Search Results

Search found 15233 results on 610 pages for 'ssis design patterns'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 246/610 | < Previous Page | 242 243 244 245 246 247 248 249 250 251 252 253  | Next Page >

  • How to Prove that using subselect queries in SQL is killing performance of server

    - by adopilot
    One of my jobs it to maintain our database, usually we have troubles with lack of performance while getting reports and working whit that base. When I start looking at queries which our ERP sending to database I see a lot of totally needlessly subselect queries inside main queries. As I am not member of developers which is creator of program we using, they do not like much when I criticize they code and job. Let say they do not taking my review as serious statements. So I asking you few questions about subselect in SQL Does subselect is taking a lot of more time then left outer joins? Does exists any blog, article or anything where I subselect is recommended not to use ? How I can prove that if we avoid subselesct in query that query is going to be faster ? Our database server is MSSQL2005

    Read the article

  • Updating multiple tables with LinqToSql in one unit of work

    - by zsharp
    Table 1: int ID-a(pk) Table 2: int ID-a(pk), int ID-b(pk) Table 3: int ID-b(pk), string C I have the data to insert into Table 1. But I do not have the ID-a, which is autogenerated. I have many string C to insert in Table 3. I am trying to insert row into Table 1, get the ID-a to insert in Table 2 along with the ID-b that is auto-Generated in Table 3 when I submit each string C, all in one submission to db. Right now I am calling dc.SubmitChanges twice in same call. Is it efficient to have to submit changes twice on same DataContext or can this be combined further?

    Read the article

  • Value objects in DDD - Why immutable?

    - by Hobbes
    I don't get why value objects in DDD should be immutable, nor do I see how this is easily done. (I'm focusing on C# and Entity Framework, if that matters.) For example, let's consider the classic Address value object. If you needed to change "123 Main St" to "123 Main Street", why should I need to construct a whole new object instead of saying myCustomer.Address.AddressLine1 = "123 Main Street"? (Even if Entity Framework supported structs, this would still be a problem, wouldn't it?) I understand (I think) the idea that value objects don't have an identity and are part of a domain object, but can someone explain why immutability is a Good Thing? EDIT: My final question here really should be "Can someone explain why immutability is a Good Thing as applied to Value Objects?" Sorry for the confusion! EDIT: To clairfy, I am not asking about CLR value types (vs reference types). I'm asking about the higher level DDD concept of Value Objects. For example, here is a hack-ish way to implement immutable value types for Entity Framework: http://rogeralsing.com/2009/05/21/entity-framework-4-immutable-value-objects. Basically, he just makes all setters private. Why go through the trouble of doing this?

    Read the article

  • Help required in adding new methods, properties into existing classes dynamically

    - by Bepenfriends
    Hi All, I am not sure whether it is possible to achieve this kind of implementation in Dot Net. Below are the information Currently we are on an application which is done in COM+, ASP, XSL, XML technologies. It is a multi tier architecture application in which COM+ acts as the BAL. The execution steps for any CRUD operation will be defined using a seperate UI which uses XML to store the information. BAL reads the XML and understands the execution steps which are defined and executes corresponding methods in DLL. Much like EDM we have our custom model (using XML) which determines which property of object is searchable, retrievable etc. Based on this information BAL constructs queries and calls procedures to get the data. In the current application both BAL and DAL are heavily customizable without doing any code change. the results will be transmitted to presentation layer in XML format which constructs the UI based on the data recieved. Now I am creating a migration project which deals with employee information. It is also going to follow the N Tier architecture in which the presentation layer communicates with BAL which connects to DAL to return the Data. Here is the problem, In our existing version we are handling every information as XML in its native form (no converstion of object etc), but in the migration project, Team is really interested in utilizing the OOP model of development where every information which is sent from BAL need to be converted to objects of its respective types (example employeeCollection, Address Collection etc). If we have the static number of data returned from BAL we can have a class which contains those nodes as properties and we can access the same. But in our case the data returned from our BAL need to be customized. How can we handle the customization in presentation layer which is converting the result to an Object. Below is an example of the XML returned <employees> <employee> <firstName>Employee 1 First Name</firstName> <lastName>Employee 1 Last Name</lastName> <addresses> <address> <addressType>1</addressType> <StreetName>Street name1</StreetName> <RegionName>Region name</RegionName> <address> <address> <addressType>2</addressType> <StreetName>Street name2</StreetName> <RegionName>Region name</RegionName> <address> <address> <addressType>3</addressType> <StreetName>Street name3</StreetName> <RegionName>Region name</RegionName> <address> <addresses> </employee> <employee> <firstName>Employee 2 First Name</firstName> <lastName>Employee 2 Last Name</lastName> <addresses> <address> <addressType>1</addressType> <StreetName>Street name1</StreetName> <RegionName>Region name</RegionName> <address> <address> <addressType>2</addressType> <StreetName>Street name2</StreetName> <RegionName>Region name</RegionName> <address> <addresses> </employee> </employees> If these are the only columns then i can write a class which is like public class Address{ public int AddressType {get;set;}; public string StreetName {get;set;}; public string RegionName {get;set;}; } public class Employee{ public string FirstName {get; set;} public string LastName {get; set;} public string AddressCollection {get; set;} } public class EmployeeCollection : List<Employee>{ public bool Add (Employee Data){ .... } } public class AddressCollection : List<Address>{ public bool Add (Address Data){ .... } } This class will be provided to customers and consultants as DLLs. We will not provide the source code for the same. Now when the consultants or customers does customization(example adding country to address and adding passport information object with employee object) they must be able to access those properties in these classes, but without source code they will not be able to do those modifications.which makes the application useless. Is there is any way to acomplish this in DotNet. I thought of using Anonymous classes but, the problem with Anonymous classes are we can not have methods in it. I am not sure how can i fit the collection objects (which will be inturn an anonymous class) Not sure about datagrid / user control binding etc. I also thought of using CODEDom to create classes runtime but not sure about the meory, performance issues. also the classes must be created only once and must use the same till there is another change. Kindly help me out in this problem. Any kind of help meterial/ cryptic code/ links will be helpful.

    Read the article

  • What is an index in MySQL?

    - by Eric
    http://i.imgur.com/JdsUK.jpg I created a table like the picture above. What are the "Indexes"? primary key? unique? It works well without setting indexes.. What do they do? why do I need them? Also, I set all String fields to TEXT because I didn't know how many characters I need. Is this a good idea? I don't see any difference. Thanks!

    Read the article

  • Use of (non) qualified names

    - by AProgrammer
    If I want to use the name baz defined in package foo|bar|quz, I've several choices: provide fbq as a short name for foo|bar|quz and use fbq|baz use foo|bar|quz|baz import baz from foo|bar|quz|baz and then use baz (or an alias given in the import process) import all public symbols from foo|bar|quz|baz and then use baz For the languages I know, my perception is that the best practice is to use the first two ways (I'll use one or the other depending on the specific package full name and the number of symbols I need from it). I'd use the third only in a language which doesn't provide the first and hunt for supporting tools to write the import statements. And in my opinion the fourth should be reserved to package designed with than import in mind, for instance if all exported symbols start with a prefix or contains the name of the package. My questions: what is in your opinion the best practice for your favorite languages? what would you suggest in a new language? what would you suggest in an old language adding such a feature?

    Read the article

  • [C++]Advantage of using a static member function instead of an equivalent non-static member function

    - by jonathanasdf
    I was wondering whether there's any advantages to using a static member function when there is a non-static equivalent. Will it result in faster execution (because of not having to care about all of the member variables), or maybe less use of memory (because of not being included in all instances)? Basically, the function I'm looking at is an utility function to rotate an integer array representing pixel colours an arbitrary number of degrees around an arbitrary centre point. It is placed in my abstract Bullet base class, since only the bullets will be using it and I didn't want the overhead of calling it in some utility class. It's a bit too long and used in every single derived bullet class, making it probably not a good idea to inline. How would you suggest I define this function? As a static member function of Bullet, of a non-static member function of Bullet, or maybe not as a member of Bullet but defined outside of the class in Bullet.h? What are the advantages and disadvantages of each?

    Read the article

  • What is the best database structure for this scenario?

    - by Ricketts
    I have a database that is holding real estate MLS (Multiple Listing Service) data. Currently, I have a single table that holds all the listing attributes (price, address, sqft, etc.). There are several different property types (residential, commercial, rental, income, land, etc.) and each property type share a majority of the attributes, but there are a few that are unique to that property type. My question is the shared attributes are in excess of 250 fields and this seems like too many fields to have in a single table. My thought is I could break them out into an EAV (Entity-Attribute-Value) format, but I've read many bad things about that and it would make running queries a real pain as any of the 250 fields could be searched on. If I were to go that route, I'd literally have to pull all the data out of the EAV table, grouped by listing id, merge it on the application side, then run my query against the in memory object collection. This also does not seem very efficient. I am looking for some ideas or recommendations on which way to proceed. Perhaps the 250+ field table is the only way to proceed. Just as a note, I'm using SQL Server 2012, .NET 4.5 w/ Entity Framework 5, C# and data is passed to asp.net web application via WCF service. Thanks in advance.

    Read the article

  • Recommendations for an in memory database vs thread safe data structures

    - by yx
    TLDR: What are the pros/cons of using an in-memory database vs locks and concurrent data structures? I am currently working on an application that has many (possibly remote) displays that collect live data from multiple data sources and renders them on screen in real time. One of the other developers have suggested the use of an in memory database instead of doing it the standard way our other systems behaves, which is to use concurrent hashmaps, queues, arrays, and other objects to store the graphical objects and handling them safely with locks if necessary. His argument is that the DB will lessen the need to worry about concurrency since it will handle read/write locks automatically, and also the DB will offer an easier way to structure the data into as many tables as we need instead of having create hashmaps of hashmaps of lists, etc and keeping track of it all. I do not have much DB experience myself so I am asking fellow SO users what experiences they have had and what are the pros & cons of inserting the DB into the system?

    Read the article

  • Migration solution for singletons in an OSGI environment

    - by Ido
    I'm working in a JEE Environment in which each application is in a war file of its own. In the WEB-INF/lib of each application war file there is a common jar that is shared by all applications. This common jar contains several Singletons which are accessed from many points in the code. Because of the war-file boundaries each application has its own instances of the Singletons. Which is how we operate today, since we want to configure some of the singletons differently in each application. Now we are moving towards an OSGi environment, where this solution will no longer work since each bundle has its own class loader, so if I try to access MySingleton which resides in bundle "common.jar" from bundle "appA.jar" or from bundle "appB.jar" I will get the same instance. Remember I "want" a different instance of a singleton per bundle. (as ironic as it sounds) Now I realize the ideal solution would be to fix the code to not rely on those singletons, however due to a tight schedule I was wondering if you guys can suggest some sort of a migration solution that would allow me to use bundle-wide singletons so each of them could be configured per bundle.

    Read the article

  • Start thread with two parameters

    - by Matt
    I've got a method that gets called on an event, which presents me with two variables varA, varB (both strings). This method gets called with new information quite frequently, thus I have created a separate method that takes in the two parameters. I want to run this method in a thread, however have struck the issue that Thread.Start will not accept parameters. I've tried a few supposed methods, but have so far had no luck.. I think my best bet is to create a separate class, and handle it there.. However I have a List which I am inserting data into, and hit a dead end when the separate class tried to access that list, since it was in a different class. Can someone help me out here please?

    Read the article

  • In Ruby, can the coerce() method know what operator it is that requires the help to coerce?

    - by Jian Lin
    In Ruby, it seems that a lot of coerce() help can be done by def coerce(something) [self, something] end that's is, when 3 + rational is needed, Fixnum 3 doesn't know how to handle adding a Rational, so it asks Rational#coerce for help by calling rational.coerce(3), and this coerce instance method will tell the caller: # I know how to handle rational + something, so I will return you the following: [self, something] # so that now you can invoke + on me, and I will deal with Fixnum to get an answer So what if most operators can use this method, but not when it is (a - b) != (b - a) situation? Can coerce() know which operator it is, and just handle those special cases, while just using the simple [self, something] to handle all the other cases where (a op b) == (b op a) ? (op is the operator).

    Read the article

  • Pros and Cons on where to place business logic: app level or DB

    - by Juri
    Hi, I always again encounter discussions about where to place the business logic: inside a business layer in the application code or down in the DB in terms of stored procedures. Personally I'd tend to the 1st approach, but I'd like to hear some opinions from your part first, without influencing you with my personal views. I know there doesn't exist a one-size-fits-all solution and it often depends on many factors, but we can discuss about that. Btw, we are in the context of web applications and our current approach is to have UI layer which accepts UI input and does a first, client-side validation Business layer with a number of service-classes which contains the business logic including validation for user input (server-side) Data Access Layer which calls stored procedures from the DB for doing persistency/read operations Many people however tend to move the business layer stuff (especially regarding the validation) down to the DB in terms of stored procedures. What do you think about it? I'd like to discuss.

    Read the article

  • Need to work out database structure

    - by jim smith
    Hi, Just need a little kickstart with this. I have Mysql/PHP, and I have 5,000 products. I have 30 companies I need to store some data for those 30 companies for each product as follows: a) prices b) stock qty I also need to store data historically on a daily basis. So the table... It makes sense that the records will be the products because there's 5000, and if I put the companies as the columns, I can store the prices, but what about the stock quantities? I could create two columns for each compoany, one for prices, one for qty. Then make the tablename the date for that day...so theer would be a new table for every day with 5000 products in it? is this the correct way? Some idea on how I'll be retreiving data the top 5 lowest prices (and the company) by product for a certain date the price and stock changes in the past 7 days by product

    Read the article

  • Dealing with dependencies between WCF services when using Castle Windsor

    - by Georgia Brown
    I have several WCF services which use castle windsor to resolve their dependencies. Now I need some of these services to talk to each other. The typical structure is service -- Business Logic -- DAL The calls to the other services need to occur at Business Logic level. What is the best approach for implementing this? Should I simply inject a service proxy into the business logic? Is this wasteful if for example, only one of two method from my service need to use this proxy? What if the services need to talk to each other? - Will castle windsor get stuck in a loop trying to resolve each services dependencies?

    Read the article

  • Active Record/ORM vs Normal Forms?

    - by Arsenal
    Hello, I've been playing around with Active Record a bit, and I have noticed that A.C./ORM always uses the following database model when creating a one-to-one relationship Person id | country_id | name | ... Country id | tld | name | ... No I wondered, isn't this a violiation of the third Normal Form? This clearly states "Every non-prime attribute is non-transitively dependent on every key of the table". Well this country_id isn't dependent of personid is it? So is this wrong or am I just not getting the point?

    Read the article

  • Architectural decision : QT or Eclipse Platform ?

    - by umanga
    We are in the process of designing a tool to be used with HDEM(High Definition Electron Microscope).We get stacks of 2D images from HDEM and first step is 'detecting borders' on the sections.After detecting edges of 2D slices ,next step is construct the 3D model using these 2D slices. This 'border detecting' algorithm(s) is/are implemented by one of professor and he has used and suggests to use C.(to gain high performance and probably will parallelise in future) We have to develop comprehensive UI ,3D viewer ,2D editor...etc and use this algorithm. Application should support usual features like project save/open.Undo,Redo...etc Our technology decisions are: A) Build entire platform from the scratch using QT. B) Use Eclipse Platform Our concerns are, if we choose A) we can easily integrate the 'border detecting' algorithm(s) because the development environment is C/C++ But we have to implement the basic features from the scratch. If we choose B) we get basic features from the Eclipse platform , but integrating C libraries going to be a tedious task. Any suggestions on this?

    Read the article

  • how do simple SQLAlchemy relationships work?

    - by Carson Myers
    I'm no database expert -- I just know the basics, really. I've picked up SQLAlchemy for a small project, and I'm using the declarative base configuration rather than the "normal" way. This way seems a lot simpler. However, while setting up my database schema, I realized I don't understand some database relationship concepts. If I had a many-to-one relationship before, for example, articles by authors (where each article could be written by only a single author), I would put an author_id field in my articles column. But SQLAlchemy has this ForeignKey object, and a relationship function with a backref kwarg, and I have no idea what any of it MEANS. I'm scared to find out what a many-to-many relationship with an intermediate table looks like (when I need additional data about each relationship). Can someone demystify this for me? Right now I'm setting up to allow openID auth for my application. So I've got this: from __init__ import Base from sqlalchemy.schema import Column from sqlalchemy.types import Integer, String class Users(Base): __tablename__ = 'users' id = Column(Integer, primary_key=True) username = Column(String, unique=True) email = Column(String) password = Column(String) salt = Column(String) class OpenID(Base): __tablename__ = 'openid' url = Column(String, primary_key=True) user_id = #? I think the ? should be replaced by Column(Integer, ForeignKey('users.id')), but I'm not sure -- and do I need to put openids = relationship("OpenID", backref="users") in the Users class? Why? What does it do? What is a backref?

    Read the article

  • PHP MVC Framework Structure

    - by bigstylee
    I am sorry about the amount of code here. I have tried to show enough for understanding while avoiding confusion (I hope). I have included a second copy of the code at Pastebin. (The code does execute without error/notice/warning.) I am currently creating a Content Management System while trying to implement the idea of Model View Controller. I have only recently come across the concept of MVC (within the last week) and trying to implement this into my current project. One of the features of the CMS is dynamic/customisable menu areas and each feature will be represented by a controller. Therefore there will be multiple versions of the Controller Class, each with specific extended functionality. I have looked at a number of tutorials and read some open source solutions to the MVC Framework. I am now trying to create a lightweight solution for my specific requirements. I am not interested in backwards compatibility, I am using PHP 5.3. An advantage of the Base class is not having to use global and can directly access any loaded class using $this->Obj['ClassName']->property/function();. Hoping to get some feedback using the basic structure outlined (with performance in mind). Specifically; a) Have I understood/implemented the concept of MVC correctly? b) Have I understood/implemented Object Orientated techniques with PHP 5 correctly? c) Should the class propertise of Base be static? d) Improvements? Thank you very much in advance! <?php /* A "Super Class" that creates/stores all object instances */ class Base { public static $Obj = array(); // Not sure this is the correct use of the "static" keyword? public static $var; static public function load_class($directory, $class) { echo count(self::$Obj)."\n"; // This does show the array is getting updated and not creating a new array :) if (!isset(self::$Obj[$class]) && !is_object(self::$Obj[$class])) //dont want to load it twice { /* Locate and include the class file based upon name ($class) */ return self::$Obj[$class] = new $class(); } return TRUE; } } /* Loads general configuration objects into the "Super Class" */ class Libraries extends Base { public function __construct(){ $this->load_class('library', 'Database'); $this->load_class('library', 'Session'); self::$var = 'Hello World!'; //testing visibility /* Other general funciton classes */ } } class Database extends Base { /* Connects to the the database and executes all queries */ public function query(){} } class Session extends Base { /* Implements Sessions in database (read/write) */ } /* General functionality of controllers */ abstract class Controller extends Base { protected function load_model($class, $method) { /* Locate and include the model file */ $this->load_class('model', $class); call_user_func(array(self::$Obj[$class], $method)); } protected function load_view($name) { /* Locate and include the view file */ #include('views/'.$name.'.php'); } } abstract class View extends Base { /* ... */ } abstract class Model extends Base { /* ... */ } class News extends Controller { public function index() { /* Displays the 5 most recent News articles and displays with Content Area */ $this->load_model('NewsModel', 'index'); $this->load_view('news', 'index'); echo $this->var; } public function menu() { /* Displays the News Title of the 5 most recent News articles and displays within the Menu Area */ $this->load_model('news/index'); $this->load_view('news/index'); } } class ChatBox extends Controller { /* ... */ } /* Lots of different features extending the controller/view/model class depending upon request and layout */ class NewsModel extends Model { public function index() { echo $this->var; self::$Obj['Database']->query(/*SELECT 5 most recent news articles*/); } public function menu() { /* ... */ } } $Libraries = new Libraries; $controller = 'News'; // Would be determined from Query String $method = 'index'; // Would be determined from Query String $Content = $Libraries->load_class('controller', $controller); //create the controller for the specific page if (in_array($method, get_class_methods($Content))) { call_user_func(array($Content, $method)); } else { die('Bad Request'. $method); } $Content::$var = 'Goodbye World'; echo $Libraries::$var . ' - ' . $Content::$var; ?> /* Ouput */ 0 1 2 3 Goodbye World! - Goodbye World

    Read the article

  • Some questions regarding Flex

    - by Rachel
    For what real time scenarios/use cases one should go to Flex Technology ? What real time problems you have solved using Flex Technology ? What real time problems have you faced because of using Flex Technology and what was your work around for that use case ?

    Read the article

  • Using Doctrine to abstract CRUD operations

    - by TomWilsonFL
    This has bothered me for quite a while, but now it is necessity that I find the answer. We are working on quite a large project using CodeIgniter plus Doctrine. Our application has a front end and also an admin area for the company to check/change/delete data. When we designed the front end, we simply consumed most of the Doctrine code right in the controller: //In semi-pseudocode function register() { $data = get_post_data(); if (count($data) && isValid($data)) { $U = new User(); $U->fromArray($data); $U->save(); $C = new Customer(); $C->fromArray($data); $C->user_id = $U->id; $C->save(); redirect_to_next_step(); } } Obviously when we went to do the admin views code duplication began and considering we were in a "get it DONE" mode so it now stinks with code bloat. I have moved a lot of functionality (business logic) into the model using model methods, but the basic CRUD does not fit there. I was going to attempt to place the CRUD into static methods, i.e. Customer::save($array) [would perform both insert and update depending on if prikey is present in array], Customer::delete($id), Customer::getObj($id = false) [if false, get all data]. This is going to become painful though for 32 model objects (and growing). Also, at times models need to interact (as the interaction above between user data and customer data), which can't be done in a static method without breaking encapsulation. I envision adding another layer to this (exposing web services), so knowing there are going to be 3 "controllers" at some point I need to encapsulate this CRUD somewhere (obviously), but are static methods the way to go, or is there another road? Your input is much appreciated.

    Read the article

  • Three level database - foreign keys

    - by poke
    I have a three level database with the following structure (simplified to only show the primary keys): Table A: a_id Table B: a_id, b_id Table C: a_id, b_id, c_id So possible values for table C would be something like this: a_id b_id c_id 1 1 1 1 1 2 1 1 3 1 2 1 1 2 2 2 1 1 2 2 1 2 2 2 ... I am now unsure, how foreign keys should be set; or if they should be set for the primary keys at all. My idea was to have a foreign key on table B B.a_id -> A.a_id, and two foreign key on C C.a_id -> A.a_id and ( C.a_id, C.b_id ) -> ( B.a_id, B.b_id ). Is that the way I should set up the foreign keys? Is the foreign key from C->A necessary? Or do I even need foreign keys at all given that all those columns are part of the primary keys? Thanks.

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 242 243 244 245 246 247 248 249 250 251 252 253  | Next Page >