I just stumbled upon a change that seems to have counterintuitive performance ramifications. Can anyone provide a possible explanation for this behavior? Original code: for (int i = 0; i < ct; ++i) { // do some stuff... int iFreq = getFreq(i); double dFreq = iFreq; if (iFreq != 0) { // do some stuff with iFre...
So i have a UNIQUE CHAR(255) column, i want to find a particular row, Would it make sense to create CHAR(10) INDEX to make search more efficient? I know a unique is also an index the engine will scan throught the index to where the 1st letter is J, then JO, then JOH but an index of 255 bytes x 1 million records, is a lot of memory "s...
I was recently asked to speed up a C#/ASP.NET/SQL Server business app website. Since I just started, I don't know too much about the internals. So where do I start? Sight unseen, what is the single most important thing affecting performance on a system like this? Database tuning? Hardware? Individual page optimization? What is the...
How often do you conduct regular maintenance such as stress test your application and/or tune your database indexes for your applications? E.G., Do you tune (defrag, reorganise or rebuild) your database indexes once a week, every six months or only after large volumes of data have been input and do you stress test your application afte...
I realise different solutions will have different variations of what "Working Days" means but in my case I mean Monday to Friday inclusive. Basically I have Created a function to do the calculation for me and my current solution works. My concern (and reason for asking this question) is that I am worried that this is a bad way of achiev...
Hi, I want to find out the reason for slow performance of some web pages of an ASP.NET intranet website. the reasons could be many like large view state, number of round trips to the server and database, inefficient code in UI/middle tier etc. most of these slow pages are complex web pages with some third party controls, user controls...
This is the output after running for around 10 minutes. Heap PSYoungGen total 7040K, used 0K [0x24060000, 0x247c0000, 0x26790000) eden space 6528K, 0% used [0x24060000,0x24060000,0x246c0000) from space 512K, 0% used [0x246c0000,0x246c0000,0x24740000) to space 512K, 0% used [0x24740000,0x24740000,0x247c0000) ParOldGen ...
I have a database for tracking customer purchases over history. One of my forms allows you to search for a customer name, and a subform displays all recent purchases. I have a total of 474 customer records. I am tracking a total of 2119 purchase records. The BE and FE are already split, which may be slowing things down, but is needed...
This question escaped my mind last night, but I remember it again. Is it possible that in the development of a vb.net application that you can reduce the amount of memory that it will consume once you deploy it. We are making a simple system that we will deploy in a small company (for free) but we don't know if the computer hardware in ...
I keep wondering about this to try to improve performance and size of my Flex swfs, how do classes vs. static methods vs. instance methods impact performance and the final compiled "executable's" size? Thinking how it might be possible to apply something like HAML and Sass to Flex... Say I am building a very large admin interface with...
I’m monitoring a web application and I am confused about a few of the asp.net performance counter. Can anyone explain the different between the ASP.NET Requests Current counter and the ASP.NET Applications Requests/sec? ...
Hi, I am doing performance tweaking of a simple app that uses MVC on IIS 7.5. I have a StopWatch starting up in Application_BeginRequest and I take a snapshot at Controller.OnActionExecuting. So I measure the time spend in the entire IIS pipeline: from request receipt to the moment execution finally gets to my controller. I obtain 700 ...
I've written this very badly optimized C code that does a simple math calculation: #include <stdio.h> #include <math.h> #include <stdlib.h> #define MIN(a, b) (((a) < (b)) ? (a) : (b)) #define MAX(a, b) (((a) > (b)) ? (a) : (b)) unsigned long long int p(int); float fullCheck(int); int main(int argc, char **argv){ int i, g, maxNumber...
Hi I have a MySQL table, let's say it is a helpdesk ticketing system. It has a CLOSED column, which I want to index. 99% of time, I will need to only select on OPEN tickets, so something like "SELECT * FROM TICKET_TABLE where CLOSED='N'; " And over time, more and more tickets are CLOSED, while a small constant number of OPEN tickets r...
Hello. I'm trying to optimize the performance of my code, but I'm not familiar with xcode's debuggers or debuggers in general. Is it possible to track the execution time and frequency of calls being made at runtime? Imagine a chain of events with some recursive calls over a fraction of a second. What's the best way to track where the...
I just read this blog post and, in short, it say that if an SQL server isn't doing a good enough job building query plans, then the last thing you want to do is start hard coding stuff. So, that got me thinking; how could you "hard code" stuff without hard coding stuff. (Yes, that's the way I tend to think.) Is the following; 1) possibl...
Is there any pattern how to deal with a lot of object instantiations (40k per second) on a mobile device? I need these objects separately and they cannot be combined. A reusage of objects would probably be a solution. Any hints? ...
Are there some good tools that can analyze the performance issues in an asp.net application? i google and found a couple like dotTrace, stimulustechnology. have anyone used a better one? thanks ...
I have a table Products with products and table Sales with all sale operations that was done on these products. These tables are connected by Sales.PRODUCT_ID column. I would like to get 10 most often sold products today and what I did is this: SELECT product.* , COUNT( sale.ID ) SUMSELL FROM Products product LEFT JOIN Sales sale ...
[Also on SuperUser - http://superuser.com/questions/116600/can-i-spead-out-a-long-running-stored-proc-accross-multiple-cpus] I have a stored procedure in SQL server the gets, and decrypts a block of data. ( Credit cards in this case. ) Most of the time, the performance is tolerable, but there are a couple customers where the process is...