Search Results

Search found 13403 results on 537 pages for '2 epm performance tuning'.

Page 469/537 | < Previous Page | 465 466 467 468 469 470 471 472 473 474 475 476  | Next Page >

• Passenger: "Missing these required gems redgreen"

  - by Michael Stum

  Hello, total ruby newbie, trying to setup a Rails/MongoDB application on Mac OS X Snow leopard. Installed Ruby 1.9.1 and RubyGems 1.3.7, which ruby and which gem point to the same directory. I'm using the Snow Leopard built-in apache and Passenger 2.2.11. I'm using the rails template from the mongo-site which seems to work okay overall. The exact error that passenger gives me is: /Users/User/Sites/feuerapp/vendor/rails/railties/lib/rails/gem_dependency.rb:119:Warning: Gem::Dependency#version_requirements is deprecated and will be removed on or after August 2010. Use #requirement **Notice: C extension not loaded. This is required for optimum MongoDB Ruby driver performance. You can install the extension as follows: gem install bson_ext If you continue to receive this message after installing, make sure that the bson_ext gem is in your load path and that the bson_ext and mongo gems are of the same version. Missing these required gems: redgreen You're running: ruby 1.9.1.376 at /usr/local/bin/ruby rubygems 1.3.7 at /Users/User/.gem/ruby/1.9.1, /usr/local/lib/ruby/gems/1.9.1 Runrake gems:installto install the missing gems. The weird thing is that redgreen is installed and looks fine to me: Dahlia:feuerapp User$ ls -la vendor/gems/ total 0 drwxr-xr-x 7 User staff 238 May 18 22:56 . drwxr-xr-x 5 User staff 170 May 18 23:00 .. drwxr-xr-x 11 User staff 374 May 18 22:56 factory_girl-1.2.4 drwxr-xr-x 11 User staff 374 May 18 22:56 mocha-0.9.8 drwxr-xr-x 7 User staff 238 May 18 22:56 mongo_mapper-0.7.6 drwxr-xr-x 7 User staff 238 May 18 22:56 redgreen-1.2.2 drwxr-xr-x 11 User staff 374 May 18 22:56 shoulda-2.10.3 Commenting out this line in environment.rb "solves" the issue, but that's not really want I want: config.gem 'redgreen' I don't understand anything of gems yet, but from my limited understanding, redgreen should be there and found?

  Read the article

• Per-pixel per-component alpha blending in Windows

  - by Crend King

  I have a 24-bit bitmaps with R, G, B color channels and a 24-bit bitmap with R, G, B alpha channels. I want to alpha blend the first bitmap to a HDC in GDI or RenderTarget in Direct2D with the alpha channels respectively. For example, suppose for one pixel, the bitmap color is (192, 192, 192), the HDC color is (0, 255, 255) and the alpha channels are (30, 40, 50). The final HDC color should be (22, 245, 242). I know I can BitBlt the HDC to a memory HDC first, do alpha blending by manually calculating the color of each pixel and finally BitBlt back. I just want to avoid the additional blitting and leave APIs do their job (faster since they are in kernel space). The first idea comes to my mind is to split the source bitmap into 3 red-only, green-only and blue-only 8-bit bitmaps, do normal alpha blending, then composite the 3 output bitmaps into the HDC. But I don't find a way to do the splitting and composition natively in Windows (would Direct2D layer help?). Also, the splitting and compositing may require many additional copying. The performance overhead would be too high. Or maybe do the alpha blending in 3 passes. Each pass apply the blending for one channel, while maintaining the other 2 unchanged. Thanks for any comment. EDIT: I found this question, and the answer should be good reference to this problem. However, besides AC_SRC_OVER, there is no other blending operation supported. Why don't Microsoft improve their API?

  Read the article

• Best pattern for storing (product) attributes in SQL Server

  - by EdH

  We are starting a new project where we need to store product and many product attributes in a database. The technology stack is MS SQL 2008 and Entity Framework 4.0 / LINQ for data access. The products (and Products Table) are pretty straightforward (a SKU, manufacturer, price, etc..). However there are also many attributes to store with each product (think industrial widgets). These may range from color to certification(s) to pipe size. Every product may have different attributes, and some may have multiples of the same attribute (Ex: Certifications). The current proposal is that we will basically have a name/value pair table with a FK back to the product ID in each row. An example of the attributes Table may look like this: ProdID AttributeName AttributeValue 123 Color Blue 123 FittingSize 1.25 123 Certification AS1111 123 Certification EE2212 123 Certification FM.3 456 Pipe 11 678 Color Red 999 Certification AE1111 ... Note: Attribute name would likely come from a lookup table or enum. So the main question here is: Is this the best pattern for doing something like this? How will the performance be? Queries will be based on a JOIN of the product and attributes table, and generally need many WHEREs to filter on specific attributes - the most common search will be to find a product based on a set of known/desired attributes. If anyone has any suggestions or a better pattern for this type of data, please let me know. Thanks! -Ed

  Read the article

• What is more viable to use? Javascript libraries or UI Programming tools?

  - by Haresh Karkar

  What is more viable to use:- Javascript Libraries: YUI, jQuery, ExtJs OR UI Programming tools: GWT, ExtGWT, SmartGWT It has become very difficult to choose between them as they are constantly increasing their capabilities to meet newer requirements. We all know the power of jQuery in UI manipulations. The latest news from Microsoft about jQuery being officially part of .Net developr’s toolkit will definitely make jQuery a preferred choice against other JavaScript libraries [See link: http://weblogs.asp.net/scottgu/archive/2008/09/28/jquery-and-microsoft.aspx]. But on the other hand, GWT is building a framework which could be used on client as well as on the sever side. This is definitely going to make developers’ life easy as it does not require developer to be an expert in browser quirks, XMLHttpRequest, and JavaScript in order to develop high-performance web applications. It includes SDK (Java API libraries, compiler, and development server which allows to write client-side applications in Java and deploy them as JavaScript), Speed Tracer and plug-in for Eclipse. GWT is used by many products like Google Wave and AdWords. So question is still un-answered, what is more viable to use? Any thoughts?

  Read the article

• Relay WCF Service

  - by Matt Ruwe

  This is more of an architectural and security question than anything else. I'm trying to determine if a suggested architecture is necessary. Let me explain my configuration. We have a standard DMZ established that essentially has two firewalls. One that's external facing and the other that connects to the internal LAN. The following describes where each application tier is currently running. Outside the firewall: Silverlight Application In the DMZ: WCF Service (Business Logic & Data Access Layer) Inside the LAN: Database I'm receiving input that the architecture is not correct. Specifically, it has been suggested that because "a web server is easily hacked" that we should place a relay server inside the DMZ that communicates with another WCF service inside the LAN which will then communicate with the database. The external firewall is currently configured to only allow port 443 (https) to the WCF service. The internal firewall is configured to allow SQL connections from the WCF service in the DMZ. Ignoring the obvious performance implications, I don't see the security benefit either. I'm going to reserve my judgement of this suggestion to avoid polluting the answers with my bias. Any input is appreciated. Thanks, Matt

  Read the article

• Flash video slooow in AIR 2 HTMLLoader component

  - by shane

  I am working on a full screen kiosk application in Flex 4/Air 2 using Flash Builder 4. We have a company training website which staff can access via the kiosk, and the main content is interactive flash training videos. Our target machines are by no means 'beefy', they are Atom n270s @ 1.6Ghz with 1Gb RAM. As it stands the videos are all but unusable when used from within the Air application, the application becomes completely unresponsive (100% cpu usage, click events take approx 5-10 seconds to register). So far I have tried: increasing the default frame rate from 24fps to 60. No improvement. nativeWindow.stage.frameRate = 60; running the videos in a stripped down version of my app, just a full screen HTMLLoader component pointed at the training website. No better than before. disabled hyper threading. The Atom CPU is split into two virtual cores, and the AIR app was only able to use one thread so maxed out at 50% CPU usage. Since the kiosk will only run the AIR app I am happy to loose hyper threading to increase the performance of the Air app. Marginal Improvement. The same website with the same videos is responsive if viewed in ie7 on the same machine, although Internet Explorer takes advantage of the CPU’s hyper threading. The flash videos are built with Adobe Captivate and from what I understand employee JavaScript to relay results back to the server. I will add more information about the video content asap as the training guru is back in the office later this week.

  Read the article

• How to make Stack.Pop threadsafe

  - by user260197

  I am using the BlockingQueue code posted in this question, but realized I needed to use a Stack instead of a Queue given how my program runs. I converted it to use a Stack and renamed the class as needed. For performance I removed locking in Push, since my producer code is single threaded. My problem is how can thread working on the (now) thread safe Stack know when it is empty. Even if I add another thread safe wrapper around Count that locks on the underlying collection like Push and Pop do, I still run into the race condition that access Count and then Pop are not atomic. Possible solutions as I see them (which is preferred and am I missing any that would work better?): Consumer threads catch the InvalidOperationException thrown by Pop(). Pop() return a nullptr when _stack-Count == 0, however C++-CLI does not have the default() operator ala C#. Pop() returns a boolean and uses an output parameter to return the popped element. Here is the code I am using right now: generic <typename T> public ref class ThreadSafeStack { public: ThreadSafeStack() { _stack = gcnew Collections::Generic::Stack<T>(); } public: void Push(T element) { _stack->Push(element); } T Pop(void) { System::Threading::Monitor::Enter(_stack); try { return _stack->Pop(); } finally { System::Threading::Monitor::Exit(_stack); } } public: property int Count { int get(void) { System::Threading::Monitor::Enter(_stack); try { return _stack->Count; } finally { System::Threading::Monitor::Exit(_stack); } } } private: Collections::Generic::Stack<T> ^_stack; };

  Read the article

• Interface Casting vs. Class Casting

  - by Legatou

  I've been led to believe that casting can, in certain circumstances, become a measurable hindrance on performance. This may be moreso the case when we start dealing with incoherent webs of nasty exception throwing\catching. Given that I wish to create more correct heuristics when it comes to programming, I've been prompted to ask this question to the .NET gurus out there: Is interface casting faster than class casting? To give a code example, let's say this exists: public interface IEntity { IParent DaddyMommy { get; } } public interface IParent : IEntity { } public class Parent : Entity, IParent { } public class Entity : IEntity { public IParent DaddyMommy { get; protected set; } public IParent AdamEve_Interfaces { get { IEntity e = this; while (this.DaddyMommy != null) e = e.DaddyMommy as IEntity; return e as IParent; } } public Parent AdamEve_Classes { get { Entity e = this; while (this.DaddyMommy != null) e = e.DaddyMommy as Entity; return e as Parent; } } } So, is AdamEve_Interfaces faster than AdamEve_Classes? If so, by how much? And, if you know the answer, why?

  Read the article

• c# (wcf) architecture file and directory structure (and instantiation)

  - by stevenrosscampbell

  Hello and thanks for any assistance. I have a wcf service that I'm trying to properly modularize. I'm interested in finding out if there is a better way or implementing the file and directory structure along with instanciatation, is there a more appropriate way of abstraction that I may be missing? Is this the best approach? especially if performance and the ability to handle thousands of simultanious request? Currently I have this following structure: -Root\Service.cs public class Service : IService { public void CreateCustomer(Customer customer) { CustomerService customerService = new CustomerService(); customerService.Create(customer); } public void UpdateCustomer(Customer customer) { CustomerService customerService = new CustomerService(); customerService.Update(customer); } } -Root\Customer\CustomerService.cs pulbic class CustomerService { public void Create(Customer customer) { //DO SOMETHING } public void Update(Customer customer) { //DO SOMETHING } public void Delete(int customerId) { //DO SOMETHING } public Customer Retrieve(int customerId) { //DO SOMETHING } } Note: I do not include the Customer Object or the DataAccess libraries in this example as I am only concerned about the service. If you could either let me know what you think, if you know a better way, or a resource that could help out. Thanks Kindly. Steven

  Read the article

• Winforms: How to speed up Invalidate()?

  - by Pedery

  I'm developing a retained mode drawing application in GDI+. The application can draw simple shapes to a canvas and perform basic editing. The math that does this is optimized to the last byte and is not an issue. I'm drawing on a panel that is using the built-in Controlstyles.DoubleBuffer. Now, my problem arises if I run my app maximized on a big monitor (HD in my case). If I try to draw a line from one corner of the (big) canvas to the diagonally oposite other, it will start to lag and the CPU goes high up. Each graphical object in my app has a boundingbox. Thus, when I invalidate the boundingbox of a line that goes from one corner of the maximized app to the oposite diagonal one, that boundingbox is virtually as big as the canvas. When a user is drawing a line, this invalidation of the boundingbox thus happens on the mousemove event, and there is a clear lag visible. This lag also exists if the line is the only object on the canvas. I've tried to optimize this in many ways. If I draw a shorter line, the CPU and the lag goes down. If I remove the Invalidate() and keep all other code, the app is quick. If I use a Region (that only spans the figure) to invalidate instead of the boundingbox, it is just as slow. If I split the boundingbox into a range of smaller boxes that lie back to back, thus reducing the invalidation area, no visible performance gain can be seen. Thus I'm at a loss here. How can I speed up the invalidation? On a side note, both Paint.Net and Mspaint suffers from the same shortcommings. Word and PowerPoint however, seem to be able to paint a line as described above with no lag and no CPU load at all. Thus it's possible to achieve the desired results, the question is how?

  Read the article

• Prefuse: Reloading of XML files

  - by John

  Hello all, I am a new to the prefuse visualization toolkit and have a couple of general questions. For my purpose, I would like to perform an initial visualization using prefuse (graphview / graphml). Once rendered, upon a user click of a node, I would like to completely reload a new xml file for a new visualization. I want to do this in order to allow me to "pre-package" graphs for display. For example. If I search for Ted. I would like to have an xml file relating to Ted load and render a display. Now in the display I see that Ted has nodes associated called Bill and Joe. When I click Joe, I would like to clear the display and load an xml file associated with Joe. And so on. I have looked into loading one very large xml file containing all node and node relationship info and allowing prefuse to handle this using the hops from one level to another. However, eventually I am sure that system performance issues will arise due to the size of data. Thanks in advance for any help, John

  Read the article

• Execute remote Lua Script

  - by Bruno Lee

  Hi, I want to make an application that executes a remote script. The user can create a script (probabily a LUA script) then stores it in the server. Then he can uses an API for execute the script. I was thinking that API could be a webservice. So my questions are: I need high performance to execute the script. So my first choice was LUA script. Someone has another sugestion? Cause I need high perfomance, I was thinking if the webservice is the best solution. Maybe I could create a TCP/IP Windows Service that hold the users request. It is important to say that I will have many user executing scripts at the same time. So I will have a concurrency problem. My scripts will query in a database. I will use Tokyo Cabinet or Tokio Tyrant. I think Tokio Tyrant is the only solution cause I will have many requests. For perfomance, Do I need to make a connection pooling? Is there anyway to share variables between webservices requests? To make the webservice or the Windows service i was thinking to use C++. Can someone help with these questions? thanks

  Read the article

• Using a .MDF SQL Server Database with ASP.NET Versus Using SQL Server

  - by Maxim Z.

  I'm currently writing a website in ASP.NET MVC, and my database (which doesn't have any data in it yet, it only has the correct tables) uses SQL Server 2008, which I have installed on my development machine. I connect to the database out of my application by using the Server Explorer, followed by LINQ to SQL mapping. Once I finish developing the site, I will move it over to my hosting service, which is a virtual hosting plan. I'm concerned about whether using the SQL Server setup that is currently working on my development machine will be hard to do on the production server, as I'll have to import all the database tables through the hosting control panel. I've noticed that it is possible to create a SQL Server database from inside Visual Studio. It is then stored in the App_Data directory. My questions are the following: Does it make sense to move my SQL Server DB out of SQL Server and into the App_Data directory as an .mdf file? If so, how can I move it? I believe this is called the Detach command, is it not? Are there any performance/security issues that can occur with a .mdf file like this? Would my intended setup work OK with a typical virtual hosting plan? I'm hoping that the .mdf database won't count against the limited number of SQL Server databases that can be created with my plan. I hope this question isn't too broad. Thanks in advance! Note: I'm just starting out with ASP.NET MVC and all this, so I might be completely misunderstanding how this is supposed to work.

  Read the article

• Codility-like sites for code golfs

  - by Adam Matan

  Hi, I've run into codility.com new cool service after listening to one of the recent stackoverflow.com podcasts. In short, it presents the user with a programming riddle to solve, within a given time frame. The user writes code in an online editor, and has the ability to run the program and view the standard output. After final submission, the user sees its final score and which tests failed him. Quoting Joel Spolsky: You are given a programming problem, you can do it in Java, C++, C#, C, Pascal, Python and PHP, which is pretty cool, and you have 30 minutes. And it gives you an editor in a webpage. And you've got to just start typing your code. And it's going to time you, basically you have to do it in a certain amount of time. And it actually runs your code and determines the performance characteristics of your code. It is intended for job interview screenings, but the idea seems very cool for code-golfs and for practicing new languages. Do you know if there's any proper open replacement? Adam

  Read the article

• .NET WF4: Should it be in the middle of everything?

  - by stimpy77

  I am aware that WF4 (Windows Workflow 4.0, part of .NET 4.0) is a significant rework and redesign of WF3, where much of what made WF3 a poor technology choice has been cleaned up in WF4. For example, as far as I can tell, WF4 (Windows Workflow 4.0) activities are more or less testable with [TestMethod] and mocking. This among other things, like improved performance, has grabbed my attention about the technology again, whereas I had previously pooh-poohed WF3. I'm working on a new architecture for essentially an n-tier collaborative application (not enterprise-class, just a smallish project with potential to grow significantly) where I'm already trying to discipline myself to use IoC and, to some extent, TDD, and I'm wondering, in general terms, whether it is wiser to just hand-code workflow logic or if I should delve into learning and integrating WF4 so that WF becomes literally the controller of the entire application, i.e. the practical C in "MVC" (not ASP.NET MVC but rather the pattern). So should workflow activities in WF4 be the primary controller for a highly expandable/growable web-based collaborative application? Or am I asking entirely the wrong question? This is a vague question, I'm sure, so abstract answers are as welcome as specific ones.

  Read the article

• Sorting GridView Formed With Data Set

  - by nani

  Following Code is for Sorting GridView Formed With DataSet Source: http://www.highoncoding.com/Articles/176_Sorting_GridView_Manually_.aspx But it is not displaying any output. There is no problem in sql connection. I am unable to trace the error, please help me. Thank You. public partial class _Default : System.Web.UI.Page { private const string ASCENDING = " ASC"; private const string DESCENDING = " DESC"; private DataSet GetData() { SqlConnection cnn = new SqlConnection("Server=localhost;Database=Northwind;Trusted_Connection=True;"); SqlDataAdapter da = new SqlDataAdapter("SELECT TOP 5 firstname,lastname,hiredate FROM EMPLOYEES", cnn); DataSet ds = new DataSet(); da.Fill(ds); return ds; } public SortDirection GridViewSortDirection { get { if (ViewState["sortDirection"] == null) ViewState["sortDirection"] = SortDirection.Ascending; return (SortDirection)ViewState["sortDirection"]; } set { ViewState["sortDirection"] = value; } } protected void GridView1_Sorting(object sender, GridViewSortEventArgs e) { string sortExpression = e.SortExpression; if (GridViewSortDirection == SortDirection.Ascending) { GridViewSortDirection = SortDirection.Descending; SortGridView(sortExpression, DESCENDING); } else { GridViewSortDirection = SortDirection.Ascending; SortGridView(sortExpression, ASCENDING); } } private void SortGridView(string sortExpression, string direction) { // You can cache the DataTable for improving performance DataTable dt = GetData().Tables[0]; DataView dv = new DataView(dt); dv.Sort = sortExpression + direction; GridView1.DataSource = dv; GridView1.DataBind(); } } aspx page asp:GridView ID="GridView1" runat="server" AllowSorting="True" OnSorting="GridView1_Sorting" /asp:GridView

  Read the article

• What are the primitive Forth operators?

  - by Barry Brown

  I'm interested in implementing a Forth system, just so I can get some experience building a simple VM and runtime. When starting in Forth, one typically learns about the stack and its operators (DROP, DUP, SWAP, etc.) first, so it's natural to think of these as being among the primitive operators. But they're not. Each of them can be broken down into operators that directly manipulate memory and the stack pointers. Later one learns about store (!) and fetch (@) which can be used to implement DUP, SWAP, and so forth (ha!). So what are the primitive operators? Which ones must be implemented directly in the runtime environment from which all others can be built? I'm not interested in high-performance; I want something that I (and others) can learn from. Operator optimization can come later. (Yes, I'm aware that I can start with a Turing machine and go from there. That's a bit extreme.) Edit: What I'm aiming for is akin to bootstrapping an operating system or a new compiler. What do I need do implement, at minimum, so that I can construct the rest of the system out of those primitive building blocks? I won't implement this on bare hardware; as an educational exercise, I'd write my own minimal VM.

  Read the article

• Shared value in parallel python

  - by Jonathan

  Hey all- I'm using ParallelPython to develop a performance-critical script. I'd like to share one value between the 8 processes running on the system. Please excuse the trivial example but this illustrates my question. def findMin(listOfElements): for el in listOfElements: if el < min: min = el import pp min = 0 myList = range(100000) job_server = pp.Server() f1 = job_server.submit(findMin, myList[0:25000]) f2 = job_server.submit(findMin, myList[25000:50000]) f3 = job_server.submit(findMin, myList[50000:75000]) f4 = job_server.submit(findMin, myList[75000:100000]) The pp docs don't seem to describe a way to share data across processes. Is it possible? If so, is there a standard locking mechanism (like in the threading module) to confirm that only one update is done at a time? l = Lock() if(el < min): l.acquire if(el < min): min = el l.release I understand I could keep a local min and compare the 4 in the main thread once returned, but by sharing the value I can do some better pruning of my BFS binary tree and potentially save a lot of loop iterations. Thanks- Jonathan

  Read the article

• iPhone - User Defaults and UIImages

  - by Staros

  Hello, I've been developing an iPhone app for the last few months. Recently I wanted to up performance and cache a few of the images that are used in the UI. The images are downloaded randomly from the web by the user so I can't add specific images to the project. I'm also already using NSUserDefaults to save other info within the app. So now I'm attempting to save a dictionary of UIImages to my NSUserDefaults object and get... -[UIImage encodeWithCoder:]: unrecognized selector sent to instance I then decided to subclass UIImage with a class named UISaveableImage and implement NSCoding. So now I'm at... @implementation UISaveableImage -(void)encodeWithCoder:(NSCoder *)encoder { [encoder encodeObject:super forKey:@"image"]; } -(id)initWithCoder:(NSCoder *)decoder { if (self=[super init]){ super = [decoder decodeObjectForKey:@"image"]; } return self; } @end which isn't any better than where I started. If I was able to convert an UIImage to NSData I would be good, but all I can find are function like UIImagePNGRepresentation which require me to know what type of image this was. Something that UIImage doesn't allow me to do. Thoughts? I feel like I might have wandered down the wrong path...

  Read the article

• Memory mapped files and "soft" page faults. Unavoidable?

  - by Robert Oschler

  I have two applications (processes) running under Windows XP that share data via a memory mapped file. Despite all my efforts to eliminate per iteration memory allocations, I still get about 10 soft page faults per data transfer. I've tried every flag there is in CreateFileMapping() and CreateFileView() and it still happens. I'm beginning to wonder if it's just the way memory mapped files work. If anyone there knows the O/S implementation details behind memory mapped files I would appreciate comments on the following theory: If two processes share a memory mapped file and one process writes to it while another reads it, then the O/S marks the pages written to as invalid. When the other process goes to read the memory areas that now belong to invalidated pages, this causes a soft page fault (by design) and the O/S knows to reload the invalidated page. Also, the number of soft page faults is therefore directly proportional to the size of the data write. My experiments seem to bear out the above theory. When I share data I write one contiguous block of data. In other words, the entire shared memory area is overwritten each time. If I make the block bigger the number of soft page faults goes up correspondingly. So, if my theory is true, there is nothing I can do to eliminate the soft page faults short of not using memory mapped files because that is how they work (using soft page faults to maintain page consistency). What is ironic is that I chose to use a memory mapped file instead of a TCP socket connection because I thought it would be more efficient. Note, if the soft page faults are harmless please note that. I've heard that at some point if the number is excessive, the system's performance can be marred. If soft page faults intrinsically are not significantly harmful then if anyone has any guidelines as to what number per second is "excessive" I'd like to hear that. Thanks.

  Read the article

• Creative ways to punish (or just curb) laziness in coworkers

  - by FerretallicA

  Like the subject suggests, what are some creative ways to curb laziness in co-workers? By laziness I'm talking about things like using variable names like "inttheemplrcd" instead of "intEmployerCode" or not keeping their projects synced with SVN, not just people who use the last of the sugar in the coffee room and don't refill the jar. So far the two most effective things I've done both involve the core library my company uses. Since most of our programs are in VB.net the lack of case sensitivity is abused a lot. I've got certain features of the library using Reflection to access data in the client apps, which has a negligible performance hit and introduces case sensitivity in a lot places where it is used. In instances where we have an agreed standard which is compromised by blatant laziness I take it a step further, like the DatabaseController class which will blatantly reject any DataTable passed to it which isn't named dtSomething (ie- must begin with dt and third letter must be capitalised). It's frustrating to have to resort to things like this but it has also gradually helped drill more attention to detail into their heads. Another is adding some code to the library's initialisation function to display a big and potentially embarrassing (only if seen by a client) message advising that the program is running in debug mode. We have had many instances where projects are sent to clients built in debug mode which has a lot of implications for us (especially with regard to error recovery) and doing that has made sure they always build to release before distributing. Any other creative (ie- not StyleCop etc) approaches like this?

  Read the article

• When optimizing database queries, what exactly is the relationship between number of queries and siz

  - by williamjones

  To optimize application speed, everyone always advises to minimize the number of queries an application makes to the database, consolidating them into fewer queries that retrieve more wherever possible. However, this also always comes with the caution that data transferred is still data transferred, and just because you are making fewer queries doesn't make the data transferred free. I'm in a situation where I can over-include on the query in order to cut down the number of queries, and simply remove the unwanted data in the application code. Is there any type of a rule of thumb on how much of a cost there is to each query, to know when to optimize number of queries versus size of queries? I've tried to Google for objective performance analysis data, but surprisingly haven't been able to find anything like that. Clearly this relationship will change for factors such as when the database grows in size, making this somewhat individualized, but surely this is not so individualized that a broad sense of the landscape can't be drawn out? I'm looking for general answers, but for what it's worth, I'm running an application on Heroku.com, which means Ruby on Rails with a Postgres database.

  Read the article

• Why not systematically attach event in WPF instead of using delegate ?

  - by user310291

  For a button to handle event, we can add a delegate to the click property of the button: this.button1.Click += new System.EventHandler(this.button1_Click); But in WPF contrary to Winform, you can also attach a handler http://msdn.microsoft.com/en-us/magazine/cc785480.aspx So why not do so for the button ? Is performance better in first case maybe ? Update: I mean this Attached Events In order to enable elements to handle events that are declared in a different element, WPF supports something called attached events. Attached events are routed events that support a hookup in XAML on elements other than the type on which the event is declared. For example, if you want the Grid element to listen for a Button.Click event to bubble past, you would simply hook it up like the following: <Grid Button.Click="myButton_Click"> <Button Name="myButton" >Click Me</Button> </Grid> The resulting code in the compile-time-generated partial class now looks like this: #line 5 "..\..\Window1.xaml" ((System.Windows.Controls.Grid)(target)).AddHandler( System.Windows.Controls.Primitives.ButtonBase.ClickEvent, new System.Windows.RoutedEventHandler(this.myButton_Click));

  Read the article

• Hibernate: order multiple one-to-many relations

  - by Markos Fragkakis

  I have a search screen, using JSF, JBoss Seam and Hibernate underneath. There are columns for A, B and C, where the relations are as follows: A (1< -- ) B (1< -- ) C A has a List< B and B has a List< C (both relations are one-to-many). The UI table supports ordering by any column (ASC or DESC), so I want the results of the query to be ordered. This is the reason I used Lists in the model. However, I got an exception that Hibernate cannot eagerly fetch multiple bags (it considers both lists to be bags). There is an interesting blog post here, and they identify the following solutions: Use @IndexColumn annotation (there is none in my DB, and what's more, I want the position of results to be determined by the ordering, not by an index column) Fetch lazily (for performance reasons, I need eager fetching) Change List to Set So, I changed the List to Set, which by the way is more correct, model-wise. First, if don't use @OrderBy, the PersistentSet returned by Hibernate wraps a HashSet, which has no ordering. Second, If I do use @OrderBy, the PersistentSet wraps a LinkedHashSet, which is what I would like, but the OrderBy property is hardcoded, so all other ordering I perform through the UI comes after it. I tried again with Sets, and used SortedSet (and its implementation, TreeSet), but I have some issues: I want ordering to take place in the DB, and not in-memory, which is what TreeSet does (either through a Comparator, or through the Comparable interface of the elements). Second, I found that there is the Hibernate annotation @Sort, which has a SortOrder.UNSORTED and you can also set a Comparator. I still haven't managed to make it compile, but I am still not convinced it is what I need. Any advice?

  Read the article

• SQLite on iPhone - Techniques for tracking down multithreading-related bugs

  - by Jasarien

  Hey guys, I'm working with an Objective-C wrapper around SQLite that I didn't write, and documentation is sparse... It's not FMDB. The people writing this wrapper weren't aware of FMDB when writing this code. It seems that the code is suffering from a bug where database connections are being accessed from multiple threads -- which according to the SQLite documentation won't work if the if SQLite is compiled with SQLITE_THREADSAFE 2. I have tested the libsqlite3.dylib provided as part of the iPhone SDK and seen that it is compiled in this manner, using the sqlite_threadsafe() routine. Using the provided sqlite library, the code regularly hits SQLITE_BUSY and SQLITE_LOCKED return codes when performing routines. To combat this, I added some code to wait a couple of milliseconds and try again, with a maximum retry count of 50. The code didn't contain any retry logic prior to this. Now when a sqlite call returns SQLITE_BUSY or SQLITE_LOCKED, the retry loop is invoked and the retry returns SQLITE_MISUSE. Not good. Grasping at straws, I replaced the provided sqlite library with a version compiled by myself setting SQLITE_THREADSAFE to 1 - which according to the documentation means sqlite is safe to be used in a multithreaded environment, effectively serialising all of the operations. It incurs a performance hit, that which I haven't measured, but it ridded the app of the SQLITE_MISUSE happening and seemed to not need the retry logic as it never hit a busy or locked state. What I would rather do is fix the problem of accessing a single db connection from multiple threads, but I can't for the life of me find where it's occurring. So if anyone has any tips on locating multithreaded bugs I would be extremely appreciative. Thanks in advance.

  Read the article

< Previous Page | 465 466 467 468 469 470 471 472 473 474 475 476  | Next Page >