performance

Which .NET performance and/or memory profilers will allow me to profile a DLL?

I write a lot of .NET based plug-ins for other programs which are usually compiled as a DLL which is up to the native application to start up. I've been using Equatec's profiler, which works great, but now would like something with more features, including the ability to profile memory usage. I tried out Red Gate's Ant Profiler, but as ...

How measure Web App performance ?

I have developed 3 simple blogging system in PHP/Apache/Mysql, Python/Ngix/Postgresql and in Erlang/Yaws/Mnesia. How can I measure performance on my server for this 3 different configuration ? ...

Speed up PostGreSQL createdb?

Is there a way to speed up PostgreSQL's createdb command? Normally I wouldn't care, but doing unit testing in Django creates a database every time, and it takes about 5 seconds. I'm using openSUSE 11.2 64-bit, PostgreSQL 8.4.2 ...

Should I reuse Points and Rectangles or create new ones?

In a method that gets called frequently, like a painting event, is it more efficient to reuse Point and Rectangle Objects (for specifying locations and bounds), or should I create new ones. ...

Garbage collection behaviour for String.intern()

If I use String.intern() to improve performance as I can use "==" to compare interned string, will I run into garbage collection issues. How does the garbage collection mechanism of interned strings differ from normal strings ? ...

OpenCV performance in different languages

I'm doing some prototyping with OpenCV for a hobby project involving processing of real time camera data. I wonder if it is worth the effort to reimplement this in C or C++ when I have it all figured out or if no significant performance boost can be expected. The program basically chains OpenCV functions, so the main part of the work sho...

SQL Server 2005 Blocking Problem (ASYNC_NETWORK_IO)

I am responsible for a third-party application (no access to source) running on IIS and SQL Server 2005 (500 concurrent users, 1TB data, 8 IIS servers). We have recently started to see significant blocking on the database (after months of running this application in production with no problems). This occurs at random intervals during t...

Using Lite Version of Entity in nHibernate Relations?

Is it a good idea to create a lighter version of an Entity in some cases just for performance reason pointing to same table but with fewer columns mapped. E.g If I have a Contact Table which has 50 Columns and in few of the related entities I might be interested in FirstName and LastName property is it a good idea to create a lightweight...

flex arraycollection - can i specify the size for an arraycollection?

Context: I use an ArrayCollection object as follows: 1) Number of elements is fixed. 2) Elements are inserted at a given position, based on some order. Question: Can I set the max size of the ArrayCollection? Will fixing the size improve the performance, as elements keep getting inserted into this collection? -Thank You ...

How to detect whether an EventWaitHandle is waiting?

I have a fairly well multi-threaded winforms app that employs the EventWaitHandle in a number of places to synchronize access. So I have code similar to this: List<int> _revTypes; EventWaitHandle _ewh = new EventWaitHandle(false, EventResetMode.ManualReset); void StartBackgroundTask() { _ewh.Reset(); Thread t = new Thread(new ...

Javascript, IE, Strings, and Performance problems

Hey guys, So we have this product, and it's really slow in IE. We've already applied a lot of the practices advised by the IE guys themselves (like this, and this), and try to sacrifice clean code for performance in the critical parts like DOM manipulation. However, as you can see in this IE profiler screenshot.. Just "String" is the...

Is C# fast enough for games

Will a game written in C# have any speed issues after long periods of play, like for 24 hours at a time? I'm specifically talking about a 2D RPG similar to old Final Fantasy or Dragon Quest games. I know that languages like Python will slow down too much, curious how C# would stand. edit: programs I write are a lot like a termite-infest...

PHP: Opening/closing tags & performance?

Hi, This may be a silly question, but as someone relatively new to PHP, I'm wondering if there are any performance-related issues to frequently opening and closing PHP tags in HTML template code, and if so, what might be best practices in terms of working with php tags? My question is not about the importance/correctness of closing tag...

Why is insertion into my tree faster on sorted input than random input?

Now I've always heard binary search trees are faster to build from randomly selected data than ordered data, simply because ordered data requires explicit rebalancing to keep the tree height at a minimum. Recently I implemented an immutable treap, a special kind of binary search tree which uses randomization to keep itself relatively ba...

How is fseek() implemented in the filesystem?

This is not a pure programming question, however it impacts the performance of programs using fseek(), hence it is important to know how it works. A little disclaimer so that it doesn't get closed. I am wondering how efficient it is to insert data in the middle of the file. Supposing I have a file with 1MB data and then I insert somethi...

How costly performance-wise are these actions in iPhone objective-C?

This is really a few questions in one, I'm wondering what the performance cost is for these things, as I haven't really been following a best practice of any sort for these. The answers may also be useful to other readers, if somebody knows these. (1) If I need the core data managed object context, is it bad to use #import "myAppDeleg...

In MySQL, what is the most effective query design for joining large tables with many to many relationships between the join predicates?

In our application, we collect data on automotive engine performance -- basically source data on engine performance based on the engine type, the vehicle running it and the engine design. Currently, the basis for new row inserts is an engine on-off period; we monitor performance variables based on a change in engine state from active to...

Efficiency of iteration: NSArray vs C array of pointers?

I'm working at the audio buffer level, mixing audio signals created by a colleciton of objects. Since I'm looping through these objects at 44.1khz, efficiency is crucial. Is there any difference in the efficiency of iterating over an NSArray vs a C array of pointers? How about NSMutableArray? ...

Fiscal year handling strategies in database design

By fiscal year I mean all the data in the database (in all tables) that occurred in the particular year. Lets say that we are building an application that allows user to choose from different years. What way of implementing this would you prefer, and why: Separate fiscal year data based on multiple separate database instances (for exa...

Slow rendering of pages due to User Controls.

How would you troubleshoot a page that is rendering slowly in ASP.NET? This issue is happening on only specific pages with a few user controls. Other pages work fine. Tracing has clarified that the issue is happening between "Begin Render" and "End Render". ...