performance

Efficient data structure for word lookup with wildcards

Hi there, I need to match a series of user inputed words against a large dictionary of words (to ensure the entered value exists). So if the user entered: "orange" it should match an entry "orange' in the dictionary. Now the catch is that the user can also enter a wildcard or series of wildcard characters like say "or__ge" which wo...

Does Visual Studio 2010 benefit from quad core vs dual core machines? Is compilation multithreaded?

I have a Windows XP machine with a dual core 3.6G CPU and 4megs. I am not very happy with the performance. I was wondering if compilation in VS 2010 is multithreaded and does VS 2010 benefit from switching from dual to quad core machine? ...

Does the order of case in Switch statement can vary the performance?

Let say I have a switch statement as below switch(alphabet) { case "f": //do something break; case "c": //do something break; case "a": //do something break; case "e": //do something break; } Now suppose I know that the frequency of having Alphabet e...

Performance of "returning" from a Try block

Exception handling on Windows boxes (at least for C++) takes a performance hit if you exit a try block prematurely (such as executing a return statement) the same as if an exception were thrown. But what about C#? Is there a performance hit for returning prematuraly from a try block, whether through a return statement or break statemen...

How is database performance impacted when the mysql innodb database is very large?

I am currently making a decision on how i can reduce the size of the database. Why is performance slowed down when a database is slow? ...

What is faster with PictureBox? Many small redraws or complete redraw.

I have a PictureBox (WinMobile 6 WinForm) on which I draw some images. There is a background image that goes in the background and it does not change. However objects that are drawn on the picturebox are moving during the application so I need to refresh the background. Since items that are redrawn fill from 50% to 80% of the surface, t...

Faster way of initializing arrays in Delphi

I'm trying to squeeze every bit of performance in my Delphi application and now I came to a procedure which works with dynamic arrays. The slowest line in it is SetLength(Result, Len); which is used to initialize the dynamic array. When I look at the code for the SetLength procedure I see that it is far from optimal. The call sequence...

Passing integer lists in a sql query, best practices

I'm currently looking at ways to pass lists of integers in a SQL query, and try to decide which of them is best in which situation, what are the benefots of each, and what are the pitfalls, what should be avoided :) Right now I know of 3 ways that we currently use in our application. 1) Table valued parameter: Create a new Table Valued...

Are there ways to improve NHibernate's performance regarding entity instantiation?

Hi folks, while profiling NHibernate with NHProf I noticed that a lot of time is spend for entity building or at least spend outside the query duration (database roundtrip). The project I'm currently working on prefetches some static data (which goes into the 2nd level cache) at application start. There are about 3000 rows in the result...

apache alias and .htacess willing to understand configuration?

On our local dev enviornment we had just one server and to add far future expires and cache control header to static images we kept a .htaccess file in the root of the application things worked fine. But on our prod we have multiple apache servers having aliases to a code base on a different server. Here in this case i am not sure where ...

Definition of Connect, Processing, Waiting in apache bench.

When I run apache bench I get results like: Command: abs.exe -v 3 -n 10 -c 1 https://mysite Connection Times (ms) min mean[+/-sd] median max Connect: 203 213 8.1 219 219 Processing: 78 177 88.1 172 359 Waiting: 78 169 84.6 156 344 Total: 281 389 86.7 391 563 I ...

Speed Up PowerShell Scripts in V2?

Hi, I'm running a number of scripts using PowerShell V2, and I have noticed a long pause when the console window first loads. What can I do to improve the performance of my scripts? Thanks, MagicAndi ...

Maximum capabilities of MySQL

How do I know when a project is just to big for MySQL and I should use something with a better reputation for scalability? Is there a max database size for MySQL before degradation of performance occurs? What factors contribute to MySQL not being a viable option compared to a commercial DBMS like Oracle or SQL Server? ...

Oracle SQL: Multiple Subqueries Unioned Without Running Original Query Multiple Times.

So I've got a very large database, and need to work on a subset ~1% of the data to dump into an excel spreadsheet to make a graph. Ideally, I could select out the subset of data and then run multiple select queries on that, which are then UNION'ed together. Is this even possible? I can't seem to find anyone else trying to do this and ...

PHP image resize on the fly vs storing resized images

I'm building a image sharing site and would like to know the pros and cons of resizing images on the fly with php and having the resized images stored. Which is faster? Which is more reliable? how big is the gap between the two methods in speed and performance? Please note that either way the images go through a PHP script for sta...

Monitoring process-level performance counters in Windows Perfmon

I am sure everybody has bumped into this. As you scale a web server that uses multiple application pools, it's valuable to collect performance counters for each application pool 24x7. The only problem is - Perfmon links counters to application pools by process ID, so whenever an application pool recycles you have to remove the counters f...

Linq to SQL - what's better?

db.Albums.FirstOrDefault(x => x.OrderId == orderId) or db.Albums.FirstOrDefault(x => x.OrderId.Equals(orderId)) ...

VB.Net IO performance

Having read this page, I can't believe that VB.Net has such a terrible performance when it comes to I/O. Is this still true today? How does the .Net Framework 2.0 perform in terms of I/O (that's the version I'm targeting)? ...

Quickest way to compare a bunch of array or list of values.

Can you please let me know on the quickest and efficient way to compare a large set of values. Its like there are a list of parent codes(string) and each code has a series of child values(string). The child lists have to be compared with each other and find out duplicates and count how many times they repeat. code1(code1_value1, code1_v...

How to calculate a operation's time in micro second precision

I want to calculate performance of a function in micro second precision on Windows platform. Now Windows itself has milisecond granuality, so how can I achieve this. I tried following sample, but not getting correct results. LARGE_INTEGER ticksPerSecond = {0}; LARGE_INTEGER tick_1 = {0}; LARGE_INTEGER tick_2 = {0}; double uSec = 10000...