Search Results

Search found 13249 results on 530 pages for 'performance tuning'.

Page 417/530 | < Previous Page | 413 414 415 416 417 418 419 420 421 422 423 424  | Next Page >

• Endianness manipulation - is there a C library for this?

  - by Malvineous

  Hi all, With the sort of programs I write (working with raw file data) I often need functions to convert between big and little endian. Usually I write these myself (which is covered by many other posts here) but I'm not that keen on doing this for a number of reasons - the main one being lack of testing. I don't really want to spend ages testing my code in a big endian emulator, and often just omit the code for big endian machines altogether. I also would rather make use of faster functions provided by various compilers, while still keeping my programs cross-platform. The only things I can find are socket calls like htons() but they require different #include files on each platform, and some GPL code like this, however that particular file, while comprehensive, seems to miss out on some of the high performance functions provided by some compilers. So, does anyone know of a library (ideally just a .h file) that is well tested and provides a standard set of functions for dealing with endianness across many compilers and platforms?

  Read the article

• Maximizing the number of threads to fully utilize all available resources without hindering overall

  - by Matt

  Let's say I have to generate a bunch of result files, and I want to make it as fast as possible. Each result file is generated independently of any other result file; in fact, one could say that each result file is agnostic to every other result file. The resources used to generate each result file is also unique to each. How can I dynamically decide the optimal number of threads to run simultaneously in order to minimize the overall run time? Is my only option to write my own thread manager that watches performance counters and adjust accordingly or does there exists some solid classes that already accomplish this?

  Read the article

• Best practice for Python Assert

  - by meade

  Is there a performance or code maintenance issue with using assert as part of the standard code instead of using it just for debugging purposes? Is assert x >= 0, 'x is less then zero' and better or worse then if x < 0: raise Exception, 'x is less then zero' Also, is there anyway to set a business rule like if x < 0 raise error that is always checked with out the try, except, finally so, if at anytime throughout the code x is < 0 an error is raised, like if you set assert x < 0 at the start of a function, anywhere within the function where x becomes less then 0 an exception is raised?

  Read the article

• Entity Framework How to specify paramter type in generated SQL (SQLServer 2005) Nvarchar vs Varchar

  - by Gratzy

  In entity framework I have an Entity 'Client' that was generated from a database. There is a property called 'Account' it is defined in the storage model as: <Property Name="Account" Type="char" Nullable="false" MaxLength="6" /> And in the Conceptual Model as: <Property Name="Account" Type="String" Nullable="false" /> When select statements are generated using a variable for Account i.e. where m.Account == myAccount... Entity Framework generates a paramaterized query with a paramater of type NVarchar(6). The problem is that the column in the table is data type of char(6). When this is executed there is a large performance hit because of the data type difference. Account is an index on the table and instead of using the index I believe an Index scan is done. Anyone know how to force EF to not use Unicode for the paramater and use Varchar(6) instead?

  Read the article

• WPF/.NET data access models - resource recommendations

  - by jasonk

  We're in the early design/prep phases of transferring/updating a rather large "legacy" 3 tier client-server app to a new version. We’re looking at doing WPF over Winforms as it appears to be the direction Microsoft is pushing development of the future and we’d like the maximize the life cycle/span of the apps. That said during the rewrite we’d like to make as many changes to our data access/presentation model to improve performance as much as possible up front as many. I’ve been doing some research along that vein but the vast majority of the resources I've found that discuss WPF focus only simple data tracking apps or focus on the very basics UI design/controls. The few items that even discuss data presentation are fairly elementary in depth. Are there any books/articles/recommended reading/other resources recommended for development related to large enterprise level business apps? Any “gotchas” that should/could be avoided? General advice to minimize the time underwater

  Read the article

• How do I get callgrind to dump source line information?

  - by Jeremybub

  I'm trying to profile a shared library on GNU/Linux which does real-time audio processing, so performance is important. I run another program which hooks it up to the audio input and output of my system, and profile that with callgrind. Looking at the results in KCacheGrind, I get great information about what functions are taking up most of my time. However, it won't let me look at the line by line information, and instead says I need to compile it with debugging symbols and run the profiling again. The program which I am profiling is not compiled with debug symbols, but the library is. And I know this, because interestingly, source code annotations for cachegrind work fine. When I run callgrind, it says the default is to dump source line information, but it just isn't doing that. Is there some way I could force it to, or figure out what's stopping it?

  Read the article

• Append in Dom taking more time in IE than Firefox or any other browser.

  - by user307635

  Hi , I m working on .net framework 3.0 visual studio 08 and Testing it in IE8 and other browsers. Whenever I m inserting new elements in DOM (ex. 300 divs at one time) than I m getting the performance very slow in IE . Why?. If its a javascript debugging which is taking time or what else. Is it really true that IE Dom Append takes much time than any other browser. Please help me , I m stuck badly.

  Read the article

• Loading a XML, but for asp.net 2.0

  - by Blankman

  I need to load an XML document into my Dictionary<string,string> object. XML looks like: <nodes> <node id="123"> <text>text goes here</text> </node> </nodes> How can I do this using XmlDocument? I want readability over performance, and I find XmlReader to be hard to read b/c you have to keep checking the node type.

  Read the article

• Avoiding Nested Queries

  - by Midhat

  How Important is it to avoid nested queries. I have always learnt to avoid them like a plague. But they are the most natural thing to me. When I am designing a query, the first thing I write is a nested query. Then I convert it to joins, which sometimes takes a lot of time to get right. And rarely gives a big performance improvement (sometimes it does) So are they really so bad. Is there a way to use nested queries without temp tables and filesort

  Read the article

• MySQL locking problem

  - by teehoo

  I have a simple setup of a set of writers and a set of readers working with a MySQL ISAM table. The writers are only inserting rows while the readers are only checking for new rows. OK, so I know that I don't need a lock in this situation, since I'm not modifying existing rows. However my Writers are accessing one more table that does need a lock. I piece of information seems irrelevant except for the following limitation stated in the MySQL documentation: A session that requires locks must acquire all the locks that it needs in a single LOCK TABLES statement. While the locks thus obtained are held, the session can access only the locked tables. For example, in the following sequence of statements, an error occurs for the attempt to access t2 because it was not locked in the LOCK TABLES statement: So to access the table I want to insert rows into, I NEED to lock it, which is causing me performance problems. Any suggestions of how to get around this?

  Read the article

• Speeding up inner joins between a large table and a small table

  - by Zaid

  This may be a silly question, but it may shed some light on how joins work internally. Let's say I have a large table L and a small table S (100K rows vs. 100 rows). Would there be any difference in terms of speed between the following two options?: OPTION 1: OPTION 2: --------- --------- SELECT * SELECT * FROM L INNER JOIN S FROM S INNER JOIN L ON L.id = S.id; ON L.id = S.id; Notice that the only difference is the order in which the tables are joined. I realize performance may vary between different SQL languages. If so, how would MySQL compare to Access?

  Read the article

• how to implement unitofwork pattern when using subsonic 2.1(Repository pattern) ?

  - by ROHITH

  I am using subsonic repository pattern(2.1) for asp.net mvc application.In my application,there are many repositories like categoryRepository,Blogrepository etc.Inside each of this repository i am calling subsonic's DB.Select().From()...ExecuteReader() and then loading domain objects from those reader. In the controller action i make multiple calls from these repositories for e.g. List<IBlog> blogs=_blogRepository.GetHottestBlogs(); List<ICategory> categories=_categoryRepository.GetAll(); do i have to implement any unitofwork pattern for this ?.My doubt is that how subsonic performs each operation DB.Update/Insert/Select .Is a TransactionScope is enough for batch update or do i have to use SharedDbConnectionScope to get better performance?

  Read the article

• Separation of static and dynamic content in Java EE applications

  - by Dan

  We work with IBM products and we typically use IBM Http Servers (read Apache) as a reverse proxy for our application servers. For performance reasons we serve static content (.gif, .jpg, .css, .html etc.) from our http servers, to ease the burden a bit from the application server. So far, we have to distribute files to http server and configure it manually (writing custom scripts at best.) The problem is the effort needed to keep everything in synch, especially when you need to update the app. Does any Java EE product support this “out of the box”? Is there a way to have application server do this automatically, like in cluster configuration for example, where master node is in charge of distributing the application to other nodes and for keeping everything in synch.

  Read the article

• MySQL triggers cannot update rows in same table the trigger is assigned to. Suggested workaround?

  - by Cory House

  MySQL doesn't currently support updating rows in the same table the trigger is assigned to since the call could become recursive. Does anyone have suggestions on a good workaround/alternative? Right now my plan is to call a stored procedure that performs the logic I really wanted in a trigger, but I'd love to hear how others have gotten around this limitation. Edit: A little more background as requested. I have a table that stores product attribute assignments. When a new parent product record is inserted, I'd like the trigger to perform a corresponding insert in the same table for each child record. This denormalization is necessary for performance. MySQL doesn't support this and throws: Can't update table 'mytable' in stored function/trigger because it is already used by statement which invoked this stored function/trigger. A long discussion on the issue on the MySQL forums basically lead to: Use a stored proc, which is what I went with for now. Thanks in advance!

  Read the article

• Java multiline string

  - by skiphoppy

  Coming from Perl, I sure am missing the "here-document" means of creating a multi-line string in source code: $string = <<"EOF" # create a three line string text text text EOF In Java I have to have cumbersome quotes and plus signs on every line as I concatenate my multiline string from scratch. What are some better alternatives? Define my string in a properties file? Edit: Two answers say StringBuilder.append() is preferable to the plus notation. Could anyone elaborate as to why they think so? It doesn't look more preferable to me at all. I'm looking for away around the fact that multiline strings are not a first-class language construct, which means I definitely don't want to replace a first-class language construct (string concatenation with plus) with method calls. Edit: To clarify my question further, I'm not concerned about performance at all. I'm concerned about maintainability and design issues.

  Read the article

• What parallel programming model do you recommend today to take advantage of the manycore processors

  - by Doctor J

  If you were writing a new application from scratch today, and wanted it to scale to all the cores you could throw at it tomorrow, what parallel programming model/system/language/library would you choose? Why? I am particularly interested in answers along these axes: Programmer productivity / ease of use (can mortals successfully use it?) Target application domain (what problems is it (not) good at?) Concurrency style (does it support tasks, pipelines, data parallelism, messages...?) Maintainability / future-proofing (will anybody still be using it in 20 years?) Performance (how does it scale on what kinds of hardware?) I am being deliberately vauge on the nature of the application in anticipation of getting good general answers useful for a variety of applications.

  Read the article

• Site images don't refresh after setting expired headers on .htaccess

  - by Miguel Hernandez

  I have a site that uses a CSS sprite for all the images. I set the .htaccess file to set the expired headers to a future time as they recommend to improve site performance. However, when I updated the sprite image none of my browsers on two different computers seem to fetch the new image. I deleted the .htaccess serveral times but no luck. I am sure this must be easy as pie to fix but right now I am out of options. Here is the code inside my .htaccess file: # CONFIGURE media caching # Header unset ETag FileETag None <FilesMatch "(?i)^.*\.(ico|flv|jpg|jpeg|png|gif|js|css)$"> Header unset Last-Modified Header set Expires "Fri, 21 Dec 2012 00:00:00 GMT" Header set Cache-Control "public, no-transform" </FilesMatch> <IfModule mod_deflate.c> <FilesMatch "\.(js|css)$"> SetOutputFilter DEFLATE </FilesMatch> </IfModule> Thanks!

  Read the article

• How many records can i store in a Sql server table before it's getting ugly?

  - by Michel

  Hi, i've been asked to do some performance tests for a new system. It is only just running with a few client, but as they expect to grow, these are the numbers i work with for my test: 200 clients, 4 years of data, and the data changes per.... 5 minutes. So for every 5 minutes for every client there is 1 record. That means 365*24*12 = 105.000 records per client per year, that means 80 milion records for my test. It has one FK to another table, one PK (uniqueidentifier) and one index on the clientID. Is this something SqlServer laughs about because it isn't scaring him, is this getting too much for one quad core 8 GB machine, is this on the edge, or..... Has anybody had any experience with these kind of numbers?

  Read the article

• Extraction Event

  - by Anicho

  So I have the following code: public override void Extract(object sender, ExtractionEventArgs e) { if (e.Response.HtmlDocument != null) { var myParam = e.Request.QueryStringParameters.Where(parameter => parameter.Name == QueryName).Select(parameter => parameter.Value).Distinct(); myParam. // add the extracted value to the web performance test context e.WebTest.Context.Add(this.ContextParameterName, myParam.ToString()); e.Success = true; return; } // If the extraction fails, set the error text that the user sees e.Success = false; e.Message = String.Format(CultureInfo.CurrentCulture, "Not Found: {0}", QueryName); } It's returning: System.Linq.Enumerable+<DistinctItem>d_81`1[system.string] I am expecting something along the lines of: 0152-1231-1231-123d My question is how do I extract the querystring's actual value from extractioneventargs. They say it's possible, but I have no idea.

  Read the article

• How can I dynamically inject code to event handlers in Delphi?

  - by mjustin

  For debugging / performance tests I would like to dynamically add logging code to all event handlers of components of a given type. For example, for all Dataset components located ona TDatamodule, I would like to add some code for the BeforeOpen and the AfterOpen event to store the start and end time and send a line to a logger with the elapsed time in the AfterOpen event. I would prefer to do this dynamically (no component subclassing), so that I can add this to all existing datamodules and forms with minimal effort only when needed. Iterating all components and filtering by their type is easy, but for the components which already have event handlers assigned, I need a way to store the existing event handlers, and assign a new modified event handler which first does the logging and then will invoke the original code which was already present. Is there a design pattern which can be applied, or even some example code which shows how to implement this in Delphi?

  Read the article

• Most Efficient Alternative Method of Storing Settings for iPhone Apps

  - by JPK

  I am not using the Settings bundle to store the settings for my app, as I prefer to allow the user to access the settings within the app (they may be changed fairly often). I do realize that there is the option to do both, but for now, I am trying to find the most optimal place to store the settings within the app. I have a good number of settings (from what I have read, probably too many for NSUserDefaults), and the two main options I am considering are: 1) storing the settings in a dictionary in the plist, loading the settings into a NSDictionary property in the app delegate and accessing them via the sharedDelegate 2) storing the settings in a Core Data entity (1 row on Settings entity), loading the settings into a Settings object in the app delegate and accessing them via the sharedDelegate Of these two, which would be the optimal method, performance wise?

  Read the article

• Caching for a Custom Repositiory Adapter for WebSphere Portal Virtual Member Manager

  - by Spike Williams

  I'm looking at writing a custom repository adapter to interact with Virtual Member Manager on WebSphere Portal 6.1. Basically, its a layer that takes a request in the form of a commonj.sco.DataObject and passes that on to an external web service, to get various information on our logged in users that is not otherwise available in LDAP. I'm concerned about the performance hit of going to a service every time we want to pull some permission from the back end. My question is, can the Virtual Member Manager handle caching of data going in and out of the custom repository adapters, or is that something I'm going to have to build into the adapter myself?

  Read the article

• Java vs Flash for webcam access

  - by Alfredo Palhares

  I will make a video chat website, but coming from PHP and Python for the web i have no experience with video steaming. What do you recommend? Java or Flash? What's more flexible ? I am thinking of even making a C++ server application for stream controlling with a PHP fronted. Since is going to be a high traffic website and performance is a must. Can you point to some direction? Any documentation? Framework?

  Read the article

• What is a good Very-High level UI framework for JavaScript?

  - by Robert Gould

  I need to write a temporary Web-based graphical front-end for a custom server system. In this case performance and scalability aren't issues, since at most 10 people may check the system simultaneously. Also it should be PHP or Python (server) & JavaScript (client) (can't use Flex or Silverlight for very specific non-programming related issues). So I know I could use YUI or jQuery, but was wondering if there is something even more high-level that would say allow me to write such a little project within a few hours of work, and get done with it. Basically I want to be as lazy as possible (this is throw-away code anyways) and get the job done in as little time as possible. Any suggestions?

  Read the article

• Attributed strings in UITableViewCells without WebView?

  - by arnekolja

  Hello, does anyone know if there's a way in with 3.0+ to display attributed strings within a UITableViewCell without using a UIWebView for that? I need to display a string with linked, tappable substrings as the typical detailTextLabel. I wouldn't mind exchanging this UILabel against another type of view, but I think a UIWebView could be just too slow when rendering a table with hundrets of cells. Or does someone have opposite experiences here? So my question is: what's the best way to achieve mixed strings in a very large table without a great performance hit? I searched for this almost a whole day now, but I can only find old posts mentioning that there's no attributed string on the iPhone (outdated, as this was pre-3.0) and/or saying that they use a UIWebView for that. But really, I don't think this would perform very well on large tables, would it? Many, many thanks in advance Arne

  Read the article

< Previous Page | 413 414 415 416 417 418 419 420 421 422 423 424  | Next Page >