I have a JSP which shows data by many aggregation types. E.g. By market, by category, by server type, etc.. What I have is the data by publisher and time. Publisher is the most granular level of data in my case. Now this data changes on every 1/2 an hour. The number of data per half an hour is almost 5K and anyone at a time looks data ...
As far as I have understood so far, every time I draw something in the drawRect: of a UIView, the whole context is erased and then redrawn. So I have to do something like this to draw a series of dots: Method A: drawing everything on every call - (void)drawRect:(CGRect)rect { CGContextRef context = UIGraphicsGetCurrentContext();...
I've been trying to reduce implicit type conversions when I use named constants in my code. For example rather than using const double foo = 5; I would use const double foo = 5.0; so that a type conversion doesn't need to take place. However, in expressions where I do something like this... const double halfFoo = foo / 2; etc. I...
Hello, Before asking this question I have googled for some time, but could not find any relevant information on this topic. My problem is simple: I have NHibernate criteria and projection and I'm trying to set DISTINCT ON(column) My code for projection is following: criteria.SetProjection( Projections.ProjectionL...
In their developer articles for Android, Google states that you should usually declare public variables rather than private ones with getters and setters to enhance performance on embedded devices (I suppose function calls are more expensive than just writing to an address). I was wondering - to what extent should performance be sacrif...
I'm trying to use async io on linux. As far as i know there're 3 options: kernel calls (io_submit and friends) libRT - uses threads in user space libRTKAIO - wrapper of kernel calls which does not use threads I'm using the last option, and i see, that in my unit test that runs a lot of async io requests in multiple threads, /proc/sy...
I require socket-like local IPC. I used named pipes and overlapped IO on windows and I want to rewrite the application to boost::ASIO so that it can use UNIX domain sockets as well. I've recently reviewed parts of the libevent library and I know it only supports socket() and select() for windows in the 1.4 version. As overlapped IO is v...
We have our ORM pretty nicely coupled with cache, so all our object gets are cached. Currently we invalidate our objects before and after our insert/update/delete of our object. What's your experience? ...
I'm using ActiveMQ on a simulation of overloading servers in Java. And mainly it goes ok, but when I get over 600 requests the thing just go WTF! I think the bottleneck is my Master Server which is this guy below. I'm already reusing the connection and creating various sessions to consume messages from clients. Like I said, I'm using a...
OK, I'm still brand new to iPhone development. I have a free game on the app store, Winner Pong, but it's just a Pong clone (who would've guessed) that uses the standard UIImageViews for the sprites. Now I want to do something a little more complicated, and port my game for the Xbox 360, Trippin Alien, to the iPhone. I obviously can't ke...
I am refactoring an existing VB.NET application to use Linq. I've been able to successfully get it to work, but it takes ages (over a minute) on the client machine! They have lots of rows in the database table, but the old version of the programme on the same machine (which uses Datasets) takes 5 seconds. My Linq queries are pretty st...
We have a Windows Forms application that uses a (third party) ActiveX control, and are noticing in the .NET performance objects under ".NET CLR Memory" that the number of "Sink Blocks" in use is constantly increasing (along with increasing memory usage), even though our application is sitting there idle. The built-in explanation for th...
Hi, I am considering rebuilding my ASP.NET portal using ASP.NET MVC. I use the same portal solution at two different web sites, and I would like to have a single place og editing and writing articles for my sites - a management site. I have considered making an "Article Web Service" that would provide me with the functionality of creati...
Hey all, I'm not much of a database guru so I would like some advice. Background We have 4 tables that are currently stored in Sybase IQ. We don't currently have any choice over this, we're basically stuck with what someone else decided for us. Sybase IQ is a column-oriented database that is perfect for a data warehouse. Unfortuna...
I just got this quite large CakePHP app (about 20k lines of code), which isn't very clean and there is no documentation at all. The app is running in production, but it has really major problems with performance. Server is Quad core with 8GB RAM, but the app can serve only about 3-4 requests/s, which is very very bad. Each request take...
Hi guys, I have a very hard problem: I have round about 20-50 objects, which I MUST (that is given for the problem, please don't spend time in thinking around it) put througt a logic EVERY SECOND. The logic itself need round about 200-600 milliseconds (90% it is 200ms - 10% it is 600ms). I try to find any solution how I can make is s...
Hi, I was trying to contact the author of a book I am reading on SQL Server query performance, but it seems the e-mail address provided in the book does not exis any more. So I decided to ask the community. I am pasting the messasge I had written below. Thanks in advance. ====== I have bought your book (SQL Server 2008 Query Performanc...
import java.net.*; import java.io.IOException; import javax.swing.*; import java.awt.*; import java.awt.event.*; public class PortScanner { public static void main(String[] args) { InetAddress ia=null; String host=null; try { host=JOptionPane.showInputDialog("Enter the Host name to scan:\n example: xx...
I'm playing with the GLGravity example to figure out some of the performance nuances related to dealing with the accelerometer. Here's the problem code: - (void)accelerometer:(UIAccelerometer*)accelerometer didAccelerate:(UIAcceleration*)acceleration { static int accelCallCount; accelCallCount++; if (accelCallCount % 100 ==...
Clearly if performance is critical it makes sense to prototype and profile. But all the same, wisdom and advice can be sought on StackOverflow :) For the handling of highly parallel tasks where inter-task communication is infrequent or suits message-passing, is there a performance disadvantage to using processes (fork() etc) or threads...