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

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6
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1answer
255 views

Optimizing hash lookup & memory performance in Go

As an exercise, I'm implementing HashLife in Go. In brief, HashLife works by memoizing nodes in a quadtree so that once a given node's value in the future has been calculated, it can just be looked ...
6
votes
1answer
545 views

What factors should I be looking at to increase performance in image resizing?

I'm setting up a web app in which people will upload images. Once uploaded the images will be watermarked then resized multiple times (Thumbnails, different sizes etc.) and finally uploaded to Amazon ...
5
votes
4answers
1k 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
2k views

Big-O for nested loop

I am reading this post on Big-O It says that the following code is O(n^2): bool ContainsDuplicates(String[] strings) { for(int i = 0; i < strings.Length; i++) { for(int j = 0; j ...
5
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4answers
489 views

How does optimization make code “greener”?

It seems clear that whatever the language used, an optimized application consumes fewer resources than a poorly written application, and require fewer servers to manage a similar number of requests ...
5
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6answers
671 views

How should I react to diminishing application performance?

Sometimes it comes to me that the biggest challenge for an engineer when he find his application getting worse in performance is lack of enough information. Imagine that you go through the weekly ...
5
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5answers
630 views

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

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 ...
5
votes
4answers
422 views

Does profiling without benchmarking lead to micro-optimization?

Read first: For a definition of the two terms ("profiling" and "benchmarking") and the need for distinguishing them, please read this answer to a previous question. I have to admit that until I saw ...
5
votes
4answers
581 views

Performance related doubt in Java with Hibernate

Suppose in some ORM based project (say Hibernate) I am trying to fetch only few columns rather then the whole Object with may be more than 20 attributes. I am writing HQL like "select attr1, attr2 ...
5
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4answers
421 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 ...
5
votes
2answers
719 views

Erlang or 'x'.. Is it worth it (vs. Python w/ GIL)?

So, I've finally gotten myself to a point where I'm comfortable enough with Python (using Pyramid as my framework of choice) to undertake a rather large personal project. As it's a personal project, I ...
5
votes
2answers
366 views

Buzzword for “performance-aware” software development

There seems to be an overabundance of buzzwords for software development styles and methodologies: Agile development, extreme programming, test-driven development, etc... well, is there any sort of ...
5
votes
1answer
588 views

Is event sourcing ready for prime time? [closed]

Event Sourcing was popularized by LMAX as a means to provide speed, performance scalability, transparent persistence and transparent live mirroring. Before being rebranded as Event Sourcing, this type ...
5
votes
2answers
334 views

What design is best for data transformation?

My company's database makes available data to a lot of external applications. So I need to transform the same data to a lot of dynamic views. I can see that a former database developer had implemented ...
5
votes
1answer
1k views

In MATLAB, how can 'preallocating' cell arrays improve performance?

I was reading this article on MathWorks about improving MATLAB performance and you will notice that one of the first suggestions is to preallocate arrays, which makes sense. But it also says that ...
5
votes
1answer
521 views

Books on improving JEE web application performance and responsiveness

Does anyone know of any good books on this topic? I did search on amazon but ones that I found are pretty old publications.
5
votes
1answer
307 views

Why use Android Fragments?

I have read the documentation and some other questions' threads about this topic and I don't really feel convinced; I don't see clearly the limits of use of this technique. Fragments are now seen as ...
5
votes
1answer
112 views

When to use shared libraries for a web framework?

tl;dr: I've found myself hosting a bunch of sites running on the same web framework (symfony 1.4). Would it be helpful if I moved all of the shared library code into the same directory and shared it ...
5
votes
2answers
317 views

Structuring Access Control In Hierarchical Object Graph

I have a Folder entity that can be Moderated by users. Folders can contain other folders. So I may have a structure like this: Folder 1 Folder 2 Folder 3 Folder 4 I have to ...
5
votes
3answers
428 views

Performance considerations when using Go for my project

I'm looking at using Go (aka golang) for a project (a SQL database, but that mostly doesn't matter here) where performance is critical, but under low load the primary bottleneck will be I/O to disk. ...
5
votes
1answer
536 views

How can I compute the Big-O notation for a given piece of code? [closed]

So I just took a data structure midterm today and I was asked to determine the run time, in Big O notation, of the following nested loop: for (int i = 0; i < n-1; i++) { for(int j = 0; j < ...
5
votes
1answer
503 views

How to apply OOP, SOLID principles and Design Patterns in a library which does parallel processing without the caller's knowledge?

I want to explore the contentions between the two hot topics: Clean code vs. Good performance. (In progress ... please post comments to help me flush out the details of this question. Thanks.) ...
5
votes
3answers
646 views

Can software performance monitoring/profiling be automated to a high degree, as in unit testing?

Unit testing consists of executable code which exercise a certain functionality and then assert some conditions. The results are either Pass or Fail. The objective is always to have all tests ...
5
votes
1answer
284 views

How can I benchmark concurrent key-value stores?

I have some concurrent key-value store implementations that are implemented with hash tables and search trees that I would like to compare. I would like to benchmark them with a real world application ...
5
votes
1answer
647 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 ...
4
votes
11answers
732 views

Is a programmer's gut instinct an acceptable answer with regard to design decisions?

There are times where I can immediately recognize and suggest a fix for a problem design pattern. However, there are other times where putting it into words just isn't possible. I know something isn't ...
4
votes
8answers
991 views

Are Bools/Bits Faster Than Integers

As the title suggests I'm wondering whether bools or bits are faster than using integers (1 and 0)? Specifically I thinking about their speed in CASE statements, even more specifically in T-SQL ...
4
votes
4answers
388 views

What are the reasons for great performance differences running the same program?

I'm no computer scientist so please bear with me. Lately I wrote a python program that has to perform some expensive spatial searches while holding lot's of data in memory. I tried to improve the ...
4
votes
2answers
4k views

Low Latency Unix/Linux

Most low latency/high frequency programming jobs (based on job specs) appear to be implemented on unix platforms. In a lot of the specs they make particular request for people with "low latency linux" ...
4
votes
7answers
4k views

Object Oriented Programming Language performance ranking

After reading this post about ideal programming language learning sequence, I am wondering what would have been the answers if the question was performance -instead of learning- oriented ? Since ...
4
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4answers
501 views

Having error codes option in C++ library for performance

I have written an open source and cross-platform C++ File Library which have exception and error codes. Exceptions can be disabled when the program is running. In that case, the user have to check the ...
4
votes
3answers
2k views

Quickest way to split a delimited String in Java

I am building a Comparator that provides multi-column sort capability on a delimited String. I am currently using the split method from String class as my preferred choice for splitting the raw String ...
4
votes
3answers
209 views

How to best approach planning and budgeting of software performance optimization efforts?

There is a software system that has been with the client for some time now. If is feature-rich, mature, complex enterprise application that client uses in production. Due to the rapid expansion of the ...
4
votes
1answer
385 views

What is Rainbow (not the CMS)

I was reading this excellent blog article regarding speeding up the badge page and in the last comment the author waffles (a.k.a Sam Saffron) mentions these tools: dapper and a bunch of custom ...
4
votes
5answers
1k 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", ...
4
votes
2answers
1k views

Performance and other issues with using floating point types in C++

Being interested in C++ performance programming there is one aspect I really have no clue about- and that is the implications of using floating point calculations vs doubles vs normal integer ...
4
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 ...
4
votes
7answers
214 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. ...
4
votes
1answer
368 views

In Java, why use bit hacks when non-bitwise technique it is more readable?

Is there any legitimate use for bit manipulation hacks in higher-level languages such as Java? I can see them being useful in speed-sensitive low-level and computation-intensive programs, e.g. ...
4
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3answers
424 views

How Immutable Sets are Manipulated

When working with an immutable set or map, like the ones found in many functional programming languages, operations that would otherwise modify the container generate a new container instead. I know ...
4
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6answers
414 views

Information about how much time in spent in a function, based on the input of this function

Is there a (quantitative) tool to measure performance of functions based on its input? So far, the tools I used to measure performance of my code, tells me how much time I spent in functions (like ...
4
votes
2answers
159 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 ...
4
votes
3answers
576 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 ...
4
votes
6answers
3k views

PHP email blasts using a cron job

My PHP application needs to send product expiry notifications to customers everyday. I am thinking of: A one-time cron job for a php script that identifies the customers from a table of 10000 rows ...
4
votes
3answers
243 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 ...
4
votes
4answers
229 views

What performance topics should I be aware of? [closed]

When coding performance-critical portions of code (not necessarily large, but code that gets executed a lot), what topics should I be aware of/take into account. I'm already fairly familiar with ...
4
votes
1answer
290 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': [ { ...
4
votes
1answer
734 views

How much usage of “likely” and “unlikely” macros is too much?

The often known as likely and unlikely macros help the compiler know whether an if is usually going to be entered or skipped. Using it results in some (rather minor) performance improvements. I ...
4
votes
2answers
559 views

How to test the render speed of my solution in a web browser?

Ok, I need to test the speed of my solution in a web browser, but I have some problems, there are 2 versions of the web solution, the original one that is on server A and the "fixed" version that is ...
4
votes
4answers
553 views

Debugging, performance tracing, profiling, tools, etc. - suite? [closed]

My client is looking to standardize on its "helper" tools suite of applications to aid developers of a very large .NET project in debugging, profiling, finding memory leaks and performance ...