Hi, this question is just speculative. I have the following implementation in C++: using namespace std; void testvector(int x) { vector<string> v; char aux[20]; int a = x * 2000; int z = a + 2000; string s("X-"); for (int i = a; i < z; i++) { sprintf(aux, "%d", i); v.push_back(s + aux); } } int main() { for ...
This is a rather general question .. What hardware setup is best for large C/C++ compile jobs, like a Linux kernel or Applications ? I remember reading a post by Joel Spolsky on experiments with solid state disks and stuff like that. Do I have to have rather more CPU power or more RAM or a fast harddisk IO solution like solid state ...
I am working with Sybase 15 in my application and there is performance issue related with nested joins. I have stored procedure which selects 2 columns from 2 tables and compares equalities of over 10 columns between this 2 tables. But when I run this stor. proc., the result takes 40 minutes. I added "set merge-join off" statement to top...
I am writing an application which needs to read fairly large files. I have always wondered what's the optimum size for the read buffer on a modern Windows XP computer. I googled and found many examples which had 1024 as the optimum size. Here is a snippet of what I mean: long pointer = 0; buffer = new byte[1024]; // What's a good size...
What is the cost of using Arrays.asList to convert static object arrays? Assuming that the object array has N items is it just an O(N) algorithm, where all of the items are copied by reference or is it merely a facade where the original array is put behind a List facade? ...
Consider the following (admittedly long) example. The sample code creates two data sets, data one with "key" variables i,j,k and data two with key variables j,k and a "value" variable x. I'd like to merge these two data sets as efficiently as possible. Both of the data sets are indexed with respect to j and k: the index for the first d...
There is a free tool called AppTimer-http://www.passmark.com/products/apptimer.htm. But i think it's not quite fit for my needs. Windows provides a tool called xperf, is there a way to use it to test/benchmark application' startup? ...
Are there any standard queries that can be run that will show the performance of a SQL Server 2005 database? Note: I need to know the performance of every aspect of the database. EDIT: I am looking for a way to measure the time it takes for typical queries to execute. I am then going to apply indexing to certain tables in the database ...
A friend has recommended that I install php APC, claiming it will help php run faster and use less memory sounds promising but I'm a little nervous about adding it to my VPS server I have one small app that I've built using codeigniter, and several sites that use the popular slideshowpro photo gallery software could install this break...
I am running through some tests about using ArrayLists and List. Speed is very important in my app. I have tested creating 10000 records in each, finding an item by index and then updating that object for example: List[i] = newX; Using the arraylist seems much faster. Is that correct? UPDATE: Using the List[i] approach, for my Li...
I'm working with a PHP developer who is, shall we say, unhappy with .NET. His complaints include having to rebuild the web application solution for every test (though I pointed out that this is usually only necessary if a .cs file has been changed, not interface .aspx files), having to include every file in the solution that is required ...
In the never-ending search for performance (and my own bludgeoning experience), I've learnt a few things that could drag down the performance of a SQL statement. Obsessive Compulsive Subqueries Disorder Doing crazy type conversions (and nest those into oblivion) Group By on aggregate functions of said crazy type conversions Where fldID ...
Hello. I have been using shared pointers for soem time now, and I have performance issues in my program... So I'd like to know if shared pointers lead to performance decrease. If so, then how hard? Thanks alot. My program is multi-threaded, using std::tr1::shared_ptr ...
Hello, Me and my friend are trying to accelerate a 2D game with OpenGL. The video chipset is Radeon X1250 which seems to be underpowered and can display up to some 80 1366x768 full frames/s. Given that we are drawing many sprites on top of each other the performace drops dramatically under the 60 FPS we are targeting at. Could you pleas...
Just want to pick the experts' brains on php output buffering. There are times when I've wanted to implement it for one reason or another, but have always managed to rearrange my code to get around it. I avoid using it because it sounds like it'll cost resources. I mean, if they can offer the coder such wonderful flexibility, why do...
Right now, the only function that I am aware of is _snprintf_s like the following double dMyValue = <some value>; _snprintf_s(pszMyBuffer, sizeof(pszMyBuffer), 12, "%.10f", dMyValue); ...
I'm making a data-entry web page in PHP that validates and parses data for entry into a MySQL database. There are more than 30 columns in the database that consist of MySQL SET or ENUM data. If you don't know much SQL, an ENUM datatype column can only hold one value from a collection of ENUM variables that you define when you create th...
Because of performance purposes I put loading of jQuery scripts at the bottom of the page (just before the closing body tag). My question is how to enable page specific scripts? I don't want to put everything inside $(document).ready method (again because of performance purposes). Update: I'm using a template system so I put jQuery loa...
I have a MySQL database in which each user has an account, and each account can have multiple permissions. My ultimate goal is to end up with the account's username, and a comma-delimited list of permissions ids. There are two ways I can accomplish this: SELECT a.username, GROUP_CONCAT(rp.permission_id) as permission_ids FROM account ...
Hello everyone, I am using the following code to try to test whether network consumption (monitored from network tab of task manager) will increase if I increase the concurrent connection number (i.e. the ClientCount application configuration value). But I find even if I increase client count from 100 to 500, the network consumption is ...