optimization

glDrawArrays() slow on iPad?

Hey guys, I was wondering how to speed up my iPad application using OpenGLES 2.0. At the moment we have every drawable object draw itself with a call to glDrawArrays(). Blend mode is on, we really need it. Without disabling blendmode, how would we improve performance for this app? For instances, if we now draw 3 textures (1024x1024, 25...

How much faster is a database running in RAM?

I"m looking to run PostgreSQL in RAM for performance enhancement. The database isn't more than 1GB and shouldn't ever grow to more than 5GB. Is it worth doing? Are there any benchmarks out there? Is it buggy? My second major concern is: How easy is it to back things up when it's running purely in RAM. Is this just like using RAM as tier...

The explain tells that the query is awful (it doesn't use a single key) but I'm using LIMIT 1. Is this a problem?

The explain command with the query: explain SELECT * FROM leituras WHERE categorias_id=75 AND textos_id=190304 AND cookie='3f203349ce5ad3c67770ebc882927646' AND endereco_ip='127.0.0.1' LIMIT 1 The result: id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE ...

Client side Image presentation optimization

Hi, I have designed a long web page and there are many photos in one column from top to bottom listed one by one. In order to create a high-level interection with the client, I want those photos loaded when the client scroll-down to the page. The more the go bottom, the more photos are loaded. For Instance -> mashable.comn) Waiting fo...

Need help with basic optimization problem

I know little of optimization problems, so hopefully this will be didactic for me: rotors = [1, 2, 3, 4...] widgets = ['a', 'b', 'c', 'd' ...] assert len(rotors) == len(widgets) part_values = [ (1, 'a', 34), (1, 'b', 26), (1, 'c', 11), (1, 'd', 8), (2, 'a', 5), (2, 'b', 17), .... ] Given a fixed number of widgets and a fixed number ...

What is the best algorithm for this array-comparison problem?

What is the most efficient for speed algorithm to solve the following problem? Given 6 arrays, D1,D2,D3,D4,D5 and D6 each containing 6 numbers like: D1[0] = number D2[0] = number ...... D6[0] = number D1[1] = another number D2[1] = another number .... ..... .... ...

Design for a Debate club assignment application

Hi all, For my university's debate club, I was asked to create an application to assign debate sessions and I'm having some difficulties as to come up with a good design for it. I will do it in Java. Here's what's needed: What you need to know about BP debates: There are four teams of 2 debaters each and a judge. The four groups are as...

Is there a way to optimise finding text items on a page (not regex)

After seeing several threads rubbishing the regexp method of finding a term to match within an HTML document, I've used the Simple HTML DOM PHP parser (http://simplehtmldom.sourceforge.net/) to get the bits of text I'm after, but I want to know if my code is optimal. It feels like I'm looping too many times. Is there a way to optimise th...

online CSS optimizer?

Is there an online CSS optimizer equivalent to Googles JavaScript Closure Optimizer. I've found plenty of CSS compressors online, but I'm looking for a CSS optimizer ... where it actually removes redundant/conflicting attributes ...

Java Optimization String vs Char Arrays

In a program I am writing I am doing a lot of string manipulation. I am trying to increase performance and am wondering if using char arrays would show a decent performance increase. Any suggestions? ...

optimizing iPhone OpenGL ES fill rate

I have an Open GL ES game on the iPhone. My framerate is pretty sucky, ~20fps. Using the Xcode OpenGL ES performance tool on an iPhone 3G, it shows: Renderer Utilization: 95% to 99% Tiler Utilization: ~27% I am drawing a lot of pretty large images with a lot of blending. If I reduce the number of images drawn, framerates go from ~20 ...

mysql query optimization

I would need some help on how to optimize the query. select * from transaction where id < 7500001 order by id desc limit 16 when i do an explain plan on this - the type is "range" and rows is "7500000" According to the some online reference's this is explained as, it took the query 7,500,000 rows to scan and get the data. Is there an...

In ArrayBlockingQueue, why copy final member field into local final variable?

In ArrayBlockingQueue, any method that requires lock will get set 'final' local variable before calling 'lock()'. public boolean offer(E e) { if (e == null) throw new NullPointerException(); final ReentrantLock lock = this.lock; lock.lock(); try { if (count == items.length) return false; else ...

An image from byte to optimized web page presentation

I get the data of the stored image on database as byte[] array; then I convert it to System.Drawing.Image like the code shown below; public System.Drawing.Image CreateImage(byte[] bytes) { System.IO.MemoryStream memoryStream = new System.IO.MemoryStream(bytes); System.Drawing.Image image = System.Drawi...

Fastest sort of fixed length 6 int array

Answering to another StackOverflow question (this one) I stumbled upon an interresting sub-problem. What is the fastest way to sort an array of 6 ints ? As the question is very low level (will be executed by a GPU): we can't assume libraries are available (and the call itself has it's cost), only plain C to avoid emptying instruction ...

MySQL subqueries

Can we do this query without subqueries? SELECT login, post_n, (SELECT SUM(vote) FROM votes WHERE votes.post_n=posts.post_n)AS votes, (SELECT COUNT(comments.post_n) FROM comments WHERE comments.post_n=posts.post_n)AS comments_count FROM users, posts WHERE posts.id=users.id AND (visibility=2 OR visibility=3) ORDER BY date DESC LIMI...

Optimize slow ranking query

I need to optimize a query for a ranking that is taking forever (the query itself works, but I know it's awful and I've just tried it with a good number of records and it gives a timeout). I'll briefly explain the model. I have 3 tables: player, team and player_team. I have players, that can belong to a team. Obvious as it sounds, playe...

improving drawing pythagoras tree

Hello. I have written program for drawing pythagoras tree fractal. Can anybody see any way of improving it ? Now it is 89 LOC. import java.awt.*; import java.util.Scanner; import javax.swing.*; public class Main extends JFrame {; public Main(int n) { setSize(900, 900); setTitle("Pythagoras tree"); add(new D...

Draw Rectangle with XNA

Hey guys, I was working on game, and wanted to highlight a spot on the screen when something happens, I created a class to do this for me, and found a bit of code to draw the rectangle static private Texture2D CreateRectangle(int width, int height, Color colori) { Texture2D rectangleTexture = new Texture2D(game.GraphicsDevice, width...

Reduce Processing Time of accessing databse

hello all, I m making an app which requires remote databse connection. I want the values in picker from database but when I click on button to invoke picker it takes some time to fetch the values and displaying. Is there any way to do it fast? and also is there any way to reduce the time of transition between 2 views? Thanx ...