that makes a good deal of transactional NHibernate calls. Occasionally we were seeing SQL timeouts, even though the calls were updating different rows and the tables were set to row level locking. After digging into the logs, it looks like different threads were entering the same point in the code (our transaction using block), and an update was hanging on commit. It didn't make sense, though, because we believed that the following service class attribute was forcing a unique execution thread per service call: [ServiceBehavior(ConcurrencyMode = ConcurrencyMode.Multiple, InstanceContextMode = InstanceContextMode.PerCall)] We recently changed the concurrency mode to ConcurrencyMode.Single and haven't yet run into any issues, but the bug was very difficult to reproduce (if anyone has any thoughts on flushing a bug like that out, let me know!). Anyway, that all brings me to my question: shouldn't an InstanceContextMode of PerCall enforce thread-safety within the service, even if the ConcurrencyMode is set to multiple? How would it be possible for two calls to be serviced by the same service instance? Thanks!

  Read the article

• How to create temporary files on the client machine, from Web Application?

  - by Gaurav Srivastava

  I am creating a Web Application using JSP, Struts, EJB and Servlets. The Application is a combined CRM and Accounting Package so the Database size is very huge. So, in order to make Execution faster, I want prevent round trips to the Database. For that purpose, what I want to do is create some temporary XML files on the client Machine and use them whenever required. How can I do this, as Javascript do not permits me to do so. Is there any way of doing this? Or, is there any other solution which I can adopt in order to make my application Faster?

  Read the article

• Is Alpha Five Version 10 really all that its reported to be?

  - by Gary B2312321321

  I came across this RDMS via the advert on stackoverflow. Seems to be in the vein of MS Access / Filemaker / Apex database devlopment tools but focused on web based applications. It quotes rave reviews from EWeek and a favourable mention from Dr Dobbs regarding its ability to create AJAX web applications without coding. The Eweek review, apparently written by an ASP.NET programmer, goes on to proclaim the ease at which apps can be extended using the inbuilt XBasic language and how custom javascript can easily be added without wading through code. Has anyone here built a web app with Alpha 5? Does anyone have comments on the development process, the speed of it or limitations they encountered along the way? To me it seems Oracle APEX comes closest to the feature set, has anyone programmed in both and have any comments?

  Read the article

• How to retrieve a bigint from a database and place it into an Int64 in SSIS

  - by b0fh

  I ran into this problem a couple years back and am hoping there has been a fix and I just don't know about it. I am using an 'Execute SQL Task' in the Control Flow of an SSIS package to retrieve a 'bigint' ID value. The task is supposed to place this in an Int64 SSIS variable but I getting the error: "The type of the value being assigned to variable "User::AuditID" differs from the current variable type. Variables may not change type during execution. Variable types are strict, except for variables of type Object." When I brought this to MS' attention a couple years back they stated that I had to 'work around' this by placing the bigint into an SSIS object variable and then converting the value to Int64 as needed. Does anyone know if this has been fixed or do I still have to 'work around' this mess? edit: Server Stats Product: Microsoft SQL Server Enterprise Edition Operating System: Microsoft Windows NT 5.2 (3790) Platform: NT INTEL X86 Version: 9.00.1399.06

  Read the article

• Visual Studio Debugger Voodoo

  - by LoveMeSomeCode

  Ok, maybe this isn't so amazing considering I don't really understand how the debugger works in the first place, let alone Edit and Continue, which is totally amazing. But I was wondering if anyone knew what the debugger is doing with variable declarations in this scenario. I can be debugging through my code, move the line of execution ahead - past a variables initial declaration and assignment, and the code still runs ok. If it's a value type it will have it's default value, for a ref type, null. So if I create a function that uses a variable before it's declared it won't compile, but if I use the debugger to run it that way it will still run without error. Why is this? And is this related to the fact that you can't put a breakpoint on a declaration?

  Read the article

< Previous Page | 257 258 259 260 261 262 263 264 265 266 267 268  | Next Page >