Search Results

Search found 55521 results on 2221 pages for 'class design'.

Page 81/2221 | < Previous Page | 77 78 79 80 81 82 83 84 85 86 87 88  | Next Page >

• Cutting down repeating code in c# Class

  - by Tom Gullen

  This is a wrapper for an API I'm working on, am I doing it sort of right? I'm not particularly fond of all the repeating code in the constructor, if someone can show me if I can reduce that it would be very helpful! public class WebWizForumVersion { // Properties of returned data public string Software { get; private set; } public string Version { get; private set; } public string APIVersion { get; private set; } public string Copyright { get; private set; } public string BoardName { get; private set; } public string URL { get; private set; } public string Email { get; private set; } public string Database { get; private set; } public string InstallationID { get; private set; } public bool NewsPad { get; private set; } public string NewsPadURL { get; private set; } public WebWizForumVersion(XmlReader Data) { try { Data.ReadToFollowing("Software"); this.Software = Data.ReadElementContentAsString(); Data.ReadToFollowing("Version"); this.Version = Data.ReadElementContentAsString(); Data.ReadToFollowing("ApiVersion"); this.APIVersion = Data.ReadElementContentAsString(); Data.ReadToFollowing("Copyright"); this.Copyright = Data.ReadElementContentAsString(); Data.ReadToFollowing("BoardName"); this.BoardName = Data.ReadElementContentAsString(); Data.ReadToFollowing("URL"); this.URL = Data.ReadElementContentAsString(); Data.ReadToFollowing("Email"); this.Email = Data.ReadElementContentAsString(); Data.ReadToFollowing("Database"); this.Database = Data.ReadElementContentAsString(); Data.ReadToFollowing("InstallID"); this.InstallationID = Data.ReadElementContentAsString(); Data.ReadToFollowing("NewsPad"); this.NewsPad = bool.Parse(Data.ReadElementContentAsString()); Data.ReadToFollowing("NewsPadURL"); this.NewsPadURL = Data.ReadElementContentAsString(); } catch (Exception e) { } } }

  Read the article

• Super class variables not printing through sub class

  - by Abhishek Singh

  Can u tell me why this code is not displaying any result on the console. class employee { protected String name; protected double salary; protected String dob; public employee(String name, double salary, String dob) { this.name = name; this.salary = salary; this.dob = dob; } public employee(String name, double salary) { this.name = name; this.salary = salary; } } public class Manage extends employee { String dept1; public Manage(String name, double salary, String dob, String dept1) { super(name, salary, dob); this.dept1 = dept1; } public Manage(String name, double salary, String dept1) { super(name, salary); this.dept1 = dept1; } public static void main(String args[]) { employee e = new employee("Vikas", 122345); employee e2 = new employee("Vikas", 122345, "12-2-1991"); Manage m = (Manage) new Manage("Vikas", 122345, "Sales"); Manage m2 = new Manage("Vikas", 122345, "12-2-1991", "sales"); m.display(); m2.display(); } public void display() { System.out.println("Name " + name); System.out.println("Salary " + salary); System.out.println("Birth " + dob); System.out.println("Department " + dept1); } }

  Read the article

• How to achieve interaction between GUI class with logic class

  - by volting

  Im new to GUI programming, and haven't done much OOP. Im working on a basic calculator app to help me learn GUI design and to brush up on OOP. I understand that anything GUI related should be kept seperate from the logic, but Im unsure how to implement interaction between logic an GUI classes when needed i.e. basically passing variables back and forth... Im using TKinter and when I pass a tkinter variable to my logic it only seems to hold the string PY_VAR0. def on_equal_btn_click(self): self.entryVariable.set(self.entryVariable.get() + "=") calculator = Calc(self.entryVariable) self.entryVariable.set(calculator.calculate()) Im sure that im probably doing something fundamentally wrong and probabaly really stupid, I spent a considerable amount of time experimenting (and searching for answers online) but Im getting no where. Any help would be appreciated. Thanks, V The Full Program (well just enough to show the structure..) import Tkinter class Gui(Tkinter.Tk): def __init__(self,parent): Tkinter.Tk.__init__(self,parent) self.parent = parent self.initialize() def initialize(self): self.grid() self.create_widgets() """ grid config """ #self.grid_columnconfigure(0,weight=1,pad=0) self.resizable(False, False) def create_widgets(self): """row 0 of grid""" """Create Text Entry Box""" self.entryVariable = Tkinter.StringVar() self.entry = Tkinter.Entry(self,width=30,textvariable=self.entryVariable) self.entry.grid(column=0,row=0, columnspan = 3 ) self.entry.bind("<Return>", self.on_press_enter) """create equal button""" equal_btn = Tkinter.Button(self,text="=",width=4,command=self.on_equal_btn_click) equal_btn.grid(column=3, row=0) """row 1 of grid""" """create number 1 button""" number1_btn = Tkinter.Button(self,text="1",width=8,command=self.on_number1_btn_click) number1_btn.grid(column=0, row=1) . . . def on_equal_btn_click(self): self.entryVariable.set(self.entryVariable.get() + "=") calculator = Calc(self.entryVariable) self.entryVariable.set(calculator.calculate()) class Calc(): def __init__(self, equation): self.equation = equation def calculate(self): #TODO: parse string and calculate... return self.equation if __name__ == "__main__": app = Gui(None) app.title('Calculator') app.mainloop()

  Read the article

• Cast base class object to derived class

  - by Popgalop

  Lets say I have two classes, animal and dog like this. class Animal { }; class Dog : public Animal { }; And I have an animal object named animal, that is actually an instance of dog, how would I cast it back to dog? This may seem like an odd question, but I need it because I am writing a programming language interpreter, and on the stack everything is stored as a BaseObject, and all the other datatypes extend BaseObject. How would I cast the base object from the stack, to a specific data type? I have tried something like this Dog dog = static_cast<Dog>(animal); But it gives me an error 1>------ Build started: Project: StackTests, Configuration: Debug Win32 ------ 1> StackTests.cpp 1>c:\users\owner\documents\visual studio 2012\projects\stacktests\stacktests\stacktests.cpp(173): error C2440: 'static_cast' : cannot convert from 'Animal' to 'Dog' 1> No constructor could take the source type, or constructor overload resolution was ambiguous 1>c:\users\owner\documents\visual studio 2012\projects\stacktests\stacktests\stacktests.cpp(173): error C2512: 'Dog' : no appropriate default constructor available ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

  Read the article

• Identifying a class which is extending an abstract class

  - by Simon A. Eugster

  Good Evening, I'm doing a major refactoring of http://wiki2xhtml.sourceforge.net/ to finally get better overview and maintainability. (I started the project when I decided to start programming, so – you get it, right? ;)) At the moment I wonder how to solve the problem I'll describe now: Every file will be put through several parsers (like one for links, one for tables, one for images, etc.): public class WikiLinks extends WikiTask { ... } public class WikiTables extends WikiTask { ... } The files will then be parsed about this way: public void parse() { if (!parse) return; WikiTask task = new WikiLinks(); do { task.parse(this); } while ((task = task.nextTask()) != null); } Sometimes I may want to use no parser at all (for files that only need to be copied), or only a chosen one (e.g. for testing purposes). So before running task.parse() I need to check whether this certain parser is actually necessary/desired. (Perhaps via Blacklist or Whitelist.) What would you suggest for comparing? An ID for each WikiTask (how to do?)? Comparing the task Object itself against a new instance of a WikiTask (overhead)?

  Read the article

• Calling a class method within a method definition in the same class

  - by user1786288

  So I'm writing a program for an intro Java class. I'm defining a method to add two fractions together within the class Fraction. Fraction has 2 variables, numerator and denominator. Each of these variables has a setter and a getter. Anyway, I have a problem with my addition method, which is shown below. I've just sort of tried to implement it in a way that made sense, but I'm sure I did something with calling methods/using objects that doesn't work. public void add(Fraction fraction1, Fraction fraction2) { Fraction fraction3 = new Fraction(); int a = fraction1.getNumerator; int b = fraction1.getDenominator; int c = fraction2.getNumerator; int d = fraction2.getDenominator; fraction3.setNumerator((a * d) + (b * c)); fraction3.setDenominator(b * d); } I don't know if the problem is in the method definition, if I can use the object type that way, or if there's something else wrong. any help would be appreciated, and if I need to provide any information, I'll do so ASAP.

  Read the article

• Override ToString() in your Classes

  - by psheriff

  One of the reasons I love teaching is because of the questions that I get from attendees. I was giving a presentation at DevConnections and was showing a collection of Product objects. When I hovered over the variable that contained the collection, it looked like Figure 2. As you can see in the collection, I have actual product names of my videos from www.pdsa.com/videos being displayed. To get your data to appear in the data tips you must override the ToString() method in your class. To illustrate this, take the following simple Product class shown below: public class Product{  public string ProductName { get; set; }  public int ProductId { get; set; }} This class does not have an override of the ToString() method so if you create a collection of Product objects you will end up with data tips that look like Figure 1. Below is the code I used to create a collection of Product objects. I have shortened the code in this blog, but you can get the full source code for this sample by following the instructions at the bottom of this blog entry. List<Product> coll = new List<Product>();Product prod; prod = new Product()  { ProductName = "From Zero to HTML 5 in 60 Minutes",     ProductId = 1 };coll.Add(prod);prod = new Product()   { ProductName = "Architecting Applications …",     ProductId = 2 };coll.Add(prod);prod = new Product()  { ProductName = "Introduction to Windows Phone Development",    ProductId = 3 };coll.Add(prod);prod = new Product()   { ProductName = "Architecting a Business  …",     ProductId = 4 };coll.Add(prod);......   Figure 1: Class without overriding ToString() Now, go back to the Product class and add an override of the ToString() method as shown in the code listed below: public class Product{  public string ProductName { get; set; }  public int ProductId { get; set; }   public override string ToString()  {    return ProductName;  }} In this simple sample, I am just returning the ProductName property. However, you can create a whole string of information if you wish to display more data in your data tips. Just concatenate any properties you want from your class and return that string. When you now run the application and hover over the collection object you will now see something that looks like Figure 2. Figure 2: Overriding ToString() in your Class Another place the ToString() override comes in handy is if you forget to use a DisplayMemberPath in your ListBox or ComboBox. The ToString() method is called automatically when a class is bound to a list control. Summary You should always override the ToString() method in your classes as this will help you when debugging your application. Seeing relevant data immediately in the data tip without having to drill down one more layer and maybe scroll through a complete list of properties should help speed up your development process. NOTE: You can download the sample code for this article by visiting my website at http://www.pdsa.com/downloads. Select “Tips & Tricks”, then select “Override ToString” from the drop down list.  

  Read the article

• In MVC , DAO should be called from Controller or Model

  - by tito

  I have seen various arguments against the DAO being called from the Controller class directly and also the DAO from the Model class.Infact I personally feel that if we are following the MVC pattern , the controller should not coupled with the DAO , but the Model class should invoke the DAO from within and controller should invoke the model class.Why because , we can decouple the model class apart from a webapplication and expose the functionalities for various ways like for a REST service to use our model class. If we write the DAO invocation in the controller , it would not be possible for a REST service to reuse the functionality right ? I have summarized both the approaches below. Approach #1 public class CustomerController extends HttpServlet { proctected void doPost(....) { Customer customer = new Customer("xxxxx","23",1); new CustomerDAO().save(customer); } } Approach #2 public class CustomerController extends HttpServlet { proctected void doPost(....) { Customer customer = new Customer("xxxxx","23",1); customer.save(customer); } } public class Customer { ........... private void save(Customer customer){ new CustomerDAO().save(customer); } } Note- Here is what a definition of Model is : Model: The model manages the behavior and data of the application domain, responds to requests for information about its state (usually from the view), and responds to instructions to change state (usually from the controller). In event-driven systems, the model notifies observers (usually views) when the information changes so that they can react. I would need an expert opinion on this because I find many using #1 or #2 , So which one is it ?

  Read the article

• What type of pattern would be used in this case

  - by Admiral Kunkka

  I want to know how to tackle this type of scenario. We are building a person's background, from scratch, and I want to know, conceptually, how to proceed with a secure object pattern in both design and execution... I've been reading on Factory patterns, Model-View-Controller types, Dependency injection, Singleton approaches... and I can't seem to grasp or 'fit' these types of designs decisions into what I'm trying to do.. First and foremost, I started with having a big jack-of-all-trades class, then I read some more, and some tips were to make sure your classes only have a single purpose.. which makes sense and I started breaking down certain things into other classes. Okay, cool. Now I'm looking at dependency injection and kind of didn't really know what's going on. Example/insight of what kind of heirarchy I need to accomplish... class Person needs to access and build from a multitude of different classes. class Culture needs to access a sub-class for culture benefits class Social needs to access class Culture, and other sub-classes class Birth needs to access Social, Culture, and other sub-classes class Childhood/Adolescence/Adulthood need to access everything. Also, depending on different rolls, this class heirarchy needs to create multiple people as well, such as Family, and their backgrounds using some, if not all, of these same classes. Think of it as a people generator, all random, with backgrounds and things that happen to them. Ageing, death of loved ones, military careers, e.t.c. Most of the generation is done randomly, making calls to a mt_rand function to pick from most of the selections inside the classes, guaranteeing the data to be absolutely random. I have most of the bulk-data down, and was looking for some insight from fellow programmers, what do you think?

  Read the article

• Static / Shared Helper Functions vs Built-In Methods

  - by Nathan

  This is a simple question but a design consideration that I often run across in my day to day development work. Lets say that you have a class that represents some kinds of collection. Public Class ModifiedCustomerOrders Public Property Orders as List(Of ModifiedOrders) End Class Within this class you do all kinds of important work, such as combining many different information sources and, eventually, build the Modified Customer Orders. Now, you have different processes that consume this class, each of which needs a slightly different slice of the ModifiedCustomerOrders items. To enable this, you want to add filtering functionality. How do you go about this? Do you: Add Filtering calls to the ModifiedCustomerOrders class so that you can say: MyOrdersClass.RemoveCanceledOrders() Create a Static / Shared "tooling" class that allows you to call: OrdersFilters.RemoveCanceledOrders(MyOrders) Create an extension method to accomplish the same feat as #2 but with less typing: MyOrders.RemoveCanceledOrders() Create a "Service" method that handles the getting of Orders as appropriate to the calling function, while using one of the previous approaches "under the hood". OrdersService.GetOrdersForProcessA() Others? I tend to prefer the tooling / extension method approaches as they make testing a little bit simpler. Although I dependency inject all my sourcing data into the ModifiedCustomerOrders, having it as part of the class makes it a little bit more complicated to test. Typically, I choose to use extension methods where I am doing parameterless transformations / filters. As they get more complex, I will move it into a static class instead. Thoughts on this approach? How would you approach it?

  Read the article

• Object desing problem for simple school application

  - by Aragornx

  I want to create simple school application that provides grades,notes,presence,etc. for students,teachers and parents. I'm trying to design objects for this problem and I'm little bit confused - because I'm not very experienced in class designing. Some of my present objects are : class PersonalData() { private String name; private String surename; private Calendar dateOfBirth; [...] } class Person { private PersonalData personalData; } class User extends Person { private String login; private char[] password; } class Student extends Person { private ArrayList<Counselor> counselors = new ArrayList<>(); } class Counselor extends Person { private ArrayList<Student> children = new ArrayList<>(); } class Teacher extends Person { private ArrayList<ChoolClass> schoolClasses = new ArrayList<>(); private ArrayList<Subject> subjects = new ArrayList<>(); } This is of course a general idea. But I'm sure it's not the best way. For example I want that one person could be a Teacher and also a Parent(Counselor) and present approach makes me to have two Person objects. I want that user after successful logging in get all roles that it has (Student or Teacher or (Teacher & Parent) ). I think I should make and use some interfaces but I'm not sure how to do this right. Maybe like this: interface Role { } interface TeacherRole implements Role { void addGrade( Student student, Grade grade, [...] ); } class Teacher implements TeacherRole { private Person person; [...] } class User extends Person{ ArrayList<Role> roles = new ArrayList<>(); } Please if anyone could help me to make this right or maybe just point me to some literature/article that covers practical objects design.

  Read the article

• Fiscal year handling strategies in database design

  - by Sapphire

  By fiscal year I mean all the data in the database (in all tables) that occurred in the particular year. Lets say that we are building an application that allows user to choose from different years. What way of implementing this would you prefer, and why: Separate fiscal year data based on multiple separate database instances (for example, on every fiscal year start you could create a new instance with no data) Have everything in one database, but with logic that automatically separates records from different years. Personally, I have "seen" both methods, and I would choose the second. The only argument I can think of for the first method is to have less records in case that these are really big databases - but still, you could "archive" old records by joining them in summaries or by some other way. What do you think?

  Read the article

• Database design for summarized data

  - by holden

  I have a new table I'm going to add to a bunch of other summarized data, basically to take some of the load off by calculating weekly avgs. My question is whether I would be better off with one model over the other. One model with days of the week as a column with an additional column for price or another model as a series of fields for the DOW each taking a price. I'd like to know which would save me in speed and/or headaches? Or at least the trade off. IE. ID OBJECT_ID MON TUE WED THU FRI SAT SUN SOURCE OR ID OBJECT_ID DAYOFWEEK PRICE SOURCE

  Read the article

• Web-design / UI advice

  - by Damian

  I'm working on a website on a Fmylife style. Now the homepage is the page showing the list of the latest posts. But I think there is a problem with that: The most "interesting" page is the one showing the top posts of the last days, but that page has very few visits compared to the main page. I suppose that's only because the main page is the "default" one. So, I've been thinking of making a home page that shows no posts (only one at the top of the page) but 4 big buttons showing the visitors what are the options to browse the content. But I'm also afraid that most users will not click any option and leave the site having seen no posts. So I don't know what to do. Obviously I have no idea of what will be good from a usability/efficiency point of view. Maybe a mix of the two options will be the best, but I don't know how to mix them. Any advice or idea will be greatly appreciated. The current home page looks like this: http://soquestion.latest.secretsapp.appspot.com/latest The new home page would look like this: http://soquestion.latest.secretsapp.appspot.com/

  Read the article

• MVVM Good Design. DataSet or a RowViewModel

  - by LnDCobra

  I have just started learning MVVM and having a dilemna. If I have a a main ViewModel and inside this model I have a number of datasets. Now should I be creating a new ViewModel for each row inside the dataset? Or expose the DataSet itself as a DependencyProperty? For now the dataset has about 20 rows inside it, and the thought of iterating through each row to create a ViewModel binding to each row.... might not be the best option for performance reasons and memory reasons in the future, like when there are 1000+ rows. Should I still go ahead and create a RowViewModel and iterate through the dataset? And have an ObservableCollection of it or just expose the dataset? Any help would be greatly appreciated.

  Read the article

• Value vs Entity objects (Domain Driven Design)

  - by StackUnderflow

  I have just started reading DDD. I am unable to completely grasp the concept of Entity vs Value objects.. Can someone please explain the problems (maintainability, performance.. etc) a system could face when a Value object is designed as a Entity object. Example would be great... Thanks

  Read the article

• Language Design: Combining Gotos and Functions

  - by sub

  I'm designing and currently rethinking a low-level interpreted programming language with similarities to assembler. I very soon came across the functions/loops/gotos decision problem and thought that while loops like while and for would be too high-level and unfitting, gotos would be too low level, unmaintainable and generally evil again. Functions like you know them from most languages that have return values and arguments aren't fitting in the language's concept either. So I tried to figure out something between a function and a goto which is capable of Recursion Efficient loops After some thinking I came up with the idea of subroutines: They have a beginning and an end like a function They have a name but no arguments like a goto You can go into one with jump and go out of it again before its end with return (doesn't give back any result, only stops the subroutine) Handled just like normal code - Global scope like goto So I wanted to know: Is the idea above good? What are the (dis)advantages? Would there be a better combination of function and goto or even a completely new idea?

  Read the article

• Query Object Pattern (Design Pattern)

  - by The Elite Gentleman

  Hi Guys, I need to implement a Query Object Pattern in Java for my customizable search interface (of a webapp I'm writing). Does anybody know where I can get an example/tutorial of Query Object Pattern (Martin Fowler's QoP)? Thanks in Advance ADDITION How to add a Query Pattern to an existing DAO pattern?

  Read the article

• Design by contract: predict methods needed, discipline yourself and deal with code that comes to min

  - by fireeyedboy

  I like the idea of designing by contract a lot (at least, as far as I understand the principal). I believe it means you define intefaces first before you start implementing actual code, right? However, from my limited experience (3 OOP years now) I usually can't resist the urge to start coding pretty early, for several reasons: because my limited experience has shown me I am unable to predict what methods I will be needing in the interface, so I might as well start coding right away. or because I am simply too impatient to write out the whole interfaces first. or when I do try it, I still wind up implementing bits of code already, because I fear I might forget this or that imporant bit of code, that springs to mind when I am designing the interfaces. As you see, especially with the last two points, this leads to a very disorderly way of doing thing. Tasks get mixed up. I should draw a clear line between designing interfaces and actual coding. If you, unlike me, are a good/disciplined planner, as intended above, how do you: ...know the majority of methods you will be needing up front so well? Especially if it's components that implement stuff you are not familiar with yet. ...keep yourself from resisting the urge to start coding right away? ...deal with code that comes to mind when you are designing the intefaces?

  Read the article

• Android: ListActivity design - changing the content of the List Adapter

  - by Rob

  Hi, I would like to write a rather simple content application which displays a list of textual items (along with a small pic). I have a standard menu in which each menu item represents a different category of textual items (news, sports, leisure etc.). Pressing a menu item will display a list of textual items of this category. Now, having a separate ListActivity for each category seems like an overkill (or does it?..) Naturally, it makes much more sense to use one ListActivity and replace the data of its adapter when each category is loaded. My concern is when "back" is pressed. The adapter is loaded with items of the current category and now I need to display list of the previous category (and enable clicking on list items too...). Since I have only one activity - I thought of backup and load mechanism in onPause() and onResume() functions as well as making some distinction whether these function are invoked as a result of a "new" event (menu item selected) or by a "back" press. This seems very cumbersome for such a trivial usage... Am I missing something here? Thanks, Rob

  Read the article

• a good book about software design

  - by Idan

  i'm looking for a book that talks about sofware decision like : when should i use thread pool and shouldn't. and in the first case, explains how. how should i acess my DB , how big my transactions should be how to read XML, to use DOM or SAX, what library to choose, and best ways to parse how to handle client-server app best efficient way and more stuff like that. is a book like that exist ? (preferably in c++ but not that important)

  Read the article

• Missing ideas in programming language design

  - by meyka

  I wanted to try something new and so I designed some programming languages and wrote interpreters for them: A rather low-level, not very expressive language. (I didn't want to parse complex expressions right at the beginning) It featured: Variables (yay) Subroutines, with a call stack Basic arithmetic functions, basic string manipulation, ... Code in the language looks like this: set i 0 inc i print i Very, very basic you see. A more high-level language I decided to make it structured and so it featured things like if-else, while, functions, and so on. The stuff most programming languages have. Ended up like a unworthy Python clone, I hated that. A code-golf language Which ended up similar to J, golfcode, APL, etc. Nothing special As you can see: I don't lack the skills but the ideas. I can't figure out anything new, not even bad, unneccessary things, for my languages. - Do you know of some weird things I could implement in my languages, which don't try to make programming harder (like most esoteric languages) but funnier or more different from other languages? It can't be possible that every weird thing has been tried out so far, or?

  Read the article

• Table design issues - should I create separate fields or store as a blob

  - by Ali

  Hi guys I'm working on my web based ordering system and we would like to maintain a kind of task history for each of our orders. A hsitory in the sense that we would like to maintain a log of who did what on an order like lets say an order has been entered - we would like to know if the order was acknowledged for an example. Or lets say somebody followed up on the order - etc. Consider that there are numerous situations like this for each order would it be wise to create a schema on the lines of: Orders ID - title - description - date - is_ack - is_follow - ack_by ..... That accounts to a lot of fields - on teh other hand I could have one LongText field called 'history' and fill it with a serialised object holding all the information. However in the latter case I can't run a query to lets say retrieve all orders that have not been acknowledged and stuff like that. With time requirements woudl change and I would be required to modify it to allow for more detailed tracking and that is why I need to set up a way which would be feasible to scale upon yet I don't want to be restricted on the SQL side too much.

  Read the article

• SQL Server to PostgreSQL - Migration and design concerns

  - by youwhut

  Currently migrating from SQL Server to PostgreSQL and attempting to improve a couple of key areas on the way: I have an Articles table: CREATE TABLE [dbo].[Articles]( [server_ref] [int] NOT NULL, [article_ref] [int] NOT NULL, [article_title] [varchar](400) NOT NULL, [category_ref] [int] NOT NULL, [size] [bigint] NOT NULL ) Data (comma delimited text files) is dumped on the import server by ~500 (out of ~1000) servers on a daily basis. Importing: Indexes are disabled on the Articles table. For each dumped text file Data is BULK copied to a temporary table. Temporary table is updated. Old data for the server is dropped from the Articles table. Temporary table data is copied to Articles table. Temporary table dropped. Once this process is complete for all servers the indexes are built and the new database is copied to a web server. I am reasonably happy with this process but there is always room for improvement as I strive for a real-time (haha!) system. Is what I am doing correct? The Articles table contains ~500 million records and is expected to grow. Searching across this table is okay but could be better. i.e. SELECT * FROM Articles WHERE server_ref=33 AND article_title LIKE '%criteria%' has been satisfactory but I want to improve the speed of searching. Obviously the "LIKE" is my problem here. Suggestions? SELECT * FROM Articles WHERE article_title LIKE '%criteria%' is horrendous. Partitioning is a feature of SQL Server Enterprise but $$$ which is one of the many exciting prospects of PostgreSQL. What performance hit will be incurred for the import process (drop data, insert data) and building indexes? Will the database grow by a huge amount? The database currently stands at 200 GB and will grow. Copying this across the network is not ideal but it works. I am putting thought into changing the hardware structure of the system. The thought process of having an import server and a web server is so that the import server can do the dirty work (WITHOUT indexes) while the web server (WITH indexes) can present reports. Maybe reducing the system down to one server would work to skip the copying across the network stage. This one server would have two versions of the database: one with the indexes for delivering reports and the other without for importing new data. The databases would swap daily. Thoughts? This is a fantastic system, and believe it or not there is some method to my madness by giving it a big shake up. UPDATE: I am not looking for help with relational databases, but hoping to bounce ideas around with data warehouse experts.

  Read the article

• Service Oriented Architecture & Domain-Driven Design

  - by Michael

  I've always developed code in a SOA type of way. This year I've been trying to do more DDD but I keep getting the feeling that I'm not getting it. At work our systems are load balanced and designed not to have state. The architecture is: Website ===Physical Layer== Main Service ==Physical Layer== Server 1/Service 2/Service 3/Service 4 Only Server 1,Service 2,Service 3 and Service 4 can talk to the database and the Main Service calls the correct service based on products ordered. Every physical layer is load balanced too. Now when I develop a new service, I try to think DDD in that service even though it doesn't really feel like it fits. I use good DDD principles like entities, value types, repositories, aggregates, factories and etc. I've even tried using ORM's but they just don't seem like they fit in a stateless architecture. I know there are ways around it, for example use IStatelessSession instead of ISession with NHibernate. However, ORM just feel like they don't fit in a stateless architecture. I've noticed I really only use some of the concepts and patterns DDD has taught me but the overall architecture is still SOA. I am starting to think DDD doesn't fit in large systems but I do think some of the patterns and concepts do fit in large systems. Like I said, maybe I'm just not grasping DDD or maybe I'm over analyzing my designs? Maybe by using the patterns and concepts DDD has taught me I am using DDD? Not sure if there is really a question to this post but more of thoughts I've had when trying to figure out where DDD fits in overall systems and how scalable it truly is. The truth is, I don't think I really even know what DDD is?

  Read the article

< Previous Page | 77 78 79 80 81 82 83 84 85 86 87 88  | Next Page >