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

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505 views

Shared Cache - Invalidation Best Practice

I'd like to know what would be a better approach to invalidate/update cache objects. Prerequisites Having remote memcached server (serving as cache for multiple applications) All servers are hosted ...
7
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4answers
824 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 ...
7
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3answers
10k 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 ...
7
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2answers
264 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 ...
7
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2answers
218 views

Are Concurrency Abstractions Emulating UNIX Processes?

OK, I was pondering this today, and I've come to ask for completely subjective and bias opinions on it. Paradoxically, despite this, I don't think it's flame-war fodder either. I think there is room ...
6
votes
1answer
364 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 ...
6
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3answers
352 views

Fine Line: Readability Vs Speed [duplicate]

Is there a line between readability vs compile or processing speed? Aside from the extreme cases, I wouldn't think it would be even worth saving that little bit extra in favor of legibility... For ...
6
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4answers
2k views

Is it a performance hit to create threads that loop a lot to check for things?

This is a generic question that I've always wondered. In general, is it intensive for a CPU to create threads that perform "while not true ..." loops or similar? For example, suppose I do: // ...
6
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3answers
1k views

A question regarding linked list vs vector insert/remove results comparison

I was reading this blog post: http://kjellkod.wordpress.com/2012/02/25/why-you-should-never-ever-ever-use-linked-list-in-your-code-again/ and I found there a code to run: http://ideone.com/62Emz ...
6
votes
2answers
749 views

Does javascript support numerically indexed arrays with a more optimized algorithm than an associative array?

I know that Python, Perl, Java, Lua and obviously C (as it's the only array that's in ANSI standard afaik) support faster looking of numerically indexed arrays than doing a hash lookup or anything ...
6
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2answers
646 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 ...
6
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2answers
329 views

How does the Hip hop virtual machine (HHVM) theoretically improve PHP runtime performance?

From a high level, how does Facebook, et. al use to improve PHP performance with the Hip Hop Virtual Machine? How does it differ from executing code using the traditional zend engine? Is it because ...
6
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1answer
713 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 ...
6
votes
4answers
599 views

Issues to be considered while loading jQuery?

I have seen many answers in SO regarding using Google's CDN to load jQuery instead of loading it from the local server. In essence I understand this is the issue related with decreased latency, ...
6
votes
4answers
603 views

What are the options when Sql generated by ORM needs tuning?

I am starting working on a web project using django. While researching whether to use Sqlalchemy or raw sql when django orm is not sufficient which is also a question I asked here Raw Sql vs ...
6
votes
2answers
1k views

Should I group all of my .js files into one large bundle?

One of the difficulties I'm running into with my current project is that the previous developer spaghetti'd the javascript code in lots of different files. We have modal dialogs that are reused in ...
6
votes
1answer
2k views

Performing client-side OAuth authorized Twitter API calls versus server side, how much of a difference is there in terms of performance?

I'm working on a Twitter application in Ruby on Rails. One of the biggest arguments that I have with other people on the project is the method of calling the Twitter API. Before, everything was done ...
6
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2answers
439 views

Versioned Resources to Improve Cacheability

Here's an API concept which could be useful for performance optimisation. It's an example of key-based cache expiry applied to a broader internet-wide context instead of the internal Memcached-style ...
6
votes
1answer
671 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 < ...
6
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1answer
274 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
651 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
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
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4answers
3k 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
542 views

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

I wrote a Python program that has to perform some expensive spatial searches while holding lots of data in memory. I tried to improve the performance, that is tried different approaches (see my ...
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6answers
682 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 ...
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7answers
1k views

Are mutliple database calls really significant with a network call for a web API?

At one of my employers, we worked on a REST (but it also applies to SOAP) API. The client, which is the application UI, would make calls over the web (LAN in typical production deployments) to the ...
5
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3answers
10k 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 ...
5
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5answers
2k views

Is Moore's law (empirically) the same for both memory capacity and processing speed?

Or, in other words, has memory and processing power increased over time around basically in the same rate, or we could say that one or the other has increased more? Has cost decreased in the same ...
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7answers
5k 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 ...
5
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2answers
747 views

Where is the evidence for the performance of Node.js?

A lot of developers, especially ones who haven't used Node.js in production, seem to believe that Node.js is faster than other interpreted languages such as PHP, Python, and Ruby. These claims ...
5
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2answers
116 views

When designing a replacement application, how can I compare its performance to the original, if there are no existing statistics?

I don't believe there are any performance statistics kept for the application I'm being asked to replace, and don't want to ask the individuals doing the work to manually record things like how long ...
5
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4answers
3k 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 ...
5
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2answers
2k 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 ...
5
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5answers
3k 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", ...
5
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4answers
578 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
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4answers
898 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
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 ...
5
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2answers
949 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
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1answer
285 views

Kth selection routine - Floyd Algorithm 489

I have recently come across a promising Kth selection routine that reportedly outperforms quickselect the Floyd, Rivest Select routine. This Wikipedia article provides a pseudocode version which I ...
5
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1answer
799 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. ...
5
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1answer
311 views

Why does Haskell's built in max function run faster than mine?

I noticed that for some reason, Haskell's built in max function (which returns the greatest of two numbers) runs much faster than the one I wrote, even though they are essentially identical. From ...
5
votes
2answers
539 views

Buzzword for “performance-aware” software development [closed]

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
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2answers
340 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
2k 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
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1answer
605 views

Books on improving JEE web application performance and responsiveness [closed]

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
2k 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 ...
5
votes
1answer
125 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
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2answers
455 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
473 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
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1answer
534 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.) ...