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• Designing a large database with multiple sources

  - by CatchingMonkey

  I have been tasked with redesigning, or at worst optimising the structure of a database for a data warehouse. Currently, the database has 4 other source databases (which is due to expand to X number of others), all of which have their own data structures, naming conventions etc. At the moment an overnight SSIS package pulls the data from the various source and then for each source coverts the data into a standardised, usable format. These tables are then appended to each other creating a 60m row, 40 column beast!. This table is then used in a variety of ways from an OLAP cube to a web front end. The structure has been in place for a very long time, and the work I have been able to prove the advantages of normalisation, and this is the way I would like to go. The problem for me is that the overnight process takes so long I don't then want to spend additional time normalising the last table into something usable. Can anyone offer any insight or ideas into the best way to restructure or optimise the database efficiently? Edit: All the databases are MS SQL Server 2008 R2 Thanks in advance CM

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• How to name an subclass that add a minor, detailed thing?

  - by Louis Rhys

  What is the most concise (yet descriptive) way of naming a subclass that only add a specific minor thing to the parent? I encountered this case a lot in WPF, where sometime I have to add a small functionality to an out-of-the-box control for specific cases. Example: TreeView doesn't change the SelectedItem on right-click, but I have to make one that does in my application. Some possible names are TreeViewThatChangesSelectedItemOnRightClick (way too wordy and maybe difficult to read because there is so many words concantenated together) TreeView_SelectedItemChangesOnRightClick (slightly more readable, but still too wordy and the underscore also breaks the normal convention for class names) TreeViewThatChangesSIOnRC (non-obvious acronym), ExtendedTreeView (more concise, but doesn't describe what it is doing. Besides, I already found a class called this in the library, that I don't want to use/modify in my application). LouisTreeView, MyTreeView, etc. (doesn't describe what it is doing). It seems that I can't find a name which sounds right. What do you do in situation like this?

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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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• Factors to consider when building an algorithm for gun recoil

  - by Nate Bross

  What would be a good algorithm for calculating the recoil of a shooting guns cross-hairs? What I've got now, is something like this: Define min/max recoil based on weapon size Generate random number of "delta" movement Apply random value to X, Y, or both of cross-hairs (only "up" on the Y axis) Multiply new delta based on time from the previous shot (more recoil for full-auto) What I'm worried about is that this feels rather predicable, what other factors should one take into account when building recoil? While I'd like it to be somewhat predictable, I'd also like to keep players on their toes. I'm thinking about increasing the min/max recoil values by a large amount (relatively) and adding a weighting, so large recoils will be more rare -- it seems like a lot of effort to go into something I felt would be simple. Maybe this is just something that needs to be fine-tuned with additional playtesting, and more playtesters? I think that it's important to note, that the recoil will be a large part of the game, and is a key factor in the game being fun/challenging or not.

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• One page using querystring or many folders and pages?

  - by ClarkeyBoy

  I have an application where I have the 'core' code in one folder for which there is a virtual directory in the root, such that I can include any core files using /myApp/core/bla.asp. I then have two folders outside of this with a default.asp which currently use the querystring to define what page should be displayed. One page is for general users, the other will only be accessible to users who have permission to manage users / usergroups / permissions. The core code checks the querystring and then checks the permissions for that user. An example of this as it is now is default.asp?action=view&viewtype=list&objectid=server. I am not worried about SEO as this is an internal app and uses Windows Auth. My question is, is it better the way it is now or would it be better to have something like the following: /server/view/list/ /server/view/?id=123 /server/create/ /server/edit/?id=123 /server/remove/?id=123 In the above folders I would have a home page which defines all the variables which are currently determined by the querystring - in /server/create/ for example, I would define the action as 'create', object name as 'server' and so on. In terms of future development, I really have no idea which method would be best. I think the 2nd method would be best in terms of following what page does what but this is such a huge change to make at this stage that I would really like some opinions, preferably based on experience. PS Sorry if the tags are wrong - I am new to this forum and thought this was a bit too much of a discussion for StackOverflow as that is very much right / wrong answer based. I got the idea SE is more discussion based.

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• Dapper and object validation/business rules enforcement

  - by Eugene

  This isn't really Dapper-specific, actually, as it relates to any XML-serializeable object.. but it came up when I was storing an object using Dapper. Anyways, say I have a user class. Normally, I'd do something like this: class User { public string SIN {get; private set;} public string DisplayName {get;set;} public User(string sin) { if (string.IsNullOrWhiteSpace(sin)) throw new ArgumentException("SIN must be specified"); this.SIN = sin; } } Since a SIN is required, I'd just create a constructor with a sin parameter, and make it read-only. However, with a Dapper (and probably any other ORM), I need to provide a parameterless constructor, and make all properties writeable. So now I have this: class User: IValidatableObject { public int Id { get; set; } public string SIN { get; set; } public string DisplayName { get; set; } public IEnumerable<ValidationResult> Validate(ValidationContext validationContext) { // implementation } } This seems.. can't really pick the word, a bad smell? A) I'm allowing to change properties that should not be changed ever after an object has been created (SIN, userid) B) Now I have to implement IValidatableObject or something like that to test those properties before updating them to db. So how do you go about 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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• Multithreaded UI desktop application issues

  - by igor

  I am involved into development a rich UI project: desktop windows application. Application uses asynchronous invocations and in its turn it should be ready to process external messages (events). The problem is clear: at first time it was built as a simple prototype and it was not stress tested and all was fine. Then application was grown: the number of calls to server and number of events from server are high and performance is low. What is more users noticed that sometimes performance is extremal low. Asynchronous invocations based on thread pool (BeginInvoke, EndInvoke), external events are going from WCF service (.NET 3.5). My goal is synchronization of all tasks and putting priorities to every executions in desktop application. My question is: is there any practice how to reach my goal: patterns, task priority list, others? What should I do at first, second and next times? Thanks

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• Can I use access used by Visual Basic for building a database [on hold]

  - by user3413537

  I am the only programmer where I work (summer job) and I am a student with only a few years of programming experience. So I was asked to build a database and I am very excited about this project because hopefully I can learn a lot from this. Using this database my manager is supposed to be able to assign work (dealing with businesses) to different people within the company using an interface (all workers have a shared drive). When workers are done with that paperwork related to the business, they can check off that its done, add comments at the bottom of the interface, and then move on to the next business. The only experience I've had with databases is some querying with SQL, and I've built GUI interfaces with JAVA. The information on the interface will be populated from Excel so workers know what businesses they are dealing with. I've done some research and I believe the best way to build this would be building a GUI using Microsoft Visual Studio (Visual Basic) first, then figuring out a way to populate the Interface from Excel. Also because the data is pretty straight forward and not complicated I will be using MS Access to store and track the database. I know this won't be easy, but for all you geniuses out there, is this on the right path? Thanks.

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• What is the value in hiding the details through abstractions? Isn't there value in transparency?

  - by user606723

  Background I am not a big fan of abstraction. I will admit that one can benefit from adaptability, portability and re-usability of interfaces etc. There is real benefit there, and I don't wish to question that, so let's ignore it. There is the other major "benefit" of abstraction, which is to hide implementation logic and details from users of this abstraction. The argument is that you don't need to know the details, and that one should concentrate on their own logic at this point. Makes sense in theory. However, whenever I've been maintaining large enterprise applications, I always need to know more details. It becomes a huge hassle digging deeper and deeper into the abstraction at every turn just to find out exactly what something does; i.e. having to do "open declaration" about 12 times before finding the stored procedure used. This 'hide the details' mentality seems to just get in the way. I'm always wishing for more transparent interfaces and less abstraction. I can read high level source code and know what it does, but I'll never know how it does it, when how it does it, is what I really need to know. What's going on here? Has every system I've ever worked on just been badly designed (from this perspective at least)? My philosophy When I develop software, I feel like I try to follow a philosophy I feel is closely related to the ArchLinux philosophy: Arch Linux retains the inherent complexities of a GNU/Linux system, while keeping them well organized and transparent. Arch Linux developers and users believe that trying to hide the complexities of a system actually results in an even more complex system, and is therefore to be avoided. And therefore, I never try to hide complexity of my software behind abstraction layers. I try to abuse abstraction, not become a slave to it. Question at heart Is there real value in hiding the details? Aren't we sacrificing transparency? Isn't this transparency valuable?

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• Representation of data in application versus database

  - by user1815201

  I'm going to make an application that will be given data to put in a database. The data will for the most part be the same, but the way it is formatted will vary a lot (could be in anything from text files to .xls to .doc). I'm not a very experienced developer, but I can see some potential issues and I want to minimize them. First off I have decided to use the DAO pattern, so that I can easily support new file formats or file suddenly formatted in different ways. What I really wonder about though, is how I should manage the data itself within my application. I'm thinking that the database DAO should have models representing each table of the database with the same relations between them, to make the uploading process easy. But should the filesystem DAO's have to use the same models? I can imaging that when the database changes, the change will suddenly propagate throughout the entire system, all DAOs and models alike. And that is obviously a bad thing. I'm a little bit tired and out of time. Will update with what ever questions you have. Thanks!

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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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• Multithreded UI desktop application issues

  - by igor

  I am involved into development a rich UI project: desktop windows application. Application uses asynchronous invocations and in its turn it should be ready to process external messages (events). The problem is clear: at first time it was built as a simple prototype and it was not stress tested and all was fine. Then application was grown: the number of calls to server and number of events from server are high and performance is low. What is more users noticed that sometimes performance is extremal low. Asynchronous invocations based on thread pool (BeginInvoke, EndInvoke), external events are going from WCF service (.NET 3.5). My goal is synchronization of all tasks and putting priorities to every executions in desktop application. My question is: is there any practice how to reach my goal: patterns, task priority list, others? What should I do at first, second and next times? Thanks

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• Can an aggregate root hold references of members of another aggregate root?

  - by Rushino

  Hello, I know outside aggregates cant change anything inside an aggregate without passing by his root. That said i would like to know if an aggregate root can hold references of members (objects insides) of another aggregate root? (fellowing DDD rules) Example : a Calendar contain a list of phases which contain a list of sequences which contain a list of assignations Calendar is root because phases and sequences and assignations only work in context of a calendar. You also have Students and Groups of student (called groups) It is possible (fellowing DDD rules) to make Groups holding references of assignations or it need to pass by the root for accessing groups from assignations ? Thanks.

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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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• 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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• How to ...set up new Java environment - largely interfaces...

  - by Chris Kimpton

  Hi, Looks like I need to setup a new Java environment for some interfaces we need to build. Say our system is X and we need to interfaces to systems A, B and C. Then we will be writing interfaces X-A, X-B, X-C. Our system has a bus within it, so the publishing on our side will be to the bus and the interface processes will be taking from the bus and mapping to the destination system. Its for a vendor based system - so most of the core code we can't touch. Currently thinking we will have several processes, one per interface we need to do. The question is how to structure things. Several of the APIs we need to work with are Java based. We could go EJB, but prefer to keep it simple, one process per interface, so that we can restart them individually. Similarly SOA seems overkill, although I am probably mixing my thoughts about implementations of it compared to the concepts behind it... Currently thinking that something Spring based is the way to go. In true, "leverage a new tech if possible"-style, I am thinking maybe we can shoe horn some jruby into this, perhaps to make the APIs more readable, perhaps event-machine-like and to make the interface code more business-friendly, perhaps even storing the mapping code in the DB, as ruby snippets that get mixed in... but thats an aside... So, any comments/thoughts on the Spring approach - anything more up-to-date/relevant these days. EDIT: Looking a JRuby further, I am tempted to write it fully in JRuby... in which case do we need any frameworks at all, perhaps some gems to make things clearer... Thanks in advance, Chris

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• Alchemy like game for the web, open source. Any ideas for element combinations?

  - by JohnDel

  I created a web game like the Android game Alchemy. It's open source and in the back-end you can create your own elements / your own game. I was wondering what elements - ideas would be good to implement as a prototype / demo? Some ideas are: Colors Programming languages Chemical Compounds Same as the original alchemy Evolution of biological organisms What do you think? Any specific combination ideas?

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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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• 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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• As webdevelopment is it same to legal issues to make a sex dating sites?

  - by YumYumYum

  Like i have created many other normal sites which are not related to any dating/sexual content. Is it for a developer same rules and regulation while making a sex related dating sites? where people meet together, learn each others, for having a sex relaionship (you know what i mean), having also a feature of webcam sex but not explicitly a porno sites. Does those sites have any special legal terms and condition's for the developers comparing with non sexual/dating sites legal terms and conditions?

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• Do immutable objects and DDD go together?

  - by SnOrfus

  Consider a system that uses DDD (as well: any system that uses an ORM). The point of any system realistically, in nearly every use case, will be to manipulate those domain objects. Otherwise there's no real effect or purpose. Modifying an immutable object will cause it to generate a new record after the object is persisted which creates massive bloat in the datasource (unless you delete previous records after modifications). I can see the benefit of using immutable objects, but in this sense, I can't ever see a useful case for using immutable objects. Is this wrong?

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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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• 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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• Evolution of an Application: how to manage and improve core engine?

  - by Phil Carter

  The web application I work on has been live for a year now, but it's time for it to evolve and one of the ways in which it is evolving is into a multi-brand application - in this case several different companies using the application, different templates/content and some slight business logic changes between them. The problem I'm facing is implementing a best practice across the site where there are differences in business logic for each brand. These will mostly be very superficial, using a an alternative mailing list provider or capturing some extra data in a form. I don't want to have if(brand === x) { ... } else { ... } all over the site especially as most of what needs to be changed can be handled with extending the existing class. I've thought of several methods that could be used to instantiate the correct class, but I'm just not sure which is going to be best especially as some seem to lead to duplication of more code than should be necessary. Here's what I've considered: 1) Use a Static Loader similar to Zend_Loader which can take the class being requested, and has knowledge of the Brand and can then return the correct object. $class = App_Loader::getObject('User', $brand); 2) Factory classes. We use these in the application already for Products but we could utilise them here also to provide a transparent interface to the class. 3) Routing the page request to a specific brand controller. This however seems like it would duplicate a lot of code/logic. Is there a pattern or something else I should be considering to solve this problem? 4) How to manage a growing project that has multiple custom instances in production? Update This is a PHP application so the decisions on which class to load are made per request. There could be upwards of 100+ different 'brands' running.

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