performance

Is there any performance overhead in using RaiseEvent in .net

Is there any performance overhead in using RaiseEvent in .net I have a code which is similar to following. Dim _startTick As Integer = Environment.TickCount 'Do some Task' Dim duration As Integer = Environment.TickCount - _startTick Logger.Debug("Time taken : {0}", duration) RaiseEvent Datarece...

pumpevents - customized look and feel java taking too much system resources

I make my own GUI see here but system is taking too much resources on further looking into the issue i have found that java pumpevents method is talking too much time. Any resolutions ???? pump events more detail pump event detail ...

android mobile development performance vs extensibility

im developing a game in android, and i've been thinking about subdividing many of the elements of the game (e.g. game objects) into separate classes and sub-classes. but i know that method calls to these objects will cause some overhead. would it be better to improve performance or to improve extensibility? ...

Speeding Up Slow, CPU-Intensive Scrolling in WinForms

How can I speed up the scrolling of UserControls in a WinForms app.? My main form has trouble scrolling quickly on slow machines--painting for each of the small scroll increments is CPU intensive. My form has roughly fifty UserControls (with multiple fields) positioned one below the other. I’ve tried intercepting OnScroll and UserPa...

Oracle Query Optimization: Why is My Second Query Faster?

I was having some performance issues with an Oracle query, so I downloaded a trial of the Quest SQL Optimizer for Oracle, which made some changes that dramatically improved the query's performance. I'm not exactly sure why the recommended query had such an improvement; can anyone provide an explanation? Before: SELECT t1.version_id, ...

c# - SQL - speed up code to DB

I have a page with 26 sections - one for each letter of the alphabet. I'm retrieving a list of manufacturers from the database, and for each one, creating a link - using a different field in the Database. So currently, I leave the connection open, then do a new SELECT by each letter, WHERE the Name LIKE that letter. It's very slow, thoug...

mysql view performance

I have a table for about 100,000 users in it. First Case: explain select state, count(*) as cnt from users where state = 'ca' when i do an explain plan for the above query i got the cost as 5200 Second Case: Create or replace view vw_users as select state, count(*) as cnt from users Explain select cnt from vw_users where state = '...

Help speed this MySQL query which is taking too long because of an aggregate function

Hi all, I am using a following query in MySQL for fetching data from a table. Its taking too long because the conditional check within the aggregate function.Please help how to make it faster SELECT testcharfield , SUM(IF (Type = 'pi',quantity, 0)) AS OB , SUM(IF (Type = 'pe',quantity, 0)) AS CB FROM Table1 WHERE sequence...

ASP.Net Web Farm Monitoring

I am looking for suggestions on doing some simple monitoring of an ASP.Net web farm as close to real-time as possible. The objectives of this question are to: Identify the best way to monitor several Windows Server production boxes during short (minutes long) period of ridiculous load Receive near-real-time feedback on a few key metric...

iPhone and Vertex Buffer Objects

I've just started playing around with opengl es on the iphone the past couple of weeks and i'm looking at refactoring some of my code to use Vertex Buffer Objects(VBO). Before I do though I would like to make sure it'll be worth it. The problem is that afaik the only reason you create VBO's is to shift a chunk of data onto the graphics c...

Is Objective C fast enough for DSP/audio programming

I've been making some progress with audio programming for iPhone. Now I'm doing some performance tuning, trying to see if I can squeeze more out of this little machine. Running Shark, I see that a significant part of my cpu power (16%) is getting eaten up by objc_msgSend. I understand I can speed this up somewhat by storing pointers to f...

How to handle large dataset with JPA (or at least with Hibernate)?

I need to make my web-app work with really huge datasets. At the moment I get either OutOfMemoryException or output which is being generated 1-2 minutes. Let's put it simple and suppose that we have 2 tables in DB: Worker and WorkLog with about 1000 rows in the first one and 10 000 000 rows in the second one. Latter table has several fi...

PHP array include performance

What type of performance hit can I expect if I include a huge PHP array? For example, lets say I have a 1GB PHP array in "data.php" that looks like $data = array( //1GB worth of data ) If I include that huge "data.php" file on "header.php", how will it affect the performance of "header.php" when it executes? Thanks! ...

Does breaking chained Select()s in LINQ to objects hurt performance?

Take the following pseudo C# code: using System; using System.Data; using System.Linq; using System.Collections.Generic; public IEnumerable<IDataRecord> GetRecords(string sql) { // DB logic goes here } public IEnumerable<IEmployer> Employers() { string sql = "select EmployerID from employer"; var ids = GetRecords(sql).S...

Usual hibernate performance pitfall

Hi, We have just finish to profile our application. ( she's begin to be slow ). the problem seems to be "in hibernate". It's a legacy mapping. Who work's, and do it's job. The relational shema behind is ok too. But some request are slow as hell. So, we would appreciate any input on common and usual mistake made with hibernate who ...

Performance of a proposed JEE architecture

I have concerns about the performance of the following architecture: j2ee application in an appserver, ejb session bean and DAOs remote (rich) client, a swing app. A classic, form-based client only one stateless ejb, the ejb is accessed via web services, not rmi, through a homegrown framework each web service request will get authentic...

What is the time complexity of LinkedList.getLast() in Java?

I have a private LinkedList in a Java class & will frequently need to retrieve the last element in the list. The lists need to scale, so I'm trying to decide whether I need to keep a reference to the last element when I make changes (to achieve O(1)) or if the LinkedList class does that already with the getLast() call. What is the big-...

Fastest way for inserting very large number of records into a Table in SQL

The problem is, we have a huge number of records (more than a million) to be inserted into a single table from a Java application. The records are created by the Java code, it's not a move from another table, so INSERT/SELECT won't help. Currently, my bottleneck is the INSERT statements. I'm using PreparedStatement to speed-up the proce...

Most efficient algorithm for merging sorted IEnumerable<T>

Hello, I have several huge sorted enumerable sequences that I want to merge. Theses lists are manipulated as IEnumerable but are already sorted. Since input lists are sorted, it should be possible to merge them in one trip, without re-sorting anything. I would like to keep the defered execution behavior. I tried to write a naive algor...

Hitting a memory limit slows down the .Net application

We have a 64bit C#/.Net3.0 application that runs on a 64bit Windows server. From time to time the app can use large amount of memory which is available. In some instances the application stops allocating additional memory and slows down significantly (500+ times slower).When I check the memory from the task manager the amount of the memo...