Questions related to improving application performance, this can be range from selection software architecture to selection of algorithms.

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4
votes
5answers
668 views

Would “Efficient C++” book be irrelevant now due to compiler improvements? [closed]

I am planning on purchasing this book to learn more about C++ programming with regards to fast code. However, the book was published in 1999 and I am worried most of it may be irrelevant now due to ...
2
votes
1answer
1k views

What metrics should be used to measure memory consumption of a program for performance test?

I am asked to provide performance statistics for a program, one of them being memory consumption. I noticed that in perfmon or in .NET API there is apparently many variable related to memory usage, ...
0
votes
1answer
310 views

Splitting an image into many pieces to improve perceived performance? Good or Bad? [closed]

Time to time, I have to work on a website that involves a huge background in size and resolution (1920 x 1080 in resolution, over 2mb in size). I've been using preloaders and it worked very well, ...
1
vote
7answers
9k views

Merge sort versus quick sort performance

I have implemented merge sort and quick sort using C (GCC 4.4.3 on Ubuntu 10.04 running on a 4 GB RAM laptop with an Intel DUO CPU at 2GHz) and I wanted to compare the performance of the two ...
3
votes
1answer
3k views

Magic square check for N×N matrix with minimum complexity

Is there any algorithm that works better than O(n²) to verify whether a square matrix is a magic one (e.g. such as sum of all the rows, cols and diagonally are equal to each other)? I did see someone ...
10
votes
4answers
9k views

How can I monitor the JVM memory in a proper way?

I'm thinking of how we do JVM memory monitor in a low overhead way in production environment even under busy hour. Suppose I have two tomcat app server in production, load balance set up behind them. ...
5
votes
5answers
2k views

Structuring database for multi-object “activity” and “following” functionalities

I am working on a web application which operate with different types of objects such as user, profiles, pages etc. All objects have unique object_id. When objects interact it may produce "activity", ...
0
votes
2answers
361 views

Desktop GUI loading slow

I am developing desktop based GUI (single form) using wxPython and loads it using remote citrix access from client private network. Suppose, the GUI has certain group of select and text boxes which ...
1
vote
7answers
4k views

Performance analysis of C++ programs [closed]

How can I measure the performance of my C++ programs using C++? Specific metrics I want to measure are: Memory used (space) Duration taken (time)
0
votes
2answers
185 views

How can describe slow connection issues?

I have been working on a website containing 3d maps, virtual 3d tours, etc. All of the content is large like images and video. The problem is the site performs well under normal speed connections but ...
-1
votes
2answers
243 views

How should I group these variables?

I have a shape that will be defined by: char s_type; char color; double height; double width; These variables are scanned in from a request string sent to my server and passed into my printing ...
4
votes
1answer
329 views

Inexpensive generation of hierarchical unique IDs

My application is building a hierarchical structure like this: root = { 'id': 'root', 'children': [ { 'name': 'root_foo', 'children': [] }, { 'id': 'root_foo2', 'children': [ { ...
17
votes
2answers
12k views

Writing low latency Java [closed]

Are there any Java-specific techniques (things which wouldnt apply to C++) for writing low latency code, in Java? I often see Java low latency roles and they ask for experience writing low latency ...
1
vote
1answer
2k views

Improving performance for web scraping code

I have a website in which the code scrapes other websites for getting the accurate data. While the code works good but there a decent lag in performance because the code firsts downloads the html ...
5
votes
4answers
2k views

JSF for an internet facing, high traffic web application

I, perhaps, made a wrong choice of going with a Component-based Framework like JSF for an internet facing, high traffic web application. Development with JSF has although been easier but what I fear ...
7
votes
4answers
674 views

Is there a performance benefit to using immutable objects in a scripting language?

As I understand it, writing your objects in an immutable style can help the performance of your program for compiled languages, as the compiler tends to rewrite your code in single static assignment ...
4
votes
2answers
162 views

Is performance testing applicable to a QA or business user testing?

Performance testing is something that I, as a developer do when optimizing. However, if the change is purely optimization, should the QA or business user perform their own performance testing? I would ...
8
votes
2answers
2k views

Eclipse runs my java program 6 times faster… Can I achieve this performance without using it?

I've written a java program that generates all repetitive permutations based on the characters and the length given. When I execute my code in Eclipse, it generates a file with 1,000,000 permutations ...
0
votes
1answer
166 views

Data structure to use for complex lookups in an event engine?

What would be an optimal way to organize arbitrary data types into a structure that allows for complex (non-index based) lookups into the data without performing full loop-through's? For a little ...
3
votes
7answers
215 views

Throwing an Exception if a Query Doesn't Use an Index

I'm working on a largish webapp that was developed by several other programmers and I keep running into performance issues caused by poorly written SQL queries and queries that don't use an index. ...
1
vote
4answers
2k views

How do I speed up XML parsing operation?

I currently have a php script set up to do some xml parsing. Sometimes the script is set as an on page include and other times it is accessed via an ajax call. The problem is the load time for this ...
6
votes
2answers
538 views

Session size management

From what I know, the session information is usually saved on the server. In Java the data is handled as a Map which I guess contains the a String identifier and an object reference which points to a ...
3
votes
2answers
185 views

Where can I find good example of techniques to compact data in-memory? [closed]

I'm writing a Java framework to manipulate a large amount of data in-memory, where many "cells" that are near each other will have the same value. I'm looking for algorithms and/or techniques ...
3
votes
1answer
204 views

How to optimize methodology to collect Market Data?

I am working on Application which goes and get's market data from different sources, I am using polling mechanism where vendor/broker put his data file and my application would go and hit that ftp ...
1
vote
1answer
214 views

Where is a good place to start to learn about custom caching in .Net

I'm looking to make some performance enhancements to our site, but I'm not sure exactly where to begin. We have some custom object caching, but I think that we can do better. Our Business We ...
32
votes
5answers
16k views

Performance of Scala compared to Java

First of all I would like to make it clear that this is not a language-X-versus-language-Y question to determine which is better. I have been using Java for a long time and I intend to keep using it. ...
9
votes
4answers
316 views

Is it a good idea to measure the performance of a method by using unit test timeout?

In a project where there are non-functional requirements which specify the maximum execution time for a specific action, QA must check the performance of this action on a dedicated machine using ...
5
votes
1answer
749 views

Coded ui to measure performance

I have been tasked with using coded UI to measure performance on a proprietary windows desktop application. The need is to measure how long it takes for the next page/screen to display after a user ...
6
votes
1answer
355 views

Should web browsers include popular web framework libraries?

What reasons are there for web browsers to not have a library of popular web frameworks. For example if a web page included jQuery, why shouldn't the browser have it's own static version, which is ...
15
votes
5answers
2k views

Resources on Writing Efficient C Code for Micro-controllers? [closed]

Serious help needed here. I love programming. I've been reading bunch of books(such as K&R) and articles/forums online for C language lately. Even tried looking into Linux code(although, i was ...
4
votes
3answers
606 views

Question about a “Benchmark” regarding Java and .NET

To get that out of the way - i am not asking about which platform is faster or try to start a flame war. Question: Why is the .NET version slower 5x in the first test ? The results i got were: .NET ...
2
votes
2answers
3k views

How can I separate the user interface from the business logic while still maintaining efficiency?

Let's say that I want to show a form that represents 10 different objects on a combobox. For example, I want the user to pick one hamburguer from 10 different ones that contain tomatoes. Since I want ...
9
votes
6answers
599 views

Examples of general purpose algorithms that have benefited from running on a GPU? [closed]

I am looking for examples of general purpose algorithms (meaning non-graphics related) that have been proven to run an order of magnitude faster on a GPU than on a CPU. I will use these examples to ...
3
votes
2answers
195 views

What percentage of code and runtime do you typically allow for testing?

When I write code, a certain amount of it is just for the purpose of logging, tracing, or otherwise "testing" what the program is doing. This not unit testing; this is not when it is running in ...
4
votes
2answers
2k views

InterviewStreet (Vertical Sticks) just a tip where to get started

Having a lot of trouble with this question in interviewstreet.com: Given array of integers Y=y1,...,yn, we have n line segments such that endpoints of segment i are (i, 0) and (i, yi). Imagine that ...
0
votes
3answers
110 views

Should I decompress zips before I archive?

I am writing a small personal archiving tool. I frequently work with a lot of client databases for short periods, what my tool will do is in overnight batch jobs it will detach the database and zip up ...
6
votes
3answers
3k views

What performance can we expect from std::string's c_str()? Always constant time?

I've been doing some needed optimizations lately. One thing I've been doing is changing some ostringstreams -> sprintfs. I'm sprintf'ing a bunch of std::strings to a c style array, ala char foo[500]; ...
0
votes
2answers
227 views

Algorithm for searching the neighbors neighbor of a directed graph

Is there an algorithm to search a directed graph (tree) for its neighbors neighbor? My current brute-force solution works as follows: for each node n: for each child c of n for each parent ...
6
votes
3answers
8k views

Practical size limits of a Hashtable and Dictionary in c#

What are the practical limits for the number of items a C# 4 Dictionary or Hashtable can contain and the total number of bytes these structures can reasonable contain. I'll be working with large ...
4
votes
1answer
526 views

Is there a formula to figure out the total execution time of sequential asyncronous processes?

I have a set of steps that need to run sequentially over a list of data. However each step only operates on a single piece of data at a time. Because of this, I can run the steps asynchronously. For ...
9
votes
4answers
4k views

Increase Performance of VS 2010 by using a SSD [closed]

After searching on the internet for performance improvements when using Visual Studio 2010 with a solid state hard drive, I heard a lot of different opinions. A lot of people said that there isn't ...
2
votes
3answers
231 views

How should we deal with multiple transaction-report requests?

We are developing a system for the retail market and of its features will enable clients (actually consumer clubs) to go through all transactions made by end-clients. One of the ways to get this ...
2
votes
4answers
273 views

How one could use a live editor

I was thinking about a live editing environment where code / a source file is synchronized so that changes made by one user would be carried across to all others editing the file. Something like ...
7
votes
2answers
261 views

What are the benefits of archiving?

I always see sites that only keeps fresh content on the home or subsections, and the rest of the content is kept in a separate section called 'archive'. Recently I have also heard that NoSQL DB's ...
5
votes
4answers
2k views

Why scalability issues cannot be solved by more servers ?

I know that big websites suffer from scalability issues and I guess that more servers (hardware) can help to handle scalabililty issues but I see that big websites are stuck about scalability even if ...
5
votes
4answers
424 views

One stop shop for good coding practices and performance tips? [closed]

While this may be a very subjective question I was wondering if there's a place (or many places) on the web where one can read up about good coding and performance tips for different languages and how ...
3
votes
5answers
779 views

Good techniques to speed up database execution

I have an ASP.Net application that is using a MySQL database. My queries are not executing as fast as I would like them too. Are there some standard ways to increase the speed of a MySQL database ...
0
votes
4answers
261 views

Count a row VS Save the Row count after each update

I want to know whether saving row count in a table is better than counting it each time of the proccess. Quick Example : A visitor goes to Group Clan, the page displays clan information and Members ...
1
vote
3answers
576 views

How to design a performance comparison between two data structures

I want to compare the performance of two search trees of integers (an AVL tree and a RedBlack tree). How should I design/engineer the tests to accomplish this? For example, let's consider the insert ...
4
votes
3answers
301 views

For performance critical situations is storing file metadata in a database better?

As per the title of this question, for extremely performance critical situations, is storing a file's metadata (e.g. location, size, download on, etc) in a database going to allow for better ...