What makes a program inefficient?
are there any main factors in which the programs efficiency depends? ...
performance
How to bind DataGrid to display only 25 records of a table having more than 1000 records ..??
I have a datagrid control which is bound to a table which containing more than 1000 records. And i want to show only 25 records once a time. I have used paging in datagrid. But each time the next page index is set, query is fired again. This takes lots of time. So what is the easiest way to bound data in this case to improve performance....
Performance intensive string splitting and manipulation in java
What is the most efficient way to split a string by a very simple separator? Some background: I am porting a function I wrote in C with a bunch of pointer arithmetic to java and it is incredibly slow(After some optimisation still 5* slower). Having profiled it, it turns out a lot of that overhead is in String.split The function in que...
Does Adding more namespace in the code file affect performace ?
If we imports more namespace in the code file(cs file) then it affects on perfomance ? Like we should add namespace in the cs file as needed. That is adding more namespace in the cs file affects performance ? Like using System; using System.Data.Sql; using System.Collections.Generic; using System.Data; using System.IO; using System.Linq...
Mod_rewrite on all website images
I'm designing an image repository. I want to uncouple the filename from the image html link. For instance: image in filesystem is called images/items/12543.jpg HTML is <img src="images/car.jpg" /> Does anyone strongly discourages me to rewrite all image requests using PHP so when retrieving images/car.jpg, Apache really replies conte...
Extending the .NET type system so the compiler enforces semantic meaning of primitive values in certain cases
I'm working developing a system right now that deals with lots of conversions between semantically different values that have the same primitive .NET type (double/string/int). This means that it's possible to get confused about which 'semantic type' you are using, either by not converting or converting too many times. Ideally I'd like ...
Apache modules: C module vs mod_wsgi python module - Performance
Hi A client of ours is asking us to implement a module in C in Apache webserver for performance reasons. This module should handle RESTful uri's, access a database and return results in json format. Many people here have recommended python mod_wsgi instead - but for simplicity of programming reasons. Can anyone tell me if there is a ...
Determining the best audio quality.
How can you determine the best audio quality in a list of audio files of the same audio clip, with out looking at the audio file's header. The tricky part is that all of the files came from different formats and bit rates and they where all transcoded to the same format and bit rate. How can this be done efficiently? ...
Performance of WCF Web Service Call
I have a windows application that calls into a WCF web service. On the server side I am using S#arp Architecture as a base framework. When making calls to the server the application isn't as responsive as it should be with calls to the server taking in the region of a couple of seconds. I profiled the application with Ants Profiler ...
WPF slow to start on x64 in .NET Framework 4.0
I've noticed that if I build my WPF application for Any CPU/x64, it takes MUCH longer to start (on the order of about 20 seconds) or to load new controls than it does if started on x86 (in release & debug modes, inside or outside of VS). This occurs with even the simplest WPF apps. The problem is discussed in this MSDN thread, but no ans...
SQL query performance optimization (TimesTen)
Hi community, I need some help with TimesTen DB query optimization. I made some measures with Java profiler and found the code section that takes most of the time (this code section executes the SQL query). What is strange that this query becomes expensive only for some specific input data. Here’s the example. We have two tables that ...
Is it worth the trouble to avoid using the SqlParameterCollection.AddWithValue method?
Several articles tells you that you should avoid using AddWithValue method because it can lead to poor execution plans and performance. Should I go through my DAL and change all parameters to specify the SqlDbType? Is it worth the loss in maintainability? (If I change a column-type from varchar(50) to varchar(100) I would need to change ...
What kind of data processing problems would CUDA help with?
Hi, I've worked on many data matching problems and very often they boil down to quickly and in parallel running many implementations of CPU intensive algorithms such as Hamming / Edit distance. Is this the kind of thing that CUDA would be useful for? What kinds of data processing problems have you solved with it? Is there really an upl...
Win32 threads synchronization/performance monitoring tools
would Intel(R) VTune(TM) Thread profiler be able to tell if threads synchronization was successful? I'm never profiled any application, where do i start? ...
Perl launched from Java takes forever
I know this is an absolute shot in the dark, but we're absolutely perplexed. A perl (5.8.6) script run by Java (1.5) is taking more than an hour to complete. The same script, when run manually from the command line takes 12 minutes to complete. This is on a Linux host. Logging is the same in both cases and the script is run with the ...
Does allocation speed depend on the garbage collector being used?
My app is allocating a ton of objects (>1mln per second; most objects are byte arrays of size ~80-100 and strings of the same size) and I think it might be the source of its poor performance. The app's working set is only tens of megabytes. Profiling the app shows that GC time is negligibly small. However, I suspect that perhaps the al...
What is the performance impact of CSS's universal selector?
I'm trying to find some simple client-side performance tweaks in a page that receives millions of monthly pageviews. One concern that I have is the use of the CSS universal selector (*). As an example, consider a very simple HTML document like the following: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" ...
Preloading Winforms using a Stack and Hidden Form
I am currently working on a project where we have a couple very control heavy user controls that are being used inside a MDI Controller. This is a Line of Business app and it is very data driven. The problem that we were facing was the aforementioned controls would load very very slowly, we dipped our toes into the waters of multi-threa...
How to find CPU-intensive class in Java?
I have a big program in Java that uses multithreading. In some cases, the program starts using 100% of three cores of my eight core system. In normal use, the program use all cores at 1-2%. How can I find the class that's overloading cores? ...
ASP.NET problem - Firebug shows odd behaviour
I have an ASP.NET application that does a large database read. It loads up a gridview inside an update panel. In VS2008, just running on my local machine, it runs fantastically. In production (identical code, just published and put on one of our network servers), it runs slow as dirt. Debug is set to false, so this is not the cause of t...