Search Results

Search found 14553 results on 583 pages for 'programming techniques'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 406/583 | < Previous Page | 402 403 404 405 406 407 408 409 410 411 412 413  | Next Page >

  • Do I need JDK or only JRE?

    - by Camran
    I use Solr in my website, and now I am about to configure my VPS account. I am at the stage where I need to install java in order to make Solr work. Now, I only plan on running solr, and using it as it is (I have no java programming skills at all), so my Q is, do I need the entire JDK which includes JRE, or is JRE enough? Thanks BTW: My server OS is Linux (ubuntu 9.10). Thanks

    Read the article

  • .NET DataSource Clarification

    - by Steven
    I'm fairly new to database programming in .NET. If I want to call several existing queries from the same database for different tasks, should I have one DataSource per database, per database connection, or per query?

    Read the article

  • remove repeated vaules _stack&array

    - by Fatimah
    I want to write a program to implement an array-based stack, which accept integer numbers entered by the user.the program will then identify any occurrences of a given value from user and remove the repeated values from the stack,(using Java programming language). I just need your help of writing (removing values method) e.g. input:6 2 3 4 3 8 output:6 2 4 8

    Read the article

  • Access message editor from app

    - by user367248
    Hello, I´m thinking about writing an android app, but have no experience in programming such apps. My question is whether it is possible to access the standart message editor of android with my app and add for example additional information to it or would it be neccesary to write a complete new editor which would be started as a seperate app. greetings

    Read the article

  • Searching major search engines with text such as <%#

    - by Daniel Dyson
    If I type '<%# vs <%"' into any of the major search engines, everything is stripped out except the 'vs'. I understand why they do this. I would just like to know if anyone knows of a way to escape illegal characters so that they are searched properly. I know this is not strictly a programming question, but it is relevant.

    Read the article

  • NEED PROGRAM in visualc++ opengl [closed]

    - by HAREEFML
    I AM NEW IN OPENGL VISUALC++ PROGRAMMING.I NEEDED A PROGRAM THAT, THE ROTATING OBJECTS.WHERE THE CUBE,CYLINDER,TRIANGLE & CONE AND THESE OBJECTS ROTATE AS THE KEYBOARD ARROW KEYS ARE PRESSED AND EACH OBJECTS START ROTATION WHEN THE KEYBOARD NUMBERS 1,2,3,4 ARE PRESSED. CAN I GET PROGRAM LIKE THIS? THANKS IN ADVANCE.

    Read the article

  • What is the proper way to test is variable is empty in a batch file, If NOT "%1" == "" GOTO SomeLabe

    - by blak3r
    I need to test if a variable is set or not. I've tried several techniques but they seem to fail whenever %1 is surrounded by quotes such as the case when %1 = "c:\some path with spaces". IF NOT %1 GOTO MyLabel // This is invalid syntax IF "%1" == "" GOTO MyLabel // Works unless %1, otherwise fatally kills bat execution IF %1 == GOTO MyLabel // Gives an unexpected GOTO error. According to this site. These are the support IF syntax types. So, I don't see a way to do it. IF [NOT] ERRORLEVEL number command IF [NOT] string1==string2 command IF [NOT] EXIST filename command

    Read the article

  • PHP crashing (seg-fault) under mod_fcgi, apache

    - by Andras Gyomrey
    I've been programming a site using: Zend Framework 1.11.5 (complete MVC) PHP 5.3.6 Apache 2.2.19 CentOS 5.6 i686 virtuozzo on vps cPanel WHM 11.30.1 (build 4) Mysql 5.1.56-log Mysqli API 5.1.56 The issue started here http://stackoverflow.com/questions/6769515/php-programming-seg-fault. In brief, php is giving me random segmentation-faults. [Wed Jul 20 17:45:34 2011] [error] mod_fcgid: process /usr/local/cpanel/cgi-sys/php5(11562) exit(communication error), get unexpected signal 11 [Wed Jul 20 17:45:34 2011] [warn] [client 190.78.208.30] (104)Connection reset by peer: mod_fcgid: error reading data from FastCGI server [Wed Jul 20 17:45:34 2011] [error] [client 190.78.208.30] Premature end of script headers: index.php About extensions. When i compile php with "--enable-debug" flag, i have to disable this line: zend_extension="/usr/local/IonCube/ioncube_loader_lin_5.3.so" Otherwise, the server doesn't accept requests and i get a "The connection with the server was reset". It is possible that i have to disable eaccelerator too because of the same reason. I still don't get why apache gets running it some times and some others not: extension="eaccelerator.so" Anyway, after i get httpd running, seg-faults can occurr randomly. If i don't compile php with "--enable-debug" flag, i can get DETERMINISTICALLY a php crash: <?php class Admin_DbController extends Controller_BaseController { public function updateSqlDefinitionsAction() { $db = Zend_Registry::get('db'); $row = $db->fetchRow("SHOW CREATE TABLE 222AFI"); } } ?> BUT if i compile php with "--enable-debug" flag, it's really hard to get this error. I must add some complexity to make it crash. I have to be doing many paralell requests for a few seconds to get a crash: <?php class Admin_DbController extends Controller_BaseController { public function updateSqlDefinitionsAction() { $db = Zend_Registry::get('db'); $tableList = $db->listTables(); foreach ($tableList as $tableName){ $row = $db->fetchRow("SHOW CREATE TABLE " . $db->quoteIdentifier($tableName)); file_put_contents( DB_DEFINITIONS_PATH . '/' . $tableName . '.sql', $row['Create Table'] . ';' ); } } } ?> Please notice this is the same script, but creating DDL for all tables in database rather than for one. It seems that if php is heavy loaded (with extensions and me doing many paralell requests) it's when i get php to crash. About starting httpd with "-X": i've tried. The thing is, it is already hard to make php crash with --enable-debug. With "-X" option (which only enables one child process) i can't do parallel requests. So i haven't been able to create to proper debug backtrace: https://bugs.php.net/bugs-generating-backtrace.php My concrete question is, what do i do to get a coredump? root@GWT4 [~]# httpd -V Server version: Apache/2.2.19 (Unix) Server built: Jul 20 2011 19:18:58 Cpanel::Easy::Apache v3.4.2 rev9999 Server's Module Magic Number: 20051115:28 Server loaded: APR 1.4.5, APR-Util 1.3.12 Compiled using: APR 1.4.5, APR-Util 1.3.12 Architecture: 32-bit Server MPM: Prefork threaded: no forked: yes (variable process count) Server compiled with.... -D APACHE_MPM_DIR="server/mpm/prefork" -D APR_HAS_SENDFILE -D APR_HAS_MMAP -D APR_HAVE_IPV6 (IPv4-mapped addresses enabled) -D APR_USE_SYSVSEM_SERIALIZE -D APR_USE_PTHREAD_SERIALIZE -D SINGLE_LISTEN_UNSERIALIZED_ACCEPT -D APR_HAS_OTHER_CHILD -D AP_HAVE_RELIABLE_PIPED_LOGS -D DYNAMIC_MODULE_LIMIT=128 -D HTTPD_ROOT="/usr/local/apache" -D SUEXEC_BIN="/usr/local/apache/bin/suexec" -D DEFAULT_PIDLOG="logs/httpd.pid" -D DEFAULT_SCOREBOARD="logs/apache_runtime_status" -D DEFAULT_LOCKFILE="logs/accept.lock" -D DEFAULT_ERRORLOG="logs/error_log" -D AP_TYPES_CONFIG_FILE="conf/mime.types" -D SERVER_CONFIG_FILE="conf/httpd.conf"

    Read the article

  • Setting up a minimalist linux environment

    - by Nate
    All right, I've been messing around with various linux distros and a variety of window managers (I seem to change operating systems like most people change their pants), and I've gotten to the point where I know what I want but I'm not sure the best way to set it up. Here's what I want out of my programming machine: I don't want a status bar. I don't want a menu bar. When there are no windows open, the screen should show my desktop background and nothing else. I'll use alt+f2 to run things, and my shell prompt will tell me my battery life and the time. I'll open network controls and volume controls when I need them, no need for them to pollute the screen all the time. I want a good, simple terminal emulator. I'll be using it with tmux. It should have no title bar and, if possible, no app frame. It's ok if I have to run it in full screen mode to remove the app frame, but only if it still plays nicely with alt-tab and workspaces. I want a dirt-simple window manager. It needs to support transparency: I don't have a lot of screen real-estate and I often overlay the terminal on the browser and type out commands. I don't want a tiling-only system, for the above reason. Bonus points for tiling and overlaying. I'd like multiple workspaces. I prefer to have one gui per workspace. If I could 'pin' the terminal emulator to always show up in each workspace, that's bonus points. If not, I can have a terminal emulator in each workspace attached to the same tmux instance. I'd like a way to set up a keypress that always takes me to the current open terminal emulator. Currently, 90% of the time I only have two windows open: the terminal emulator and something else. In this scenario, alt-tab works like a toggle between the two. If I have another gui open (like a developer window with a web browser), this throws a wrench in my workflow. I'd like a way to assign, for example, 'super-T' to switch to the first open terminal emulator. Bonus points if I can also assign 'super-B' (or whatever) to switch to the first open browser. So far I've been messing around with gnome and tweaking it heavily to match my preferences, but that seems like overkill and I can never get it quite right. I've toyed with xmonad, but it's more for handling many windows, and I usually only have the two. and am considering fluxbox, but I was wondering if any of your minimalists out there had suggestions that might better match my workflow. I'm sick of fighting the window manager, I just want it to get out of my way. Edit: To make things clear, I am not considering switching to a mac/windows environment. I find programming in windows to be a bore, and I have no interest in buying new (read: mac) hardware. Thanks! -Nate

    Read the article

  • Open-source and client-side IRC-Client

    - by user125197
    I'm administrating a homepage with an IRC-Webclient. At the moment, it uses a Java-client, modified to be SSL-compatible and compatible with whatever design I want to use. The usual PJIRC thing, with users wishes and concerns implemented (I'll give you SSL-PJIRC if you want - no problem. The login-script will be improved for IE6-support this weekend, means write the object tag if an old IE is found, that's it. Rest runs perfectly well). But still, the better user experience would be a client that only requires the user to enable JavaScript. So, before I go into rewriting and customizing a complete Java-IRC-solution, I'd like to ask some other people - after researching for half a year of time. The requirements are: a) Free hosting, no cgi-bin is acceptable. A lot of hosters also have CGI supported, but it doesn't allow IRC-access. So, seems you are limited to x10-hosting for CGI:IRC. b) Solution must be open source (not free as in free beer, but free as in free speech - I want to be able to read every line of the code). c) Hosting cannot be limited to Windows-hosting. Free operation systems (anything with Linux, BSD, whatever - I think you get what I mean) must be possible. d) No server-side technology. I'm limited to everything that runs client-side only. (Well, a Java-Applet does...). d) Solution must support SSL. e) The side must be able to move. Means, you register to a new free hoster, load your things up via FileZilla and the thing simply runs. No server-concerning implementations needed. f) Old browsers must be supported. From all my research, there are two ways a) Java-Applet b) Use HTML5-Websockets (it is impossible to use the JavaScript-library I found, as it depends on ActiveX - means, Windows hosting). b) means "you are going to enter very unstable content". I worked with HTML5 for month, and, well ... Though, HTML5 also is not suitable for older browsers (old browser support is an absolutely necessary requirement). PHP by the way is a server side solution ... so no line of PHP. My idea now was a Java Applet, and a fallback which again is embedded and proprietary, but only requieres JavaScript (wsirc or Mibbit are great here, whilst I prefer wsirc ... and zooming fonts that are plainly to small, but worse, cannot read the code). So my question is - with free hosting, not installation on server, plain upload - do you see and open source, complelety client-side, ssl-compatible way to use or write a client? This wouldn't be my first programming project, I'm not afraid of the code. If there was a way and I had to write it, even from scratch, I'd do. From all I know, there sadly is none. But maybe some experienced admin has an idea? Best Wishes, yetanotheruser Sry my English isn't perfect. It's enough for programming at least.

    Read the article

  • SQLAuthority News – SafePeak’s SQL Server Performance Contest – Winners

    - by pinaldave
    SafePeak, the unique automated SQL performance acceleration and performance tuning software vendor, announced the winners of their SQL Performance Contest 2011. The contest quite unique: the writer of the best / most interesting and most community liked “performance story” would win an expensive gadget. The judges were the community DBAs that could participating and Like’ing stories and could also win expensive prizes. Robert Pearl SQL MVP, was the contest supervisor. I liked most of the stories and decided then to contact SafePeak and suggested to participate in the give-away and they have gladly accepted the same. The winner of best story is: Jason Brimhall (USA) with a story about a proc with a fair amount of business logic. Congratulations Jason! The 3 participants won the second prize of $100 gift card on amazon.com are: Michael Corey (USA), Hakim Ali (USA) and Alex Bernal (USA). And 5 participants won a printed copy of a book of mine (Book Reviews of SQL Wait Stats Joes 2 Pros: SQL Performance Tuning Techniques Using Wait Statistics, Types & Queues) are: Patrick Kansa (USA), Wagner Bianchi (USA), Riyas.V.K (India), Farzana Patwa (USA) and Wagner Crivelini (Brazil). The winners are welcome to send safepeak their mail address to receive the prizes (to “info ‘at’ safepeak.com”). Also SafePeak team asked me to welcome you all to continue sending stories, simply because they (and we all) like to read interesting stuff) as well as to send them ideas for future contests. You can do it from here: www.safepeak.com/SQL-Performance-Contest-2011/Submit-Story Congratulations to everybody! I found this very funny video about SafePeak: It looks like someone (maybe the vendor) played with video’s once and created this non-commercial like video: SafePeak dynamic caching is an immediate plug-n-play performance acceleration and scalability solution for cloud, hosted and business SQL server applications. By caching in memory result sets of queries and stored procedures, while keeping all those cache correct and up to date using unique patent pending technology, SafePeak can fix SQL performance problems and bottlenecks of most applications – most importantly: without actual code changes. By the way, I checked their website prior this contest announcement and noticed that they are running these days a special end year promotion giving between 30% to 45% discounts. Since the installation is quick and full testing can be done within couple of days – those have the need (performance problems) and have budget leftovers: I suggest you hurry. A free fully functional trial is here: www.safepeak.com/download, while those that want to start with a quote should ping here www.safepeak.com/quote. Good luck! Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Performance, SQL Puzzle, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

    Read the article

  • Consume WCF Service InProcess using Agatha and WCF

    - by REA_ANDREW
    I have been looking into this lately for a specific reason.  Some integration tests I want to write I want to control the types of instances which are used inside the service layer but I want that control from the test class instance.  One of the problems with just referencing the service is that a lot of the time this will by default be done inside a different process.  I am using StructureMap as my DI of choice and one of the tools which I am using inline with RhinoMocks is StructureMap.AutoMocking.  With StructureMap the main entry point is the ObjectFactory.  This will be process specific so if I decide that the I want a certain instance of a type to be used inside the ServiceLayer I cannot configure the ObjectFactory from my test class as that will only apply to the process which it belongs to. This is were I started thinking about two things: Running a WCF in process Being able to share mocked instances across processes A colleague in work pointed me to a project which is for the latter but I thought that it would be a better solution if I could run the WCF Service in process.  One of the projects which I use when I think about WCF Services is AGATHA, and the one which I have to used to try and get my head around doing this. Another asset I have is a book called Programming WCF Services by Juval Lowy and if you have not heard of it or read it I would definately recommend it.  One of the many topics that is inside this book is the type of configuration you need to communicate with a service in the same process, and it turns out to be quite simple from a config point of view. <system.serviceModel> <services> <service name="Agatha.ServiceLayer.WCF.WcfRequestProcessor"> <endpoint address ="net.pipe://localhost/MyPipe" binding="netNamedPipeBinding" contract="Agatha.Common.WCF.IWcfRequestProcessor"/> </service> </services> <client> <endpoint name="MyEndpoint" address="net.pipe://localhost/MyPipe" binding="netNamedPipeBinding" contract="Agatha.Common.WCF.IWcfRequestProcessor"/> </client> </system.serviceModel>   You can see here that I am referencing the Agatha object and contract here, but also that my binding and the address is something called Named Pipes.  THis is sort of the “Magic” which makes it happen in the same process. Next I need to open the service prior to calling the methods on a proxy which I also need.  My initial attempt at the proxy did not use any Agatha specific coding and one of the pains I found was that you obviously need to give your proxy the known types which the serializer can be aware of.  So we need to add to the known types of the proxy programmatically.  I came across the following blog post which showed me how easy it was http://bloggingabout.net/blogs/vagif/archive/2009/05/18/how-to-programmatically-define-known-types-in-wcf.aspx. First Pass So with this in mind, and inside a console app this was my first pass at consuming a service in process.  First here is the proxy which I made making use of the Agatha IWcfRequestProcessor contract. public class InProcProxy : ClientBase<Agatha.Common.WCF.IWcfRequestProcessor>, Agatha.Common.WCF.IWcfRequestProcessor { public InProcProxy() { } public InProcProxy(string configurationName) : base(configurationName) { } public Agatha.Common.Response[] Process(params Agatha.Common.Request[] requests) { return Channel.Process(requests); } public void ProcessOneWayRequests(params Agatha.Common.OneWayRequest[] requests) { Channel.ProcessOneWayRequests(requests); } } So with the proxy in place I could then use this after opening the service so here is the code which I use inside the console app make the request. static void Main(string[] args) { ComponentRegistration.Register(); ServiceHost serviceHost = new ServiceHost(typeof(Agatha.ServiceLayer.WCF.WcfRequestProcessor)); serviceHost.Open(); Console.WriteLine("Service is running...."); using (var proxy = new InProcProxy()) { foreach (var operation in proxy.Endpoint.Contract.Operations) { foreach (var t in KnownTypeProvider.GetKnownTypes(null)) { operation.KnownTypes.Add(t); } } var request = new GetProductsRequest(); var responses = proxy.Process(new[] { request }); var response = (GetProductsResponse)responses[0]; Console.WriteLine("{0} Products have been retrieved", response.Products.Count); } serviceHost.Close(); Console.WriteLine("Finished"); Console.ReadLine(); } So what I used here is the KnownTypeProvider of Agatha to easily get all the types I need for the service/proxy and add them to the proxy.  My Request handler for this was just a test one which always returned 2 products. public class GetProductsHandler : RequestHandler<GetProductsRequest,GetProductsResponse> { public override Agatha.Common.Response Handle(GetProductsRequest request) { return new GetProductsResponse { Products = new List<ProductDto> { new ProductDto{}, new ProductDto{} } }; } } Second Pass Now after I did this I started reading up some more on some resources including more by Davy Brion and others on Agatha.  Now it turns out that the work I did above to create a derived class of the ClientBase implementing Agatha.Common.WCF.IWcfRequestProcessor was not necessary due to a nice class which is present inside the Agatha code base, RequestProcessorProxy which takes care of this for you! :-) So disregarding that class I made for the proxy and changing my code to use it I am now left with the following: static void Main(string[] args) { ComponentRegistration.Register(); ServiceHost serviceHost = new ServiceHost(typeof(Agatha.ServiceLayer.WCF.WcfRequestProcessor)); serviceHost.Open(); Console.WriteLine("Service is running...."); using (var proxy = new RequestProcessorProxy()) { var request = new GetProductsRequest(); var responses = proxy.Process(new[] { request }); var response = (GetProductsResponse)responses[0]; Console.WriteLine("{0} Products have been retrieved", response.Products.Count); } serviceHost.Close(); Console.WriteLine("Finished"); Console.ReadLine(); }   Cheers for now, Andy References Agatha WCF InProcess Without WCF StructureMap.AutoMocking Cross Process Mocking Agatha Programming WCF Services by Juval Lowy

    Read the article

  • Parallelism in .NET – Part 5, Partitioning of Work

    - by Reed
    When parallelizing any routine, we start by decomposing the problem.  Once the problem is understood, we need to break our work into separate tasks, so each task can be run on a different processing element.  This process is called partitioning. Partitioning our tasks is a challenging feat.  There are opposing forces at work here: too many partitions adds overhead, too few partitions leaves processors idle.  Trying to work the perfect balance between the two extremes is the goal for which we should aim.  Luckily, the Task Parallel Library automatically handles much of this process.  However, there are situations where the default partitioning may not be appropriate, and knowledge of our routines may allow us to guide the framework to making better decisions. First off, I’d like to say that this is a more advanced topic.  It is perfectly acceptable to use the parallel constructs in the framework without considering the partitioning taking place.  The default behavior in the Task Parallel Library is very well-behaved, even for unusual work loads, and should rarely be adjusted.  I have found few situations where the default partitioning behavior in the TPL is not as good or better than my own hand-written partitioning routines, and recommend using the defaults unless there is a strong, measured, and profiled reason to avoid using them.  However, understanding partitioning, and how the TPL partitions your data, helps in understanding the proper usage of the TPL. I indirectly mentioned partitioning while discussing aggregation.  Typically, our systems will have a limited number of Processing Elements (PE), which is the terminology used for hardware capable of processing a stream of instructions.  For example, in a standard Intel i7 system, there are four processor cores, each of which has two potential hardware threads due to Hyperthreading.  This gives us a total of 8 PEs – theoretically, we can have up to eight operations occurring concurrently within our system. In order to fully exploit this power, we need to partition our work into Tasks.  A task is a simple set of instructions that can be run on a PE.  Ideally, we want to have at least one task per PE in the system, since fewer tasks means that some of our processing power will be sitting idle.  A naive implementation would be to just take our data, and partition it with one element in our collection being treated as one task.  When we loop through our collection in parallel, using this approach, we’d just process one item at a time, then reuse that thread to process the next, etc.  There’s a flaw in this approach, however.  It will tend to be slower than necessary, often slower than processing the data serially. The problem is that there is overhead associated with each task.  When we take a simple foreach loop body and implement it using the TPL, we add overhead.  First, we change the body from a simple statement to a delegate, which must be invoked.  In order to invoke the delegate on a separate thread, the delegate gets added to the ThreadPool’s current work queue, and the ThreadPool must pull this off the queue, assign it to a free thread, then execute it.  If our collection had one million elements, the overhead of trying to spawn one million tasks would destroy our performance. The answer, here, is to partition our collection into groups, and have each group of elements treated as a single task.  By adding a partitioning step, we can break our total work into small enough tasks to keep our processors busy, but large enough tasks to avoid overburdening the ThreadPool.  There are two clear, opposing goals here: Always try to keep each processor working, but also try to keep the individual partitions as large as possible. When using Parallel.For, the partitioning is always handled automatically.  At first, partitioning here seems simple.  A naive implementation would merely split the total element count up by the number of PEs in the system, and assign a chunk of data to each processor.  Many hand-written partitioning schemes work in this exactly manner.  This perfectly balanced, static partitioning scheme works very well if the amount of work is constant for each element.  However, this is rarely the case.  Often, the length of time required to process an element grows as we progress through the collection, especially if we’re doing numerical computations.  In this case, the first PEs will finish early, and sit idle waiting on the last chunks to finish.  Sometimes, work can decrease as we progress, since previous computations may be used to speed up later computations.  In this situation, the first chunks will be working far longer than the last chunks.  In order to balance the workload, many implementations create many small chunks, and reuse threads.  This adds overhead, but does provide better load balancing, which in turn improves performance. The Task Parallel Library handles this more elaborately.  Chunks are determined at runtime, and start small.  They grow slowly over time, getting larger and larger.  This tends to lead to a near optimum load balancing, even in odd cases such as increasing or decreasing workloads.  Parallel.ForEach is a bit more complicated, however. When working with a generic IEnumerable<T>, the number of items required for processing is not known in advance, and must be discovered at runtime.  In addition, since we don’t have direct access to each element, the scheduler must enumerate the collection to process it.  Since IEnumerable<T> is not thread safe, it must lock on elements as it enumerates, create temporary collections for each chunk to process, and schedule this out.  By default, it uses a partitioning method similar to the one described above.  We can see this directly by looking at the Visual Partitioning sample shipped by the Task Parallel Library team, and available as part of the Samples for Parallel Programming.  When we run the sample, with four cores and the default, Load Balancing partitioning scheme, we see this: The colored bands represent each processing core.  You can see that, when we started (at the top), we begin with very small bands of color.  As the routine progresses through the Parallel.ForEach, the chunks get larger and larger (seen by larger and larger stripes). Most of the time, this is fantastic behavior, and most likely will out perform any custom written partitioning.  However, if your routine is not scaling well, it may be due to a failure in the default partitioning to handle your specific case.  With prior knowledge about your work, it may be possible to partition data more meaningfully than the default Partitioner. There is the option to use an overload of Parallel.ForEach which takes a Partitioner<T> instance.  The Partitioner<T> class is an abstract class which allows for both static and dynamic partitioning.  By overriding Partitioner<T>.SupportsDynamicPartitions, you can specify whether a dynamic approach is available.  If not, your custom Partitioner<T> subclass would override GetPartitions(int), which returns a list of IEnumerator<T> instances.  These are then used by the Parallel class to split work up amongst processors.  When dynamic partitioning is available, GetDynamicPartitions() is used, which returns an IEnumerable<T> for each partition.  If you do decide to implement your own Partitioner<T>, keep in mind the goals and tradeoffs of different partitioning strategies, and design appropriately. The Samples for Parallel Programming project includes a ChunkPartitioner class in the ParallelExtensionsExtras project.  This provides example code for implementing your own, custom allocation strategies, including a static allocator of a given chunk size.  Although implementing your own Partitioner<T> is possible, as I mentioned above, this is rarely required or useful in practice.  The default behavior of the TPL is very good, often better than any hand written partitioning strategy.

    Read the article

  • SQL Server – Learning SQL Server Performance: Indexing Basics – Video

    - by pinaldave
    Today I remember one of my older cartoon years ago created for Indexing and Performance. Every single time when Performance is discussed, Indexes are mentioned along with it. In recent times, data and application complexity is continuously growing.  The demand for faster query response, performance, and scalability by organizations is increasing and developers and DBAs need to now write efficient code to achieve this. DBA and Developers A DBA’s role is critical, because a production environment has to run 24×7, hence maintenance, trouble shooting, and quick resolutions are the need of the hour.  The first baby step into any performance tuning exercise in SQL Server involves creating, analysing, and maintaining indexes. Though we have learnt indexing concepts from our college days, indexing implementation inside SQL Server can vary.  Understanding this behaviour and designing our applications appropriately will make sure the application is performed to its highest potential. Video Learning Vinod Kumar and myself we often thought about this and realized that practical understanding of the indexes is very important. One can not master every single aspects of the index. However there are some minimum expertise one should gain if performance is one of the concern. We decided to build a course which just addresses the practical aspects of the performance. In this course, we explored some of these indexing fundamentals and we elaborated on how SQL Server goes about using indexes.  At the end of this course of you will know the basic structure of indexes, practical insights into implementation, and maintenance tips and tricks revolving around indexes.  Finally, we will introduce SQL Server 2012 column store indexes.  We have refrained from discussing internal storage structure of the indexes but have taken a more practical, demo-oriented approach to explain these core concepts. Course Outline Here are salient topics of the course. We have explained every single concept along with a practical demonstration. Additionally shared our personal scripts along with the same. Introduction Fundamentals of Indexing Index Fundamentals Index Fundamentals – Visual Representation Practical Indexing Implementation Techniques Primary Key Over Indexing Duplicate Index Clustered Index Unique Index Included Columns Filtered Index Disabled Index Index Maintenance and Defragmentation Introduction to Columnstore Index Indexing Practical Performance Tips and Tricks Index and Page Types Index and Non Deterministic Columns Index and SET Values Importance of Clustered Index Effect of Compression and Fillfactor Index and Functions Dynamic Management Views (DMV) – Fillfactor Table Scan, Index Scan and Index Seek Index and Order of Columns Final Checklist: Index and Performance Well, we believe we have done our part, now waiting for your comments and feedback. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Index, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, SQLServer, T SQL, Technology, Video

    Read the article

  • Displaying an image on a LED matrix with a Netduino

    - by Bertrand Le Roy
    In the previous post, we’ve been flipping bits manually on three ports of the Netduino to simulate the data, clock and latch pins that a shift register expected. We did all that in order to control one line of a LED matrix and create a simple Knight Rider effect. It was rightly pointed out in the comments that the Netduino has built-in knowledge of the sort of serial protocol that this shift register understands through a feature called SPI. That will of course make our code a whole lot simpler, but it will also make it a whole lot faster: writing to the Netduino ports is actually not that fast, whereas SPI is very, very fast. Unfortunately, the Netduino documentation for SPI is severely lacking. Instead, we’ve been reliably using the documentation for the Fez, another .NET microcontroller. To send data through SPI, we’ll just need  to move a few wires around and update the code. SPI uses pin D11 for writing, pin D12 for reading (which we won’t do) and pin D13 for the clock. The latch pin is a parameter that can be set by the user. This is very close to the wiring we had before (data on D11, clock on D12 and latch on D13). We just have to move the latch from D13 to D10, and the clock from D12 to D13. The code that controls the shift register has slimmed down considerably with that change. Here is the new version, which I invite you to compare with what we had before: public class ShiftRegister74HC595 { protected SPI Spi; public ShiftRegister74HC595(Cpu.Pin latchPin) : this(latchPin, SPI.SPI_module.SPI1) { } public ShiftRegister74HC595(Cpu.Pin latchPin, SPI.SPI_module spiModule) { var spiConfig = new SPI.Configuration( SPI_mod: spiModule, ChipSelect_Port: latchPin, ChipSelect_ActiveState: false, ChipSelect_SetupTime: 0, ChipSelect_HoldTime: 0, Clock_IdleState: false, Clock_Edge: true, Clock_RateKHz: 1000 ); Spi = new SPI(spiConfig); } public void Write(byte buffer) { Spi.Write(new[] {buffer}); } } All we have to do here is configure SPI. The write method couldn’t be any simpler. Everything is now handled in hardware by the Netduino. We set the frequency to 1MHz, which is largely sufficient for what we’ll be doing, but it could potentially go much higher. The shift register addresses the columns of the matrix. The rows are directly wired to ports D0 to D7 of the Netduino. The code writes to only one of those eight lines at a time, which will make it fast enough. The way an image is displayed is that we light the lines one after the other so fast that persistence of vision will give the illusion of a stable image: foreach (var bitmap in matrix.MatrixBitmap) { matrix.OnRow(row, bitmap, true); matrix.OnRow(row, bitmap, false); row++; } Now there is a twist here: we need to run this code as fast as possible in order to display the image with as little flicker as possible, but we’ll eventually have other things to do. In other words, we need the code driving the display to run in the background, except when we want to change what’s being displayed. Fortunately, the .NET Micro Framework supports multithreading. In our implementation, we’ve added an Initialize method that spins a new thread that is tied to the specific instance of the matrix it’s being called on. public LedMatrix Initialize() { DisplayThread = new Thread(() => DoDisplay(this)); DisplayThread.Start(); return this; } I quite like this way to spin a thread. As you may know, there is another, built-in way to contextualize a thread by passing an object into the Start method. For the method to work, the thread must have been constructed with a ParameterizedThreadStart delegate, which takes one parameter of type object. I like to use object as little as possible, so instead I’m constructing a closure with a Lambda, currying it with the current instance. This way, everything remains strongly-typed and there’s no casting to do. Note that this method would extend perfectly to several parameters. Of note as well is the return value of Initialize, a common technique to add some fluency to the API and enabling the matrix to be instantiated and initialized in a single line: using (var matrix = new LedMS88SR74HC595().Initialize()) The “using” in the previous line is because we have implemented IDisposable so that the matrix kills the thread and clears the display when the user code is done with it: public void Dispose() { Clear(); DisplayThread.Abort(); } Thanks to the multi-threaded version of the matrix driver class, we can treat the display as a simple bitmap with a very synchronous programming model: matrix.Set(someimage); while (button.Read()) { Thread.Sleep(10); } Here, the call into Set returns immediately and from the moment the bitmap is set, the background display thread will constantly continue refreshing no matter what happens in the main thread. That enables us to wait or read a button’s port on the main thread knowing that the current image will continue displaying unperturbed and without requiring manual refreshing. We’ve effectively hidden the implementation of the display behind a convenient, synchronous-looking API. Pretty neat, eh? Before I wrap up this post, I want to talk about one small caveat of using SPI rather than driving the shift register directly: when we got to the point where we could actually display images, we noticed that they were a mirror image of what we were sending in. Oh noes! Well, the reason for it is that SPI is sending the bits in a big-endian fashion, in other words backwards. Now sure you could fix that in software by writing some bit-level code to reverse the bits we’re sending in, but there is a far more efficient solution than that. We are doing hardware here, so we can simply reverse the order in which the outputs of the shift register are connected to the columns of the matrix. That’s switching 8 wires around once, as compared to doing bit operations every time we send a line to display. All right, so bringing it all together, here is the code we need to write to display two images in succession, separated by a press on the board’s button: var button = new InputPort(Pins.ONBOARD_SW1, false, Port.ResistorMode.Disabled); using (var matrix = new LedMS88SR74HC595().Initialize()) { // Oh, prototype is so sad! var sad = new byte[] { 0x66, 0x24, 0x00, 0x18, 0x00, 0x3C, 0x42, 0x81 }; DisplayAndWait(sad, matrix, button); // Let's make it smile! var smile = new byte[] { 0x42, 0x18, 0x18, 0x81, 0x7E, 0x3C, 0x18, 0x00 }; DisplayAndWait(smile, matrix, button); } And here is a video of the prototype running: The prototype in action I’ve added an artificial delay between the display of each row of the matrix to clearly show what’s otherwise happening very fast. This way, you can clearly see each of the two images being displayed line by line. Next time, we’ll do no hardware changes, focusing instead on building a nice programming model for the matrix, with sprites, text and hardware scrolling. Fun stuff. By the way, can any of my reader guess where we’re going with all that? The code for this prototype can be downloaded here: http://weblogs.asp.net/blogs/bleroy/Samples/NetduinoLedMatrixDriver.zip

    Read the article

  • .NET Reflector Pro Coming…

    The very best software is almost always originally the creation of a single person. Readers of our 'Geek of the Week' will know of a few of them.  Even behemoths such as MS Word or Excel started out with one programmer.  There comes a time with any software that it starts to grow up, and has to move from this form of close parenting to being developed by a team.  This has happened several times within Red-Gate: SQL Refactor, SQL Compare, and SQL Dependency Tracker, not to mention SQL Backup, were all originally the work of a lone coder, who subsequently handed over the development to a structured team of programmers, test engineers and usability designers. Because we loved .NET Reflector when Lutz Roeder wrote and nurtured it, and, like many other .NET developers, used it as a development tool ourselves, .NET Reflector's progress from being the apple of Lutz's eye to being a Red-Gate team-based development  seemed natural.  Lutz, after all, eventually felt he couldn't afford the time to develop it to the extent it deserved. Why, then, did we want to take on .NET Reflector?  Different people may give you different answers, but for us in the .NET team, it just seemed a natural progression. We're always very surprised when anyone suggests that we want to change the nature of the tool since it seems right just as it is. .NET Reflector will stay very much the tool we all use and appreciate, although the new version will support .NET 4, and will have many improvements in the accuracy of its decompiling. Whilst we've made a lot of improvements to Reflector, the radical addition, which we hope you'll want to try out as well, is '.NET Reflector Pro'. This is an extension to .NET Reflector that allows the debugging of decompiled code using the Visual Studio debugger. It is an add-in, but we'll be charging for it, mainly because we prefer to live indoors with a warm meal, rather than outside in tents, particularly when the winter's been as cold as this one has. We're hoping (we're even pretty confident!) that you'll share our excitement about .NET Reflector Pro. .NET Reflector Pro integrates .NET Reflector into Visual Studio, allowing you to seamlessly debug into third-party code and assemblies, even if you don't have the source code for them. You can now treat decompiled assemblies much like your own code: you can step through them and use all the debugging techniques that you would use on your own code. Try the beta now. span.fullpost {display:none;}

    Read the article

  • Open Data, Government and Transparency

    - by Tori Wieldt
    A new track at TDC (The Developer's Conference in Sao Paulo, Brazil) is titled Open Data. It deals with open data, government and transparency. Saturday will be a "transparency hacker day" where developers are invited to create applications using open data from the Brazilian government.  Alexandre Gomes, co-lead of the track, says "I want to inspire developers to become "Civic hackers:" developers who create apps to make society better." It is a chance for developers to do well and do good. There are many opportunities for developers, including monitoring government expenditures and getting citizens involved via social networks. The open data movement is growing worldwide. One initiative, the Open Government Partnership, is working to make government data easier to find and access. Making this data easily available means that with the right applications, it will be easier for people to make decisions and suggestions about government policies based on detailed information. Last April, the Open Government Partnership held its annual meeting in Brasilia, the capitol of Brazil. It was a great success showcasing the innovative work being done in open data by governments, civil societies and individuals around the world. For example, Bulgaria now publishes daily data on budget spending for all public institutions. Alexandre Gomes Explains Open Data At TDC, the Open Data track will include a presentation of examples of successful open data projects, an introduction to the semantic web, how to handle big data sets, techniques of data visualization, and how to design APIs.The other track lead is Christian Moryah Miranda, a systems analyst for the Brazilian Government's Ministry of Planning. "The Brazilian government wholeheartedly supports this effort. In order to make our data available to the public, it forces us to be more consistent with our data across ministries, and that's a good step forward for us," he said. He explained the government knows they cannot achieve everything they would like without help from the public. "It is not the government versus the people, rather citizens are partners with the government, and together we can achieve great things!" Miranda exclaimed. Saturday at TDC will be a "transparency hacker day" where developers will be invited to create applications using open data from the Brazilian government. Attendees are invited to pitch their ideas, work in small groups, and present their project at the end of the conference. "For example," Gomes said, "the Brazilian government just released the salaries of all government employees and I can't wait to see what developers can do with that." Resources Open Government Partnership  U.S. Government Open Data ProjectBrazilian Government Open Data ProjectU.K. Government Open Data Project 2012 International Open Government Data Conference 

    Read the article

  • Who IS Brian Solis?

    - by Michael Snow
    Q: Brian, Welcome to the WebCenter Blog. Can you tell our readers your current role and what career path brought you here? A: I’m proudly serving as a principal analyst at Altimeter Group, a research based advisory firm in Silicon Valley. My career path, well, let’s just say it’s a long and winding road. As a kid, I was fascinated with technology. I learned programming at an early age and found myself naturally drawn to all things tech. I started my career as a database programmer at a technology marketing agency in Southern California. When I saw the chance to work with tech companies and help them better market their capabilities to businesses and consumers, I switched focus from programming to marketing and advertising. As technologist, my approach to marketing was different. I didn’t believe in hype, fluff or buzz words. I believed in translating features into benefits and specifications and capabilities into solutions for real world problems and opportunities. In the mid 90’s I experimented with direct to consumer/customer engagement in dedicated technology forums and boards. I quickly realized that the entire approach to do so would need to change. Therefore, I learned and developed new methods for a more social and informed way of engaging people in ways that helped them, marketed the company, and also tied to tangible benefits for the company. This work would lead me to start an agency in 1999 dedicated to interactive marketing. As I continued to experiment with interactive platforms, I developed interesting methods for converting one-to-many forms of media into one-to-one-to-many programs. I ran that company until joining Altimeter Group. Along the way, in the early 2000s, I realized that everything was changing and that there were others like me finding success in what would become a more social form of media. I dedicated a significant amount of my time to sharing everything that I learned in the form of articles, blogs, and eventually books. My mission became to share my experience with anyone who’d listen. It would later become much bigger than marketing, this would lead to a decade of work, that still continues, in business transformation. Then and now, I find myself always assuming the role of a student. Q: As an industry analyst & technology change evangelist, what are you primarily focused on these days? A: As a digital analyst, I study how disruptive technology impacts business. As an aspiring social scientist, I study how technology affects human behavior. I explore both horizons professionally and personally to better understand the future of popular culture and also the opportunities that exist for organizations to improve relationships and experiences with customers and the people that are important to them. Q: People cite that the line between work and life is getting more and more blurred. Do you see your personal life influencing your professional work? A: The line between work and life isn’t blurred it’s been overtly crossed and erased. We live in an always on society. The digital lifestyle keeps us connected to one another it keeps us connected all the time. Whether your sending or checking email, trying to catch up, or simply trying to get ahead, people are spending the equivalent of an extra day at work in the time they spend out of work…working. That’s absurd. It’s a matter of survival. It’s also a matter of unintended, subconscious self-causation. We brought this on ourselves and continue to do so. Think about your day. You’re in meetings for the better part of each day. You probably spend evenings and weekends catching up on email and actually doing the work you couldn’t get to during the day. And, your co-workers and executives are doing the same thing. So if you try to slow down, you find yourself at a disadvantage as you’re willfully pulling yourself out of an unfortunate culture of whenever wherever business dynamics. If you’re unresponsive or unreachable, someone within your organization or on your team is accessible. Over time, this could contribute to unfavorable impressions. I choose to steer my life balance in ways that complement one another. But, I don’t pretend to have this figured out by any means. In fact, I find myself swimming upstream like those around me. It’s essentially a competition for relevance and at some point I’ll learn how to earn attention and relevance while redrawing the line between work and life. Q: How can people keep up with what you’re working on? A: The easy answer is that people can keep up with me at briansolis.com. But, I also try to reach people where their attention is focused. Whether it’s Facebook (facebook.com/briansolis), Twitter (@briansolis), Google+ (+briansolis), Youtube (briansolis.tv) or through books and conferences, people can usually find me in a place of their choosing. Q: Recently, you’ve been working with us here at Oracle on something exciting coming up later this week. What’s on the horizon? A: I spent some time with the Oracle team reviewing the idea of Digital Darwinism and how technology and society are evolving faster than many organizations can adapt. Digital Darwinism: How Brands Can Survive the Rapid Evolution of Society and Technology Thursday, December 13, 2012, 10 a.m. PT / 1 p.m. ET Q: You’ve been very actively pursued for media interviews and conference and company speaking engagements – anything you’d like to share to give us a sneak peak of what to expect on Thursday’s webcast? A: We’re inviting guests to join us online as we dive into the future of business and how the convergence of technology and connected consumerism would ultimately impact how business is done. It’ll be an exciting and revealing conversation that explores just how much everything is changing. We’ll also review the importance of adapting to emergent trends and how to compete for the future. It’s important to recognize that change is not happening to us, it’s happening because of us. We are part of the revolution and therefore we need to help organizations adapt from the inside out. Watch the Entire Oracle Social Business Thought Leaders Webcast Series On-Demand and Stay Tuned for More to Come in 2013!

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 402 403 404 405 406 407 408 409 410 411 412 413  | Next Page >