Search Results

Search found 39456 results on 1579 pages for 'why do you'.

Page 446/1579 | < Previous Page | 442 443 444 445 446 447 448 449 450 451 452 453  | Next Page >

  • Working with Google Webmaster Tools

    - by com
    My first question is about Crawl errors in Google Webmaster Tools. Crawl errors is devided into few sections. One of them is HTTP. I assume that all broken links in HTTP was somehow found by crawler, this is not the links from sitemap. If this was found by scanning all sitemap pages for links, why it doesn't mention what was the source page, like in sitemap section with column Linked From. And what the meaning of Linked From, I thought if the name of section is sitemap, therefore all URLs should be taken from sitemap, so why there is Linked From? The second question, what is the best way to trreat searching on the site. How come the searching result page are getting indexed? Because of the fact that all searching result page are getting indexed, I have to many page in Linked From. What's the right practice? Question three: In order to improve response time in WMT, can I redirect all crawler's requests to designated free web server? Is this good practice? Question four: How should I treat Google Analytics Code (with parameters PageView, PageLoadTime), in the case user request non existing page, should I render Google code or not? Right now I use Google Analytics Code on the common template page, such that every page, also non existing page with error message contains Google Analytics Code, it seems like it has influence on WMT.

    Read the article

  • Getting into the details of game engine programming

    - by Darkslash
    I am interested in learning game programming, but I really have an interest in the lower level engineering in games. I have OpenGL experience, and I am really interested in learning more about implementing AI, Physics, etc. I have a computer science degree, so I really like getting into technical stuff. Many times when I ask about this sort of thing, I get a lot of "Use an engine", "Use Unity3d", "Why waste your time writing code that already exists", etc, etc. My idea was to use simpler libraries such as SFML or XNA so that I could learn how to implement the more complex systems. The thing is, although I do want to write games, I want to learn things that using something like Unity simply doesn't teach you. My goal is not to make a current generation quality 3D game to sell, I just want to make some cool smaller games and learn all I can about the programming side of game development. Is this something that people just do not do anymore? It seems like everywhere I turn people are using Unity or UDK or GameMaker. I fully understand why you would use a tool like these, but I cant see how they would suit my purposes. So where does someone like myself turn? Am I trying to learn something that people just do not bother doing anymore? Is the innovation in this area gone and just all about gameplay now? I'm sorry if this question seems silly, but I am genuinely interested in knowing more about this and meeting more people who are interested in this sort of thing.

    Read the article

  • Poll on Entity Framework 4 &ndash; one year on

    - by Eric Nelson
    12 months back (today is March 15th 2010) on the 16th of  March 2009 I created a poll on Entity Framework v1 – the marmite of ORMs? A quick poll…. Entity Framework v1 was getting a mixed reception at the time – I met developers who genuinely hated it and I met developers who were loving the productivity improvements they were seeing. There were definitely issues with v1, too many IMHO. Which is why the product team placed a huge effort on listening to the community to drive the feature set for v2 (which ultimately was named Entity Framework 4 as it ships with .NET 4). I think overall the team have done a great job. It isn’t perfect in .NET 4 (which is why the team are busy on post .NET 4 improvements) but I would happily use it and recommend it for a wide variety of projects – much wider than I would have with v1. I am speaking on EF 4 at www.devweek.com this Wednesday and I thought it would be fun to put a new version of the poll out and see how v4 is being received. Obviously the big difference is we have not yet shipped EF4 vs when I did the original poll on EF1. March 2010 poll – please vote Summary of March 2009 poll – it was a tie between positive and negative Total votes 150 Positive about EF v1 42 (15 + 19 + 8) Negative about EF v1  43 (34 + 9)

    Read the article

  • Oracle Forms: Walking the path to FMW Platform – webcast September 24th 2012

    - by JuergenKress
    The next 5 year Strategy Preparing for the Next Generation Applications Oracle Forms, a component of Oracle Fusion Middleware, is Oracle's long-established technology to design and build enterprise applications quickly and efficiently. Oracle remains committed to the development of this technology, and to the ongoing release as a component of the Oracle platform. This continuing commitment to Forms technology enables you to leverage your existing investment by easily upgrading and integrating existing Oracle Forms applications to take advantage of web technologies and service oriented architectures (SOA). For more information please visit our Forms OTN page. Agenda Why update? – New business imperatives What is the path? Why walk it with Oracle? Support Lifetime – upgrade to updates Summary Audience Enterprise & Solution Architects R&D leaders Project Managers and Project Leaders Delivery Format This FREE online LIVE eSeminar will be delivered over the Web and Conference Call. Duration 1 hour Forms: Walking the path to FMW September 24th, 2012, 9am BST Register Here! WebLogic Partner Community For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Mix Forum Wiki Technorati Tags: Forms,PTS,future of forms,forms roadmap,forms soa,WebLogic Community,Oracle,OPN,Jürgen Kress

    Read the article

  • Interfaces on an abstract class

    - by insta
    My coworker and I have different opinions on the relationship between base classes and interfaces. I'm of the belief that a class should not implement an interface unless that class can be used when an implementation of the interface is required. In other words, I like to see code like this: interface IFooWorker { void Work(); } abstract class BaseWorker { ... base class behaviors ... public abstract void Work() { } protected string CleanData(string data) { ... } } class DbWorker : BaseWorker, IFooWorker { public void Work() { Repository.AddCleanData(base.CleanData(UI.GetDirtyData())); } } The DbWorker is what gets the IFooWorker interface, because it is an instantiatable implementation of the interface. It completely fulfills the contract. My coworker prefers the nearly identical: interface IFooWorker { void Work(); } abstract class BaseWorker : IFooWorker { ... base class behaviors ... public abstract void Work() { } protected string CleanData(string data) { ... } } class DbWorker : BaseWorker { public void Work() { Repository.AddCleanData(base.CleanData(UI.GetDirtyData())); } } Where the base class gets the interface, and by virtue of this all inheritors of the base class are of that interface as well. This bugs me but I can't come up with concrete reasons why, outside of "the base class cannot stand on its own as an implementation of the interface". What are the pros & cons of his method vs. mine, and why should one be used over another?

    Read the article

  • Updating, etc., automatically

    - by Steve D
    Is there a way to set up Ubuntu 12.04 (or earlier versions) so that all recommended updates are done automatically, say once a week? When I say automatically, I mean no password entry or user intervention required. This sounds like a stupid request, so let me tell why I'm asking. My grandfather knows nothing about computers; he uses his solely to read Yahoo! mail. I want to get rid of his clunky, spyware-ridden Windows XP and install Ubuntu. I want to set it up so when he turns the computer on, after a couple minutes, voila!, Yahoo! mail, already signed in, ready to go. The problem is I don't want to have to go over there every week or so and make sure everything is up-to-date, he hasn't accidentally installed any spyware, etc. So can this be done? Is this the best way to set things up for my grandfather? Are there other things I should be worried about when it comes to keeping things hassle-free for him? Please don't post anything like "why not teach him how to... blah blah blah". My grandfather is 80 years old and has made it clear email is the only thing he will ever use a computer for! Thanks!

    Read the article

  • Alternatives to time tracking methodologies [closed]

    - by Brandon Wamboldt
    Question first: What are some feasible alternatives to time tracking for employees in a web/software development company, and why are they better options Explanation: I work at a company where we work like this. Everybody is paid salary. We have 3 types of work, Contract, Adhoc and Internal (Non billable). Adhoc is just small changes that take a few hours and we just bill the client at the end of the month. Contracts are signed and we have this big long process, the usual. We figure out how much to charge by getting an estimation of the time involved (From the design and the developers), multiplying it by our hourly rate and that's it. So say we estimate 50 hours for a website. We have time tracking software and have to record the time in 15 we spend on it (7:00 to 7:15 for example), the project name, and give it some comments. Now if we go over the 50 hours, we are both losing money and are inefficient. Now that I've explained how the system works, my question is how else can it be done if a better method exists (Which I'm sure one must). Nobody here likes the current system, we just can't find an alternative. I'd be more than willing to work after hours longer hours on a project to get it done in time, but I'm much inclined to do so with the current system. I'd love to be able to sum up (Or link) to this post for my manager to show them why we should use abc system instead of this system.

    Read the article

  • Choosing a JavaScript Asynch-Loader

    - by Prisoner ZERO
    I’ve been looking at various asynchronous resource-loaders and I’m not sure which one to use yet. Where I work we have disparate group-efforts whose class-modules may use different versions of jQuery (etc). As such, nested dependencies may differ, as well. I have no control over this, so this means I need to dynamically load resources which may use alternate versions of the same library. As such, here are my requirements: Load JavaScript and CSS resource files asynchronously. Manage dependency-order and nested-dependencies across versions. Detect if a resource is already loaded. Must allow for cross-domain loading (CDN's) (optional) Allow us to unload a resource. I’ve been looking at: Curl RequireJS JavaScriptMVC LABjs I might be able to fake these requirements myself by loading versions into properly-namespaced variables & using an array to track what is already loaded...but (hopefully) someone has already invented this. So my questions are: Which ones do you use? And why? Are there others that my satisfy my requirements fully? Which do you find most eloquent and easiest to work with? And why?

    Read the article

  • Would having an undergraduate certificate in Computer Science help me get employed as a computer programmer? [on hold]

    - by JDneverSleeps
    I am wondering how would employers perceive the Universtiy Certificate in Computing and Information Systems offered by Athabasca University (a distance education institution... The university is legit and accredited by the Government of Alberta, Canada). I already have a BSc in Statistics from University of Alberta (a classic brick and mortar public university in Alberta, Canada)...so I can state in my resume that I have a "university degree"..... Luckily, I was able to secure a very good employment in my field after the graduation from the U of A. The main reason why I am interested in taking the certificate program through Athabasca is because knowing how to program can increase the chance for promotion in my current job. I also believe that if something turns out bad in my current job and if I ever need to look for a new place to work, having the certificate in computer science will help me get employed as a computer programmer (i.e. my choice for the new job wouldn't be restricted to the field of Statistics). Athabasca University is claiming that the certificate program is meant to be equivalent to the undergraduate minor in computing science. I carefully looked at the certificate's curriculum and as far as I am concerned, the certificate program does have the same level of rigour as the undergraduate minor in Computer Science programs offered by other Canadian universities. I am also confident that the certificate program will get me to pick up enough skills/background to start a career as a computer programmer. The reasons why I am not 100% sure on getting the certificate is worth the tuition are: Athabasca University is a distance education institution (accredited by government but still) The credential that I will receive is "university certificate", not a "undergraduate degree" Do you think it's a good idea for me to pursue the certificate, given the two facts above? again, I already have my Bachelor's degree - although it is not in CS Thanks,

    Read the article

  • Can someone explain the (reasons for the) implications of colum vs row major in multiplication/concatenation?

    - by sebf
    I am trying to learn how to construct view and projection matrices, and keep reaching difficulties in my implementation owing to my confusion about the two standards for matrices. I know how to multiply a matrix, and I can see that transposing before multiplication would completely change the result, hence the need to multiply in a different order. What I don't understand though is whats meant by only 'notational convention' - from the articles here and here the authors appear to assert that it makes no difference to how the matrix is stored, or transferred to the GPU, but on the second page that matrix is clearly not equivalent to how it would be laid out in memory for row-major; and if I look at a populated matrix in my program I see the translation components occupying the 4th, 8th and 12th elements. Given that: "post-multiplying with column-major matrices produces the same result as pre-multiplying with row-major matrices. " Why in the following snippet of code: Matrix4 r = t3 * t2 * t1; Matrix4 r2 = t1.Transpose() * t2.Transpose() * t3.Transpose(); Does r != r2 and why does pos3 != pos for: Vector4 pos = wvpM * new Vector4(0f, 15f, 15f, 1); Vector4 pos3 = wvpM.Transpose() * new Vector4(0f, 15f, 15f, 1); Does the multiplication process change depending on whether the matrices are row or column major, or is it just the order (for an equivalent effect?) One thing that isn't helping this become any clearer, is that when provided to DirectX, my column major WVP matrix is used successfully to transform vertices with the HLSL call: mul(vector,matrix) which should result in the vector being treated as row-major, so how can the column major matrix provided by my math library work?

    Read the article

  • "Unmet Dependencies" problem when trying apt-get install

    - by GChorn
    Anytime I try to install python packages using the command: sudo apt-get install python-package I get the following output: Reading package lists... Done Building dependency tree Reading state information... Done You might want to run 'apt-get -f install' to correct these: The following packages have unmet dependencies: linux-headers-generic : Depends: linux-headers-3.2.0-36-generic but it is not going to be installed linux-headers-generic-pae : Depends: linux-headers-3.2.0-36-generic-pae but it is not going to be installed linux-image-generic : Depends: linux-image-3.2.0-36-generic but it is not going to be installed E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution). This seems to have started when these same three packages showed up in Ubuntu's Update Manager and kicked an error when I tried to install them there. Based on the suggestion in the output above, I tried running: sudo apt-get -f install But this only gave me several instances of the following error: dpkg: error processing /var/cache/apt/archives/linux-image-3.2.0-36-generic_3.2.0-36.57_i386.deb (--unpack): unable to create `/lib/modules/3.2.0-36-generic/kernel/drivers/net/wireless/ath/carl9170/carl9170.ko.dpkg-new' (while processing `./lib/modules/3.2.0-36-generic/kernel/drivers/net/wireless/ath/carl9170/carl9170.ko'): No space left on device Now maybe I'm way off-base here, but I'm wondering if the error could be coming from the "No space left on device" part? The thing is, I'm running Ubuntu as a VirtualBox VM but I've got it set to dynamically increase its virtual hard drive space as needed, so why am I still getting this error? Here's my output when I use dh -f: Filesystem Size Used Avail Use% Mounted on /dev/sda1 6.9G 5.7G 869M 88% / udev 494M 4.0K 494M 1% /dev tmpfs 201M 784K 200M 1% /run none 5.0M 0 5.0M 0% /run/lock none 501M 76K 501M 1% /run/shm VB_Shared_Folder 466G 271G 195G 59% /media/sf_VB_Shared_Folder When I perform sudo apt-get -f install and the system says, After this operation, 192 MB of additional disk space will be used. Does that mean 192 MB of my virtual machine's current memory, or 192 MB on top of the rest of my free space? As I said, my machine normally dynamically allocates additional memory from the host machine, so I don't see why there would be memory restrictions at all...

    Read the article

  • Do there exist programming languages where a variable can truly know its own name?

    - by Job
    In PHP and Python one can iterate over the local variables and, if there is only once choice where the value matches, you could say that you know what the variable's name is, but this does not always work. Machine code does not have variable names. C compiles to assembly and does not have any native reflection capabilities, so it would not know it's name. (Edit: per Anton's answer the pre-processor can know the variable's name). Do there exist programming languages where a variable would know it's name? It gets tricky if you do something like b = a and b does not become a copy of a but a reference to the same place. EDIT: Why in the world would you want this? I can think of one example: error checking that can survive automatic refactoring. Consider this C# snippet: private void CheckEnumStr(string paramName, string paramValue) { if (paramName != "pony" && paramName != "horse") { string exceptionMessage = String.Format( "Unexpected value '{0}' of the parameter named '{1}'.", paramValue, paramName); throw new ArgumentException(exceptionMessage); } } ... CheckEnumStr("a", a); // Var 'a' does not know its name - this will not survive naive auto-refactoring There are other libraries provided by Microsoft and others that allow to check for errors (sorry the names have escaped me). I have seen one library which with the help of closures/lambdas can accomplish error checking that can survive refactoring, but it does not feel idiomatic. This would be one reason why I might want a language where a variable knows its name.

    Read the article

  • Top 4 Lame Tech Blogging Posts

    - by jkauffman
    From a consumption point of view, tech blogging is a great resource for one-off articles on niche subjects. If you spend any time reading tech blogs, you may find yourself running into several common, useless types of posts tech bloggers slip into. Some of these lame posts may just be natural due to common nerd psychology, and some others are probably due to lame, lemming-like laziness. I’m sure I’ll do my fair share of fitting the mold, but I quickly get bored when I happen upon posts that hit these patterns without any real purpose or personal touches. 1. The Content Regurgitation Posts This is a common pattern fueled by the starving pan-handlers in the web traffic economy. These are posts that are terse opinions or addendums to an existing post. I commonly see these involve huge block quotes from the linked article which almost always produces over 50% of the post itself. I’ve accidentally gone to these posts when I’m knowingly only interested in the source material. Web links can degrade as well, so if the source link is broken, then, well, I’m pretty steamed. I see this occur with simple opinions on technologies, Stack Overflow solutions, or various tech news like posts from Microsoft. It’s not uncommon to go to the linked article and see the author announce that he “added a blog post” as a response or summary of the topic. This is just rude, but those who do it are probably aware of this. It’s a matter of winning that sweet, juicy web traffic. I doubt this leeching is fooling anybody these days. I would like to rally human dignity and urge people to avoid these types of posts, and just leave a comment on the source material. 2. The “Sorry I Haven’t Posted In A While” Posts This one is far too common. You’ll most likely see this quote somewhere in the body of the offending post: I have been really busy. If the poster is especially guilt-ridden, you’ll see a few volleys of excuses. Here are some common reasons I’ve seen, which I’ll list from least to most painfully awkward. Out of town Vague allusions to personal health problems (these typically includes phrases like “sick”, “treatment'”, and “all better now!”) “Personal issues” (which I usually read as "divorce”) Graphic or specific personal health problems (maximum awkwardness potential is achieved if you see links to charity fund websites) I can’t help but to try over-analyzing why this occurs. Personally, I see this an an amalgamation of three plain factors: Life happens Us nerds are duty-driven, and driven to guilt at personal inefficiencies Tech blogs can become personal journals I don’t think we can do much about the first two, but on the third I think we could certainly contain our urges. I’m a pretty boring guy and, whether or I like it or not, I have an unspoken duty to protect the world from hearing about my unremarkable existence. Nobody cares what kind of sandwich I’m eating. Similarly, if I disappear for a while, it’s unlikely that anybody who happens upon my blog would care why. Rest assured, if I stop posting for a while due to a vasectomy, you will be the first to know. 3. The “At A Conference”, or “Conference Review” Posts I don’t know if I’m like everyone else on this one, but I have never been successfully interested in these posts. It even sounds like a good idea: if I can’t make it to a particular conference (like the KCDC this year), wouldn’t I be interested in a concentrated summary of events? Apparently, no! Within this realm, I’ve never read a post by a blogger that held my interest. What really baffles is is that, for whatever reason, I am genuinely engaged and interested when talking to someone in person regarding the same topic. I have noticed the same phenomenon when hearing about others’ vacations. If someone sends me an email about their vacation, I gloss over it and forget about it quickly. In contrast, if I’m speaking to that individual in person about their vacation, I’m actually interested. I’m unsure why the written medium eradicates the intrigue. I was raised by a roaming pack of friendly wild video games, so that may be a factor. 4. The “Top X Number of Y’s That Z” Posts I’ve seen this one crop up a lot more in the past few of years. Here are some fabricated examples: 5 Easy Ways to Improve Your Code Top 7 Good Habits Programmers Learn From Experience The 8 Things to Consider When Giving Estimates Top 4 Lame Tech Blogging Posts These are attention-grabbing headlines, and I’d assume they rack up hits. In fact, I enjoy a good number of these. But, I’ve been drawn to articles like this just to find an endless list of identically formatted posts on the blog’s archive sidebar. Often times these posts have overlapping topics, too. These types of posts give the impression that the author has given thought to prioritize and organize the points as a result of a comprehensive consideration of a particular topic. Did the author really weigh all the possibilities when identifying the “Top 4 Lame Tech Blogging Patterns”? Unfortunately, probably not. What a tool. To reiterate, I still enjoy the format, but I feel it is abused. Nowadays, I’m pretty skeptical when approaching posts in this format. If these trends continue, my brain will filter these blog posts out just as effectively as it ignores the encroaching “do xxx with this one trick” advertisements. Conclusion To active blog readers, I hope my guide has served you precious time in being able to identify lame blog posts at a glance. Save time and energy by skipping over the chaff of the internet! And if you author a blog, perhaps my insight will help you to avoid the occasional urge to produce these needless filler posts.

    Read the article

  • Finding the problem on a partially succeeded build

    - by Martin Hinshelwood
    Now that I have the Build failing because of a genuine bug and not just because of a test framework failure, lets see if we can trace through to finding why the first test in our new application failed. Lets look at the build and see if we can see why there is a red cross on it. First, lets open that build list. On Team Explorer Expand your Team Project Collection | Team Project and then Builds. Double click the offending build. Figure: Opening the Build list is a key way to see what the current state of your software is.   Figure: A test is failing, but we can now view the Test Results to find the problem      Figure: You can quite clearly see that the test has failed with “The device is not ready”. To me the “The Device is not ready” smacks of a System.IO exception, but it passed on my local computer, so why not on the build server? Its a FaultException so it is most likely coming from the Service and not the client, so lets take a look at the client method that the test is calling: bool IProfileService.SaveDefaultProjectFile(string strComputerName) { ProjectFile file = new ProjectFile() { ProjectFileName = strComputerName + "_" + System.DateTime.Now.ToString("yyyyMMddhhmmsss") + ".xml", ConnectionString = "persist security info=False; pooling=False; data source=(local); application name=SSW.SQLDeploy.vshost.exe; integrated security=SSPI; initial catalog=SSWSQLDeployNorthwindSample", DateCreated = System.DateTime.Now, DateUpdated = System.DateTime.Now, FolderPath = @"C:\Program Files\SSW SQL Deploy\SampleData\", IsComplete=false, Version = "1.3", NewDatabase = true, TimeOut = 5, TurnOnMSDE = false, Mode="AutomaticMode" }; string strFolderPath = "D:\\"; //LocalSettings.ProjectFileBasePath; string strFileName = strFolderPath + file.ProjectFileName; try { using (FileStream fs = new FileStream(strFileName, FileMode.Create)) { DataContractSerializer serializer = new DataContractSerializer(typeof(ProjectFile)); using (XmlDictionaryWriter writer = XmlDictionaryWriter.CreateTextWriter(fs)) { serializer.WriteObject(writer, file); } } } catch (Exception ex) { //TODO: Log the exception throw ex; return false; } return true; } Figure: You can see on lines 9 and 18 that there are calls being made to specific folders and disks. What is wrong with this code? What assumptions mistakes could the developer have made to make this look OK: That every install would be to “C:\Program Files\SSW SQL Deploy” That every computer would have a “D:\\” That checking in code at 6pm because the had to go home was a good idea. lets solve each of these problems: We are in a web service… lets store data within the web root. So we can call “Server.MapPath(“~/App_Data/SSW SQL Deploy\SampleData”) instead. Never reference an explicit path. If you need some storage for your application use IsolatedStorage. Shelve your code instead. What else could have been done? Code review before check-in – The developer should have shelved their code and asked another dev to look at it. Use Defensive programming – Make sure that any code that has the possibility of failing has checks. Any more options? Let me know and I will add them. What do we do? The correct things to do is to add a Bug to the backlog, but as this is probably going to be fixed in sprint, I will add it directly to the sprint backlog. Right click on the failing test Select “Create Work Item | Bug” Figure: Create an associated bug to add to the backlog. Set the values for the Bug making sure that it goes into the right sprint and Area. Make your steps to reproduce as explicit as possible, but “See test” is valid under these circumstances.   Figure: Add it to the correct Area and set the Iteration to the Area name or the Sprint if you think it will be fixed in Sprint and make sure you bring it up at the next Scrum Meeting. Note: make sure you leave the “Assigned To” field blank as in Scrum team members sign up for work, you do not give it to them. The developer who broke the test will most likely either sign up for the bug, or say that they are stuck and need help. Note: Visual Studio has taken care of associating the failing test with the Bug. Save… Technorati Tags: WCF,MSTest,MSBuild,Team Build 2010,Team Test 2010,Team Build,Team Test

    Read the article

  • Initial Review - Mastering Unreal Technology I: Introduction to Level Design with Unreal Engine 3

    - by Matt Christian
    Recently I purchased 3 large volumes on using the Unreal 3 Engine to create levels and custom games.  This past weekend I cracked the spine of the first and started reading.  Here are my early impressions (I'm ~250 pages into it, with appendices it's about 900). Pros Interestingly, the book starts with an overview of the Unreal engines leading up to Unreal 3 (including Gears of War) and follows with some discussion on planning a mod and what goes into the game development process.  This is nice for an intro to the book and is much preferred rather than a simple chapter detailing what is on the included CD, how to install and setup UnrealEd, etc...  While the chapter on Unreal history and planning can be considered 'fluff', it's much less 'fluffy' than most books provide. I need to mention one thing here that is pretty crucial in the way I'm going to continue reviewing this book.  Most technical books like this are used as a shelf reference; as a thick volume you use for looking up techniques every now and again.  Even so, I prefer reading from cover to cover, including chapters I may already be knowledgable on (I'm sure this is typical for most people).  If there was a chapter on installing UnrealEd (the previously mentioned 'fluff'), I would probably force myself to read it, even though I've installed the game and engine multiple times on different systems. Chapter 3 is where we really get to the introduction piece of UnrealEd, creating your first basic level.  This large chapter details creating two small rooms, adding static meshes, adding lighting, creating and adding particle emitters, creating a door that animates with Unreal Matinee and Kismet, static meshes with physics, and other little additions to make your level look less beginner.  This really is a chapter that overviews the entire rest of the book, as each chapter following details the creation and intermediate usages of Static Meshes, Materials, Lighting, etc... One other very nice part to this book is the way the tutorials are setup.  Each tutorial builds off the previous and all are step-by-step.  If you haven't completed one yet, you can find all the starting files on the CD that comes with the book. Cons While the description of the overview chapter (Chapter 3) is fresh in your mind, let me start the cons by saying this chapter is setup extremely confusing for the noob.  At one point, you end up creating a door mesh and setting it up as a InteropMesh so that it is ready to be animated, only to switch to particles and spend a good portion of time working on a different piece of the level.  Yes, this is actually how I develop my levels (jumping back and forth), though it's very odd for a book to jump out of sequence. The next item might be a positive or a negative depending on your skill level with UnrealEd.  Most of the introduction to the editor layout is found in one of the Appendices instead of before Chapter 3.  For new readers, this might lead to confusion as Appendix A would typically be read between Chapter 2 and 3.  However, this is a positive for those with some experience in UnrealEd as they don't have to force themselves through a 'learn every editor button' chapter.  I'm listing this in the Cons section as the book is 'Introduction to...' and is probably going to be directed toward a lot of very beginner developers. Finally, there's a lack of general description to a lot of the underlying engine and what each piece in UnrealEd is or does.  Sometimes you'll be performing Tutorial after Tutorial with barely a paragraph in between describing ANY of what you've just done.  Tutorial 1.1 Step 6 says to press Button X, so you do.  But why?  This is in part a problem with the structure of the tutorials rather than the content of the book.  Since the tutorials are so focused on a step-by-step (or procedural) description of a process, you learn the process and not why you're doing that.  For example, you might learn how to size a material to a surface, but will only learn what buttons to press and not what each one does. This becomes extremely apparent in the chapter on Static Meshes as most of the chapter is spent in 3D Studio Max.  Since there are books on 3DSM and modelling, the book really only tells you the steps and says to go grab a book on modelling if you're really interested in 3DSM.  Again, I've learned the process to develop my own meshes in 3DSM, but I don't know the why behind the steps. Conclusion So far the book is very good though I would have a hard time recommending it to a complete beginner.  I would suggest anyone looking at this book (obviously including the other 2, more advanced volumes) to pick up a copy of UDK or Unreal 3 (available online or via download services such as Steam) and watch some online tutorials and play with it first.  You'll find plenty of online videos available that were created by the authors and may suit as a better introduction to the editor.

    Read the article

  • How to Automate your Database Documentation

    - by Jonathan Hickford
    In my previous post, “Automating Deployments with SQL Compare command line” I looked at how teams can automate the deployment and post deployment validation of SQL Server databases using the command line versions of Red Gate tools. In this post I’m looking at another use for the command line tools, namely using them to generate up-to-date documentation with every database change. There are many reasons why up-to-date documentation is valuable. For example when somebody new has to work on or administer a database for the first time, or when a new database comes into service. Having database documentation reduces the risks of making incorrect decisions when making changes. Documentation is very useful to business intelligence analysts when writing reports, for example in SSRS. There are a couple of great examples talking about why up to date documentation is valuable on this site:  Database Documentation – Lands of Trolls: Why and How? and Database Documentation Using SQL Doc. The short answer is that it can save you time and reduce risk when you need that most! SQL Doc is a fast simple tool that automatically generates database documentation. It can create documents in HTML, Word or pdf files. The documentation contains information about object definitions and dependencies, along with any other information you want to associate with each object. The SQL Doc GUI, which is included in Red Gate’s SQL Developer Bundle and SQL Toolbelt, allows you to add additional notes to objects, and customise which objects are shown in the docs.  These settings can be saved as a .sqldoc project file. The SQL Doc command line can use this project file to automatically update the documentation every time the database is changed, ensuring that documentation that is always up to date. The simplest way to keep documentation up to date is probably to use a scheduled task to run a script every day. However if you have a source controlled database, or are using a Continuous Integration (CI) server or a build server, it may make more sense to use that instead. If  you’re using SQL Source Control or SSDT Database Projects to help version control your database, you can automatically update the documentation after each change is made to the source control repository that contains your database. To get this automation in place,  you can use the functionality of a Continuous Integration (CI) server, which can trigger commands to run when a source control repository has changed. A CI server will also capture and save the documentation that is created as an artifact, so you can always find the exact documentation for a specific version of the database. This forms an always up to date data dictionary. If you don’t already have a CI server in place there are several you can use, such as the free open source Jenkins or the free starter editions of TeamCity. I won’t cover setting these up in this article, but there is information about using CI servers for automating database tasks on the Red Gate Database Delivery webpage. You may be interested in Red Gate’s SQL CI utility (part of the SQL Automation Pack) which is an easy way to update a database with the latest changes from source control. The PowerShell example below shows how to create the documentation from a database. That database might be your integration database or a shared development database that is always up to date with the latest changes. $serverName = "server\instance" $databaseName = "databaseName" # If you want to document multiple databases use a comma separated list $userName = "username" $password = "password" # Path to SQLDoc.exe $SQLDocPath = "C:\Program Files (x86)\Red Gate\SQL Doc 3\SQLDoc.exe" $arguments = @( "/server:$($serverName)", "/database:$($databaseName)", "/username:$($userName)", "/password:$($password)", "/filetype:html", "/outputfolder:.", # "/project:$args[0]", # If you already have a .sqldoc project file you can pass it as an argument to this script. Values in the project will be overridden with any options set on the command line "/name:$databaseName Report", "/copyrightauthor:$([Environment]::UserName)" ) write-host $arguments & $SQLDocPath $arguments There are several options you can set on the command line to vary how your documentation is created. For example, you can document multiple databases or exclude certain types of objects. In the example above, we set the name of the report to match the database name, and use the current Windows user as the documentation author. For more examples of how you can customise the report from the command line please see the SQL Doc command line documentation If you already have a .sqldoc project file, or wish to further customise the report by including or excluding specific objects, you can use this project on the command line. Any settings you specify on the command line will override the defaults in the project. For details of what you can customise in the project please see the SQL Doc project documentation. In the example above, the line to use a project is commented out, but you can uncomment this line and then pass a path to a .sqldoc project file as an argument to this script.  Conclusion Keeping documentation about your databases up to date is very easy to set up using SQL Doc and PowerShell. By using a CI server to run this process you can trigger the documentation to be run on every change to a source controlled database, and keep historic documentation available. If you are considering more advanced database automation, e.g. database unit testing, change script generation, deploying to large numbers of targets and backup/verification, please email me at [email protected] for further script samples or if you have any questions.

    Read the article

  • SQL Developer Data Modeler v3.3 Early Adopter: Collaborative Design via Excel?

    - by thatjeffsmith
    As you may have heard last week, we have a new version of Oracle SQL Developer Data Modeler now available as an Early Adopter release. Version 3.3 has quite a few new features and I’ll be previewing them here. Today’s topic is our new Excel integration. It builds off of last week’s lesson: Search, so you may want to go read that first. They say it takes a village to raise a child. I say it takes a team to build a data model. You have your techie folks, your business folks, your in-betweeners, and your database geeks. Who gets to define how customers are represented and stored in your database? That data lives forever, so you better get it right from the beginning, or you’ll be living in a hacker’s paradise for years to come. Lots of good rantings, ravings, and advice on this topic in general on Karen Lopez’s (@datachick) blog. But let’s say you are the primary modeler on a project. You dutifully interview the business folks for their requirements. You sit down and start to model and think you’re pretty close. Now you need someone to confirm your assumptions and provide some feedback. Do you send your model over? Take a screenshot and blow it up on a whiteboard? Export to HTML and let them take a magic marker to their monitors? Or maybe you bite the bullet and install your modeling software on their desktops and take the hours or days required to train them up on how to use the the tool. Wouldn’t it be nice if they could just mark up their corrections in Excel and let you suck the updates back in? This is what we have started to build in Oracle SQL Developer Data Modeler. Let’s say you have a new table called ‘UT_STARTUPS.’ It looks a little something like this: A table in Oracle SQL Developer Data Modeler What I would like to do is have my team or co-worker review how I have defined those columns. Perhaps TIMESTAMP is overkill or maybe the column names themselves aren’t up to snuff. What I am going to do is now search for all the columns in my table, then export that to Excel. So do a search for UT_STARTUPS. Search, filter, then Report With the filter set to ‘Columns,’ if I do a report I’ll be only getting the columns that are resolving to my search term. So as long as my table name is unique in the model, I should get what I’m looking for. Here’s what I see when I click on the Report button: XLS or XLSX, either format is just fine I want to decide how the Column data is exported to Excel though, so I’m going to create a report template that I can use going forward. So click the ‘Manage’ button and setup a new template. I’m going to call mine ‘CollaborativeDevelopment.’ The templates allow me to define what properties are included in the reports. Once this is set, I’ll have the XLS file generated, and get to work Now let the Excel junkies do their stuff Note that not ALL of the report properties are update-able (yes, I made up a new word there) via Excel. We’ll have the full list of properties documented going forward, but in my Excel sheet, note that I can’t change the table name or the data types for the columns. I’m going to update some column names and supply ‘nice’ comments so the database users know what’s what. Here’s my input for the designer/architect/database dude: Be kind, please rew…use comments. Save the file, email it back to your modeler. Update the model from Excel That’s right, it’s a right mouse click from your model in the tree If everything goes right, you’ll see a nice confirmation message: It’s alive! Another to-do item on tap – making this dialog more informative. We’ll be showing exactly what in your model was updated from Excel. Let’s take another look at the model now Voila! Why are we doing this again? The goal is to reduce the number of round-trips from the modeler and the business process owner. One is used to working with Excel – why not allow them to mark up their changes in the tool they already know? This is an early adopter release and I anticipate this feature getting a good bit of tuning up before we release. Why don’t you download 3.3, give it a whirl, and let us know what you think?

    Read the article

  • The ugly evolution of running a background operation in the context of an ASP.NET app

    - by Jeff
    If you’re one of the two people who has followed my blog for many years, you know that I’ve been going at POP Forums now for over almost 15 years. Publishing it as an open source app has been a big help because it helps me understand how people want to use it, and having it translated to six languages is pretty sweet. Despite this warm and fuzzy group hug, there has been an ugly hack hiding in there for years. One of the things we find ourselves wanting to do is hide some kind of regular process inside of an ASP.NET application that runs periodically. The motivation for this has always been that a lot of people simply don’t have a choice, because they’re running the app on shared hosting, or don’t otherwise have access to a box that can run some kind of regular background service. In POP Forums, I “solved” this problem years ago by hiding some static timers in an HttpModule. Truthfully, this works well as long as you don’t run multiple instances of the app, which in the cloud world, is always a possibility. With the arrival of WebJobs in Azure, I’m going to solve this problem. This post isn’t about that. The other little hacky problem that I “solved” was spawning a background thread to queue emails to subscribed users of the forum. This evolved quite a bit over the years, starting with a long running page to mail users in real-time, when I had only a few hundred. By the time it got into the thousands, or tens of thousands, I needed a better way. What I did is launched a new thread that read all of the user data in, then wrote a queued email to the database (as in, the entire body of the email, every time), with the properly formatted opt-out link. It was super inefficient, but it worked. Then I moved my biggest site using it, CoasterBuzz, to an Azure Website, and it stopped working. So let’s start with the first stupid thing I was doing. The new thread was simply created with delegate code inline. As best I can tell, Azure Websites are more aggressive about garbage collection, because that thread didn’t queue even one message. When the calling server response went out of scope, so went the magic background thread. Duh, all I had to do was move the thread to a private static variable in the class. That’s the way I was able to keep stuff running from the HttpModule. (And yes, I know this is still prone to failure, particularly if the app recycles. For as infrequently as it’s used, I have not, however, experienced this.) It was still failing, but this time I wasn’t sure why. It would queue a few dozen messages, then die. Running in Azure, I had to turn on the application logging and FTP in to see what was going on. That led me to a helper method I was using as delegate to build the unsubscribe links. The idea here is that I didn’t want yet another config entry to describe the base URL, appended with the right path that would match the routing table. No, I wanted the app to figure it out for you, so I came up with this little thing: public static string FullUrlHelper(this Controller controller, string actionName, string controllerName, object routeValues = null) { var helper = new UrlHelper(controller.Request.RequestContext); var requestUrl = controller.Request.Url; if (requestUrl == null) return String.Empty; var url = requestUrl.Scheme + "://"; url += requestUrl.Host; url += (requestUrl.Port != 80 ? ":" + requestUrl.Port : ""); url += helper.Action(actionName, controllerName, routeValues); return url; } And yes, that should have been done with a string builder. This is useful for sending out the email verification messages, too. As clever as I thought I was with this, I was using a delegate in the admin controller to format these unsubscribe links for tens of thousands of users. I passed that delegate into a service class that did the email work: Func<User, string> unsubscribeLinkGenerator = user => this.FullUrlHelper("Unsubscribe", AccountController.Name, new { id = user.UserID, key = _profileService.GetUnsubscribeHash(user) }); _mailingListService.MailUsers(subject, body, htmlBody, unsubscribeLinkGenerator); Cool, right? Actually, not so much. If you look back at the helper, this delegate then will depend on the controller context to learn the routing and format for the URL. As you might have guessed, those things were turning null after a few dozen formatted links, when the original request to the admin controller went away. That this wasn’t already happening on my dedicated server is surprising, but again, I understand why the Azure environment might be eager to reclaim a thread after servicing the request. It’s already inefficient that I’m building the entire email for every user, but going back to check the routing table for the right link every time isn’t a win either. I put together a little hack to look up one generic URL, and use that as the basis for a string format. If you’re wondering why I didn’t just use the curly braces up front, it’s because they get URL formatted: var baseString = this.FullUrlHelper("Unsubscribe", AccountController.Name, new { id = "--id--", key = "--key--" }); baseString = baseString.Replace("--id--", "{0}").Replace("--key--", "{1}"); Func unsubscribeLinkGenerator = user => String.Format(baseString, user.UserID, _profileService.GetUnsubscribeHash(user)); _mailingListService.MailUsers(subject, body, htmlBody, unsubscribeLinkGenerator); And wouldn’t you know it, the new solution works just fine. It’s still kind of hacky and inefficient, but it will work until this somehow breaks too.

    Read the article

  • XNA Notes 005

    - by George Clingerman
    Another week and another crazy amount of activity going on in the XNA community. I’m fairly certain I missed over half of it. In fact, if I am missing things, make sure to email me and I’ll try and make sure I catch it next week! ([email protected]). Also, if you’ve got any advice, things you like/don’t like about the way these XNA Notes are going let me know. I always appreciate feedback (currently spammers are leaving me the nicest comments so you guys have work to do!) Without further ado, here’s this week’s notes! Time Critical XNA News The XNA Team Blob reminds us that February 7th is the last day to submit XNA 3.1 games to peer review! http://blogs.msdn.com/b/xna/archive/2011/01/31/7-days-left-to-submit-xna-gs-3-1-games-on-app-hub.aspx XNA MVPS Chris Williams kicks off the marketing campaign for our book http://geekswithblogs.net/cwilliams/archive/2011/01/28/143680.aspx Catalin Zima posts the comparison cheat sheet for why Angry Birds is different than Chickens Can’t Fly http://www.amusedsloth.com/2011/02/comparison-cheat-sheet-for-chickens-cant-fly-and-angry-birds/ Jim Perry congratulates the developers selected by Game Developer Magazine for Best Xbox LIVE Indie Games of 2010 http://machxgames.com/blog/?p=24 @NemoKrad posts his XNAKUUG talks for all to enjoy http://twitter.com/NemoKrad/statuses/33142362502864896 http://xna-uk.net/blogs/randomchaos/archive/2011/02/03/xblig-uk-2011-january-amp-february-talk.aspx George  (that’s me!) preps for his XNA talk coming up on the 8th http://twitter.com/clingermangw/statuses/32669550554124288 http://www.portlandsilverlight.net/Meetings/Details/15 XNA Developers FireFly posts the last tutorial in his XNA Tower Defense tutorial series http://forums.create.msdn.com/forums/p/26442/451460.aspx#451460 http://xnatd.blogspot.com/2011/01/tutorial-14-polishing-game.html @fredericmy posts the main difference when porting a game from Windows Phone 7 to Xbox 360 http://fairyengine.blogspot.com/2011/01/main-differences-when-porting-game-from.html @ElementCy creates a pretty rad video of a MineCraft type terrain created using XNA http://www.youtube.com/watch?v=Waw1f7wnl9I Andrew Russel gets the first XNA badge on gamedev.stackexchange http://twitter.com/_AndrewRussell/statuses/32322877004972032 http://gamedev.stackexchange.com/badges?tab=tags And his funding for ExEn has passed $7000 only $3000 to go http://twitter.com/_AndrewRussell/statuses/33042412804771840 Subodh Pushpak blogs about his Windows Phone 7 XNA talk http://geekswithblogs.net/subodhnpushpak/archive/2011/02/01/windows-phone-7-silverlight--xna-development-talk.aspx Slyprid releases the latest version of Transmute and needs more people to test http://twitter.com/slyprid/statuses/32452488418299904 http://forgottenstarstudios.com/ SpynDoctorGames celebrates the 1 year anniversary of Your Doodles Are Bugged! Congrats! http://twitter.com/SpynDoctorGames/statuses/32511689068908544 Noogy (creator of Dust the Elysian Tail) prepares his conversion to XNA 4.0 http://twitter.com/NoogyTweet/statuses/32522008449253376 @philippedasilva posts about the Indiefreaks Game Framework v0.2.0.0 Input management system http://twitter.com/philippedasilva/statuses/32763393957957632 http://indiefreaks.com/2011/02/02/behind-smart-input-system-feature/ Mommy’s Best Games debates what to do about High Scores with their new update http://mommysbest.blogspot.com/2011/02/high-score-shake-up.html @BinaryTweedDeej want to know if there’s anything the community needs to make XNA games for the PC. Give him some feedback! http://twitter.com/BinaryTweedDeej/status/32895453863354368 @mikebmcl promises to write us all a book (I can’t wait to read it!) http://twitter.com/mikebmcl/statuses/33206499102687233 @werezompire is going to live, LIVE, thanks to all the generosity and support from the community! http://twitter.com/werezompire/statuses/32840147644977153 Xbox LIVE Indie Games (XBLIG) Making money in Xbox 360 indie game development. Is it possible? http://www.bitmob.com/articles/making-money-in-xbox-360-indie-game-development-is-it-possible @AlejandroDaJ posts some thoughts abut the bitmob article http://twitter.com/AlejandroDaJ/statuses/31068552165330944 http://www.apathyworks.com/blog/view.php?id=00215 Kobun gets my respect as an XBLIG champion. I’m not sure who Kobun is, but if you’ve every read through the comment sections any time Kotaku writes about XBLIGs you’ll see a lot of confusion, disinformation in there. Kobun has been waging a secret war battling that lack of knowledge and he does it well. Also he’s running a pretty kick ass site for Xbox LIVE Indie Game reviews http://xboxindies.teamkobun.com/ @radiangames releases his last Xbox LIVE Indie Game...for now http://bit.ly/gMK6lE Playing Avaglide with the Kinect controller http://www.youtube.com/watch?v=UqAYbHww53o http://www.joystiq.com/2011/01/30/kinect-hacks-take-to-the-skies-with-avaglide/ Luke Schneider of Radiangames interviewed in Edge magazine http://www.next-gen.biz/features/radiangames-venture Digital Quarters posts thoughts on why XBLIG’s online requirement kills certain genres http://digitalquarters.blogspot.com/2011/02/thoughts-why-xbligs-online-requirement.html Mommy’s Best Games shares the news that several XBLIGs were featured in the March 2011 issue of Famitsu 360 http://forums.create.msdn.com/forums/p/33455/451487.aspx#451487 NaviFairy continues with his Indie-Game-A-Day http://gaygamer.net/2011/02/indie_game_a_day_epic_dungeon.html http://gaygamer.net/2011/02/indie_game_a_day_break_limit_r.html and more every day...that’s kind of the point! Keep your eye on this series! VVGTV continues with it’s awesome reviews/promotions for XBLIGs http://vvgtv.com/ http://vvgtv.com/2011/02/03/iredia-atrams-secret-xblig-review-2/ http://vvgtv.com/2011/02/02/poopocalypse-coming-soon-to-xblig/ ….and even more, you get the point. Magicka is an Indie Game doing really well on Steam AND it’s made using XNA http://www.magickagame.com/ http://twitter.com/Magickagame/statuses/32712762580799488 GameMarx reviews Antipole http://www.gamemarx.com/reviews/73/antipole-is-vvvvvvery-good.aspx Armless Octopus review Alpha Squad http://www.armlessoctopus.com/2011/01/28/xbox-indie-review-alpha-squad/ An interesting article about Kodu that Jim Perry found http://twitter.com/MachXGames/statuses/32848044105924608 http://www.develop-online.net/news/36915/10-year-old-Jordan-makes-games-The-UK-needs-more-like-her XNA Game Development Sgt. Conker posts about the Natur beta, a new book and whether you can make money with XBLIG http://www.sgtconker.com/ http://www.sgtconker.com/2011/01/a-new-book-on-the-block-and-a-new-natur-beta/ http://www.sgtconker.com/2011/01/making-money-in-xbox-360-indie-game-development-is-it-possible/ Tips for setting up SVN http://bit.ly/fKxgFh @bsimser found tons of royalty free music and soundfx for your XNA Games http://twitter.com/bsimser/statuses/31426632933711872 Post on the new features in the next Sunburn Editor http://www.synapsegaming.com/blogs/fivesidedbarrel/archive/2011/01/28/new-editor-features-prefabs-components-and-more.aspx @jasons_novaleaf posts source code for light pre-pass optimizations for #xna http://twitter.com/jasons_novaleaf/statuses/33348855403642880 http://jcoluna.wordpress.com/2011/02/01/xna-4-0-light-pre-pass-optimization-round-one/ I’ve been learning about doing an A.I. for turn based games and this article was a great resource. http://www.gamasutra.com/view/feature/1535/designing_ai_algorithms_for_.php?print=1

    Read the article

  • What Did You Do? is a Bad Question

    - by Ajarn Mark Caldwell
    Brian Moran (blog | Twitter) did a great presentation today for the PASS Professional Development Virtual Chapter on The Art of Questions.  One of the points that Brian made was that there are good questions and bad (or at least not-as-good) questions.  Good questions tend to open-up the conversation and engender positive reactions (perhaps even trust and respect) between the participants; and bad questions tend to close-down a conversation either through the narrow list of possible responses (e.g. strictly Yes/No) or through the negative reactions they can produce.  And this explains why I so frequently had problems troubleshooting real-time problems with users in the past.  I’ll explain that in more detail below, but before we go on, let me recommend that you watch the recording of Brian’s presentation to learn why the question Why is often problematic in the U.S. and yet we so often resort to it. For a short portion (3 years) of my career, I taught basic computer skills and Office applications in an adult vocational school, and this gave me ample opportunity to do live troubleshooting of user challenges with computers.  And like many people who ended up in computer related jobs, I also have had numerous times where I was called upon by less computer-savvy individuals to help them with some challenge they were having, whether it was part of my job or not.  One of the things that I noticed, especially during my time as a teacher, was that when I was helping somebody, typically the first question I would ask them was, “What did you do?”  This seemed to me like a good way to start my detective work trying to figure out what happened, what went wrong, how to fix it, and how to help the person avoid it again in the future.  I always asked it in a polite tone of voice as I was just trying to gather the facts before diving in deeper.  However; 99.999% of the time, I always got the same answer, “Nothing!”  For a long time this frustrated me because (remember I’m in detective mode at that point) I knew it could not possibly be true.  They HAD to have done SOMETHING…just tell me what were the last actions you took before this problem presented itself.  But no, they always stuck with “Nothing”.  At which point, with frustration growing, and not a little bit of disdain for their lack of helpfulness, I would usually ask them to move aside while I took over their machine and got them out of whatever they had gotten themselves into.  After a while I just grew used to the fact that this was the answer I would usually receive, but I always kept asking because for the .001% of the people who would actually tell me, I could then help them understand what went wrong and how to avoid it in the future. Now, after hearing Brian’s talk, I understand what the problem was.  Even though I meant to just be in an information gathering mode, the words I was using, “What did YOU do?” have such a strong negative connotation that people would instinctively go into defense-mode and stop sharing information that might make them look bad.  Many of them probably were not even consciously aware that they had gone on the defensive, but the self-preservation instinct, especially self-preservation of the ego, is so strong that people would end up there without even realizing it. So, if “What did you do” is a bad question, what would have been better?  Well, one suggestion that Brian makes in his talk is something along the lines of, “Can you tell me what led up to this?” or “what was happening on the computer right before this came up?”  It’s subtle, but the point is to take the focus off of the person and their behavior; instead depersonalizing it and talk about events from more of a 3rd-party observer point of view.  With this approach, people will be more likely to talk about what the computer did and what they did in response to it without feeling the interrogation spotlight is on them.  They are also more likely to mention other events that occurred around the same time that may or may not be related, but which could certainly help you troubleshoot a larger problem if it is not just user actions.  And that is the ultimate goal of your asking the questions.  So yes, it does matter how you ask the question; and there are such things as good questions and bad questions.  Excellent topic Brian!  Thanks for getting the thinking gears churning! (Cross-posted to the Professional Development Virtual Chapter blog.)

    Read the article

  • Know more about Cache Buffer Handle

    - by Liu Maclean(???)
    ??????«latch free:cache buffer handles???SQL????»?????cache buffer handle latch?????,?????????: “?????pin?buffer header???????buffer handle,??buffer handle?????????cache buffer handles?,??????cache buffer handles??????,???????cache???buffer handles,?????(reserved set)?????????????_db_handles_cached(???5)???,?????????????????SQL??????????????????????,????pin??????,????????handle,?????????5?cached buffer handles???handle????????????????,Oracle?????????????????pin?”????“?buffer,????????????????handle???db_block_buffers/processes,????_cursor_db_buffers_pinned???????cache buffer handles?????,??????,????????????SQL,????cache?buffer handles?????????,??????????????,???????????/?????” ????T.ASKMACLEAN.COM????,??????cache Buffer handle?????: cache buffer handle ??: ------------------------------ | Buffer state object | ------------------------------ | Place to hang the buffer | ------------------------------ | Consistent Get? | ------------------------------ | Proc Owning SO | ------------------------------ | Flags(RIR) | ------------------------------ ???? cache buffer handle SO: 70000046fdfe530, type: 24, owner: 70000041b018630, flag: INIT/-/-/0×00(buffer) (CR) PR: 70000048e92d148 FLG: 0×500000lock rls: 0, class bit: 0kcbbfbp: [BH: 7000001c7f069b0, LINK: 70000046fdfe570]where: kdswh02: kdsgrp, why: 0BH (7000001c7f069b0) file#: 12 rdba: 0×03061612 (12/398866) class: 1 ba: 7000001c70ee000set: 75 blksize: 8192 bsi: 0 set-flg: 0 pwbcnt: 0dbwrid: 2 obj: 66209 objn: 48710 tsn: 6 afn: 12hash: [700000485f12138,700000485f12138] lru: [70000025af67790,700000132f69ee0]lru-flags: hot_bufferckptq: [NULL] fileq: [NULL] objq: [700000114f5dd10,70000028bf5d620]use: [70000046fdfe570,70000046fdfe570] wait: [NULL]st: SCURRENT md: SHR tch: 0flags: affinity_lockLRBA: [0x0.0.0] HSCN: [0xffff.ffffffff] HSUB: [65535]where: kdswh02: kdsgrp, why: 0 # Example:#   (buffer) (CR) PR: 37290 FLG:    0#   kcbbfbp    : [BH: befd8, LINK: 7836c] (WAITING) Buffer handle (X$KCBBF) kernel cache, buffer buffer_handles Query x$kcbbf  – lists all the buffer handles ???? _db_handles             System-wide simultaneous buffer operations ,no of buffer handles_db_handles_cached      Buffer handles cached each process , no of processes  default 5_cursor_db_buffers_pinned  additional number of buffers a cursor can pin at once_session_kept_cursor_pins       Number of cursors pins to keep in a session When a buffer is pinned it is attached to buffer state object. ??? ???????? cache buffer handles latch ? buffer pin???: SESSION A : SQL> select * from v$version; BANNER ---------------------------------------------------------------- Oracle Database 10g Enterprise Edition Release 10.2.0.5.0 - 64bi PL/SQL Release 10.2.0.5.0 - Production CORE    10.2.0.5.0      Production TNS for Linux: Version 10.2.0.5.0 - Production NLSRTL Version 10.2.0.5.0 - Production SQL> create table test_cbc_handle(t1 int); Table created. SQL> insert into test_cbc_handle values(1); 1 row created. SQL> commit; Commit complete. SQL> select rowid from test_cbc_handle; ROWID ------------------ AAANO6AABAAAQZSAAA SQL> select * from test_cbc_handle where rowid='AAANO6AABAAAQZSAAA';         T1 ----------          1 SQL> select addr,name from v$latch_parent where name='cache buffer handles'; ADDR             NAME ---------------- -------------------------------------------------- 00000000600140A8 cache buffer handles SQL> select to_number('00000000600140A8','xxxxxxxxxxxxxxxxxxxx') from dual; TO_NUMBER('00000000600140A8','XXXXXXXXXXXXXXXXXXXX') ----------------------------------------------------                                           1610694824 ??cache buffer handles????parent latch ??? child latch ???SESSION A hold ??????cache buffer handles parent latch ???? oradebug call kslgetl ??, kslgetl?oracle??get latch??? SQL> oradebug setmypid; Statement processed. SQL> oradebug call kslgetl 1610694824 1; Function returned 1 ?????SESSION B ???: SQL> select * from v$latchholder;        PID        SID LADDR            NAME                                                                   GETS ---------- ---------- ---------------- ---------------------------------------------------------------- ----------         15        141 00000000600140A8 cache buffer handles                                                    119 cache buffer handles latch ???session A hold??,????????acquire cache buffer handle latch SQL> select * from test_cbc_handle where rowid='AAANO6AABAAAQZSAAA';         T1 ----------          1 ?????Server Process?????? read buffer, ????????"_db_handles_cached", ??process?cache 5? cache buffer handle ??"_db_handles_cached"=0,?process????5????cache buffer handle , ???? process ???pin buffer,???hold cache buffer handle latch??????cache buffer handle SQL> alter system set "_db_handles_cached"=0 scope=spfile; System altered. ????? shutdown immediate; startup; session A: SQL> oradebug setmypid; Statement processed. SQL> oradebug call kslgetl 1610694824 1; Function returned 1 session B: select * from test_cbc_handle where rowid='AAANO6AABAAAQZSAAA'; session B hang!! WHY? SQL> oradebug setmypid; Statement processed. SQL> oradebug dump systemstate 266; Statement processed.   SO: 0x11b30b7b0, type: 2, owner: (nil), flag: INIT/-/-/0x00   (process) Oracle pid=22, calls cur/top: (nil)/0x11b453c38, flag: (0) -             int error: 0, call error: 0, sess error: 0, txn error 0   (post info) last post received: 0 0 0               last post received-location: No post               last process to post me: none               last post sent: 0 0 0               last post sent-location: No post               last process posted by me: none     (latch info) wait_event=0 bits=8       holding    (efd=4) 600140a8 cache buffer handles level=3   SO: 0x11b305810, type: 2, owner: (nil), flag: INIT/-/-/0x00   (process) Oracle pid=10, calls cur/top: 0x11b455ac0/0x11b450a58, flag: (0) -             int error: 0, call error: 0, sess error: 0, txn error 0   (post info) last post received: 0 0 0               last post received-location: No post               last process to post me: none               last post sent: 0 0 0               last post sent-location: No post               last process posted by me: none     (latch info) wait_event=0 bits=2         Location from where call was made: kcbzgs:       waiting for 600140a8 cache buffer handles level=3 FBD93353:000019F0    10   162 10005   1 KSL WAIT BEG [latch: cache buffer handles] 1610694824/0x600140a8 125/0x7d 0/0x0 FF936584:00002761    10   144 10005   1 KSL WAIT BEG [latch: cache buffer handles] 1610694824/0x600140a8 125/0x7d 0/0x0 PID=22 holding ??cache buffer handles latch PID=10 ?? cache buffer handles latch, ????"_db_handles_cached"=0 ?? process??????cache buffer handles ??systemstate???? kcbbfbp cache buffer handle??, ?? "_db_handles_cached"=0 ? cache buffer handles latch?hold ?? ????cache buffer handles latch , ??? buffer?pin?????????? session A exit session B: SQL> select * from v$latchholder; no rows selected SQL> insert into test_cbc_handle values(2); 1 row created. SQL> commit; Commit complete. SQL> SQL> select t1,rowid from test_cbc_handle;         T1 ROWID ---------- ------------------          1 AAANPAAABAAAQZSAAA          2 AAANPAAABAAAQZSAAB SQL> select spid,pid from v$process where addr = ( select paddr from v$session where sid=(select distinct sid from v$mystat)); SPID                PID ------------ ---------- 19251                10 ? GDB ? SPID=19215 ?debug , ?? kcbrls ????breakpoint ??? ????release buffer [oracle@vrh8 ~]$ gdb $ORACLE_HOME/bin/oracle 19251 GNU gdb (GDB) Red Hat Enterprise Linux (7.0.1-37.el5) Copyright (C) 2009 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.  Type "show copying" and "show warranty" for details. This GDB was configured as "x86_64-redhat-linux-gnu". For bug reporting instructions, please see: <http://www.gnu.org/software/gdb/bugs/>... Reading symbols from /s01/oracle/product/10.2.0.5/db_1/bin/oracle...(no debugging symbols found)...done. Attaching to program: /s01/oracle/product/10.2.0.5/db_1/bin/oracle, process 19251 Reading symbols from /s01/oracle/product/10.2.0.5/db_1/lib/libskgxp10.so...(no debugging symbols found)...done. Loaded symbols for /s01/oracle/product/10.2.0.5/db_1/lib/libskgxp10.so Reading symbols from /s01/oracle/product/10.2.0.5/db_1/lib/libhasgen10.so...(no debugging symbols found)...done. Loaded symbols for /s01/oracle/product/10.2.0.5/db_1/lib/libhasgen10.so Reading symbols from /s01/oracle/product/10.2.0.5/db_1/lib/libskgxn2.so...(no debugging symbols found)...done. Loaded symbols for /s01/oracle/product/10.2.0.5/db_1/lib/libskgxn2.so Reading symbols from /s01/oracle/product/10.2.0.5/db_1/lib/libocr10.so...(no debugging symbols found)...done. Loaded symbols for /s01/oracle/product/10.2.0.5/db_1/lib/libocr10.so Reading symbols from /s01/oracle/product/10.2.0.5/db_1/lib/libocrb10.so...(no debugging symbols found)...done. Loaded symbols for /s01/oracle/product/10.2.0.5/db_1/lib/libocrb10.so Reading symbols from /s01/oracle/product/10.2.0.5/db_1/lib/libocrutl10.so...(no debugging symbols found)...done. Loaded symbols for /s01/oracle/product/10.2.0.5/db_1/lib/libocrutl10.so Reading symbols from /s01/oracle/product/10.2.0.5/db_1/lib/libjox10.so...(no debugging symbols found)...done. Loaded symbols for /s01/oracle/product/10.2.0.5/db_1/lib/libjox10.so Reading symbols from /s01/oracle/product/10.2.0.5/db_1/lib/libclsra10.so...(no debugging symbols found)...done. Loaded symbols for /s01/oracle/product/10.2.0.5/db_1/lib/libclsra10.so Reading symbols from /s01/oracle/product/10.2.0.5/db_1/lib/libdbcfg10.so...(no debugging symbols found)...done. Loaded symbols for /s01/oracle/product/10.2.0.5/db_1/lib/libdbcfg10.so Reading symbols from /s01/oracle/product/10.2.0.5/db_1/lib/libnnz10.so...(no debugging symbols found)...done. Loaded symbols for /s01/oracle/product/10.2.0.5/db_1/lib/libnnz10.so Reading symbols from /usr/lib64/libaio.so.1...(no debugging symbols found)...done. Loaded symbols for /usr/lib64/libaio.so.1 Reading symbols from /lib64/libdl.so.2...(no debugging symbols found)...done. Loaded symbols for /lib64/libdl.so.2 Reading symbols from /lib64/libm.so.6...(no debugging symbols found)...done. Loaded symbols for /lib64/libm.so.6 Reading symbols from /lib64/libpthread.so.0...(no debugging symbols found)...done. [Thread debugging using libthread_db enabled] Loaded symbols for /lib64/libpthread.so.0 Reading symbols from /lib64/libnsl.so.1...(no debugging symbols found)...done. Loaded symbols for /lib64/libnsl.so.1 Reading symbols from /lib64/libc.so.6...(no debugging symbols found)...done. Loaded symbols for /lib64/libc.so.6 Reading symbols from /lib64/ld-linux-x86-64.so.2...(no debugging symbols found)...done. Loaded symbols for /lib64/ld-linux-x86-64.so.2 Reading symbols from /lib64/libnss_files.so.2...(no debugging symbols found)...done. Loaded symbols for /lib64/libnss_files.so.2 0x00000035c000d940 in __read_nocancel () from /lib64/libpthread.so.0 (gdb) break kcbrls Breakpoint 1 at 0x10e5d24 session B: select * from test_cbc_handle where rowid='AAANPAAABAAAQZSAAA'; select hang !! GDB (gdb) c Continuing. Breakpoint 1, 0x00000000010e5d24 in kcbrls () (gdb) bt #0  0x00000000010e5d24 in kcbrls () #1  0x0000000002e87d25 in qertbFetchByUserRowID () #2  0x00000000030c62b8 in opifch2 () #3  0x00000000032327f0 in kpoal8 () #4  0x00000000013b7c10 in opiodr () #5  0x0000000003c3c9da in ttcpip () #6  0x00000000013b3144 in opitsk () #7  0x00000000013b60ec in opiino () #8  0x00000000013b7c10 in opiodr () #9  0x00000000013a92f8 in opidrv () #10 0x0000000001fa3936 in sou2o () #11 0x000000000072d40b in opimai_real () #12 0x000000000072d35c in main () SQL> oradebug setmypid; Statement processed. SQL> oradebug dump systemstate 266; Statement processed. ?????? kcbbfbp buffer cache handle ?  SO state object ? BH BUFFER HEADER  link???     ----------------------------------------     SO: 0x11b452348, type: 3, owner: 0x11b305810, flag: INIT/-/-/0x00     (call) sess: cur 11b41bd18, rec 0, usr 11b41bd18; depth: 0       ----------------------------------------       SO: 0x1182dc750, type: 24, owner: 0x11b452348, flag: INIT/-/-/0x00       (buffer) (CR) PR: 0x11b305810 FLG: 0x108000       class bit: (nil)       kcbbfbp: [BH: 0xf2fc69f8, LINK: 0x1182dc790]       where: kdswh05: kdsgrp, why: 0       BH (0xf2fc69f8) file#: 1 rdba: 0x00410652 (1/67154) class: 1 ba: 0xf297c000         set: 3 blksize: 8192 bsi: 0 set-flg: 2 pwbcnt: 272         dbwrid: 0 obj: 54208 objn: 54202 tsn: 0 afn: 1         hash: [f2fc47f8,1181f3038] lru: [f2fc6b88,f2fc6968]         obj-flags: object_ckpt_list         ckptq: [1182ecf38,1182ecf38] fileq: [1182ecf58,1182ecf58] objq: [108712a28,108712a28]         use: [1182dc790,1182dc790] wait: [NULL]         st: XCURRENT md: SHR tch: 12         flags: buffer_dirty gotten_in_current_mode block_written_once                 redo_since_read         LRBA: [0xc7.73b.0] HSCN: [0x0.1cbe52] HSUB: [1]         Using State Objects           ----------------------------------------           SO: 0x1182dc750, type: 24, owner: 0x11b452348, flag: INIT/-/-/0x00           (buffer) (CR) PR: 0x11b305810 FLG: 0x108000           class bit: (nil)           kcbbfbp: [BH: 0xf2fc69f8, LINK: 0x1182dc790]           where: kdswh05: kdsgrp, why: 0         buffer tsn: 0 rdba: 0x00410652 (1/67154)         scn: 0x0000.001cbe52 seq: 0x01 flg: 0x02 tail: 0xbe520601         frmt: 0x02 chkval: 0x0000 type: 0x06=trans data tab 0, row 0, @0x1f9a tl: 6 fb: --H-FL-- lb: 0x0  cc: 1 col  0: [ 2]  c1 02 tab 0, row 1, @0x1f94 tl: 6 fb: --H-FL-- lb: 0x2  cc: 1 col  0: [ 2]  c1 15 end_of_block_dump         (buffer) (CR) PR: 0x11b305810 FLG: 0x108000 st: XCURRENT md: SHR tch: 12 ? buffer header?status= XCURRENT mode=KCBMSHARE KCBMSHR     current share ?????  x$kcbbf ????? cache buffer handle SQL> select distinct KCBBPBH from  x$kcbbf ; KCBBPBH ---------------- 00 00000000F2FC69F8            ==>0xf2fc69f8 SQL> select * from x$kcbbf where kcbbpbh='00000000F2FC69F8'; ADDR                   INDX    INST_ID KCBBFSO_TYP KCBBFSO_FLG KCBBFSO_OWN ---------------- ---------- ---------- ----------- ----------- ----------------   KCBBFFLG    KCBBFCR    KCBBFCM KCBBFMBR         KCBBPBH ---------- ---------- ---------- ---------------- ---------------- KCBBPBF          X0KCBBPBH        X0KCBBPBF        X1KCBBPBH ---------------- ---------------- ---------------- ---------------- X1KCBBPBF        KCBBFBH            KCBBFWHR   KCBBFWHY ---------------- ---------------- ---------- ---------- 00000001182DC750        748          1          24           1 000000011B452348    1081344          1          0 00               00000000F2FC69F8 00000001182DC750 00               00000001182DC750 00 00000001182DC7F8 00                      583          0 SQL> desc x$kcbbf;  Name                                      Null?    Type  ----------------------------------------- -------- ----------------------------  ADDR                                               RAW(8)  INDX                                               NUMBER  INST_ID                                            NUMBER  KCBBFSO_TYP                                        NUMBER  KCBBFSO_FLG                                        NUMBER  KCBBFSO_OWN                                        RAW(8)  KCBBFFLG                                           NUMBER  KCBBFCR                                            NUMBER  KCBBFCM                                            NUMBER  KCBBFMBR                                           RAW(8)  KCBBPBH                                            RAW(8)  KCBBPBF                                            RAW(8)  X0KCBBPBH                                          RAW(8)  X0KCBBPBF                                          RAW(8)  X1KCBBPBH                                          RAW(8)  X1KCBBPBF                                          RAW(8)  KCBBFBH                                            RAW(8)  KCBBFWHR                                           NUMBER  KCBBFWHY                                           NUMBER gdb ?? ?process??????kcbrls release buffer? ???cache buffer handle??? SQL> select distinct KCBBPBH from  x$kcbbf ; KCBBPBH ---------------- 00

    Read the article

  • Scripting out Contained Database Users

    - by Argenis
      Today’s blog post comes from a Twitter thread on which @SQLSoldier, @sqlstudent144 and @SQLTaiob were discussing the internals of contained database users. Unless you have been living under a rock, you’ve heard about the concept of contained users within a SQL Server database (hit the link if you have not). In this article I’d like to show you that you can, indeed, script out contained database users and recreate them on another database, as either contained users or as good old fashioned logins/server principals as well. Why would this be useful? Well, because you would not need to know the password for the user in order to recreate it on another instance. I know there is a limited number of scenarios where this would be necessary, but nonetheless I figured I’d throw this blog post to show how it can be done. A more obscure use case: with the password hash (which I’m about to show you how to obtain) you could also crack the password using a utility like hashcat, as highlighted on this SQLServerCentral article. The Investigation SQL Server uses System Base Tables to save the password hashes of logins and contained database users. For logins it uses sys.sysxlgns, whereas for contained database users it leverages sys.sysowners. I’ll show you what I do to figure this stuff out: I create a login/contained user, and then I immediately browse the transaction log with, for example, fn_dblog. It’s pretty obvious that only two base tables touched by the operation are sys.sysxlgns, and also sys.sysprivs – the latter is used to track permissions. If I connect to the DAC on my instance, I can query for the password hash of this login I’ve just created. A few interesting things about this hash. This was taken on my laptop, and I happen to be running SQL Server 2014 RTM CU2, which is the latest public build of SQL Server 2014 as of time of writing. In 2008 R2 and prior versions (back to 2000), the password hashes would start with 0x0100. The reason why this changed is because starting with SQL Server 2012 password hashes are kept using a SHA512 algorithm, as opposed to SHA-1 (used since 2000) or Snefru (used in 6.5 and 7.0). SHA-1 is nowadays deemed unsafe and is very easy to crack. For regular SQL logins, this information is exposed through the sys.sql_logins catalog view, so there is really no need to connect to the DAC to grab an SID/password hash pair. For contained database users, there is (currently) no method of obtaining SID or password hashes without connecting to the DAC. If we create a contained database user, this is what we get from the transaction log: Note that the System Base Table used in this case is sys.sysowners. sys.sysprivs is used as well, and again this is to track permissions. To query sys.sysowners, you would have to connect to the DAC, as I mentioned previously. And this is what you would get: There are other ways to figure out what SQL Server uses under the hood to store contained database user password hashes, like looking at the execution plan for a query to sys.dm_db_uncontained_entities (Thanks, Robert Davis!) SIDs, Logins, Contained Users, and Why You Care…Or Not. One of the reasons behind the existence of Contained Users was the concept of portability of databases: it is really painful to maintain Server Principals (Logins) synced across most shared-nothing SQL Server HA/DR technologies (Mirroring, Availability Groups, and Log Shipping). Often times you would need the Security Identifier (SID) of these logins to match across instances, and that meant that you had to fetch whatever SID was assigned to the login on the principal instance so you could recreate it on a secondary. With contained users you normally wouldn’t care about SIDs, as the users are always available (and synced, as long as synchronization takes place) across instances. Now you might be presented some particular requirement that might specify that SIDs synced between logins on certain instances and contained database users on other databases. How would you go about creating a contained database user with a specific SID? The answer is that you can’t do it directly, but there’s a little trick that would allow you to do it. Create a login with a specified SID and password hash, create a user for that server principal on a partially contained database, then migrate that user to contained using the system stored procedure sp_user_migrate_to_contained, then drop the login. CREATE LOGIN <login_name> WITH PASSWORD = <password_hash> HASHED, SID = <sid> ; GO USE <partially_contained_db>; GO CREATE USER <user_name> FROM LOGIN <login_name>; GO EXEC sp_migrate_user_to_contained @username = <user_name>, @rename = N’keep_name’, @disablelogin = N‘disable_login’; GO DROP LOGIN <login_name>; GO Here’s how this skeleton would look like in action: And now I have a contained user with a specified SID and password hash. In my example above, I renamed the user after migrated it to contained so that it is, hopefully, easier to understand. Enjoy!

    Read the article

  • ct.sym steals the ASM class

    - by Geertjan
    Some mild consternation on the Twittersphere yesterday. Marcus Lagergren not being able to find the ASM classes in JDK 8 in NetBeans IDE: And there's no such problem in Eclipse (and apparently in IntelliJ IDEA). Help, does NetBeans (despite being incredibly awesome) suck, after all? The truth of the matter is that there's something called "ct.sym" in the JDK. When javac is compiling code, it doesn't link against rt.jar. Instead, it uses a special symbol file lib/ct.sym with class stubs. Internal JDK classes are not put in that symbol file, since those are internal classes. You shouldn't want to use them, at all. However, what if you're Marcus Lagergren who DOES need these classes? I.e., he's working on the internal JDK classes and hence needs to have access to them. Fair enough that the general Java population can't access those classes, since they're internal implementation classes that could be changed anytime and one wouldn't want all unknown clients of those classes to start breaking once changes are made to the implementation, i.e., this is the rt.jar's internal class protection mechanism. But, again, we're now Marcus Lagergen and not the general Java population. For the solution, read Jan Lahoda, NetBeans Java Editor guru, here: https://netbeans.org/bugzilla/show_bug.cgi?id=186120 In particular, take note of this: AFAIK, the ct.sym is new in JDK6. It contains stubs for all classes that existed in JDK5 (for compatibility with existing programs that would use private JDK classes), but does not contain implementation classes that were introduced in JDK6 (only API classes). This is to prevent application developers to accidentally use JDK's private classes (as such applications would be unportable and may not run on future versions of JDK). Note that this is not really a NB thing - this is the behavior of javac from the JDK. I do not know about any way to disable this except deleting ct.sym or the option mentioned above. Regarding loading the classes: JVM uses two classpath's: classpath and bootclasspath. rt.jar is on the bootclasspath and has precedence over anything on the "custom" classpath, which is used by the application. The usual way to override classes on bootclasspath is to start the JVM with "-Xbootclasspath/p:" option, which prepends the given jars (and presumably also directories) to bootclasspath. Hence, let's take the first option, the simpler one, and simply delete the "ct.sym" file. Again, only because we need to work with those internal classes as developers of the JDK, not because we want to hack our way around "ct.sym", which would mean you'd not have portable code at the end of the day. Go to the JDK 8 lib folder and you'll find the file: Delete it. Start NetBeans IDE again, either on JDK 7 or JDK 8, doesn't make a difference for these purposes, create a new Java application (or use an existing one), make sure you have set the JDK above as the JDK of the application, and hey presto: The above obviously assumes you have a build of JDK 8 that actually includes the ASM package. And below you can see that not only are the classes found but my build succeeded, even though I'm using internal JDK classes. The yellow markings in the sidebar mean that the classes are imported but not used in the code, where normally, if I hadn't removed "ct.sym", I would have seen red error marking instead, and the code wouldn't have compiled. Note: I've tried setting "-XDignore.symbol.file" in "netbeans.conf" and in other places, but so far haven't got that to work. Simply deleting the "ct.sym" file (or back it up somewhere and put it back when needed) is quite clearly the most straightforward solution. Ultimately, if you want to be able to use those internal classes while still having portable code, do you know what you need to do? You need to create a JDK bug report stating that you need an internal class to be added to "ct.sym". Probably you'll get a motivation back stating WHY that internal class isn't supposed to be used externally. There must be a reason why those classes aren't available for external usage, otherwise they would have been added to "ct.sym". So, now the only remaining question is why the Eclipse compiler doesn't hide the internal JDK classes. Apparently the Eclipse compiler ignores the "ct.sym" file. In other words, at the end of the day, far from being a bug in NetBeans... we have now found a (pretty enormous, I reckon) bug in Eclipse. The Eclipse compiler does not protect you from using internal JDK classes and the code that you create in Eclipse may not work with future releases of the JDK, since the JDK team is simply going to be changing those classes that are not found in the "ct.sym" file while assuming (correctly, thanks to the presence of "ct.sym" mechanism) that no code in the world, other than JDK code, is tied to those classes.

    Read the article

  • Know More About Oracle Row Lock

    - by Liu Maclean(???)
    ??????Oracle??????????row lock,??ORACLE????????????????????,row lock???????????????????????????????,??Server Process?pin????block buffer????????? ????????,?process A ??update???????? Z?????????, ???????rollback???commit;??Process B??????DML??, ???????rowid???? Z???, ???????????process A????????ITL???,????????cleanout??,????????row???????????commit, ???????Process B????”enq: TX – row lock contention”??????? ????Process B????????????? ?????????Process A???????row,??Process B???????”enq: TX – row lock contention”???? ????????  ????????: SESSION A: SQL> select * from v$version; BANNER ---------------------------------------------------------------- Oracle Database 10g Enterprise Edition Release 10.2.0.5.0 - 64bi PL/SQL Release 10.2.0.5.0 - Production CORE    10.2.0.5.0      Production TNS for Linux: Version 10.2.0.5.0 - Production NLSRTL Version 10.2.0.5.0 - Production SQL> select * from global_name; GLOBAL_NAME -------------------------------------------------------------------------------- www.oracledatabase12g.com SQL> create table maclean_lock(t1 int); Table created. SQL> insert into maclean_lock values (1); 1 row created. SQL> commit; Commit complete. SQL> select dbms_rowid.rowid_block_number(rowid),dbms_rowid.rowid_relative_fno(rowid) from maclean_lock; DBMS_ROWID.ROWID_BLOCK_NUMBER(ROWID) DBMS_ROWID.ROWID_RELATIVE_FNO(ROWID) ------------------------------------ ------------------------------------                                67642                                    1 SQL>  select distinct sid from v$mystat;        SID ----------        142 SQL> select pid,spid from v$process where addr = ( select paddr from v$session where sid=(select distinct sid from v$mystat));        PID SPID ---------- ------------         17 15636 ??SESSION A ????savepoint ,?update ?????????         SQL>  savepoint NONLOCK; Savepoint created. SQL> select * From v$Lock where sid=142; no rows selected SQL> set linesize 140 pagesize 1400 SQL>  update maclean_lock set t1=t1+2; 1 row updated. SQL> select * From v$Lock where sid=142; ADDR             KADDR                   SID TY        ID1        ID2      LMODE    REQUEST      CTIME      BLOCK ---------------- ---------------- ---------- -- ---------- ---------- ---------- ---------- ---------- ---------- 0000000091FC69F0 0000000091FC6A18        142 TM      55829          0          3          0          6          0 00000000914B4008 00000000914B4040        142 TX     393232        609          6          0          6          0         SQL> select dump(3,16) from dual; DUMP(3,16) -------------------------------------------------------------------------------- Typ=2 Len=2: c1,4 ALTER SYSTEM DUMP DATAFILE 1 BLOCK 67642;  Object id on Block? Y  seg/obj: 0xda16  csc: 0x00.234718  itc: 2  flg: O  typ: 1 - DATA      fsl: 0  fnx: 0x0 ver: 0x01  Itl           Xid                  Uba         Flag  Lck        Scn/Fsc 0x01   0x000a.00f.000001e0  0x00800075.02a6.29  C---    0  scn 0x0000.00234711 0x02   0x0007.018.000001fe  0x0080065c.017a.02  ----    1  fsc 0x0000.00000000 data_block_dump,data header at 0x81d185c =============== tsiz: 0x1fa0 hsiz: 0x14 pbl: 0x081d185c bdba: 0x0041083a      76543210 flag=-------- ntab=1 nrow=1 frre=-1 fsbo=0x14 fseo=0x1f9a avsp=0x1f83 tosp=0x1f83 0xe:pti[0]      nrow=1  offs=0 0x12:pri[0]     offs=0x1f9a block_row_dump: tab 0, row 0, @0x1f9a tl: 6 fb: --H-FL-- lb: 0x2  cc: 1 col  0: [ 2]  c1 04 end_of_block_dump ?? BLOCK DUMP ???? ??????XID=0x0007.018.000001fe ?transaction?? lb:0x1 ??SESSION B ,?????UPDATE?? ???enq: TX - row lock contention ?? SQL> select distinct sid from v$mystat;        SID ----------        140 SQL> select pid,spid from v$process where addr = ( select paddr from v$session where sid=(select distinct sid from v$mystat));        PID SPID ---------- ------------         24 15652 SQL> alter system set "_trace_events"='10000-10999:255:24'; System altered.         SQL> update maclean_lock set t1=t1+2; select * From v$Lock where sid=142 or sid=140 order by sid; SESSION C: SQL> select * From v$Lock where sid=142 or sid=140 order by sid; ADDR             KADDR                   SID TY        ID1        ID2      LMODE    REQUEST      CTIME      BLOCK ---------------- ---------------- ---------- -- ---------- ---------- ---------- ---------- ---------- ---------- 0000000091FC6B10 0000000091FC6B38        140 TM      55829          0          3          0         84          0 00000000924F4A58 00000000924F4A78        140 TX     458776        510          0          6         84          0 00000000914B51E8 00000000914B5220        142 TX     458776        510          6          0        312          1 0000000091FC69F0 0000000091FC6A18        142 TM      55829          0          3          0        312          0 ???? SESSION B SID=140 ?SESSION A ?TX ENQUEUE ?X mode?REQUEST SQL> oradebug dump systemstate 266; Statement processed. SESSION B waiter's enqueue lock       SO: 0x924f4a58, type: 5, owner: 0x92bb8dc8, flag: INIT/-/-/0x00       (enqueue) TX-00070018-000001FE    DID: 0001-0018-00000022       lv: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  res_flag: 0x6       req: X, lock_flag: 0x0, lock: 0x924f4a78, res: 0x925617c0       own: 0x92b76be0, sess: 0x92b76be0, proc: 0x92a737a0, prv: 0x925617e0 TX-00070018-000001FE=> TX 458776 510 SESSION A owner's enqueue lock       SO: 0x914b51e8, type: 40, owner: 0x92b796d0, flag: INIT/-/-/0x00       (trans) flg = 0x1e03, flg2 = 0xc0000, prx = 0x0, ros = 2147483647 bsn = 0xed5 bndsn = 0xee7 spn = 0xef7       efd = 3       file:xct.c lineno:1179       DID: 0001-0011-000000C2       parent xid: 0x0000.000.00000000       env: (scn: 0x0000.00234718  xid: 0x0007.018.000001fe  uba: 0x0080065c.017a.02  statement num=0  parent xid: xid: 0x0000.000.00000000  scn: 0x00 00.00234718 0sch: scn: 0x0000.00000000)       cev: (spc = 7818  arsp = 914e8310  ubk tsn: 1 rdba: 0x0080065c  useg tsn: 1 rdba: 0x00800069             hwm uba: 0x0080065c.017a.02  col uba: 0x00000000.0000.00             num bl: 1 bk list: 0x91435070)             cr opc: 0x0 spc: 7818 uba: 0x0080065c.017a.02       (enqueue) TX-00070018-000001FE    DID: 0001-0011-000000C2       lv: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  res_flag: 0x6       mode: X, lock_flag: 0x0, lock: 0x914b5220, res: 0x925617c0       own: 0x92b796d0, sess: 0x92b796d0, proc: 0x92a6ffd8, prv: 0x925617d0        xga: 0x8b7c6d40, heap: UGA       Trans IMU st: 2 Pool index 65535, Redo pool 0x914b58d0, Undo pool 0x914b59b8       Redo pool range [0x86de640 0x86de640 0x86e0e40]       Undo pool range [0x86dbe40 0x86dbe40 0x86de640]         ----------------------------------------         SO: 0x91435070, type: 39, owner: 0x914b51e8, flag: -/-/-/0x00         (List of Blocks) next index = 1         index   itli   buffer hint   rdba       savepoint         -----------------------------------------------------------             0      2   0x647f1fc8    0x41083a     0xee7 ?SESSION A? ROLLBACK ?savepoint: SQL> rollback to NONLOCK; Rollback complete. ????savepoint ??update??????? ??UPDATE???????? ROLLBACK: SQL> select * From v$Lock where sid=142 or sid=140; ADDR             KADDR                   SID TY        ID1        ID2      LMODE    REQUEST      CTIME      BLOCK ---------------- ---------------- ---------- -- ---------- ---------- ---------- ---------- ---------- ---------- 00000000924F4A58 00000000924F4A78        140 TX     458776        510          0          6        822          0 0000000091FC6B10 0000000091FC6B38        140 TM      55829          0          3          0        822          0 00000000914B51E8 00000000914B5220        142 TX     458776        510          6          0       1050          1 ???? SESSION A 142 ???SAVEPOINT ???????TM LOCK ????? ROLLBACK TO SAVEPOINT?????SESSION???TX LOCK!!!! ??????SESSION 142???TX ID1=458776 ID2=510, ????ROLLBACK TO SAVEPOINT?????????ABORT TRANSACTION ?? SESSION B  SID=140??  SESSION A ?? , ?????????SESSION B? update???HANG?? ?????????CACHE?????:  Object id on Block? Y  seg/obj: 0xda16  csc: 0x00.2347b7  itc: 2  flg: O  typ: 1 - DATA      fsl: 0  fnx: 0x0 ver: 0x01  Itl           Xid                  Uba         Flag  Lck        Scn/Fsc 0x01   0x000a.00f.000001e0  0x00800075.02a6.29  C---    0  scn 0x0000.00234711 0x02   0x0000.000.00000000  0x00000000.0000.00  ----    0  fsc 0x0000.00000000 data_block_dump,data header at 0x745d85c =============== tsiz: 0x1fa0 hsiz: 0x14 pbl: 0x0745d85c bdba: 0x0041083a      76543210 flag=-------- ntab=1 nrow=1 frre=-1 fsbo=0x14 fseo=0x1f9a avsp=0x1f83 tosp=0x1f83 0xe:pti[0]      nrow=1  offs=0 0x12:pri[0]     offs=0x1f9a block_row_dump: tab 0, row 0, @0x1f9a tl: 6 fb: --H-FL-- lb: 0x0  cc: 1 col  0: [ 2]  c1 02 end_of_block_dump ???? ITL=0x02? ?????????,col  0: [ 2]  c1 02 ????????? ?????????SESSION D ,??????row lock?? ?UPDATE???????? SESSION D: SQL> update maclean_lock set t1=t1+2; 1 row updated. SQL> rollback; Rollback complete. ??SESSION B ??????????? ?????ORACLE????????, ??????????? TX lock?? row lock , ????????2??? row lock?????????, ?TX lock????????ENQUEUE LOCK???? ?????????PROCESS K?DML???????????????????????,??????????TX LOCK, ????PROCESS Z?????????????????????????ROW LOCK????????, ???????OLTP?????????????????????? ??ROW LOCK?Release ??????TX?ENQUEUE LOCK,?????????Process J ????????????, Process K??????????? ,Process K?????????,???row piece?lb??0x0 ,?????ITL, Process Z???ITL???????Process J????XID,?????Process J?????TX lock, PROCESS K ???TX resource?Enqueue Waiter Linked List?????X mode(exclusive)?enqueue lock? ???Process J??TX lock?,Process J?????TX resource?Enqueue Waiter Linked List ???Process K??????,??POST?????Process K? TX lock??????, ???????row lock???????,????????? ?????????? ?????: SESSION A ???PID =17 ?????????????????? SESSION B ???PID =24 ??????? "_trace_events"='10000-10999:255:24';  KST trace ??????? Server Process??? SESSION A PID=17  ?? acqure?SX mode???TM Lock ,?? ????Transaction?????UNDO SEGMENT 7,???XID 7.24.510, ?acquire ?X mode? TX-00070018-000001fe ? ?????? 00070018-000001fe ???? 7- 24 - 510? XID ? 781F4B8A:007A569C    17   142 10704  83 ksqgtl: acquire TM-0000da15-00000000 mode=SX flags=GLOBAL|XACT why="contention" 781F4B92:007A569D    17   142 10704  19 ksqgtl: SUCCESS 781F4BB3:007A569E    17   142 10812   2 0x000000000041083A 0x0000000000000000 0x0000000000234717 781F4BBA:007A569F    17   142 10812   3 0x0000000000000000 0x0000000000000000 0x0000000000000000 781F4BC0:007A56A0    17   142 10812   4 0x0000000000000000 0x0000000000000000 0x0000000000000000 781F4BD3:007A56A1    17   142 10812   5 0x000000000041083A 0x0000000000000000 0x0000000000000000 781F4BFE:007A56A2    17   142 10811   1 0x000000000041083A 0x0000000000000000 0x0000000000234711 0x0000000000000002 781F4C06:007A56A3    17   142 10811   2 0x000000000041083A 0x0000000000000000 0x0000000000234718 0x00007FA074EDA560 781F4C26:007A56A4    17   142 10813   1 ktubnd: Bind usn 7 nax 1 nbx 0 lng 0 par 0 781F4C43:007A56A5    17   142 10813   2 ktubnd: Txn Bound xid: 7.24.510 781F4C4A:007A56A6    17   142 10704  83 ksqgtl: acquire TX-00070018-000001fe mode=X flags=GLOBAL|XACT why="contention" 781F4C51:007A56A7    17   142 10704  19 ksqgtl: SUCCESS ?????????? ???????? 781F4CBF:007A56A8    17   142 10005   1 KSL WAIT BEG [SQL*Net message to client] 1650815232/0x62657100 1/0x1 0/0x0 781F4CCC:007A56A9    17   142 10005   2 KSL WAIT END [SQL*Net message to client] 1650815232/0x62657100 1/0x1 0/0x0 time=13 781F4CDE:007A56AA    17   142 10005   1 KSL WAIT BEG [SQL*Net message from client] 1650815232/0x62657100 1/0x1 0/0x0 786BD85D:007A57E0    17   142 10005   2 KSL WAIT END [SQL*Net message from client] 1650815232/0x62657100 1/0x1 0/0x0 time=5016447 786BD966:007A57E1    17   142 10005   1 KSL WAIT BEG [SQL*Net message to client] 1650815232/0x62657100 1/0x1 0/0x0 786BD96E:007A57E2    17   142 10005   2 KSL WAIT END [SQL*Net message to client] 1650815232/0x62657100 1/0x1 0/0x0 time=8 SESSION B ???PID =24  ,??????? SX mode? TM lock,??row lock? acquire X mode?TX-00070018-000001fe ksqgtl: acquire TM-0000da15-00000000 mode=SX flags=GLOBAL|XACT why="contention" ksqgtl: SUCCESS 0x000000000041083A 0x0000000000000000 0x00000000002354F8 0x0000000000000000 0x0000000000000000 0x0000000000000000 0x0000000000000000 0x0000000000000000 0x0000000000000000 0x000000000041083A 0x0000000000000000 0x00000000002354F8 0x0000000000000001 0x000000000041083A 0x0000000000000000 0x00000000002354F8 0x0000000008A63780 0x0000000000000001 0x0000000000800861 0x0000000000000241 0x0000000000000001 0x000000000041083A 0x0000000000000001 0x0000000000000001 0x000000000041083A 0x0000000000000000 0x00000000002354F9 0x0000000000000002 ksqgtl: acquire TX-00070018-000001fe mode=X flags=GLOBAL|LONG why="row lock contention" C4048EBD:007F52B6    24   140 10005   2 KSL WAIT END [enq: TX - row lock contention] 1415053318/0x54580006 458776/0x70018 510/0x1fe time=2929879 C4048ED4:007F52B7    24   140 10005   1 KSL WAIT BEG [enq: TX - row lock contention] 1415053318/0x54580006 458776/0x70018 510/0x1fe C43146CA:007F535E    24   140 10005   2 KSL WAIT END [enq: TX - row lock contention] 1415053318/0x54580006 458776/0x70018 510/0x1fe time=2930676 ????????? ,PID=24 ??????ksqcmi???????? deadlock C43146D9:007F535F    24   140 10704 134 ksqcmi: performing local deadlock detection on TX-00070018-000001fe C43146F8:007F5360    24   140 10704 150 ksqcmi: deadlock not detected on TX-00070018-000001fe ?? ??? PID 17 ??ROLLBACK ???? ,????????: PID 17 ROLLBACK; D7A495BB:007F9D3E    17   142 10005   4 KSL POST SENT postee=24 loc='ksqrcl' id1=0 id2=0 name=   type=0 D7A495D8:007F9D3F    17   142 10444  12 ABORT TRANSACTION - xid: 0x0007.018.000001fe ??  PID 17 ??? TX resource?Enqueue Waiter linked List ???PID 24???,????KSL POST SENT ?? PID 24, ???ksqrcl???ENQUEUE LOCK ?PID 24??????KSL POST (KSL POST RCVD poster=17), ?ksqgtl???? TX-00070018-000001fe ?? ksqrcl??, ??PID 24???????? TX lock?USN ,??????? USN 3 XID 3.11.582 ,???acquire TX-0003000b-00000246 D7A49616:007F9D41    24   140 10005   3 KSL POST RCVD poster=17 loc='ksqrcl' id1=0 id2=0 name=   type=0 fac#=0 facpost=1 D7A4961C:007F9D42    24   140 10704  19 ksqgtl: SUCCESS D7A4967D:007F9D43    24   140 10704 117 ksqrcl: release TX-00070018-000001fe mode=X D7A496A5:007F9D44    24   140 10813   1 ktubnd: Bind usn 3 nax 1 nbx 0 lng 0 par 0 D7A496C2:007F9D45    24   140 10813   2 ktubnd: Txn Bound xid: 3.11.582 D7A496C7:007F9D46    24   140 10704  83 ksqgtl: acquire TX-0003000b-00000246 mode=X flags=GLOBAL|XACT why="contention" D7A496E4:007F9D47    24   140 10704  19 ksqgtl: SUCCESS ROW LOCK?Release ??????TX?ENQUEUE LOCK,?????????Process J ????????????, Process K??????????? ,Process K?????????,???row piece?lb??0×0 ,?????ITL,Process Z???ITL???????Process J????XID,?????Process J?????TX lock,PROCESS K ???TX resource?Enqueue Waiter Linked List?????X mode(exclusive)?enqueue lock? ???Process J??TX lock?,Process J?????TX resource?Enqueue Waiter Linked List ???Process K??????,??POST?????Process K? TX lock??????,???????row lock???????,?????????

    Read the article

  • Some non-generic collections

    - by Simon Cooper
    Although the collections classes introduced in .NET 2, 3.5 and 4 cover most scenarios, there are still some .NET 1 collections that don't have generic counterparts. In this post, I'll be examining what they do, why you might use them, and some things you'll need to bear in mind when doing so. BitArray System.Collections.BitArray is conceptually the same as a List<bool>, but whereas List<bool> stores each boolean in a single byte (as that's what the backing bool[] does), BitArray uses a single bit to store each value, and uses various bitmasks to access each bit individually. This means that BitArray is eight times smaller than a List<bool>. Furthermore, BitArray has some useful functions for bitmasks, like And, Xor and Not, and it's not limited to 32 or 64 bits; a BitArray can hold as many bits as you need. However, it's not all roses and kittens. There are some fundamental limitations you have to bear in mind when using BitArray: It's a non-generic collection. The enumerator returns object (a boxed boolean), rather than an unboxed bool. This means that if you do this: foreach (bool b in bitArray) { ... } Every single boolean value will be boxed, then unboxed. And if you do this: foreach (var b in bitArray) { ... } you'll have to manually unbox b on every iteration, as it'll come out of the enumerator an object. Instead, you should manually iterate over the collection using a for loop: for (int i=0; i<bitArray.Length; i++) { bool b = bitArray[i]; ... } Following on from that, if you want to use BitArray in the context of an IEnumerable<bool>, ICollection<bool> or IList<bool>, you'll need to write a wrapper class, or use the Enumerable.Cast<bool> extension method (although Cast would box and unbox every value you get out of it). There is no Add or Remove method. You specify the number of bits you need in the constructor, and that's what you get. You can change the length yourself using the Length property setter though. It doesn't implement IList. Although not really important if you're writing a generic wrapper around it, it is something to bear in mind if you're using it with pre-generic code. However, if you use BitArray carefully, it can provide significant gains over a List<bool> for functionality and efficiency of space. OrderedDictionary System.Collections.Specialized.OrderedDictionary does exactly what you would expect - it's an IDictionary that maintains items in the order they are added. It does this by storing key/value pairs in a Hashtable (to get O(1) key lookup) and an ArrayList (to maintain the order). You can access values by key or index, and insert or remove items at a particular index. The enumerator returns items in index order. However, the Keys and Values properties return ICollection, not IList, as you might expect; CopyTo doesn't maintain the same ordering, as it copies from the backing Hashtable, not ArrayList; and any operations that insert or remove items from the middle of the collection are O(n), just like a normal list. In short; don't use this class. If you need some sort of ordered dictionary, it would be better to write your own generic dictionary combining a Dictionary<TKey, TValue> and List<KeyValuePair<TKey, TValue>> or List<TKey> for your specific situation. ListDictionary and HybridDictionary To look at why you might want to use ListDictionary or HybridDictionary, we need to examine the performance of these dictionaries compared to Hashtable and Dictionary<object, object>. For this test, I added n items to each collection, then randomly accessed n/2 items: So, what's going on here? Well, ListDictionary is implemented as a linked list of key/value pairs; all operations on the dictionary require an O(n) search through the list. However, for small n, the constant factor that big-o notation doesn't measure is much lower than the hashing overhead of Hashtable or Dictionary. HybridDictionary combines a Hashtable and ListDictionary; for small n, it uses a backing ListDictionary, but switches to a Hashtable when it gets to 9 items (you can see the point it switches from a ListDictionary to Hashtable in the graph). Apart from that, it's got very similar performance to Hashtable. So why would you want to use either of these? In short, you wouldn't. Any gain in performance by using ListDictionary over Dictionary<TKey, TValue> would be offset by the generic dictionary not having to cast or box the items you store, something the graphs above don't measure. Only if the performance of the dictionary is vital, the dictionary will hold less than 30 items, and you don't need type safety, would you use ListDictionary over the generic Dictionary. And even then, there's probably more useful performance gains you can make elsewhere.

    Read the article

< Previous Page | 442 443 444 445 446 447 448 449 450 451 452 453  | Next Page >