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

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1answer
67 views

When the result set doesn't matter should Left Join or Inner Join be used

When you have a query where you're joining from a non-null foreign key to the foreign table it doesn't matter if you use LEFT JOIN or INNER JOIN from a result standpoint (since there won't be any ...
5
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1answer
82 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 ...
2
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1answer
461 views

How many Angular Controllers and/or Directives is too many?

I'm building a large, editable data table with angular, and I'm trying to figure out what the best practice is. The table will be a couple of hundred rows, with a couple of dozen columns, so upwards ...
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1answer
53 views

How do hybrid interpreter-JIT compilers work?

Chrome's V8 compiler, the Java HotSpot compiler, and many more have multiple tiers of interpretation and compilation. A function starts off as interpreted in HotSpot and then, if it is run often ...
4
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1answer
206 views

Is Collection.stream().filter().forEach() inefficient compared to a standard for each loop?

IntelliJ IDEA recommended to me just now to replace the following for-each loop with a Java 8 "forEach" call: for (Object o : objects) { if (o instanceof SomeObject) { ...
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3answers
92 views

What is the explication for the difference execution time for the same instruction?

As you know when we run instruction in our code like long a = b; we will not have the same ticks each to be executed. first exeution it take 2ticks; second exeution it take 3ticks; third exeution it ...
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0answers
30 views

Truncating HTML content at specific content blocks

I have HTML content in my DB and I would like to present a list of these individual items but truncate each of them so they're not fully displayed. I would like to keep truncated items ...
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5answers
146 views

Should I use BLOB or Tables for storing large data?

Problem Currently investigating a solution to improve the performance of a web application. The application works well for small projects, but faces performance issues in the UI when working with ...
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1answer
77 views

Java - Concept question: LinkedHashMaps vs POJOs?

EDIT: I'm just going to ask a single question instead of presenting a problem and asking for advice on a specific design decision in the solution. Given a batch of data from a database, collected ...
2
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2answers
170 views

Will using multiple recordsets in one database request be more efficient?

I am redeveloping an old ecommerce website which is currently written in C# ASP.NET 2.0. Because this is a reasonably high volume website and has suffered performance issues I want to develop in the ...
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2answers
47 views

Solutions To Partial ORM Retrieval

I have read the following question regarding whether it is best to use objects with fully or partially populated data members. The 3 suggestions were: that perhaps using a fully populated ORM model ...
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0answers
24 views

ASP.NET: Testing performance and memory Usage [closed]

I am developing a website that have to be prepared for supporing a lot of concurrent users, so i need to test that. I would like to see what happen with the CPU consuming, Memory Usage, etc, when ...
12
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7answers
473 views

500 databases or 1 database with 500 tables or just 1 table with all the records? [duplicate]

I currently have an application that is used by a single end customer. For ease of discussion assume the application only needs a single database table for all records. I now need to support ...
2
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1answer
118 views

What happens when one reaches their framework's maximum requests per second?

I've been dabbling in code for many years now but it's always been personal projects. I don't have experience with much traffic. I was recently reading through a "Hello, World." tutorial for ...
121
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30answers
11k views

Is micro-optimisation important when coding?

I recently asked a question on Stack Overflow to find out why isset() was faster than strlen() in PHP. This raised questions around the importance of readable code and whether performance improvements ...
59
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7answers
10k views

Is a 1 < 10 comparison less expensive than 1 < 1000000?

I just used ~1 billion as the count for a z-index in CSS, and was thinking about the comparisons that must go on. Is there a difference in performance on the ALU level in comparisons between very ...
3
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1answer
272 views

Why is iterating through List<T> more expensive than iterating through Array in .NET?

According to the answers in this post, List<T> is backed by an Array. According to this article, list iteration is considerably slower than array iteration. If Lists are arrays 'under the ...
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4answers
528 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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2answers
102 views

Reading Element Names vs Reading Element Attributes: Speed

I am working on a project where there are a whole bunch of strings being stored in an XML file for later retrieval. Stored with each string are between 0-10 tags that a user can use to access and sort ...
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10answers
12k views

Why Should I Avoid Inline Scripting?

A knowledgeable friend recently looked at a website I helped launch, and commented something like "very cool site, shame about the inline scripting in the source code". I'm definitely in a position ...
4
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3answers
853 views

On access scans and Visual Studio

Where I work McAfee On Access scan is enforced to be on for all our machines. Visual Studio 2010 isn't exactly the speediest program at times but combining a large website, several build ...
2
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2answers
89 views

Is storing data directly in a list node better than storing a pointer to data?

Suppose we have two different doubly-linked list structures: One has content of the node embedded directly in the node: struct Content { // some stuff }; struct Node { struct Node *next; ...
2
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0answers
50 views

Argument over performance using Convert.ChangeType in Web Applications [duplicate]

A debate has been going on at work about using Convert.ChangeType. A couple of fundamental assumptions to this discussion are delineated below: 1. The discussion is within the context of web ...
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0answers
57 views

Heavy-duty use of C++ initializer_lists of containers [closed]

I've proposed and developed an optimization bringing move semantics to std::initializer_list. It seems like a slam dunk, but some on the committee saw the proposal as a waste of time, never mind ...
138
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13answers
32k views

Should we avoid object creation in Java?

I was told by a colleague that in Java object creation is the most expensive operation you could perform. So I can only conclude to create as few objects as possible. This seems somewhat to defeat ...
4
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1answer
231 views

How does modulus work?

I am not asking asking how the mathematical concept of modulus works, or how 20 % 3 == 2 I understand this fine. I'm more curious how the compiler/interpreter determines this. I can think of a very ...
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2answers
108 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 ...
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2answers
2k views

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

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 ...
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3answers
481 views

Enterprise software: Where should the code go? [duplicate]

I recently went for an interview with a software company that claims to write enterprise level software. During the interview, the interviewer remarked that its better to use the database simply to ...
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3answers
195 views

Compile-time vs. run-time configuration

I'm starting new project and need to decide on how to handle configuration. I recently run into suckless project. While it has its own issues, I really liked its approach to configuration - just a ...
2
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3answers
192 views

fast, say O(log2(N)), sliding median algorithm

So I know how to do a fast O(log2(N)) sliding max or sliding min algorithm. Brookes: "Algorithms for Max and Min Filters with Improved Worst-Case Performance" IEEE TRANSACTIONS ON CIRCUITS AND ...
2
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2answers
4k 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 ...
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4answers
164 views

List comparing techniques for faster performance

I need to cross names from two lists, and find all occurrences of one name in the other. The lists are too big, one have 50k elements and the other 400k. For a small list I would use two foreach ...
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10answers
3k views

Is template “metaprogramming” in Java a good idea?

There is a source file in a rather large project with several functions that are extremely performance-sensitive (called millions of times per second). In fact, the previous maintainer decided to ...
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1answer
141 views

Are there real world examples demonstrating reasonable performance improvement by using move semantics?

(I've asked a similar question on SO but unfortunately it might not be proper, so I also put here; please kindly point out if you think it's a duplicate.) I've heard many words about the move ...
1
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1answer
111 views

Excel worksheet population and fomatting is slow

I have written a VSTO plugin in C# which populates several worksheets. During the population process cell values or formula are added one at a time according to user-definable criteria taken from a ...
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11answers
2k views

Does Refactoring towards Looser Coupling, Smaller Functions, and Separate Classes affect System Performance? (and Should I Care)

In Computer Science field, I have noticed a notable shift in thinking when it comes to programming. The advice as it stands now is write smaller, more testable code refactor existing code into ...
1
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1answer
54 views

Does grouping threads by task improve performance?

This is kind of a lazy question on my part, since I gave up after trying only a few google terms. But when I read about multi-threaded performance, I read about context switching being bad for ...
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1answer
151 views

Correct usage of Bluebird promise

This is related to this question on promise performance. The current top answer states that using new Promise is an anti-pattern in bluebird And that promisify should be used instead. I ...
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1answer
431 views

Why are native ES6 promises slower and more memory-intensive than bluebird?

In this benchmark, the suite takes 4 times longer to complete with ES6 promises compared to Bluebird promises, and uses 3.6 times as much memory. How can a JavaScript library be so much faster and ...
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2answers
80 views

Is using triggers best solution for this scenario

A large SQL transactional database has more than 100 tables (and it will grow). One of them is called Order. Then, there is another table WorkLoad which derives from Order and many other joined table ...
13
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1answer
323 views

Is there a performance benefit to using the method reference syntax instead of lambda syntax in Java 8?

Do method references skip the overhead of the lambda wrapper? Might they in the future? According to the Java Tutorial on Method References: Sometimes... a lambda expression does nothing but ...
3
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1answer
118 views

Can SSE (or AVX) be used to do large bsf?

I'm faced with having to do a bsf (find the first bit set) in a 512bits bitmap. This is in the hot path so I'd like to see how I can speed things up. Right now I'm maintaining a header entry to know ...
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2answers
145 views

Line intersection detection algorithm

I'm trying to detect if a line drawn by the user intersects itself. I'm using a line intersection detection algorithm that goes through each waypoint of the line and checks if intersects with any ...
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9answers
445 views

How often is software speed evident in the eyes of customers?

In theory, customers should be able to feel the software performance improvements from first-hand experience. In practice, sometimes the improvements are not noticible enough, such that in order to ...
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2answers
517 views

Is there any better approach to shortest path finding within a (vehicular) traffic network?

Dear fellow programmers, We're developing software which simulates vehicular traffic. Part of the process called "assignment" is concerned with assigning vehicles to their routes and has to use some ...
1
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1answer
96 views

How to evaluate the performance of a Data Access Layer b/w two ORM's?

I am currently working on a project where I am going to replace the Data Access Layer from a custom ORM to Entity Framework.(The product is almost complete and mostly any changes that will follow ...
0
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1answer
42 views

Tags DB structure - tags table using one join and GROUP BY, or pivot (join) table using two joins?

I'm implementing tags into my question and answer application. Users will be limited to the tags available by the app, so they can't choose their own. So maybe only 30-50 tags will be available. This ...
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1answer
206 views

Object caching in this code too expensive?

I'm having some trouble with a game developed in Java which is kinda slow. I benchmarked it a little bit and found the problem: most of the time, the JVM is in the Object.<init>() since there ...
2
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2answers
181 views

How to store data in memory(RAM) using php without using Memcache/Redis or any other software? [closed]

I want to implement a cache system in PHP consisting of following features 1) It should be able to store any(large or small) amount of data as long as the memory serves.(key value pair i.e. get & ...