performance

How does LLBLGen Pro Stack up Against Nhibernate Performance Wise

I have search the internet high and low looking for any performance information for LLBLGen Pro. None found. Just wanted to know how does LLBLGen Pro perform compared the Nhibernate. Thanks ...

jQuery animate overhead at speed 0 compared to setting css directly

Often times in applications I have a property that would normally .animate(), but every now and then must change instantly. Usually I just set the speed to 0 when doing this, but in an application I'm developing now, my situation is the opposite and performance is much more important. This property is set with .css() on window .resize(),...

System.DirectoryServices is slow?

I'm using the code below to look up information in active directory when a user logs on to a website. Running against a local domain it's very quick, but running over a VPN to a remote trusted domain, it's very slow (takes around 7 or 8 seconds). Running dsa.msc from the same box to the remote domain is almost as quick as running it loca...

Execution-time performance of code in class created using reflection versus a 'normal' class.

Is the execution time (run-time) performance of code in a class that is loaded via reflection identical to the same code when the class is created using the new keyword? I say yes. But I was discussing this with a colleague who believes that the reflection oriented code is always slower. My view is that regardless of how the class wa...

Combine SQL queries for simplicity and performance gains

I am trying to combine a few SQL queries to reduce the number of queries performed and hopefully increase performance at the same time. I have lots of products, split into categories. Some of the products have articles written for them (most don't though). At the moment I fetch all the products for a category a bit like this... // * us...

Nhibernate 2.1.0.4000 slower than 2.0.1.4000? Any NH default setting changed?

I just switched to Nhibernate2.1.0.4000 with Nfluent 1.0RTM and Linq To Nhibernate 1.0.0. Suddenly I found that now a simple session.Save takes a minute compared to before not more than 10 secs. As I switch back times are back to normal... I dumbfounded. Has anyone made the same experience? What could cause the drag ? some changed defaul...

How negligible is ParameterizedBeanPropertyRowMapper's performance hit?

The javadoc says: Please note that this class is designed to provide convenience rather than high performance. For best performance consider using a custom RowMapper. How slow is it in the real world? ...

Using Jmeter to fill out a form?

Can anyone help me figure out how to use jmeter and force it to fill out and submit a form automatically? For example, I need to fill out the google search box and then click the I'm Feeling Lucky button? ...

Efficient switch statement

In the following two versions of switch case, I am wondering which version is efficient. 1: string* convertToString(int i) { switch(i) { case 1: return new string("one"); case 2: return new string("two"); case 3: return new string("three"); . . default: return new...

On the Design of zero-copy Memory allocators used in high volume fast-path code.

Disclaimer: please do not bother reading this long post unless you are an embedded programmer, or a kernel developer, or a high performance system software programmer. It is about memory allocators and might not be of any interest to you. I am building a library for high-volume high-performance same machine IPC, using OS specific pipes...

Simple Suggestion / Recommendation Algorithm

I am looking for a simple suggestion algorithm to implement in to my Web App. Much like Netflix, Amazon, etc... But simpler. I don't need teams of Phd's working to get a better suggestion metric. So say I have: User1 likes Object1. User2 likes Object1 and Object2. I want to suggest to User1 they might also like Object2. I can obvi...

MySQL: splitting one table to multiple tables (same columns) for performace increase?

This question is about performance, not about possible solutions. My system holds many items of different categories. Each category has its own table since each table has many rows AND the fields are different. ItemA - id, fld1, fld2 ItemB - id, fld1, fld3, fld4 ItemC - id, fld1, fld3, fld5 .... Now there's a need to manage user inve...

Stored procedure performance randomly plummets; trivial ALTER fixes it. Why?

I have a couple of stored procedures on SQL Server 2005 that I've noticed will suddenly take a significantly long time to complete when invoked from my ASP.NET MVC app running in an IIS6 web farm of four servers. Normal, expected completion time is less than a second; unexpected anomalous completion time is 25-45 seconds. The problem doe...

Why is scaling down a UIImage from the camera so slow?

resizing a camera UIImage returned by the UIImagePickerController takes a ridiculously long time if you do it the usual way as in this post. [update: last call for creative ideas here! my next option is to go ask Apple, I guess.] Yes, it's a lot of pixels, but the graphics hardware on the iPhone is perfectly capable of drawing lots of...

Overhead for MySQL SELECTS - Better to Use One, or Many In Sequence

Is there an appreciable performance difference between having one SELECT foo, bar, FROM users query that returns 500 rows, and 500 SELECT foo, bar, FROM users WHERE id = x queries coming all at once? In a PHP application I'm writing, I'm trying to choose between a writing clear, readable section of code that would produce about 500 SEL...

Replacing a Regex Match Collection in C#

I need to find in a text everything that starts with [ and ends with ] and replace it with the value that a function returns. So, here is an example of what I'm doing: public string ProcessTemplate(string input) { return Regex.Replace(input, @"\[(.*?)\]", new MatchEvaluator(delegate(Match match) { ...

Fast sine/cosine for ARMv7+NEON: looking for testers…

Could somebody with access to an iPhone 3GS or a Pandora please test the following assembly routine I just wrote? It is supposed to compute sines and cosines really really fast on the NEON vector FPU. I know it compiles fine, but without adequate hardware I can't test it. If you could just compute a few sines and cosines and compare the...

Performance of one huge unix directory VS a directory tree?

My PHP project will use thousands of pictures and each needs only a single number for it's storage name. My initial idea was to put all of the pictures in a single directory and name the files "0.jpg", "1.jpg", "2.jpg", and all the way to "4294967295.jpg" . Would it be better performance-wise to create a directory tree structure and na...

glBitmap() without GL_COLOR_INDEX

Is it somehow possible to get glBitmap() to draw a GL_RGBA bitmap? glBitmap() is a lot quicker than glDrawPixels(), but perhaps that has to do with that the format is GL_COLOR_INDEX instead of GL_RGBA? I'm running my glDrawPixels() in a display list; is there perhaps some smart way to speed it up? ...

Are there performance issue of using while loop vs foreach/for loop?

What are the performance issue of using while loop v/s foreach/for loop or vice-versa ? Also is it always preferable to use foreach loop v/s while in php ? ...