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• Adventures in the Land of CloudDB/NoSQL/NoAcid

  - by KKline

  Cloud, Bunny, or CloudBunny? Last year, some of my friends from Quest Software attended Hadoop World in New York. In 2009, I never would've guessed that Quest would be there with products, community initiatives, as a major sponsor and with presenters? There were just under 1,000 attendees who weren’t the typical devheads and geekasaurs you'd normally see at very techie events like Code Camps, SQL Saturdays, Cloud Camps and or even other NoSQL events such as the Cassandra Summit. We're talkin' enterprise...(read more)

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• Cluster Nodes as RAID Drives

  - by BuckWoody

  I'm unable to sleep tonight so I thought I would push this post out VERY early. When you don't sleep your mind takes interesting turns, which can be a good thing. I was watching a briefing today by a couple of friends as they were talking about various ways to arrange a Windows Server Cluster for SQL Server. I often see an "active" node of a cluster with a "passive" node backing it up. That means one node is working and accepting transactions, and the other is not doing any work but simply "standing by" waiting for the first to fail over. The configuration in the demonstration I saw was a bit different. In this example, there were three nodes that were actively working, and a fourth standing by for all three. I've put configurations like this one into place before, but as I was looking at their architecture diagram, it looked familar - it looked like a RAID drive setup! And that's not a bad way to think about your cluster arrangements. The same concerns you might think about for a particular RAID configuration provides a good way to think about protecting your systems in general. So even if you're not staying awake all night thinking about SQL Server clusters, take this post as an opportunity for "lateral thinking" - a way of combining in your mind the concepts from one piece of knowledge to another. You might find a new way of making your technical environment a little better. Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

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• Using virtual functions

  - by Tucker Morgan

  I am starting to use virtual functions, and i am programming a simple text game, my question is this, if i have a virtual function called spec_abil with in a Super class called rpg_class. If you allow the player to class what class they want to play, say a mage class, a archer class, and a warrior class, which all have their own spec_abil function. How do you write it so that the program knows which one to use depending on the chosen class.

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• ASP.NET MVC: Moving code from controller action to service layer

  - by DigiMortal

  I fixed one controller action in my application that doesn’t seemed good enough for me. It wasn’t big move I did but worth to show to beginners how nice code you can write when using correct layering in your application. As an example I use code from my posting ASP.NET MVC: How to implement invitation codes support. Problematic controller action Although my controller action works well I don’t like how it looks. It is too much for controller action in my opinion. [HttpPost] public ActionResult GetAccess(string accessCode) {     if(string.IsNullOrEmpty(accessCode.Trim()))     {         ModelState.AddModelError("accessCode", "Insert invitation code!");         return View();     }       Guid accessGuid;       try     {         accessGuid = Guid.Parse(accessCode);     }     catch     {         ModelState.AddModelError("accessCode", "Incorrect format of invitation code!");         return View();                    }       using(var ctx = new EventsEntities())     {         var user = ctx.GetNewUserByAccessCode(accessGuid);         if(user == null)         {             ModelState.AddModelError("accessCode", "Cannot find account with given invitation code!");             return View();         }           user.UserToken = User.Identity.GetUserToken();         ctx.SaveChanges();     }       Session["UserId"] = accessGuid;       return Redirect("~/admin"); } Looking at this code my first idea is that all this access code stuff must be located somewhere else. We have working functionality in wrong place and we should do something about it. Service layer I add layers to my application very carefully because I don’t like to use hand grenade to kill a fly. When I see real need for some layer and it doesn’t add too much complexity I will add new layer. Right now it is good time to add service layer to my small application. After that it is time to move code to service layer and inject service class to controller. public interface IUserService {     bool ClaimAccessCode(string accessCode, string userToken,                          out string errorMessage);       // Other methods of user service } I need this interface when writing unit tests because I need fake service that doesn’t communicate with database and other external sources. public class UserService : IUserService {     private readonly IDataContext _context;       public UserService(IDataContext context)     {         _context = context;     }       public bool ClaimAccessCode(string accessCode, string userToken, out string errorMessage)     {         if (string.IsNullOrEmpty(accessCode.Trim()))         {             errorMessage = "Insert invitation code!";             return false;         }           Guid accessGuid;         if (!Guid.TryParse(accessCode, out accessGuid))         {             errorMessage = "Incorrect format of invitation code!";             return false;         }           var user = _context.GetNewUserByAccessCode(accessGuid);         if (user == null)         {             errorMessage = "Cannot find account with given invitation code!";             return false;         }           user.UserToken = userToken;         _context.SaveChanges();           errorMessage = string.Empty;         return true;     } } Right now I used simple solution for errors and made access code claiming method to follow usual TrySomething() methods pattern. This way I can keep error messages and their retrieval away from controller and in controller I just mediate error message from service to view. Controller Now all the code is moved to service layer and we need also some modifications to controller code so it makes use of users service. I don’t show here DI/IoC details about how to give service instance to controller. GetAccess() action of controller looks like this right now. [HttpPost] public ActionResult GetAccess(string accessCode) {     var userToken = User.Identity.GetUserToken();     string errorMessage;       if (!_userService.ClaimAccessCode(accessCode, userToken,                                       out errorMessage))     {                       ModelState.AddModelError("accessCode", errorMessage);         return View();     }       Session["UserId"] = Guid.Parse(accessCode);     return Redirect("~/admin"); } It’s short and nice now and it deals with web site part of access code claiming. In the case of error user is shown access code claiming view with error message that ClaimAccessCode() method returns as output parameter. If everything goes fine then access code is reserved for current user and user is authenticated. Conclusion When controller action grows big you have to move code to layers it actually belongs. In this posting I showed you how I moved access code claiming functionality from controller action to user service class that belongs to service layer of my application. As the result I have controller action that coordinates the user interaction when going through access code claiming process. Controller communicates with service layer and gets information about how access code claiming succeeded.

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• Is it necessary to create a database with as few tables as possible

  - by Shaheer

  Should we create a database structure with a minimum number of tables? Should it be designed in a way that everything stays in one place or is it okay to have more tables? Will it in anyway affect anything? I am asking this question because a friend of mine modified some database structure in mediaWiki. In the end, instead of 20 tables he was using only 8, and it took him 8 months to do that (it was his college assignment). EDIT I am concluding the answer as: size of the tables does NOT matter, until the case is exceptional; in which case the denormalization may help. Thanks to everyone for the answers.

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• How to Handle frame rates and synchronizing screen repaints

  - by David Kroukamp

  I would first off say sorry if the title is worded incorrectly. Okay now let me give the scenario I'm creating a 2 player fighting game, An average battle will include a Map (moving/still) and 2 characters (which are rendered by redrawing a varying amount of sprites one after the other). Now at the moment I have a single game loop limiting me to a set number of frames per second (using Java): Timer timer = new Timer(0, new AbstractAction() { @Override public void actionPerformed(ActionEvent e) { long beginTime; //The time when the cycle begun long timeDiff; //The time it took for the cycle to execute int sleepTime; //ms to sleep (< 0 if we're behind) int fps = 1000 / 40; beginTime = System.nanoTime() / 1000000; //execute loop to update check collisions and draw gameLoop(); //Calculate how long did the cycle take timeDiff = System.nanoTime() / 1000000 - beginTime; //Calculate sleep time sleepTime = fps - (int) (timeDiff); if (sleepTime > 0) {//If sleepTime > 0 we're OK ((Timer)e.getSource()).setDelay(sleepTime); } } }); timer.start(); in gameLoop() characters are drawn to the screen ( a character holds an array of images which consists of their current sprites) every gameLoop() call will change the characters current sprite to the next and loop if the end is reached. But as you can imagine if a sprite is only 3 images in length than calling gameLoop() 40 times will cause the characters movement to be drawn 40/3=13 times. This causes a few minor anomilies in the sprited for some charcters So my question is how would I go about delivering a set amount of frames per second in when I have 2 characters on screen with varying amount of sprites?

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• How to represent a tree structure in NoSQL

  - by Vlad Nicula

  I'm new to NoSQL and have been playing around with a personal project on the MEAN stack (Mongo ExpressJs AngularJs NodeJs). I'm building a document editor of sorts that manages nodes of data. Each document is actually a tree. I have a CRUD api for documents, to create new trees and a CRUD api for nodes in a given document. Right now the documents are represented as a collection that holds everything, including nodes. The children parent relationship is done by ids. So the nodes are an map by id, and each node has references to what nodes are their children. I chose this "flat" approach because it is easier to get a node by id from a document. Being used to having a relation table between nodes and documents, a relation table between nodes and children nodes I find it a bit weird that I have to save the entire "nodes" map each time I update a node. Is there a better way to represent such a data type in NoSQL?

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• Adding a forum to an existing site

  - by Andrew Heath

  I've got a site with ~500 registered members, 300 of which are what you'd call "active". Site data is kept in a MySQL dbase. I'd like to add a myBB forum to the site, but this question applies to any forum really. What I very much want to avoid is requiring my users to register both on the site and on the forum because my userbase is not technically literate and this would confuse a lot of them. However the forum software has its own registration, login, cookie, and password management system which naturally are different from the site's mechanics. I envision the following possibilities: install myBB into the existing database and customize the login code to unify the two systems. This would probably mean changing the site's code to use the myBB system as that would likely be less painful to refactor and wouldn't hurt future myBB upgrade ability. install myBB into separate database and write a bridging script of some sort that auto-registers existing site users with the forum if they elect to participate. Also check new forum registrations against the site's username list to prevent newcomers from taking existing names. run them fully separate and force users to re-register (easiest for ME, but least desirable for them) I would like a suggested course of action from those who have trod this path before... Thank you.

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• C++ - Constructor or Initialize Method to Startup

  - by Bob Fincheimer

  I want to determine when to do non-trivial initialization of a class. I see two times to do initialization: constructor and other method. I want to figure out when to use each. Choice 1: Constructor does initialization MyClass::MyClass(Data const& data) : m_data() { // does non-trivial initialization here } MyClass::~MyClass() { // cleans up here } Choice 2: Defer initialization to an initialize method MyClass::MyClass() : m_data() {} MyClass::Initialize(Data const& data) { // does non-trivial initialization here } MyClass::~MyClass() { // cleans up here } So to try and remove any subjectivity I want to figure out which is better in a couple of situations: Class that encapsulates a resource (window/font/some sort of handle) Class that composites resources to do something (a control/domain object) Data structure classes (tree/list/etc.) [Anything else you can think of] Things to analyze: Performance Ease of use by other developers How error-prone/opportunities for bugs [Anything else you can think of]

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• How to document/verify consistent layering?

  - by Morten

  I have recently moved to the dark side: I am now a CUSTOMER of software development -- mainly websites. With this new role comes new concerns. As a programmer i know how solid an application becomes when it is properly layered, and I want to use this knowledge in my new job. I don't want business logic in my presentation layer, and certainly not presentation stuff in my data layer. Thus, I want to be able to demand from my supllier that they document the level of layering, and how neat and consistent the layering is. The big question is: How is the level of layering documented to me as a customer, and is that a reasonable demmand for me to have, so I don't have to look in the code (I'm not supposed to do that anymore)?

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• What are the downsides to using dependency injection?

  - by kerry

  I recently came across an interesting question on stack overflow with some interesting reponses.  I like this post for three reasons. First, I am a big fan of dependency injection, it forces you to decouple your code, create cohesive interfaces, and should result in testable classes. Second, the author took the approach I usually do when trying to evaluate a technique or technology; suspend personal feelings and try to find some compelling arguments against it. Third, it proved that it is very difficult to come up with a compelling argument against dependency injection. What are the downsides to using dependency injection?

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• Limit The Game Loop?

  - by user1758938

  How do I make a game go at the same speed? You probly dont understand that so here are examples: This Would Loop Too Fast while(true) { GetInput(); Render(); } This Just Wont Work, Hard To Exlplain while(true) { GetInput(); Render(); Sleep(16); } Basicly How Do I Sync It To Any FrameRate And Still Have To Input And Funtions Going At The Same Rate?

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• Beginning with first project on game development [closed]

  - by Tsvetan

  Today is the day I am going to start my first real game project. It will be a Universe simulator. Basically, you can build anything from tiny meteor to quazars and universes. It is going to be my project for an olympiad in IT in my country and I really want to make it perfect(at least a bronze medal). So, I would like to ask some questions about organization and development methodologies. Firstly, my plan is to make a time schedule. In it I would write my plans for the next month or two(because that is the time I have). With this exact plan I hope to make my organisation at its best. Of course, if I am doing sth faster than the schedule I would involve more features for the game and/or continue with the tempo I have. Also, for the organisation I would make a basic pseudocode(maybe) and just rewrite it so it is compilable. Like a basic skeleton of everything. The last is an idea I tought of in the moment, but if it is good I will use it. Secondly, for the development methodologies, obviously, I think of making object-oriented code and make everything perfect(a lot of testing, good code, documentation etc.). Also, I am going to make my own menu system(I read that OpenGL hasn't got very good one). Maybe I would implement it with an xml file, holding the info about position of buttons, text boxes, images and everything. Maybe I would do a specific CSS for it and so on. I think that is very good way of doing the menu system, because it makes the presentation layer separate of the logic. But, if there is a better way, I would do it the better way. For the logic, well, I don't have much to say. OO code, testing, debuging, good and fast algorithms and so on. Also, a good documentation must be written and this is the area I need to make some research in. I think that is for now. I hope I have been enough descriptive. If more questions come on my mind, I will ask them. Edit: I think of blogging every part of the project, or at least writing down everything in a file or something like that. My question is: Is my plan of how to do everything around the project good? And if not, what is necessary to be improved and what other things I can involve for making the project good.

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• Ati Radeon HD 3200 Graphics driver - Installation Problem

  - by samufi

  I have a fresh installation of Ubuntu 12.04 x86 and I am trying to install the proprietary driver for my "Radeon HD 3200 Graphics" video card. I know that there are already many threads about this topic, but I did not find a solution for my problem: For the installation I followed exactly these instructions: What is the correct way to install ATI Catalyst Video Drivers in 12.04 LTS? During the process I faced these problems: I executed ~$ debconf libstdc++6 dkms libqtgui4 wget execstack libelfg0 dh-modaliases and got: debconf: DbDriver "passwords" warning: could not open /var/cache/debconf/passwords.dat: Keine Berechtigung Can't exec "libstdc++6": Datei oder Verzeichnis nicht gefunden at /usr/share/perl/5.14/IPC/Open3.pm line 186. open2: exec of libstdc++6 dkms libqtgui4 wget execstack libelfg0 dh-modaliases failed at /usr/share/perl5/Debconf/ConfModule.pm line 59 (translation of the German parts: "Keine Berechtigung" means: "no permission"; "Datei oder Verzeichnis nicht gefunden" means: "File or folder not found") Because I had no idea if it was a big issue, I just continued: ~$ sudo apt-get install ia32-libs There I got: Paketlisten werden gelesen... Fertig Abhängigkeitsbaum wird aufgebaut Statusinformationen werden eingelesen... Fertig Paket ia32-libs ist nicht verfügbar, wird aber von einem anderen Paket referenziert. Das kann heißen, dass das Paket fehlt, dass es abgelöst wurde oder nur aus einer anderen Quelle verfügbar ist. E: Paket »ia32-libs« hat keinen Installationskandidaten (Translation: [...] the package ia32-libs is not available but is referenced by an other package [...] E: package »ia32-libs« has no installation candidate) Once more I went on. The next steps worked quite fine. But when I came to the point: ~$ sudo dpkg -i *.deb There I got A popup message, something like there was a problem with a system application but in the terminal no errors were reported, also the packages seemed to be installed. so now the Ati Catalyst Center works amdcccle but fglrxinfo gave me X Error of failed request: BadRequest (invalid request code or no such operation) Major opcode of failed request: 139 (ATIFGLEXTENSION) Minor opcode of failed request: 66 () Serial number of failed request: 13 Current serial number in output stream: 13 So there is something wrong. (Also there is not the possibility to enable these nice graphical features - the reason why I installed the proprietary driver) Because I worked with a completely fresh Installation I don't know how to fix the problem. If anybody could help I would be very tahnkful! =)

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• Please recommend a patterns book for iOS development

  - by Brett Ryan

  I've read several books on iOS development and Objective-C, however what a lot of them teach is how to work with interfaces and all contain the model inside the view controller, i.e. a UITableViewController based view will simply have an NSArray as it's model. I'm interested in what the best practices are for designing the structure of an application. Specifically I'm interested in best practices for the following: How to separate a model from the view controller. I think I know how to do this by simply replacing the NSArray style example with a specific model object, however what I do not know how to do is alert the view when the model changes. For example in .NET I would solve this by conforming to INotifyPropertyChanged and databinding, and similarly with Java I would use PropertyChangeListener. How to create a service model for my domain objects. For example I want to learn the best way to create a service for a hypothetical Widget object to manage an internal DB and also services for communicating with remote endpoints. I need to learn the best ways to do this in a way that interface components can subscribe to events such as widgetUpdated. These services should be singleton classes and some how dependency injected into model/controller objects. Books I've read so far are: Programming in Objective-C (4th Edition) Beginning iOS 5 Development: Exploring the iOS SDK The iOS 5 Developer's Cookbook: Expanded Electronic Edition: Essentials and Advanced Recipes for iOS Programmers Learn Objective-C on the Mac: For OS X and iOS I've also purchased the following updated books but not yet read them. The Core iOS 6 Developer's Cookbook (4th edition Programming in Objective-C (5th Edition) I come from a Java and C# background with 15 years experience, I understand that many of the ways I would do things in these languages may not fit to the ObjC way of developing applications. Any guidance on the topic is very much appreciated.

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• NCurses, scrolling of multiline items, "current item" pointer and "selected items"

  - by mjf

  I am looking for hints/ideas for the best (most effective) way on how to scroll multi-line items as well as emphasizing of the "current item" and "selected items" such as: 1 FOO ITEM 1 Foo sub-item 2 Foo sub-item 3 Foo sub-item 2 BAR ITEM 1 Bar sub-item 3 BAZ ITEM 1 Baz sub-item 2 Baz sub-item 4 RAB ITEM 5 ZZZ ITEM 1 Zzz sub-item 2 Zzz sub-item 3 Zzz sub-item 4 Zzz sub-item using NCurses (some combination of windows, sub-windows, pads, copywin? Uff! In fact, the lines could exceed the stdscr's width so that possibility to scroll left/right would be also nice - pads?)... The whole items (including the sub-items) are supposed to be emphasized as full-width window/pad areas. The "current item" (including it's set of lines) should be emphasized (i.e. using A_BOLD), selected set of items of choice (including the set of lines for each the selected item) should be emphasized in another way (i.e. using A_REVERSE). What would you choose to cope with it the most effective NCurses way? (The less redrawals/refreshes the better and terminal is supposed to have the ability to change it's size - such as XTerm running under "floating window" management.) Thank you for your ideas (or perhaps some piece of code where something similar is already solved - I was not able to find anything helpful on the Internet. I mean I am not going to copy/paste foreign code but programming NCurses properly is still somehow difficult to me). P.S.: Would you suggest to "smooth-scroll" +1/-1 screen line or rather "jump-scroll" +lines/-lines of the items? (I personally prefer the latter one.) Sincerely, -- mjf

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• Distinction between API and frontend-backend

  - by Jason

  I'm trying to write a "standard" business web site. By "standard", I mean this site runs the usual HTML5, CSS and Javascript for the front-end, a back-end (to process stuff), and runs MySQL for the database. It's a basic CRUD site: the front-end just makes pretty whatever the database has in store; the backend writes to the database whatever the user enters and does some processing. Just like most sites out there. In creating my Github repositories to begin coding, I've realized I don't understand the distinction between the front-end back-end, and the API. Another way of phrasing my question is: where does the API come into this picture? I'm going to list some more details and then questions I have - hopefully this gives you guys a better idea of what my actual question is, because I'm so confused that I don't know the specific question to ask. Some more details: I'd like to try the Model-View-Controller pattern. I don't know if this changes the question/answer. The API will be RESTful I'd like my back-end to use my own API instead of allowing the back-end to cheat and call special queries. I think this style is more consistent. My questions: Does the front-end call the back-end which calls the API? Or does the front-end just call the API instead of calling the back-end? Does the back-end just execute an API and the API returns control to the back-end (where the back-end acts as the ultimate controller, delegating tasks)? Long and detailed answers explaining the role of the API alongside the front-end back-end are encouraged. If the answer depends on the model of programming (models other than the Model-View-Controller pattern), please describe these other ways of thinking of the API. Thanks. I'm very confused.

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• Should I comment Tables or Columns in my database?

  - by jako

  I like to comment my code with various information, and I think most people nowadays do so while writing some code. But when it comes to database tables or columns, I have never seen anyone setting some comments, and, to be honest, I don't even think of looking for comments there. So I am wondering if some people are commenting their DB strcuture here, and if I should bother commenting, for instance when I create a new column to an existing table?

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• First Person Shooter game agent development

  - by LangerHansIslands

  I would like to apply (program) the Artificial intelligence methods to create a intelligent game bots for a first person shooter game. Do you have any knowledge from where can I start to develop as a Linux user? Do you have a suggestion for an easy-to-start game for which I can develop bots easily, caring more about the result of my algorithms rather than spending a lot of time dealing with the game code? I've read some publications about the applied methods to Quake 3 (c) and Open Arena. But I couldn't find the source codes and manuals describing how to start coding( for compiling, developing ai and etc.). I appreciate your help.

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• C# XNA - Sky Sphere Question

  - by Wade

  I have been banging my head against the wall trying to get a sky sphere to work appropriately in XNA 4.0. I have the sphere loading correctly, and even textured, but i would like something a little more dynamic that can support a day/night cycle. My issue is that, while i know a good amount of C# and XNA, i know next to nothing about HLSL. (I could make an ambient light shader if my life depended on it...) I also have not been able to find a tutorial on how to build a sky sphere like this. Of course i don't expect to be able to make an amazing one right off the bat, i would like to start small, with a dynamic coloring sky i'll work out the clouds and sun later. My first question: Does anyone know of any good tutorial sites that could help me get a decent grasp around HLSL? Second: Does anyone have a good example of or know where to find one of a gradient sky using XNA and C#?

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• Proper Data Structure for Commentable Comments

  - by Wesley

  Been struggling with this on an architectural level. I have an object which can be commented on, let's call it a Post. Every post has a unique ID. Now I want to comment on that Post, and I can use ID as a foreign key, and each PostComment has an ItemID field which correlates to the Post. Since each Post has a unique ID, it is very easy to assign "Top Level" comments. When I comment on a comment however, I feel like I now need a PostCommentComment, which attaches to the ID of the PostComment. Since ID's are assigned sequentially, I can no longer simply use ItemID to differentiate where in the tree the comment is assigned. I.E. both a Post and a Post Comment might have an ID of '5', so my foreign key relationship is invalid. This seems like it could go on infinitely, with PostCommentCommentComment's etc... What's the best way to solve this? Should I have a field in the comment called "IsPostComment" or something of the like to know which collection to attach the ID to? This strikes me as the best solution I've seen so far, but now I feel like I need to make recursive DataBase calls which start to get expensive. Meaning, I get a Post and get all PostComments where ItemID == Post.ID && where IsPostComment == true Then I take that as a collection, gather all the ID's of the PostComments, and do another search where ItemID == PostComment[all].ID && where IsPostComment == false, then repeat infinitely. This means I make a call for every layer, and if I'm calling 100 Posts, I might make 1000 DB calls to get 10 layers of comments each. What is the right way to do this?

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• Should a domain expert make class diagrams?

  - by Matthieu

  The domain expert in our team uses UML class diagrams to model the domain model. As a result, the class diagrams are more of technical models rather than domain models (it serves of some sort of technical specifications for developpers because they don't have to do any conception, they just have to implement the model). In the end, the domain expert ends up doing the job of the architect/technical expert right? Is it normal for a domain expert (not a developer or technical profile) to do class diagrams? If not, what kind of modeling should he be using?

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• Data structure for pattern matching.

  - by alvonellos

  Let's say you have an input file with many entries like these: date, ticker, open, high, low, close, <and some other values> And you want to execute a pattern matching routine on the entries(rows) in that file, using a candlestick pattern, for example. (See, Doji) And that pattern can appear on any uniform time interval (let t = 1s, 5s, 10s, 1d, 7d, 2w, 2y, and so on...). Say a pattern matching routine can take an arbitrary number of rows to perform an analysis and contain an arbitrary number of subpatterns. In other words, some patterns may require 4 entries to operate on. Say also that the routine (may) later have to find and classify extrema (local and global maxima and minima as well as inflection points) for the ticker over a closed interval, for example, you could say that a cubic function (x^3) has the extrema on the interval [-1, 1]. (See link) What would be the most natural choice in terms of a data structure? What about an interface that conforms a Ticker object containing one row of data to a collection of Ticker so that an arbitrary pattern can be applied to the data. What's the first thing that comes to mind? I chose a doubly-linked circular linked list that has the following methods: push_front() push_back() pop_front() pop_back() [] //overloaded, can be used with negative parameters But that data structure seems very clumsy, since so much pushing and popping is going on, I have to make a deep copy of the data structure before running an analysis on it. So, I don't know if I made my question very clear -- but the main points are: What kind of data structures should be considered when analyzing sequential data points to conform to a pattern that does NOT require random access? What kind of data structures should be considered when classifying extrema of a set of data points?

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• Database Schema Usage

  - by CrazyHorse

  I have a question regarding the appropriate use of SQL Server database schemas and was hoping that some database gurus might be able to offer some guidance around best practice. Just to give a bit of background, my team has recently shrunk to 2 people and we have just been merged with another 6 person team. My team had set up a SQL Server environment running off a desktop backing up to another desktop (and nightly to the network), whilst the new team has a formal SQL Server environment, running on a dedicated server, with backups and maintenance all handled by a dedicated team. So far it's good news for my team. Now to the query. My team designed all our tables to belong to a 3-letter schema name (e.g. User = USR, General = GEN, Account = ACC) which broadly speaking relate to specific applications, although there is a lot of overlap. My new team has come from an Access background and have implemented their tables within dbo with a 3-letter perfix followed by "_tbl" so the examples above would be dbo.USR_tblTableName, dbo.GEN_tblTableName and dbo.ACC_tblTableName. Further to this, neither my old team nor my new team has gone live with their SQL Servers yet (we're both coincidentally migrating away from Access environments) and the new team have said they're willing to consider adopting our approach if we can explain how this would be beneficial. We are not anticipating handling table updates at schema level, as we will be using application-level logins. Also, with regards to the unwieldiness of the 7-character prefix, I'm not overly concerned myself as we're using LINQ almost exclusively so the tables can simply be renamed in the DMBL (although I know that presents some challenges when we update the DBML). So therefore, given that both teams need to be aligned with one another, can anyone offer any convincing arguments either way?

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• How best do you represent a bi-directional sync in a REST api?

  - by Edward M Smith

  Assuming a system where there's a Web Application with a resource, and a reference to a remote application with another similar resource, how do you represent a bi-directional sync action which synchronizes the 'local' resource with the 'remote' resource? Example: I have an API that represents a todo list. GET/POST/PUT/DELETE /todos/, etc. That API can reference remote TODO services. GET/POST/PUT/DELETE /todo_services/, etc. I can manipulate todos from the remote service through my API as a proxy via GET/POST/PUT/DELETE /todo_services/abc123/, etc. I want the ability to do a bi-directional sync between a local set of todos and the remote set of TODOS. In a rpc sort of way, one could do POST /todo_services/abc123/sync/ But, in the "verbs are bad" idea, is there a better way to represent this action?

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