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  • Code snippets for ASP.NET MVC2 in VS 2010

    - by rajbk
    VS 2010 comes with ready made snippets which helps you save time while coding. You insert a snippet by typing the name of the code snippet and hitting the Tab key twice. You can also use the following method if you wish to see a listing of snippets available. Press Ctrl + K, Ctrl + X Select ASP.NET MVC2 with the arrow keys and hit enter to see a list of snippets available.   The MVC related snippets you get out of the box (for C#) are listed below: HTML actionlink Markup snippet for an ASP.NET MVC action link helper <%= Html.ActionLink("linktext", "actionname") %>   beginformajaxcs Markup snippet for an ASP.NET MVC AJAX-enabled form helper in C# <% using (Ajax.BeginForm("actionname", new AjaxOptions {UpdateTargetId= "elementid" })) { %> <% } %>   beginformcs Markup snippet for an ASP.NET MVC form helper in C# <% using (Html.BeginForm()) { %> <% } %>   displayforcs Markup snippet for an ASP.NET MVC templated helper. <%= Html.DisplayFor(x => x.Property) %>   editorforcs Markup snippet for an ASP.NET MVC templated helper. <%= Html.EditorFor(x => x.Property) %>   foreachcs Markup snippet for an ASP.NET MVC foreach statement in C# <% foreach (var item in collection) { %> <% } %>   ifcs Markup snippet for a code-nugget if else statement in C# <% if (true) { %> <% } %>   ifelsecs Markup snippet for a code-nugget if else statement in C# <% if (true) { %> <% } else { %> <% } %>   renderpartialcs Markup snippet for an ASP.NET MVC partial view rendering in C# <% Html.RenderPartial("viewname"); %>   textboxmvc Markup snippet for an ASP.NET MVC textbox helper <%= Html.TextBox("name") %>   validationsummarymvc Markup snippet for an ASP.NET MVC validation summary helper <%= Html.ValidationSummary() %> CS mvcaction Code snippet for an action. public ActionResult Action() {     return View(); }   mvcpostaction Code snippet for an action via http post. [HttpPost] public ActionResult Action() {     return View(); }   Enjoy!

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  • Tip 14 : Solve SmtpClient issues of delayed email and high CPU usage

    - by StanleyGu
    1. It is quite straightforward using SmtpClient class to send out an email 2. However, when you step through the above code executing smtpClient.Send(), you will notice about 2 minutes delay in receiving the email. 3. My first try to solve the issue of delayed email is to set MaxIdleTime=1 4. The first try solves the issue of delayed email very well but introduces another issue: high CPU usage. The CPU usage of my deployed windows service is consistently at 50%, which is much higher than the expected near-zero CPU usage. 5. The second try is to set MaxIdleTime=2, which solves the both issues.    

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  • Lies, damned lies, and statistics Part 2

    - by Maria Colgan
    There was huge interest in our OOW session last year on Managing Optimizer Statistics. It seems statistics and the maintenance of them continues to baffle people. In order to help dispel the mysteries surround statistics management we have created a two part white paper series on Optimizer statistics.  Part one of this series was released in November last years and describes in detail, with worked examples, the different concepts of Optimizer statistics. Today we have published part two of the series, which focuses on the best practices for gathering statistics, and examines specific use cases including, the fears that surround histograms and statistics management of volatile tables like Global Temporary Tables. Here is a quick look at the Introduction and the start of the paper. You can find the full paper here. Happy Reading! Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman","serif";} Introduction The Oracle Optimizer examines all of the possible plans for a SQL statement and picks the one with the lowest cost, where cost represents the estimated resource usage for a given plan. In order for the Optimizer to accurately determine the cost for an execution plan it must have information about all of the objects (table and indexes) accessed in the SQL statement as well as information about the system on which the SQL statement will be run. This necessary information is commonly referred to as Optimizer statistics. Understanding and managing Optimizer statistics is key to optimal SQL execution. Knowing when and how to gather statistics in a timely manner is critical to maintaining acceptable performance. This whitepaper is the second of a two part series on Optimizer statistics. The first part of this series, Understanding Optimizer Statistics, focuses on the concepts of statistics and will be referenced several times in this paper as a source of additional information. This paper will discuss in detail, when and how to gather statistics for the most common scenarios seen in an Oracle Database. The topics are · How to gather statistics · When to gather statistics · Improving the efficiency of gathering statistics · When not to gather statistics · Gathering other types of statistics How to gather statistics The preferred method for gathering statistics in Oracle is to use the supplied automatic statistics-gathering job. Automatic statistics gathering job The job collects statistics for all database objects, which are missing statistics or have stale statistics by running an Oracle AutoTask task during a predefined maintenance window. Oracle internally prioritizes the database objects that require statistics, so that those objects, which most need updated statistics, are processed first. The automatic statistics-gathering job uses the DBMS_STATS.GATHER_DATABASE_STATS_JOB_PROC procedure, which uses the same default parameter values as the other DBMS_STATS.GATHER_*_STATS procedures. The defaults are sufficient in most cases. However, it is occasionally necessary to change the default value of one of the statistics gathering parameters, which can be accomplished by using the DBMS_STATS.SET_*_PREF procedures. Parameter values should be changed at the smallest scope possible, ideally on a per-object bases. You can find the full paper here. Happy Reading! +Maria Colgan

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  • Inappropriate Updates?

    - by Tony Davis
    A recent Simple-talk article by Kathi Kellenberger dissected the fastest SQL solution, submitted by Peter Larsson as part of Phil Factor's SQL Speed Phreak challenge, to the classic "running total" problem. In its analysis of the code, the article re-ignited a heated debate regarding the techniques that should, and should not, be deemed acceptable in your search for fast SQL code. Peter's code for running total calculation uses a variation of a somewhat contentious technique, sometimes referred to as a "quirky update": SET @Subscribers = Subscribers = @Subscribers + PeopleJoined - PeopleLeft This form of the UPDATE statement, @variable = column = expression, is documented and it allows you to set a variable to the value returned by the expression. Microsoft does not guarantee the order in which rows are updated in this technique because, in relational theory, a table doesn’t have a natural order to its rows and the UPDATE statement has no means of specifying the order. Traditionally, in cases where a specific order is requires, such as for running aggregate calculations, programmers who used the technique have relied on the fact that the UPDATE statement, without the WHERE clause, is executed in the order imposed by the clustered index, or in heap order, if there isn’t one. Peter wasn’t satisfied with this, and so used the ingenious device of assuring the order of the UPDATE by the use of an "ordered CTE", based on an underlying temporary staging table (a heap). However, in either case, the ordering is still not guaranteed and, in addition, would be broken under conditions of parallelism, or partitioning. Many argue, with validity, that this reliance on a given order where none can ever be guaranteed is an abuse of basic relational principles, and so is a bad practice; perhaps even irresponsible. More importantly, Microsoft doesn't wish to support the technique and offers no guarantee that it will always work. If you put it into production and it breaks in a later version, you can't file a bug. As such, many believe that the technique should never be tolerated in a production system, under any circumstances. Is this attitude justified? After all, both forms of the technique, using a clustered index to guarantee the order or using an ordered CTE, have been tested rigorously and are proven to be robust; although not guaranteed by Microsoft, the ordering is reliable, provided none of the conditions that are known to break it are violated. In Peter's particular case, the technique is being applied to a temporary table, where the developer has full control of the data ordering, and indexing, and knows that the table will never be subject to parallelism or partitioning. It might be argued that, in such circumstances, the technique is not really "quirky" at all and to ban it from your systems would server no real purpose other than to deprive yourself of a reliable technique that has uses that extend well beyond the running total calculations. Of course, it is doubly important that such a technique, including its unsupported status and the assumptions that underpin its success, is fully and clearly documented, preferably even when posting it online in a competition or forum post. Ultimately, however, this technique has been available to programmers throughout the time Sybase and SQL Server has existed, and so cannot be lightly cast aside, even if one sympathises with Microsoft for the awkwardness of maintaining an archaic way of doing updates. After all, a Table hint could easily be devised that, if specified in the WITH (<Table_Hint_Limited>) clause, could be used to request the database engine to do the update in the conventional order. Then perhaps everyone would be satisfied. Cheers, Tony.

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  • Intel HD graphic drivers for ubuntu 10.10 64bit: the brightness says its being adjusted but it isn't

    - by James
    Hey all, I picked up an hp dm3t laptop with intel HD graphics and installed ubuntu 10.10 64 bit on it. It works great -- the only problem is that the brightness controls on the keyboard don't work. The brightness is always at full. When I try to adjust it down, the indicator graphic indicates that it's going down but the actual brightness doesn't change. Is there anything that I can try to make this work? I'd really appreciate any help. I asked this on superuser.com and someone commented that I should play around with the intel hd drivers. I'm a total noob -- how do I do that? What else can I try? I reallly don't want to do back to windows.

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  • How to concentrate on one project at a time. Divide and Conquer doesn't work for me [closed]

    - by refhat
    Possible Duplicate: Tips for staying focused and motivated on a project I have serious issues on concentrating on one project at a time. I cant even follow the Divide and Conquer Approach. Once I start a project, I try to get the things done as neatly as possible but very soon I end up messing so many components of it. I try to do divide and conquer, but my approach doesn't work smoothly, and then I then wonder here and there in other projects. Sometimes I try spending so many hours for some trivial issues, which in-fact are not even issues. How do I avoid this jargon and be a smooth developer and have a nice workflow around my projects. I tend to loose my concentration on the current project and wonder in another project.

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  • ASUS Q500A will not boot from live DVD

    - by Sly
    I just purchased a new PC yesterday, an ASUS Q500A. I downloaded Ubuntu 12.10, burned it to a DVD, and tried to install it. As expected, I came to a screen that asked if I wanted to try, install, OEM install, or check the disc. After going to try, the DVD spins up as if it's about to boot the system and then immediately spins down again to leave a black screen. I've tried several boot options: noacpi nolacpi acpi=off Removing quiet splash -- nolacpi results in the DVD drive not spinning up at all. The rest have no effect. Some stats about the system: Intel i5-3210M processor Intel Integrated Graphics 4000 Any tips on other things to try?

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  • Need assistance for domain forwarding

    - by Yusuf Andre
    Briefly my question is about combining my registered domain with the websites listening on port 80/8080 on my server. I have a web server IIS on windows 7 and two web sites listening on port 80 and 8080. I have successfully forwarded any incoming request to port 80 and 8080 to my web server. So everything works like a charm when I try to access these websites entering http://myglobalip:80/Index.aspx or http://myglobalip:8080/Index.aspx from a computer outside of the local network. So I have a domain registered, lets say www.mydomain.com. What steps should I follow in which sequence? What should I consider to do? I need a step by step guide to follow. I have registered my domain on godaddy's website and only configured forwarding so the domain forward to my webserver but when I attempt to access the web page, It always try and try until It times out.

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  • T-SQL in Chicago – the LobsterPot teams with DataEducation

    - by Rob Farley
    In May, I’ll be in the US. I have board meetings for PASS at the SQLRally event in Dallas, and then I’m going to be spending a bit of time in Chicago. The big news is that while I’m in Chicago (May 14-16), I’m going to teach my “Advanced T-SQL Querying and Reporting: Building Effectiveness” course. This is a course that I’ve been teaching since the 2005 days, and have modified over time for 2008 and 2012. It’s very much my most popular course, and I love teaching it. Let me tell you why. For years, I wrote queries and thought I was good at it. I was a developer. I’d written a lot of C (and other, more fun languages like Prolog and Lisp) at university, and then got into the ‘real world’ and coded in VB, PL/SQL, and so on through to C#, and saw SQL (whichever database system it was) as just a way of getting the data back. I could write a query to return just about whatever data I wanted, and that was good. I was better at it than the people around me, and that helped. (It didn’t help my progression into management, then it just became a frustration, but for the most part, it was good to know that I was good at this particular thing.) But then I discovered the other side of querying – the execution plan. I started to learn about the translation from what I’d written into the plan, and this impacted my query-writing significantly. I look back at the queries I wrote before I understood this, and shudder. I wrote queries that were correct, but often a long way from effective. I’d done query tuning, but had largely done it without considering the plan, just inferring what indexes would help. This is not a performance-tuning course. It’s focused on the T-SQL that you read and write. But performance is a significant and recurring theme. Effective T-SQL has to be about performance – it’s the biggest way that a query becomes effective. There are other aspects too though – such as using constructs better. For example – I can write code that modifies data nicely, but if I haven’t learned about the MERGE statement and the way that it can impact things, I’m missing a few tricks. If you’re going to do this course, a good place to be is the situation I was in a few years before I wrote this course. You’re probably comfortable with writing T-SQL queries. You know how to make a SELECT statement do what you need it to, but feel there has to be a better way. You can write JOINs easily, and understand how to use LEFT JOIN to make sure you don’t filter out rows from the first table, but you’re coding blind. The first module I cover is on Query Execution. Take a look at the Course Outline at Data Education’s website. The first part of the first module is on the components of a SELECT statement (where I make you think harder about GROUP BY than you probably have before), but then we jump straight into Execution Plans. Some stuff on indexes is in there too, as is simplification and SARGability. Some of this is stuff that you may have heard me present on at conferences, but here you have me for three days straight. I’m sure you can imagine that we revisit these topics throughout the rest of the course as well, and you’d be right. In the second and third modules we look at a bunch of other aspects, including some of the T-SQL constructs that lots of people don’t know, and various other things that can help your T-SQL be, well, more effective. I’ve had quite a lot of people do this course and be itching to get back to work even on the first day. That’s not a comment about the jokes I tell, but because people want to look at the queries they run. LobsterPot Solutions is thrilled to be partnering with Data Education to bring this training to Chicago. Visit their website to register for the course. @rob_farley

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  • Threads are facing deadlock in socket program [migrated]

    - by ankur.trapasiya
    I am developing one program in which a user can download a number of files. Now first I am sending the list of files to the user. So from the list user selects one file at a time and provides path where to store that file. In turn it also gives the server the path of file where does it exist. I am following this approach because I want to give stream like experience without file size limitation. Here is my code.. 1) This is server which gets started each time I start my application public class FileServer extends Thread { private ServerSocket socket = null; public FileServer() { try { socket = new ServerSocket(Utils.tcp_port); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } @Override public void run() { try { System.out.println("request received"); new FileThread(socket.accept()).start(); } catch (IOException ex) { ex.printStackTrace(); } } } 2) This thread runs for each client separately and sends the requested file to the user 8kb data at a time. public class FileThread extends Thread { private Socket socket; private String filePath; public String getFilePath() { return filePath; } public void setFilePath(String filePath) { this.filePath = filePath; } public FileThread(Socket socket) { this.socket = socket; System.out.println("server thread" + this.socket.isConnected()); //this.filePath = filePath; } @Override public void run() { // TODO Auto-generated method stub try { ObjectInputStream ois=new ObjectInputStream(socket.getInputStream()); try { //************NOTE filePath=(String) ois.readObject(); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } File f = new File(this.filePath); byte[] buf = new byte[8192]; InputStream is = new FileInputStream(f); BufferedInputStream bis = new BufferedInputStream(is); ObjectOutputStream oos = new ObjectOutputStream( socket.getOutputStream()); int c = 0; while ((c = bis.read(buf, 0, buf.length)) > 0) { oos.write(buf, 0, c); oos.flush(); // buf=new byte[8192]; } oos.close(); //socket.shutdownOutput(); // client.shutdownOutput(); System.out.println("stop"); // client.shutdownOutput(); ois.close(); // Thread.sleep(500); is.close(); bis.close(); socket.close(); } catch (IOException ex) { ex.printStackTrace(); } } } NOTE: here filePath represents the path of the file where it exists on the server. The client who is connecting to the server provides this path. I am managing this through sockets and I am successfully receiving this path. 3) FileReceiverThread is responsible for receiving the data from the server and constructing file from this buffer data. public class FileReceiveThread extends Thread { private String fileStorePath; private String sourceFile; private Socket socket = null; public FileReceiveThread(String ip, int port, String fileStorePath, String sourceFile) { this.fileStorePath = fileStorePath; this.sourceFile = sourceFile; try { socket = new Socket(ip, port); System.out.println("receive file thread " + socket.isConnected()); } catch (IOException ex) { ex.printStackTrace(); } } @Override public void run() { try { ObjectOutputStream oos = new ObjectOutputStream( socket.getOutputStream()); oos.writeObject(sourceFile); oos.flush(); // oos.close(); File f = new File(fileStorePath); OutputStream os = new FileOutputStream(f); BufferedOutputStream bos = new BufferedOutputStream(os); byte[] buf = new byte[8192]; int c = 0; //************ NOTE ObjectInputStream ois = new ObjectInputStream( socket.getInputStream()); while ((c = ois.read(buf, 0, buf.length)) > 0) { // ois.read(buf); bos.write(buf, 0, c); bos.flush(); // buf = new byte[8192]; } ois.close(); oos.close(); // os.close(); bos.close(); socket.close(); //Thread.sleep(500); } catch (IOException ex) { ex.printStackTrace(); } } } NOTE : Now the problem that I am facing is at the first time when the file is requested the outcome of the program is same as my expectation. I am able to transmit any size of file at first time. Now when the second file is requested (e.g. I have sent file a,b,c,d to the user and user has received file a successfully and now he is requesting file b) the program faces deadlock at this situation. It is waiting for socket's input stream. I put breakpoint and tried to debug it but it is not going in FileThread's run method second time. I could not find out the mistake here. Basically I am making a LAN Messenger which works on LAN. I am using SWT as UI framework.

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  • Computer Boot/Installation Failure

    - by Marcus
    I recently tried to insatll Kubuntu and it failed. It completely removed everything off of my HDD and there is no operating system. Everytime I try to install a Distro it fails during instillation. I got Ubuntu 13.04 to work but it required a reboot and after that it did not work. I tried to re-install Ubuntu but it failed. I have tried Ubuntu, Kubuntu, and Xubuntu and they all failed. With Kubuntu and Xubuntu I get an error saying, "The 'grub-efi-amd64-signed' package failed to install into /target/. Without the GRUB boot loader, the installed system will not boot". When I select try (distro) it loads up but the installation won't finish. I do not want to have to try the distro everytime I want to get on it. Any help?

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  • AWS .NET SDK v2: setting up queues and topics

    - by Elton Stoneman
    Originally posted on: http://geekswithblogs.net/EltonStoneman/archive/2013/10/13/aws-.net-sdk-v2-setting-up-queues-and-topics.aspxFollowing on from my last post, reading from SQS queues with the new SDK is easy stuff, but linking a Simple Notification Service topic to an SQS queue is a bit more involved. The AWS model for topics and subscriptions is a bit more advanced than in Azure Service Bus. SNS lets you have subscribers on multiple different channels, so you can send a message which gets relayed to email address, mobile apps and SQS queues all in one go. As the topic owner, when you request a subscription on any channel, the owner needs to confirm they’re happy for you to send them messages. With email subscriptions, the user gets a confirmation request from Amazon which they need to reply to before they start getting messages. With SQS, you need to grant the topic permission to write to the queue. If you own both the topic and the queue, you can do it all in code with the .NET SDK. Let’s say you want to create a new topic, a new queue as a topic subscriber, and link the two together. Creating the topic is easy with the SNS client (which has an expanded name, AmazonSimpleNotificationServiceClient, compare to the SQS class which is just called QueueClient): var request = new CreateTopicRequest(); request.Name = TopicName; var response = _snsClient.CreateTopic(request); TopicArn = response.TopicArn; In the response from AWS (which I’m assuming is successful), you get an ARN – Amazon Resource Name – which is the unique identifier for the topic. We create the queue using the same code from my last post, AWS .NET SDK v2: the message-pump pattern, and then we need to subscribe the queue to the topic. The topic creates the subscription request: var response = _snsClient.Subscribe(new SubscribeRequest { TopicArn = TopicArn, Protocol = "sqs", Endpoint = _queueClient.QueueArn }); That response will give you an ARN for the subscription, which you’ll need if you want to set attributes like RawMessageDelivery. Then the SQS client needs to confirm the subscription by allowing the topic to send messages to it. The SDK doesn’t give you a nice mechanism for doing that, so I’ve extended my AWS wrapper with a method that encapsulates it: internal void AllowSnsToSendMessages(TopicClient topicClient) { var policy = Policies.AllowSendFormat.Replace("%QueueArn%", QueueArn).Replace("%TopicArn%", topicClient.TopicArn); var request = new SetQueueAttributesRequest(); request.Attributes.Add("Policy", policy); request.QueueUrl = QueueUrl; var response = _sqsClient.SetQueueAttributes(request); } That builds up a policy statement, which gets added to the queue as an attribute, and specifies that the topic is allowed to send messages to the queue. The statement itself is a JSON block which contains the ARN of the queue, the ARN of the topic, and an Allow effect for the sqs:SendMessage action: public const string AllowSendFormat= @"{ ""Statement"": [ { ""Sid"": ""MySQSPolicy001"", ""Effect"": ""Allow"", ""Principal"": { ""AWS"": ""*"" }, ""Action"": ""sqs:SendMessage"", ""Resource"": ""%QueueArn%"", ""Condition"": { ""ArnEquals"": { ""aws:SourceArn"": ""%TopicArn%"" } } } ] }"; There’s a new gist with an updated QueueClient and a new TopicClient here: Wrappers for the SQS and SNS clients in the AWS SDK for .NET v2. Both clients have an Ensure() method which creates the resource, so if you want to create a topic and a subscription you can use:  var topicClient = new TopicClient(“BigNews”, “ImListening”); And the topic client has a Subscribe() method, which calls into the message pump on the queue client: topicClient.Subscribe(x=>Log.Debug(x.Body)); var message = {}; //etc. topicClient.Publish(message); So you can isolate all the fiddly bits and use SQS and SNS with a similar interface to the Azure SDK.

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  • Lenovo B570 doesn't boot after installation

    - by Alan
    I install my Ubuntu 11.10 64 Bits in my Notebook Lenovo B570. (I remove Win 7). I have no problems to install. But at finish, when it start, it wont boot. It search for another boot device (Network, CD/DVD). Maybe it issue is about SCSI Hard Drive. I try in BIOS set compatible mode SCSI/ATA. It try locate another boot (Networks, CD/DVD). I try to enable compatible mode in BIOS SCSI - SATA and reinstall again. "Will ubuntu be the only os on your computer or is there a 2nd os?" A:Yes. I remove Windows 7 and use All disc to Ubuntu.

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  • Detailed C++ book for a programmer already familiar with C and object-oriented programming?

    - by Anto
    I know (to some extent) a few languages, including C, Java and Python. I'm also (somewhat) familiar with Scala and Scheme, plus I can read (but not write) x86 Assembly. Say I want to learn C++, what is a good book which doesn't try to teach me what a class is, teach me inheritance, polymorphism or loosely coupled classes again, nor does try to teach me other basics, just the C++ language (as well as how to write idiomatic C++ code, not e.g. Java with C++ syntax) and its standard library? Note: "Detailed" as used in the title means that it doesn't try to cover C++ in 100 pages, I want to know the details of the language. Of course, mastery comes from practice, but I don't want to learn just a little bit of C++ from the book, but learn it quite thoroughly.

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  • How should I study programming languages?

    - by gcc
    I am a student of computer engineering. I have never done any programming before, and as you can understand, I don't know how to study it or how to make my own programs. My English is weak [edited for clarity - ed], and so if you don't like the choices I list, please feel free to provide others. How should I study? How should I learn programming languages? Study completely from a book. Don't study from a book, just try writing code. A mix of the two; study from a book, then try writing code. Study half the book, then write the code by hand on paper. Listed to the teacher, then try to solve general problems (those not from any specific chapter).

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  • Non use of persisted data

    - by Dave Ballantyne
    Working at a client site, that in itself is good to say, I ran into a set of circumstances that made me ponder, and appreciate, the optimizer engine a bit more. Working on optimizing a stored procedure, I found a piece of code similar to : select BillToAddressID, Rowguid, dbo.udfCleanGuid(rowguid) from sales.salesorderheaderwhere BillToAddressID = 985 A lovely scalar UDF was being used,  in actuality it was used as part of the WHERE clause but simplified here.  Normally I would use an inline table valued function here, but in this case it wasn't a good option. So this seemed like a pretty good case to use a persisted column to improve performance. The supporting index was already defined as create index idxBill on sales.salesorderheader(BillToAddressID) include (rowguid) and the function code is Create Function udfCleanGuid(@GUID uniqueidentifier)returns varchar(255)with schemabindingasbegin Declare @RetStr varchar(255) Select @RetStr=CAST(@Guid as varchar(255)) Select @RetStr=REPLACE(@Retstr,'-','') return @RetStrend Executing the Select statement produced a plan of : Nothing surprising, a seek to find the data and compute scalar to execute the UDF. Lets get optimizing and remove the UDF with a persisted column Alter table sales.salesorderheaderadd CleanedGuid as dbo.udfCleanGuid(rowguid)PERSISTED A subtle change to the SELECT statement… select BillToAddressID,CleanedGuid from sales.salesorderheaderwhere BillToAddressID = 985 and our new optimized plan looks like… Not a lot different from before!  We are using persisted data on our table, where is the lookup to fetch it ?  It didnt happen,  it was recalculated.  Looking at the properties of the relevant Compute Scalar would confirm this ,  but a more graphic example would be shown in the profiler SP:StatementCompleted event. Why did the lookup happen ? Remember the index definition,  it has included the original guid to avoid the lookup.  The optimizer knows this column will be passed into the UDF, run through its logic and decided that to recalculate is cheaper than the lookup.  That may or may not be the case in actuality,  the optimizer has no idea of the real cost of a scalar udf.  IMO the default cost of a scalar UDF should be seen as a lot higher than it is, since they are invariably higher. Knowing this, how do we avoid the function call?  Dropping the guid from the index is not an option, there may be other code reliant on it.   We are left with only one real option,  add the persisted column into the index. drop index Sales.SalesOrderHeader.idxBillgocreate index idxBill on sales.salesorderheader(BillToAddressID) include (rowguid,cleanedguid) Now if we repeat the statement select BillToAddressID,CleanedGuid from sales.salesorderheaderwhere BillToAddressID = 985 We still have a compute scalar operator, but this time it wasnt used to recalculate the persisted data.  This can be confirmed with profiler again. The takeaway here is,  just because you have persisted data dont automatically assumed that it is being used.

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  • Slow on browsing web, but normal when using apt-get

    - by Arif Setyawan
    I have a problem with my fresh instalation of Ubuntu 11.10. The problem happen when i start up my browser and accessing website such google, askubuntu.com, facebook and other sites. frustate on the situation i try watch the progress in system monitor. the result from monitor shows that there is no data transfer when i try to accessing the page. firstly, i assume that it is the trouble from my ISP or my home connection. But it is not. When i try pinging google it shows transaction between my computer and the network but still null from browser. Then i tried to test the aptitude and it was work fine but still the browser won't recieve any packet from the internet. Here is the detail of my tools : Laptop : Toshiba Satellite e205 (network card atheros) Operating System : Ubuntu 11.04 dual booted with Win7 Browser : Mozilla Firefox comes up with the Ubuntu 11.10 installation Chrome : Last version (just yesterday install it) Thank You before :) [this question posted via win]

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  • GRUB is not Booting Correctly

    - by msknapp
    I have a PC with three hard disks. Windows 7 is installed on the first, Ubuntu 14.04 is installed on the third. After I re-booted, it went straight to Windows 7. So I tried explicitly telling my PC to boot using the third hard disk, but that just takes me to the grub rescue prompt. I followed Scott Severence's instructions here to try and recover. Essentially, I updated grub, reinstalled grub, and then updated it again. After re-booting, absolutely nothing had changed. So instead I tried using the boot-repair tool. In the past it had failed for me, saying that I had programs running and it could not unmount drives, when I was running nothing. I never figured out how to solve that problem, but it went away when I bought another hard drive and used that for my Ubuntu installation, I don't know why. In any case, I ran the boot-repair tool and this time it said it was successful. First time for everything right? I re-booted, only to be taken straight to the grub rescue prompt. So I changed my BIOS settings to use the third hard disk for boot start up. That is the same hard drive where I have Ubuntu and grub installed, and the same one that the grub-repair tool told me to use. It still took me straight to the grub rescue prompt. So I went from not being able to boot Ubuntu, to not being able to boot either OS installed on my system. Thanks boot-repair! Boot repair gave me this URL for future troubleshooting: http://paste.ubuntu.com/8131669 When I try to boot from the third hard disk, this is my console: Loading Operating System ... error: attempt to read or write outside of disk 'hd0'. Entering rescue mode... grub rescue> grub rescue> set cmdpath=(hd0) prefix=(hd0,gpt2)/boot/grub root=hd0,gpt2 grub rescue> ls (hd0) (hd0,gpt3) (hd0,gpt2) (hd0,gpt1) (hd1) (hd2) (hd2,gpt2) (hd2,gpt1) (hd3) Those values look correct to me. I have also experimented with changing some of those values, but 'insmod normal' always throws the same error. Somebody please tell me how to fix this. I have tried everything, reinstalling grub, and running boot-repair. =========================== Update: I think the problem might be that the ubuntu installer did not partition my hard disk correctly. I booted from live USB and then launched gparted and looked at how it partitioned things. This is what gparted says: Partition, File System, Size, Used, Unused, Flags /dev/sda1 (!), unknown, 1.00 MiB, ---, ---, bios_grub /dev/sda2, ext4, 2.71 TiB, 47.30 GiB, 2.67 TiB, /dev/sda3, linux-swap, 16.00 GiB, 0.00 B, 16.00 GiB, So that first line looks problematic. It is supposed to be the /boot partition. However, it was given only 1 MiB? I am assuming that MiB is actually supposed to mean megabyte, no idea why that 'i' is there. It also says the file system is unknown. I read the answer by andrew here, and he says he had to do a custom install, explicitly configuring the boot partition. So I think that maybe Ubuntu's installer has a bug in it, where it does not set up the boot partition correctly if you are not installing on the first hard disk in your computer. I am going to try reinstalling with a custom partition scheme. I read elsewhere (askubuntu won't let me post another link) that I don't even need a /boot partition any more. So instead of following Andrew's instructions ver batim, I'm first going to try having just two partitions: one for /, and another for my 16GB swap space. Both as primary partitions. The first will be formatted as ext4. If that doesn't work, I may try again using /boot. ======================== So I did my custom install with no /boot partition, and it did not work. When I rebooted, I had an error message saying that some address did not exist. So for the hundredth time, I booted from the live USB, and ran boot-repair. Now I get this message GPT detected. Please create a BIOS-Boot partition (>1MB, unformatted filesystem, bios_grub flag). This can be performed via tools such as Gparted. Then try again. I feel like I'm running in circles and nobody will help me.

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  • kernel mem parameter

    - by Ashfame
    As a last resort to my question, I am yet to try the mem parameter of kernel to force it to use the specified amount of RAM. Short Summary - I can only see 3.2GB RAM on a 64bit OS and am not sure ifs a hardware limitation, so wants to try as I found a post on Ubuntuforums. My question is if its ok to play with my resident Ubuntu install or should I be using a live bootable usb? What values do I try (I have 6GB with only 3.2GB being usable) and how to keep it safe? I don't want to burn any of my hardware component at this point of time or make the system unbootable. Running Ubuntu 11.10 with kernel 3.0.0-13-generic

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  • Brightness control not working on HP Pavilion dm3t (Intel GMA 4500MHD)

    - by James
    Hey all, I picked up an hp dm3t laptop with intel HD graphics and installed ubuntu 10.10 64 bit on it. It works great -- the only problem is that the brightness controls on the keyboard don't work. The brightness is always at full. When I try to adjust it down, the indicator graphic indicates that it's going down but the actual brightness doesn't change. Is there anything that I can try to make this work? I'd really appreciate any help. I asked this on superuser.com and someone commented that I should play around with the intel hd drivers. I'm a total noob -- how do I do that? What else can I try? I really don't want to go back to windows.

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  • Skype 4.2 crashes and bugs on 13.10

    - by Juhani Taylor
    I've installed Skype and it appears to work fine right up until the point where I try to call someone. If I try to video call someone then the programme freezes and I have to force quit. I've tried several 'solutions' I've found on various forums but none seem to work. Now, when I try to call the Echo service as a test to see if the bug's fixed, it seems to connect and start the non-video call, except that it's completely silent. No audio at all. Any help? It seems to be 2 separate issues: audio and generic crashing. Anyone come across these and found solutions?

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  • Compress a directory in linux

    - by user9589
    I'm trying to compress a directory and ftp it to a windows ftp. I have tried ever tar command i can find to compress a directory. It appears to be ok then I try and view it's contents using winrar. Winrar keeps telling me the file is corrupt. I have viewed other .gz or .bz2 files using winrar but for some odd reason I can't get it to work. Does anyone else have a suggestion as to something else to try. I would prefer just to have it zip the files so they have a .zip extension but even then when i try to browse it's contents both windows and winrar claim it's corrupt.

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  • Ubuntu 14.04 doesn' t boot after upgrade from 12.04 installed inside Windows 8.1

    - by AdiC
    I have Ubuntu 12.04 installed like an app on windows 8.1 (Ubuntu 12.04 allow to be installed like an app in Windows 8.1 and it can be removed when you don't need it any more from Control Panel). Usually, to chose what os to boot when you start the laptop, you can choose between windows 8.1 and Ubuntu after windows logo appeared at start up and that was ok until I made this upgrade. Now when I try to choose Ubuntu the laptop try to boot it but, after that full colored screen is showed the screen go black and this messages appear: mount: mounting /dev/loop0/ on /root failed : Invalid argument mount: mounting /dev on /root/dev failed: No such file or directory mount: mounting /sys on /root/sys failed: No such file or directory mount: mounting /proc on /root/proc failed: No such file or directory Target filesystem doesn' t have requested /sbin/init No init found. Try passing init = bootarg. BusyBox v1.21.1 (Ubuntu 1:1:21.0-1ubuntu1) built-in shell (ash) Enter 'help' for a list of built-in commands (initramfs) _ I don' t know what to do after this screen appears. Please help !

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  • Problem with Using chntpw in Ubuntu to reset Windows 7 Password

    - by sandesh yadav
    I tried resetting the password of windows 7 Using 'chntpw' command in Ubuntu . It showed success . But when I try to login from Windows it does not seem to be changed. I first used live USB of ubuntu 11.10 and did ''Try Ubuntu''. Then I did sudo apt-get install chntpw and then cd /media/Vista/Windows/System32/config sudo chntpw -u username sam . I did according to this link . http://www.psychocats.net/ubuntucat/resetwindowspasswordold/ and got success like this. Hives that have changed: Name 0 Write hive files? (y/n) [n] : y 0 – OK . But when I try to login to windows with blank password , I could not login. I also tried changing the password and showed success but I could not login with that password . Thank you . Any help is very much appreciated.

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  • Unable to remove a file which have a name like a command argument

    - by Justin
    By inadvertance, I've created a file called -r into my home directory. Please don't ask me how and why, I don't recall. But the fact is that now I cannot get rid of it : rm -rf rm: missing operand Try 'rm --help' for more information. Other try : rm /-/r rm: cannot remove ‘/-/r’: No such file or directory Another one : rm \-r rm: missing operand Try 'rm --help' for more information. Is there a way to remove this file without deleting the whole directory ? Thanks.

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