In terms of performance, what would work faster? Is there a difference? Is it platform dependent? //1. Using vector<string>::iterator: vector<string> vs = GetVector(); for(vector<string>::iterator it = vs.begin(); it != vs.end(); ++it) { *it = "Am I faster?"; } //2. Using size_t index: for(size_t i = 0; i < vs.size(); ++i) { //...
We use a modified version of Jiffy to measure actual client-side performance. The most important thing we do is measure the time between when the request was received and when the page load event fires in the browser. On some pages we have iframe elements that point to external sites that we don't control - they sometimes take a long w...
I'm writing a comparatively straightforward raytracer/path tracer in D (http://dsource.org/projects/stacy), but even with full optimization it still needs several thousand processor cycles per ray. Is there anything else I can do to speed it up? More generally, do you know of good optimizations / faster approaches for ray tracing? Edit:...
I have a Windows Form (C# .NET 3.5) with a number of buttons and other controls on it, all assigned to a topmost Panel which spans the whole Form. Eg the hierarchy is: Form -> Panel -> other Controls. As soon as i assign a BackgroundImage to the Panel the Controls draw very slowly. I have the same effect if i use the Form's BackgroundIm...
I'm looking for a database that supports the following functionality: 1) Records in the database are like Python dictionaries or Perl hashes. For example, a "purchase" record might look like this: <purchase 5436> = { product: "BMX Bike", price: 99.50, city: "Springfield" } 2) The records are stored in arrays of variable length. The d...
I have observed a great difference in Sun Java performance when code is compiled through jdk1.6 as compared to jdk1.5 or jdk1.4 (over 4 folds) What changes and optimizations have been done? Is there anything worth taking home from these changes which will help to boost our application performance. Thanks for replying ...
I want to filter a table with an input box. It works but it is slow on smartphones which are my target platform - Iphone, Htc Touch HD (800 rows take about 4sec to filter). Please let me know if you can help speed this up. function time(){ var now = new Date(); var time = now.getTime(); return time } function filter (phra...
I have a class containing a number of double values. This is stored in a vector where the indices for the classes are important (they are referenced from elsewhere). The class looks something like this: Vector of classes class A { double count; double val; double sumA; double sumB; vector<double> sumVectorC; vector<double>...
I would like to read how to use caching effectively, optimize my database schema and queries, apply partitioning and load balancing. There are pretty much resources on optimizing code and low-level stuff but not the other. I've read Building Scalable Web Sites by Cal Henderson and besides a single chapter actually on scaling, which bar...
I am currently working on 9.2.0.8 Oracle database.I Have some questions related to Performace of Database that too related to Redo logs latches & contention. Answers from real practice will be highly appreciated. please help. My data is currently having 25 redo log files with 2 members in each file. Each member is of size 100m. So Is ...
Hi, I'm creating an ASP.Net website that displays large amounts of data. The data is served to me through a data access layer. From the data I'm getting I'm building up large data tables and then displaying these using either gridview's or dynamically created web controls. The problem I'm finding is that the website is slow when a lot...
I have a performance problem with an Oracle select statement that I use in a cursor. In the statement one of the terms in the SELECT clause is expensive to evaluate (it's a PL/SQL procedure call, which accesses the database quite heavily). The WHERE clause and ORDER BY clauses are straightforward, however. I expected that Oracle woul...
I am wondering if there is any difference in regards to performance between the following SELECT ... FROM ... WHERE someFIELD IN(1,2,3,4) SELECT ... FROM ... WHERE someFIELD between 0 AND 5 SELECT ... FROM ... WHERE someFIELD = 1 OR someFIELD = 2 OR someFIELD = 3 ... or will MySQL optimize the SQL in the same way compilers will opt...
I have a trigger that stores changes made in a separate table when a user edits the data. This data is written out on a web page beneath the current data in human readable format, i.e. 23/04/09 22:47 James Smith changed Tenant Name from "George Hill" to "George Hilling". The trigger I have looks a bit like this - (this is the abridged...
I will apologize in advance as this post is born out of severe frustration. I have a classic asp website that has been running on Windows 2000/IIS5 for years, and another ASP.NET 2.0 site that we've recently started running on the same servers. So far, everything is running well. Last year, I tried upgrading (fresh install) to Windows ...
I know that sqlite doesn't perform well with extremely large database files even when they are supported (there used to be a comment on the sqlite website stating that if you need file sizes above 1GB you may want to consider using an enterprise rdbms. Can't find it anymore, might be related to an older version of sqlite). However, for ...
Hi there, I know that running applications in DEBUG (build configuration) thru the visual studio adds a level of overhead but I have a WPF application that I am testing out that is painfully slow in its execution and other functions such as drag/drop of items. When I run the application in Release mode it performs like one would expect...
Calling all database guys... The situation is this: I have a DB2 database that is being written to and read from. I need to do some performance testing on programmatically executed read/writes. I know how to write a program to read/write to this database, but I am not sure as to what factors I should consider in my performance test...
I have a web app running LAMP. We recently have an increase in load and is now looking at solutions to scale. Scaling apache is pretty easy we are just going to have multiple multiple machines hosting it and round robin the incoming traffic. However, each instance of apache will talk with MySQL and eventually MySQL will be overloaded. ...
I have a method which loops over user elements, and sets a boolean value according to some given constraint: public void checkUsers( int constraint ) { for(int i=0; i<nodeUsers().size(); i++) { UserElement elem = nodeUsers().getUsersElementAt(i); switch (constraint) { case CHECK_ALL: elem.set...