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  • Object value not getting updated in the database using hibernate

    - by user1662917
    I am using Spring,hibernate,jsf with jquery in my application. I am inserting a Question object in the database through the hibernate save query . The question object contains id ,question,answertype and reference to a form object using form_id. Now I want to alter the values of Question object stored in the database by altering the value stored in the list of Question objects at the specified index position. If I alter the value in the list the value in the database is not getting altered by update query . Could you please advise. Question.java package com.otv.model; import java.io.Serializable; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.FetchType; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.JoinColumn; import javax.persistence.ManyToOne; import javax.persistence.Table; import org.apache.commons.lang.builder.ToStringBuilder; @Entity @Table(name = "questions") public class Question implements Serializable { @Id @GeneratedValue @Column(name = "id", unique = true, nullable = false) private int id; @Column(name = "question", nullable = false) private String text; @Column(name = "answertype", nullable = false) private String answertype; @ManyToOne(fetch = FetchType.EAGER) @JoinColumn(name = "form_id") private Form form; // @JoinColumn(name = "form_id") // private int formId; public Question() { } public Question(String text, String answertype) { this.text = text; this.answertype = answertype; } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getQuestion() { return text; } public void setQuestion(String question) { this.text = question; } public String getAnswertype() { return answertype; } public void setAnswertype(String answertype) { this.answertype = answertype; } @Override public int hashCode() { final int prime = 31; int result = 1; result = prime * result + ((answertype == null) ? 0 : answertype.hashCode()); result = prime * result + id; result = prime * result + ((text == null) ? 0 : text.hashCode()); return result; } @Override public boolean equals(Object obj) { if (this == obj) return true; if (obj == null) return false; if (getClass() != obj.getClass()) return false; Question other = (Question) obj; if (answertype == null) { if (other.answertype != null) return false; } else if (!answertype.equals(other.answertype)) return false; if (id != other.id) return false; if (text == null) { if (other.text != null) return false; } else if (!text.equals(other.text)) return false; return true; } public void setForm(Form form) { this.form = form; } @Override public String toString() { return ToStringBuilder.reflectionToString(this); } } Form.java package com.otv.model; import java.io.Serializable; import java.util.ArrayList; import java.util.List; import javax.persistence.CascadeType; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.FetchType; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.OneToMany; import javax.persistence.Table; import org.apache.commons.lang.builder.ToStringBuilder; @Entity @Table(name = "FORM") public class Form implements Serializable { @Id @GeneratedValue @Column(name = "id", unique = true, nullable = false) private int id; @Column(name = "name", nullable = false) private String name; @Column(name = "description", nullable = false) private String description; @OneToMany(mappedBy = "form", fetch = FetchType.EAGER, cascade = CascadeType.ALL) List<Question> questions = new ArrayList<Question>(); public Form(String name) { super(); this.name = name; } public Form() { super(); } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getDescription() { return description; } public void setDescription(String description) { this.description = description; } public List<Question> getQuestions() { return questions; } public void setQuestions(List<Question> formQuestions) { this.questions = formQuestions; } public void addQuestion(Question question) { questions.add(question); question.setForm(this); } public void removeQuestion(Question question) { questions.remove(question); question.setForm(this); } @Override public String toString() { return ToStringBuilder.reflectionToString(this); } public void replaceQuestion(int index, Question question) { Question prevQuestion = questions.get(index); // prevQuestion.setQuestion(question.getQuestion()); // prevQuestion.setAnswertype(question.getAnswertype()); question.setId(prevQuestion.getId()); question.setForm(this); questions.set(index, question); } } QuestionDAO.java package com.otv.user.dao; import java.util.List; import org.hibernate.SessionFactory; import com.otv.model.Question; public class QuestionDAO implements IQuestionDAO { private SessionFactory sessionFactory; public SessionFactory getSessionFactory() { return sessionFactory; } public void setSessionFactory(SessionFactory sessionFactory) { this.sessionFactory = sessionFactory; } public void addQuestion(Question question) { getSessionFactory().getCurrentSession().save(question); } public void deleteQuestion(Question question) { getSessionFactory().getCurrentSession().delete(question); } public void updateQuestion(Question question) { getSessionFactory().getCurrentSession().update(question); } public Question getQuestionById(int id) { List list = getSessionFactory().getCurrentSession().createQuery("from Questions where id=?") .setParameter(0, id).list(); return (Question) list.get(0); } }

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  • Using XNA ContentPipeline to export a file in a machine without full XNA GS

    - by krolth
    My game uses the Content Pipeline to load the spriteSheet at runtime. The artist for the game sends me the modified spritesheet and I do a build in my machine and send him an updated project. So I'm looking for a way to generate the xnb files in his machine (this is the output of the content pipeline) without him having to install the full XNA Game studio. 1) I don't want my artist to install VS + Xna (I know there is a free version of VS but this won't scale once we add more people to the team). 2) I'm not interested in running this editor/tool in Xbox so a Windows only solution works. 3) I'm aware of MSBuild options but they require full XNA I researched Shawn's blog and found the option of using Msbuild Sample or a new option in XNA 4.0 that looked promising here but seems like it has the same restriction: Need to install full XNA GS because the ContentPipeline is not part of the XNA redist. So has anyone found a workaround for this?

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  • How to reload sarg configuration file

    - by black sensei
    I have installed sarg for a while on ubuntu 12.04 and forgotten that I wanted it to generate reports inside /var/www/vhosts/reports.lan/htdocs. I have found out this morning and made the change in the /etc/sarg/sarg.conf. After I have manually run sarg with # sarg-reports today but it generated in the old folder /var/lib/sarg . I know I could do a symbolic link but I was surprised that I could not find a single command to reload or at least restart sarg. Can anyone give me the command to restart or reload it? Thanks

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  • Documentation utility for OpenEdge ABL

    - by glowcoder
    I have a large system in OpenEdge ABL that could use some documentation-love. Currently a team member is working on a utility that can find methods and functions and make some "Javadoc-esque" html pages out of it. It's pretty rough around the edges. Okay, it's like sawblades around the edges. I'm trying to find something like Javadoc or Doxygen that is capable of parsing OpenEdge ABL to generate some kind of API documentation. I know the market for OpenEdge isn't the best, but there is a lot of stuff that's passed along by word of mouth. It's difficult to search for because it used to be called "Progress" which throws off your search queries with non-relevant information. I'm also open to a system that lets you define the regex's to look for to define your own syntax. Then it parses and gives you an output based on that. Thanks!

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  • Cleaner HTML Markup with ASP.NET 4 Web Forms - Client IDs (VS 2010 and .NET 4.0 Series)

    This is the sixteenth in a series of blog posts Im doing on the upcoming VS 2010 and .NET 4 release. Todays post is the first of a few blog posts Ill be doing that talk about some of the important changes weve made to make Web Forms in ASP.NET 4 generate clean, standards-compliant, CSS-friendly markup.  Today Ill cover the work we are doing to provide better control over the ID attributes rendered by server controls to the client. [In addition to blogging, I am also now using Twitter...Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • Non-perfect maze generation algorithm

    - by Shylux
    I want to generate a maze with the following properties: The maze is non-perfect. Means it has loops and multiple ways to reach the exit. The maze should be random. The algorithm should output different mazes for different input parameters The maze doesn't have to be braided. Means dead-ends are allowed and appreciated. I just can't find the right resources on google. The closest i found was this description of the different types of algorithms: http://www.astrolog.org/labyrnth/algrithm.htm. All other algorithms were for perfect mazes. Can anyone give me a website where i can look this up or maybe an algorithm directly?

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  • Form, function and complexity in rule processing

    Tim Bass posted on Orwellian Event Processing.I was involved in a heated exchange in the comments, and he has more recently published a post entitled Disadvantages of Rule-Based Systems (Part 1).Whatever the rights and wrongs of our exchange, it clearly failed to generate any agreement or understanding of our different positions.I don't particularly want to promote further argument of that kind, but I do want to take the opportunity of offering a different perspective on rule-processing and an explanation...Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • Visio 2010 forward engineer add-in for office 2010

    - by Ryan Ternier
    I have been scouring the internet for ages trying to see if there was a usable add-on for Visio 2010 that could export SQL Scripts. MS stopping putting that functionality in Visio since 2003 – which is a huge shame. Today I found an open source project from Alberto Ferrari. It’s an add-in for Visio 2010 that allows you to generate SQL Scripts from your DB diagram. It’s still in beta, and the source is available.   Check it out here:http://sqlblog.com/blogs/alberto_ferrari/archive/2010/04/16/visio-forward-engineer-addin-for-office-2010.aspx This saves me from having to do all my diagramming in SQL Server / VS 2010. And brings back the much needed functionality that has been lost.

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  • A new Bursting patch for EBS Customers.

    - by ashish.shrivastava
    Patch 8594771 for Bursting functionality was released last week. The patch is for EBS R12 and 11i Customers. Following bugs have been fixed against this patch. 9550733 - DELIVERYREQUEST DOES NOT ACCEPT THE COMM IN EMAIL ADDRESS ALIAS. 9483876 : XML PUBLISHER REPORT BURSTING PROGRAM NOT DEBUGGING AFTER PATCH 7352374 9433950 : JAVA.UTIL.ZIP.ZIPEXCEPTION: ZIP FILE MUST HAVE AT LEAST ONE ENTRY 9285648 : XML PUBLISHER REPORT BURSTING PROGRAM IGNORES PORT NUMBER FOR WEBDAV DELIVERY 9269498 : NOT ABLE TO GENERATE ALL TYPES OF OUTPUTS WHILE BURSTING WITH JDE INTEGRATION. 9110360 : BURSTING USING BACKGROUND AND TITLE TAGS IN BURSTING CONTROL FILE FAILS 8937963 : BURSTING - UNABLE TO USE SPECIFIC FILENAME MORE THAN ONCE CAUSING ZIPEXCEPTION 8871779 : THE CONCURRENT LOG DOES NOT CONTAIN INFO AFTER PATCH 7352374 8594771 - BURSTING DOES NOT SUPPORT ESCAPE CHARACTERS LIKE "FIRST LAST "

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  • User roles in GWT applications

    - by csaffi
    Hi everybody, I'm wondering if you could suggest me any way to implement "user roles" in GWT applications. I would like to implement a GWT application where users log in and are assigned "roles". Based on their role, they would be able to see and use different application areas. Here are two possible solution I thought: 1) A possible solution could be to make an RPC call to the server during onModuleLoad. This RPC call would generate the necessary Widgets and/or place them on a panel and then return this panel to the client end. 2) Another possible solution could be to make an RPC call on login retrieving from server users roles and inspecting them to see what the user can do. What do you think about? Thank you very much in advance for your help!

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  • Guest Post: Christian Finn: Is Facebook About to Become a Victim of its Own Success?

    - by Michael Snow
    12.00 Print 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Cambria","serif"; mso-ascii-font-family:Cambria; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:Cambria; mso-fareast-theme-font:minor-latin; mso-hansi-font-family:Cambria; mso-hansi-theme-font:minor-latin;}  Since we have a number of new members of the WebCenter Evangelist team - I thought it would be appropriate to close the week with the newest hire and leader of the global WebCenter Evangelists, Christian Finn, who has just joined the Red team after many years with the small technology company up in Redmond, WA. He gave an intro to himself in an earlier post this morning but his post below is a great example of how customer engagement takes on a life of its own in our global online connected and social digital ecosystem. Is Facebook About to Become a Victim of its Own Success? What if I told you that your brand could advertise so successfully, you wouldn’t have to pay for the ads? A recent campaign by Ford Motor Company for the Ford Focus featuring Doug the spokespuppet (I am not making this up) did just that—and it raises some interesting issues for marketers and social media alike in the brave new world of customer engagement that is the Social Web. Allow me to elaborate. An article in the Wall Street Journal last week—“Big Brands Like Facebook, But They Don’t Like to Pay” tells the story of Ford’s recently concluded online campaign for the 2012 Ford Focus. (Ford, by the way, under the leadership of people such as Scott Monty, has been a pioneer of effective social campaigns.) The centerpiece of the campaign was the aforementioned Doug, who appeared as a character on Facebook in videos and via chat. (If you are not familiar with Doug, you can see him in action here, and read the WSJ story here.) You may be thinking puppet ads are a sign of Internet Bubble 2.0 and want to stop now, but bear with me. The Journal reported that Ford spent about $95M on its overall Ford Focus campaign, with TV accounting for over $60M of that spend. The Internet buy for the campaign was just over $10M, which included ad buys to drive traffic to Facebook for people to meet and ‘Like’ Doug and some amount on Facebook ads, too, to promote Doug and by extension, the Ford Focus. So far, a fairly straightforward consumer marketing story in the Internet Era. Yet here’s the curious thing: once Doug reached 10,000 fans on Facebook, Ford stopped paying for Facebook ads. Doug had gone viral with people sharing his videos with one another; once critical mass was reached there was no need to buy more ads on Facebook. Doug went on to be Liked by over 43,000 people, and 61% of his fans said they would be more likely to consider buying a Focus. According to the article, Ford says Focus sales are up this year—and increasing sales is every marketer’s goal. And so in effect, Ford found its Facebook campaign so successful that it could stop paying for it, instead letting its target consumers communicate its messages for fun—and for free. Not only did they get a 3X increase in fans beyond their paid campaign, they had thousands of customers sharing their messages in video form for months. Since free advertising is the Holy Grail of marketing both old and new-- and it appears social networks have an advantage in generating that buzz—it seems reasonable to ask: what would happen to brands’ advertising strategies—and the media they use to engage customers, if this success were repeated at scale? It seems logical to conclude that, at least initially, more ad dollars would be spent with social networks like Facebook as brands attempt to replicate Ford’s success. Certainly Facebook ad revenues are on the rise—eMarketer expects Facebook’s ad revenues to quintuple by 2012 compared with 2009 levels, to nearly 2.9B. That’s bad news for TV and the already battered print media and good news for Facebook. But perhaps not so over the longer run. With TV buys, you have to keep paying to generate impressions. If Doug the spokespuppet is any guide, however, that may not be true for social media campaigns. After an initial outlay, if a social campaign takes off, the audience will generate more impressions on its own. Thus a social medium like Facebook could be the victim of its own success when it comes to ad revenue. It may be there is an inherent limiting factor in the ad spend they can capture, as exemplified by Ford’s experience with Dough and the Focus. And brands may spend much less overall on advertising, with as good or better results, than they ever have in the past. How will these trends evolve? Can brands create social campaigns that repeat Ford’s formula for the Focus with effective results? Can social networks find ways to capture more spend and overcome their potential tendency to make further spend unnecessary? And will consumers become tired and insulated from social campaigns, much as they have to traditional advertising channels? These are the questions CMOs and Facebook execs alike will be asking themselves in the brave new world of customer engagement. As always, your thoughts and comments are most welcome.

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  • Virtual Brown Bag Recap: NuGet, PoshCode, Code Templates

    - by Brian Schroer
    "Virtual Brown Bag" anagrams: Roving Tuba Brawl Lawn Bug Vibrator Rubbing Two Larva Vulgar Rabbi Town A Vibrant Grub Owl Blurting a Bar Vow At this week's Roving Tuba Brawl Virtual Brown Bag meeting: Claudio Lassala asked "What does your work environment look like?" He and several others shared pictures. George Mauer talked about NuGet, .NET's answer to Ruby Gems, and PoshCode, a PowerShell code repository Claudio showed how he uses CodeRush templates to quickly generate unit test code Alan Stevens showed how to do the same thing with Resharper templates For detailed notes, links, and the video recording, go to the VBB wiki page: https://sites.google.com/site/vbbwiki/main_page/2010-12-02

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  • LLBLGen Pro v3.5 has been released!

    - by FransBouma
    Last weekend we released LLBLGen Pro v3.5! Below the list of what's new in this release. Of course, not everything is on this list, like the large amount of work we put in refactoring the runtime framework. The refactoring was necessary because our framework has two paradigms which are added to the framework at a different time, and from a design perspective in the wrong order (the paradigm we added first, SelfServicing, should have been built on top of Adapter, the other paradigm, which was added more than a year after the first released version). The refactoring made sure the framework re-uses more code across the two paradigms (they already shared a lot of code) and is better prepared for the future. We're not done yet, but refactoring a massive framework like ours without breaking interfaces and existing applications is ... a bit of a challenge ;) To celebrate the release of v3.5, we give every customer a 30% discount! Use the coupon code NR1ORM with your order :) The full list of what's new: Designer Rule based .NET Attribute definitions. It's now possible to specify a rule using fine-grained expressions with an attribute definition to define which elements of a given type will receive the attribute definition. Rules can be assigned to attribute definitions on the project level, to make it even easier to define attribute definitions in bulk for many elements in the project. More information... Revamped Project Settings dialog. Multiple project related properties and settings dialogs have been merged into a single dialog called Project Settings, which makes it easier to configure the various settings related to project elements. It also makes it easier to find features previously not used  by many (e.g. type conversions) More information... Home tab with Quick Start Guides. To make new users feel right at home, we added a home tab with quick start guides which guide you through four main use cases of the designer. System Type Converters. Many common conversions have been implemented by default in system type converters so users don't have to develop their own type converters anymore for these type conversions. Bulk Element Setting Manipulator. To change setting values for multiple project elements, it was a little cumbersome to do that without a lot of clicking and opening various editors. This dialog makes changing settings for multiple elements very easy. EDMX Importer. It's now possible to import entity model data information from an existing Entity Framework EDMX file. Other changes and fixes See for the full list of changes and fixes the online documentation. LLBLGen Pro Runtime Framework WCF Data Services (OData) support has been added. It's now possible to use your LLBLGen Pro runtime framework powered domain layer in a WCF Data Services application using the VS.NET tools for WCF Data Services. WCF Data Services is a Microsoft technology for .NET 4 to expose your domain model using OData. More information... New query specification and execution API: QuerySpec. QuerySpec is our new query specification and execution API as an alternative to Linq and our more low-level API. It's build, like our Linq provider, on top of our lower-level API. More information... SQL Server 2012 support. The SQL Server DQE allows paging using the new SQL Server 2012 style. More information... System Type converters. For a common set of types the LLBLGen Pro runtime framework contains built-in type conversions so you don't need to write your own type converters anymore. Public/NonPublic property support. It's now possible to mark a field / navigator as non-public which is reflected in the runtime framework as an internal/friend property instead of a public property. This way you can hide properties from the public interface of a generated class and still access it through code added to the generated code base. FULL JOIN support. It's now possible to perform FULL JOIN joins using the native query api and QuerySpec. It's left to the developer to check whether the used target database supports FULL (OUTER) JOINs. Using a FULL JOIN with entity fetches is not recommended, and should only be used when both participants in the join aren't the target of the fetch. Dependency Injection Tracing. It's now possible to enable tracing on dependency injection. Enable tracing at level '4' on the traceswitch 'ORMGeneral'. This will emit trace information about which instance of which type got an instance of type T injected into property P. Entity Instances in projections in Linq. It's now possible to return an entity instance in a custom Linq projection. It's now also possible to pass this instance to a method inside the query projection. Inheritance fully supported in this construct. Entity Framework support The Entity Framework has been updated in the recent year with code-first support and a new simpler context api: DbContext (with DbSet). The amount of code to generate is smaller and the context simpler. LLBLGen Pro v3.5 comes with support for DbContext and DbSet and generates code which utilizes these new classes. NHibernate support NHibernate v3.2+ built-in proxy factory factory support. By default the built-in ProxyFactoryFactory is selected. FluentNHibernate Session Manager uses 1.2 syntax. Fluent NHibernate mappings generate a SessionManager which uses the v1.2 syntax for the ProxyFactoryFactory location Optionally emit schema / catalog name in mappings Two settings have been added which allow the user to control whether the catalog name and/or schema name as known in the project in the designer is emitted into the mappings.

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  • SQL SERVER – Concurrency Basics – Guest Post by Vinod Kumar

    - by pinaldave
    This guest post is by Vinod Kumar. Vinod Kumar has worked with SQL Server extensively since joining the industry over a decade ago. Working on various versions from SQL Server 7.0, Oracle 7.3 and other database technologies – he now works with the Microsoft Technology Center (MTC) as a Technology Architect. Let us read the blog post in Vinod’s own voice. Learning is always fun when it comes to SQL Server and learning the basics again can be more fun. I did write about Transaction Logs and recovery over my blogs and the concept of simplifying the basics is a challenge. In the real world we always see checks and queues for a process – say railway reservation, banks, customer supports etc there is a process of line and queue to facilitate everyone. Shorter the queue higher is the efficiency of system (a.k.a higher is the concurrency). Every database does implement this using checks like locking, blocking mechanisms and they implement the standards in a way to facilitate higher concurrency. In this post, let us talk about the topic of Concurrency and what are the various aspects that one needs to know about concurrency inside SQL Server. Let us learn the concepts as one-liners: Concurrency can be defined as the ability of multiple processes to access or change shared data at the same time. The greater the number of concurrent user processes that can be active without interfering with each other, the greater the concurrency of the database system. Concurrency is reduced when a process that is changing data prevents other processes from reading that data or when a process that is reading data prevents other processes from changing that data. Concurrency is also affected when multiple processes are attempting to change the same data simultaneously. Two approaches to managing concurrent data access: Optimistic Concurrency Model Pessimistic Concurrency Model Concurrency Models Pessimistic Concurrency Default behavior: acquire locks to block access to data that another process is using. Assumes that enough data modification operations are in the system that any given read operation is likely affected by a data modification made by another user (assumes conflicts will occur). Avoids conflicts by acquiring a lock on data being read so no other processes can modify that data. Also acquires locks on data being modified so no other processes can access the data for either reading or modifying. Readers block writer, writers block readers and writers. Optimistic Concurrency Assumes that there are sufficiently few conflicting data modification operations in the system that any single transaction is unlikely to modify data that another transaction is modifying. Default behavior of optimistic concurrency is to use row versioning to allow data readers to see the state of the data before the modification occurs. Older versions of the data are saved so a process reading data can see the data as it was when the process started reading and not affected by any changes being made to that data. Processes modifying the data is unaffected by processes reading the data because the reader is accessing a saved version of the data rows. Readers do not block writers and writers do not block readers, but, writers can and will block writers. Transaction Processing A transaction is the basic unit of work in SQL Server. Transaction consists of SQL commands that read and update the database but the update is not considered final until a COMMIT command is issued (at least for an explicit transaction: marked with a BEGIN TRAN and the end is marked by a COMMIT TRAN or ROLLBACK TRAN). Transactions must exhibit all the ACID properties of a transaction. ACID Properties Transaction processing must guarantee the consistency and recoverability of SQL Server databases. Ensures all transactions are performed as a single unit of work regardless of hardware or system failure. A – Atomicity C – Consistency I – Isolation D- Durability Atomicity: Each transaction is treated as all or nothing – it either commits or aborts. Consistency: ensures that a transaction won’t allow the system to arrive at an incorrect logical state – the data must always be logically correct.  Consistency is honored even in the event of a system failure. Isolation: separates concurrent transactions from the updates of other incomplete transactions. SQL Server accomplishes isolation among transactions by locking data or creating row versions. Durability: After a transaction commits, the durability property ensures that the effects of the transaction persist even if a system failure occurs. If a system failure occurs while a transaction is in progress, the transaction is completely undone, leaving no partial effects on data. Transaction Dependencies In addition to supporting all four ACID properties, a transaction might exhibit few other behaviors (known as dependency problems or consistency problems). Lost Updates: Occur when two processes read the same data and both manipulate the data, changing its value and then both try to update the original data to the new value. The second process might overwrite the first update completely. Dirty Reads: Occurs when a process reads uncommitted data. If one process has changed data but not yet committed the change, another process reading the data will read it in an inconsistent state. Non-repeatable Reads: A read is non-repeatable if a process might get different values when reading the same data in two reads within the same transaction. This can happen when another process changes the data in between the reads that the first process is doing. Phantoms: Occurs when membership in a set changes. It occurs if two SELECT operations using the same predicate in the same transaction return a different number of rows. Isolation Levels SQL Server supports 5 isolation levels that control the behavior of read operations. Read Uncommitted All behaviors except for lost updates are possible. Implemented by allowing the read operations to not take any locks, and because of this, it won’t be blocked by conflicting locks acquired by other processes. The process can read data that another process has modified but not yet committed. When using the read uncommitted isolation level and scanning an entire table, SQL Server can decide to do an allocation order scan (in page-number order) instead of a logical order scan (following page pointers). If another process doing concurrent operations changes data and move rows to a new location in the table, the allocation order scan can end up reading the same row twice. Also can happen if you have read a row before it is updated and then an update moves the row to a higher page number than your scan encounters later. Performing an allocation order scan under Read Uncommitted can cause you to miss a row completely – can happen when a row on a high page number that hasn’t been read yet is updated and moved to a lower page number that has already been read. Read Committed Two varieties of read committed isolation: optimistic and pessimistic (default). Ensures that a read never reads data that another application hasn’t committed. If another transaction is updating data and has exclusive locks on data, your transaction will have to wait for the locks to be released. Your transaction must put share locks on data that are visited, which means that data might be unavailable for others to use. A share lock doesn’t prevent others from reading but prevents them from updating. Read committed (snapshot) ensures that an operation never reads uncommitted data, but not by forcing other processes to wait. SQL Server generates a version of the changed row with its previous committed values. Data being changed is still locked but other processes can see the previous versions of the data as it was before the update operation began. Repeatable Read This is a Pessimistic isolation level. Ensures that if a transaction revisits data or a query is reissued the data doesn’t change. That is, issuing the same query twice within a transaction cannot pickup any changes to data values made by another user’s transaction because no changes can be made by other transactions. However, this does allow phantom rows to appear. Preventing non-repeatable read is a desirable safeguard but cost is that all shared locks in a transaction must be held until the completion of the transaction. Snapshot Snapshot Isolation (SI) is an optimistic isolation level. Allows for processes to read older versions of committed data if the current version is locked. Difference between snapshot and read committed has to do with how old the older versions have to be. It’s possible to have two transactions executing simultaneously that give us a result that is not possible in any serial execution. Serializable This is the strongest of the pessimistic isolation level. Adds to repeatable read isolation level by ensuring that if a query is reissued rows were not added in the interim, i.e, phantoms do not appear. Preventing phantoms is another desirable safeguard, but cost of this extra safeguard is similar to that of repeatable read – all shared locks in a transaction must be held until the transaction completes. In addition serializable isolation level requires that you lock data that has been read but also data that doesn’t exist. Ex: if a SELECT returned no rows, you want it to return no. rows when the query is reissued. This is implemented in SQL Server by a special kind of lock called the key-range lock. Key-range locks require that there be an index on the column that defines the range of values. If there is no index on the column, serializable isolation requires a table lock. Gets its name from the fact that running multiple serializable transactions at the same time is equivalent of running them one at a time. Now that we understand the basics of what concurrency is, the subsequent blog posts will try to bring out the basics around locking, blocking, deadlocks because they are the fundamental blocks that make concurrency possible. Now if you are with me – let us continue learning for SQL Server Locking Basics. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: Concurrency

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  • Does code-generation increase the code quality?

    - by platzhirsch
    Arguing for code-generation I am looking for some reasons, if howsoever, code generation increases the code quality, respectively is in favor for quality insurance. To clarify what I mean with code-generation I can talk only about a project of mine: We use XML files to describe different relationships, in fact our database schema. These XML files are used to generate our ORM framework and HTML forms which can be used to add, delete and modify entities. To my mind, it increases the quality, as the human error is reduced. If someone was implemented wrong, it is broken in the model. This is good, because the error might appear a lot faster, as more generated code is broken, too.

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  • SQL SERVER – Example of Performance Tuning for Advanced Users with DB Optimizer

    - by Pinal Dave
    Performance tuning is such a subject that everyone wants to master it. In beginning everybody is at a novice level and spend lots of time learning how to master the art of performance tuning. However, as we progress further the tuning of the system keeps on getting very difficult. I have understood in my early career there should be no need of ego in the technology field. There are always better solutions and better ideas out there and we should not resist them. Instead of resisting the change and new wave I personally adopt it. Here is a similar example, as I personally progress to the master level of performance tuning, I face that it is getting harder to come up with optimal solutions. In such scenarios I rely on various tools to teach me how I can do things better. Once I learn about tools, I am often able to come up with better solutions when I face the similar situation next time. A few days ago I had received a query where the user wanted to tune it further to get the maximum out of the performance. I have re-written the similar query with the help of AdventureWorks sample database. SELECT * FROM HumanResources.Employee e INNER JOIN HumanResources.EmployeeDepartmentHistory edh ON e.BusinessEntityID = edh.BusinessEntityID INNER JOIN HumanResources.Shift s ON edh.ShiftID = s.ShiftID; User had similar query to above query was used in very critical report and wanted to get best out of the query. When I looked at the query – here were my initial thoughts Use only column in the select statements as much as you want in the application Let us look at the query pattern and data workload and find out the optimal index for it Before I give further solutions I was told by the user that they need all the columns from all the tables and creating index was not allowed in their system. He can only re-write queries or use hints to further tune this query. Now I was in the constraint box – I believe * was not a great idea but if they wanted all the columns, I believe we can’t do much besides using *. Additionally, if I cannot create a further index, I must come up with some creative way to write this query. I personally do not like to use hints in my application but there are cases when hints work out magically and gives optimal solutions. Finally, I decided to use Embarcadero’s DB Optimizer. It is a fantastic tool and very helpful when it is about performance tuning. I have previously explained how it works over here. First open DBOptimizer and open Tuning Job from File >> New >> Tuning Job. Once you open DBOptimizer Tuning Job follow the various steps indicates in the following diagram. Essentially we will take our original script and will paste that into Step 1: New SQL Text and right after that we will enable Step 2 for Generating Various cases, Step 3 for Detailed Analysis and Step 4 for Executing each generated case. Finally we will click on Analysis in Step 5 which will generate the report detailed analysis in the result pan. The detailed pan looks like. It generates various cases of T-SQL based on the original query. It applies various hints and available hints to the query and generate various execution plans of the query and displays them in the resultant. You can clearly notice that original query had a cost of 0.0841 and logical reads about 607 pages. Whereas various options which are just following it has different execution cost as well logical read. There are few cases where we have higher logical read and there are few cases where as we have very low logical read. If we pay attention the very next row to original query have Merge_Join_Query in description and have lowest execution cost value of 0.044 and have lowest Logical Reads of 29. This row contains the query which is the most optimal re-write of the original query. Let us double click over it. Here is the query: SELECT * FROM HumanResources.Employee e INNER JOIN HumanResources.EmployeeDepartmentHistory edh ON e.BusinessEntityID = edh.BusinessEntityID INNER JOIN HumanResources.Shift s ON edh.ShiftID = s.ShiftID OPTION (MERGE JOIN) If you notice above query have additional hint of Merge Join. With the help of this Merge Join query hint this query is now performing much better than before. The entire process takes less than 60 seconds. Please note that it the join hint Merge Join was optimal for this query but it is not necessary that the same hint will be helpful in all the queries. Additionally, if the workload or data pattern changes the query hint of merge join may be no more optimal join. In that case, we will have to redo the entire exercise once again. This is the reason I do not like to use hints in my queries and I discourage all of my users to use the same. However, if you look at this example, this is a great case where hints are optimizing the performance of the query. It is humanly not possible to test out various query hints and index options with the query to figure out which is the most optimal solution. Sometimes, we need to depend on the efficiency tools like DB Optimizer to guide us the way and select the best option from the suggestion provided. Let me know what you think of this article as well your experience with DB Optimizer. Please leave a comment. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Joins, SQL Optimization, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • SQL SERVER – Weekly Series – Memory Lane – #033

    - by Pinal Dave
    Here is the list of selected articles of SQLAuthority.com across all these years. Instead of just listing all the articles I have selected a few of my most favorite articles and have listed them here with additional notes below it. Let me know which one of the following is your favorite article from memory lane. 2007 Spatial Database Definition and Research Documents Here is the definition from Wikipedia about spatial database : A spatial database is a database that is optimized to store and query data related to objects in space, including points, lines and polygons. While typical databases can understand various numeric and character types of data, additional functionality needs to be added for databases to process spatial data types. Select Only Date Part From DateTime – Best Practice A very common question which I receive is how to only get Date or Time part from datetime value. In this blog post I explain the same in very simple words. T-SQL Paging Query Technique Comparison (OVER and ROW_NUMBER()) – CTE vs. Derived Table I have received few emails and comments about my post SQL SERVER – T-SQL Paging Query Technique Comparison – SQL 2000 vs SQL 2005. The main question was is this can be done using CTE? Absolutely! What about Performance? It is identical! Please refer above mentioned article for the history of paging. SQL SERVER – Cannot resolve collation conflict for equal to operation One of the very first error I ever encountered in my career was to resolve this conflict. I have blogged about it and I have realized that many others like me who are facing this error. LEN and DATALENGTH of NULL Simple Example Here is the question for you what is the LEN of NULL value? Well it is very easy – just read the blog. Recovery Models and Selection Very simple and easy explanation of the Database Backup Recovery Model and how to select the best option for you. Explanation SQL SERVER Hash Join Hash join gives best performance when two more join tables are joined and at-least one of them have no index or is not sorted. It is also expected that smaller of the either of table can be read in memory completely (though not necessary). Easy Sequence of SELECT FROM JOIN WHERE GROUP BY HAVING ORDER BY SELECT yourcolumns FROM tablenames JOIN tablenames WHERE condition GROUP BY yourcolumns HAVING aggregatecolumn condition ORDER BY yourcolumns NorthWind Database or AdventureWorks Database – Samples Databases In this blog post we learn how to install Northwind database. I also shared the source where one can download this database as that is used in many examples on MSDN help files. sp_HelpText for sp_HelpText – Puzzle A simple quick puzzle – do you know the answer of it? If not, go ahead and read the blog. 2008 SQL SERVER – 2008 – Step By Step Installation Guide With Images When SQL Server 2008 was newly introduced lots of people had no clue how to install SQL Server 2008 and the amount of the question which I used to receive were so much. I wrote this blog post with the spirit that this will help all the newbies to install SQL Server 2008 with the help of images. Still today this blog post has been bible for all of the people who are confused with SQL Server installation. Inline Variable Assignment I loved this feature. I have always wanted this feature to be present in SQL Server. The last time when I met developers from Microsoft SQL Server, I had talked about this feature. I think this feature saves some time but make the code more readable. Introduction to Policy Management – Enforcing Rules on SQL Server If our company policy is to create all the Stored Procedure with prefix ‘usp’ that developers should be just prevented to create Stored Procedure with any other prefix. Let us see a small tutorial how to create conditions and policy which will prevent any future SP to be created with any other prefix. 2009 Performance Counters from System Views – By Kevin Mckenna Many of you are not aware of this fact that access to performance information is readily available in SQL Server and that too without querying performance counters using a custom application or via perfmon. Till now, this fact has remained undisclosed but through this post I would like to explain you can easily access SQL Server performance counter information. Without putting much effort you will come across the system viewsys.dm_os_performance_counters. As the name suggests, this provides you easy access to the SQL Server performance counter information that is passed on to perfmon, but you can get at it via tsql. Customize Toolbar – Remove Debug Button from Toolbar I was fond of SQL Server Debugger feature in SQL Server 2000. To my utter disappointment, this feature was withdrawn from SQL Server 2005. The button of the debugger is similar to a play button and is used to run debugging commands of Visual Studio. Because of this reason, it gets very much infuriating for developers when they are developing on both – Visual Studio and SSMS. Let us now see how we can remove debugging button from SQL Server Management Studio. Effect of Normalization on Index and Performance A very interesting conversation which started from twitter. If you want to read one link this is the link I encourage you to read it. SSMS Feature – Multi-server Queries Using SQL Server Management Studio (SSMS) DBAs can now query multiple servers from one window. It is quite common for DBAs with large amount of servers to maintain and gather information from multiple SQL Servers and create report. This feature is a blessing for the DBAs, as they can now assemble all the information instantaneously without going anywhere. Query Optimizer Hint ROBUST PLAN – Question to You “ROBUST PLAN” is a kind of query hint which works quite differently than other hints. It does not improve join or force any indexes to use; it just makes sure that a query does not crash due to over the limit size of row. Let me elaborate upon it in the blog post. 2010 Do you really know the difference between various date functions available in SQL Server 2012? Here is a three part story where we explored the same with examples: Fastest Way to Restore the Database Difference Between DATETIME and DATETIME2 Difference Between DATETIME and DATETIME2 – WITH GETDATE Shrinking NDF and MDF Files – Readers’ Opinion Shrinking Database always creates performance degradation and increases fragmentation in the database. I suggest that you keep that in mind before you start reading the following comment. If you are going to say Shrinking Database is bad and evil, here I am saying it first and loud. Now, the comment of Imran is written while keeping in mind only the process showing how the Shrinking Database Operation works. Imran has already explained his understanding and requests further explanation. I have removed the Best Practices section from Imran’s comments, as there are a few corrections. 2011 Solution – Puzzle – SELECT * vs SELECT COUNT(*) This is very interesting question and I am very confident that not every one knows the answer to this question. Let me ask you again – Which will be faster SELECT* or SELECT COUNT (*) or do you think this is apples and oranges comparison. 2012 Service Broker and CAP_CPU_PERCENT – Limiting SQL Server Instances to CPU Usage In SQL Server 2012 there are a few enhancements with regards to SQL Server Resource Governor. One of the enhancement is how the resources are allocated. Let me explain you with examples. Let us understand the entire discussion with the help of three different examples. Finding Size of a Columnstore Index Using DMVs One of the very common question I often see is need of the list of columnstore index along with their size and corresponding table name. I quickly re-wrote a script using DMVs sys.indexes and sys.dm_db_partition_stats. This script gives the size of the columnstore index on disk only. I am sure there will be advanced script to retrieve details related to components associated with the columnstore index. However, I believe following script is sufficient to start getting an idea of columnstore index size. Developer Training Resources and Summary Roundup Developer Training - Importance and Significance - Part 1 In this part we discussed the importance of training in the real world. The most important and valuable resource any company is its employee. Employees who have been well-trained will be better at their jobs and produce a better product.  An employee who is well trained obviously knows more about their job and all the technical aspects. I have a very high opinion about training employees and it is the most important task. Developer Training – Employee Morals and Ethics – Part 2 In this part we discussed the most crucial components of training. Often employees are expecting the company to pay for their training and the company expresses no interest in training the employee. Quite often training expenses are the real issue for both the employee and employer. Developer Training – Difficult Questions and Alternative Perspective - Part 3 This part was the most difficult to write as I tried to address a few difficult questions and answers. Training is such a sensitive issue that many developers when not receiving chance for training think about leaving the organization. Developer Training – Various Options for Developer Training – Part 4 In this part I tried to explore a few methods and options for training. The generic feedback I received on this blog post was short and I should have explored each of the subject of the training in details. I believe there are two big buckets of training 1) Instructor Lead Training and 2) Self Lead Training. Developer Training – A Conclusive Summary- Part 5 There is no better motivation than a personal desire to learn new technology. Honestly there is nothing more personal learning. That “change is the only constant” and “adapt & overcome” are the essential lessons of life. One cannot stop the learning and resist the change. In the IT industry “ego of knowing all” and the “resistance to change” are the most challenging issues. A Quick Look at Logging and Ideas around Logging Question: What is the first thing comes to your mind when you hear the word “Logging”? Strange enough I got a different answer every single time. Let me just list what answer I got from my friends. Let us go over them one by one. Beginning Performance Tuning with SQL Server Execution Plan Solution of Puzzle – Swap Value of Column Without Case Statement Earlier this week I asked a question where I asked how to Swap Values of the column without using CASE Statement. Read here: SQL SERVER – A Puzzle – Swap Value of Column Without Case Statement. I have proposed 3 different solutions in the blog posts itself. I had requested the help of the community to come up with alternate solutions and honestly I am stunned and amazed by the qualified entries. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Memory Lane, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • SQL Spatial: Getting “nearest” calculations working properly

    - by Rob Farley
    If you’ve ever done spatial work with SQL Server, I hope you’ve come across the ‘nearest’ problem. You have five thousand stores around the world, and you want to identify the one that’s closest to a particular place. Maybe you want the store closest to the LobsterPot office in Adelaide, at -34.925806, 138.605073. Or our new US office, at 42.524929, -87.858244. Or maybe both! You know how to do this. You don’t want to use an aggregate MIN or MAX, because you want the whole row, telling you which store it is. You want to use TOP, and if you want to find the closest store for multiple locations, you use APPLY. Let’s do this (but I’m going to use addresses in AdventureWorks2012, as I don’t have a list of stores). Oh, and before I do, let’s make sure we have a spatial index in place. I’m going to use the default options. CREATE SPATIAL INDEX spin_Address ON Person.Address(SpatialLocation); And my actual query: WITH MyLocations AS (SELECT * FROM (VALUES ('LobsterPot Adelaide', geography::Point(-34.925806, 138.605073, 4326)),                        ('LobsterPot USA', geography::Point(42.524929, -87.858244, 4326))                ) t (Name, Geo)) SELECT l.Name, a.AddressLine1, a.City, s.Name AS [State], c.Name AS Country FROM MyLocations AS l CROSS APPLY (     SELECT TOP (1) *     FROM Person.Address AS ad     ORDER BY l.Geo.STDistance(ad.SpatialLocation)     ) AS a JOIN Person.StateProvince AS s     ON s.StateProvinceID = a.StateProvinceID JOIN Person.CountryRegion AS c     ON c.CountryRegionCode = s.CountryRegionCode ; Great! This is definitely working. I know both those City locations, even if the AddressLine1s don’t quite ring a bell. I’m sure I’ll be able to find them next time I’m in the area. But of course what I’m concerned about from a querying perspective is what’s happened behind the scenes – the execution plan. This isn’t pretty. It’s not using my index. It’s sucking every row out of the Address table TWICE (which sucks), and then it’s sorting them by the distance to find the smallest one. It’s not pretty, and it takes a while. Mind you, I do like the fact that it saw an indexed view it could use for the State and Country details – that’s pretty neat. But yeah – users of my nifty website aren’t going to like how long that query takes. The frustrating thing is that I know that I can use the index to find locations that are within a particular distance of my locations quite easily, and Microsoft recommends this for solving the ‘nearest’ problem, as described at http://msdn.microsoft.com/en-au/library/ff929109.aspx. Now, in the first example on this page, it says that the query there will use the spatial index. But when I run it on my machine, it does nothing of the sort. I’m not particularly impressed. But what we see here is that parallelism has kicked in. In my scenario, it’s split the data up into 4 threads, but it’s still slow, and not using my index. It’s disappointing. But I can persuade it with hints! If I tell it to FORCESEEK, or use my index, or even turn off the parallelism with MAXDOP 1, then I get the index being used, and it’s a thing of beauty! Part of the plan is here: It’s massive, and it’s ugly, and it uses a TVF… but it’s quick. The way it works is to hook into the GeodeticTessellation function, which is essentially finds where the point is, and works out through the spatial index cells that surround it. This then provides a framework to be able to see into the spatial index for the items we want. You can read more about it at http://msdn.microsoft.com/en-us/library/bb895265.aspx#tessellation – including a bunch of pretty diagrams. One of those times when we have a much more complex-looking plan, but just because of the good that’s going on. This tessellation stuff was introduced in SQL Server 2012. But my query isn’t using it. When I try to use the FORCESEEK hint on the Person.Address table, I get the friendly error: Msg 8622, Level 16, State 1, Line 1 Query processor could not produce a query plan because of the hints defined in this query. Resubmit the query without specifying any hints and without using SET FORCEPLAN. And I’m almost tempted to just give up and move back to the old method of checking increasingly large circles around my location. After all, I can even leverage multiple OUTER APPLY clauses just like I did in my recent Lookup post. WITH MyLocations AS (SELECT * FROM (VALUES ('LobsterPot Adelaide', geography::Point(-34.925806, 138.605073, 4326)),                        ('LobsterPot USA', geography::Point(42.524929, -87.858244, 4326))                ) t (Name, Geo)) SELECT     l.Name,     COALESCE(a1.AddressLine1,a2.AddressLine1,a3.AddressLine1),     COALESCE(a1.City,a2.City,a3.City),     s.Name AS [State],     c.Name AS Country FROM MyLocations AS l OUTER APPLY (     SELECT TOP (1) *     FROM Person.Address AS ad     WHERE l.Geo.STDistance(ad.SpatialLocation) < 1000     ORDER BY l.Geo.STDistance(ad.SpatialLocation)     ) AS a1 OUTER APPLY (     SELECT TOP (1) *     FROM Person.Address AS ad     WHERE l.Geo.STDistance(ad.SpatialLocation) < 5000     AND a1.AddressID IS NULL     ORDER BY l.Geo.STDistance(ad.SpatialLocation)     ) AS a2 OUTER APPLY (     SELECT TOP (1) *     FROM Person.Address AS ad     WHERE l.Geo.STDistance(ad.SpatialLocation) < 20000     AND a2.AddressID IS NULL     ORDER BY l.Geo.STDistance(ad.SpatialLocation)     ) AS a3 JOIN Person.StateProvince AS s     ON s.StateProvinceID = COALESCE(a1.StateProvinceID,a2.StateProvinceID,a3.StateProvinceID) JOIN Person.CountryRegion AS c     ON c.CountryRegionCode = s.CountryRegionCode ; But this isn’t friendly-looking at all, and I’d use the method recommended by Isaac Kunen, who uses a table of numbers for the expanding circles. It feels old-school though, when I’m dealing with SQL 2012 (and later) versions. So why isn’t my query doing what it’s supposed to? Remember the query... WITH MyLocations AS (SELECT * FROM (VALUES ('LobsterPot Adelaide', geography::Point(-34.925806, 138.605073, 4326)),                        ('LobsterPot USA', geography::Point(42.524929, -87.858244, 4326))                ) t (Name, Geo)) SELECT l.Name, a.AddressLine1, a.City, s.Name AS [State], c.Name AS Country FROM MyLocations AS l CROSS APPLY (     SELECT TOP (1) *     FROM Person.Address AS ad     ORDER BY l.Geo.STDistance(ad.SpatialLocation)     ) AS a JOIN Person.StateProvince AS s     ON s.StateProvinceID = a.StateProvinceID JOIN Person.CountryRegion AS c     ON c.CountryRegionCode = s.CountryRegionCode ; Well, I just wasn’t reading http://msdn.microsoft.com/en-us/library/ff929109.aspx properly. The following requirements must be met for a Nearest Neighbor query to use a spatial index: A spatial index must be present on one of the spatial columns and the STDistance() method must use that column in the WHERE and ORDER BY clauses. The TOP clause cannot contain a PERCENT statement. The WHERE clause must contain a STDistance() method. If there are multiple predicates in the WHERE clause then the predicate containing STDistance() method must be connected by an AND conjunction to the other predicates. The STDistance() method cannot be in an optional part of the WHERE clause. The first expression in the ORDER BY clause must use the STDistance() method. Sort order for the first STDistance() expression in the ORDER BY clause must be ASC. All the rows for which STDistance returns NULL must be filtered out. Let’s start from the top. 1. Needs a spatial index on one of the columns that’s in the STDistance call. Yup, got the index. 2. No ‘PERCENT’. Yeah, I don’t have that. 3. The WHERE clause needs to use STDistance(). Ok, but I’m not filtering, so that should be fine. 4. Yeah, I don’t have multiple predicates. 5. The first expression in the ORDER BY is my distance, that’s fine. 6. Sort order is ASC, because otherwise we’d be starting with the ones that are furthest away, and that’s tricky. 7. All the rows for which STDistance returns NULL must be filtered out. But I don’t have any NULL values, so that shouldn’t affect me either. ...but something’s wrong. I do actually need to satisfy #3. And I do need to make sure #7 is being handled properly, because there are some situations (eg, differing SRIDs) where STDistance can return NULL. It says so at http://msdn.microsoft.com/en-us/library/bb933808.aspx – “STDistance() always returns null if the spatial reference IDs (SRIDs) of the geography instances do not match.” So if I simply make sure that I’m filtering out the rows that return NULL… …then it’s blindingly fast, I get the right results, and I’ve got the complex-but-brilliant plan that I wanted. It just wasn’t overly intuitive, despite being documented. @rob_farley

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  • Unity3d generating a file in iOS and saving it on a linux machine

    - by N0xus
    I've done a little research and don't know if the following is possible. At the moment I have created a small application in Unity that generates an XML file. This file will be used to help set up my game. It's done in Unity due to it being cross platform with no need to re-write a single line of code. Eventually this will run on an iPad. However, my game will be running on a linux computer and I need to pass over the XML file to the computer that will be running the final game (please don't ask why I'm doing that, it's something I need to do). So what I want to know is the following: Can I generate my XML file on an iPad and have that XML file be saved, and transmitted to a linux machine, without the need to manually copy the file over. If so, how is this possible?

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  • tfs 2010 RC Agile Process template update New Task progress report

    Maybe my next post will just be about why I am so excited and impressed with the out of the box templates.  But, for this first blog with my new focus, I thought I would just walk through the process I went through to create a task progress report (to enhance the out of the box Agile template). So, I started with the MSF for Agile Development 5.0 RC template.  After reviewing the template, I came away pretty excited about many of the new reports.  I am especially excited about the reporting services reports.  The big advantage I see here is that these are querying the Warehouse directly instead of the Analysis Services Cube which means that they are much closer to real-time which I find very important for reports like Burndown and task status.  One report that I focused on right away was the User Story Progress Report.  An overview is shown below: This report is very useful, but a lot of our internal managers really prefer to manage at the task level and either dont have stories in TFS or would like to view this type of report for tasks in addition to the User Stories.  So, what did I do? Step 1: Download the Agile Template In VS 2010 RC, open Process Template Manager from Team->Team Project Collection Settings.  Download the MSF for Agile Development template to your local file system.  A project template is a folder of xml files.  There is a ProcessTemplate.xml in the root and then a bunch of directories for things like Work Item Definitions and Queries, Reports, Shared Documents and Source Control Settings.  Step 2: Copy the folder My plan here is to make a new template with all of my modifications.  You can also just enhance update the MSF template.  However, I think it is cleaner when you start making modifications to make your own template.  So, copy the folder and name it with your new template name. Step 3: Change Template Name Open ProcessTemplate.xml and change the <name> of the template. Step 4: Copy the rdl of the Report you want to use a starting point In my case, I copied Stories Progress.rdl and named the file Task Progress Breakdown.rdl.  I reviewed the requirements for the new report with some of the users here and came up with this plan.  Should show tasks and be expandable to show subtasks.  Should add Assigned To and Estimated Finish Date as 2 extra columns. Step 5: Walkthrough the existing report to understand how it works The main thing that I do here is try to get the sql to run in SQL Management Studio.  So, I can walkthrough the process of building up the data for the report. After analyzing this particular report I found a couple of very useful things.  One, this report is already built to display subtasks if I just flip the IncludeTasks flag to 1.  So, if you are using Stories and have tasks assigned to each story.  This might give you everything you want.  For my purposes, I did make that change to the Stories Progress report as I find it to be a more useful report to be able to see the tasks that comprise each story.  But, I still wanted a task only version with the additional fields. Step 6: Update the report definition I tend to work on rdl in visual studio directly as xml.  Especially when I am just altering an existing report, I find it easier than trying to deal with the BI Studio designer.  For my report I made the following changes. Updated Fields Removed Stack Rank and Replaced with Priority since we dont use Stack Rank Added FinishDate and AssignedTo Changed the root deliverable SQL to pull @tasks instead of @deliverablecategory and added a join CurrentWorkItemView for FinishDate and Assigned to SELECT cwi.[System_Id] AS ID FROM [CurrentWorkItemView] cwi             WHERE cwi.[System_WorkItemType] IN (@Task)             AND cwi.[ProjectNodeGUID] = @ProjectGuid SELECT lh.SourceWorkItemID AS ID FROM FactWorkItemLinkHistory lh             INNER JOIN [CurrentWorkItemView] cwi ON lh.TargetWorkItemID = cwi.[System_Id]             WHERE lh.WorkItemLinkTypeSK = @ParentWorkItemLinkTypeSK                 AND lh.RemovedDate = CONVERT(DATETIME, '9999', 126)                 AND lh.TeamProjectCollectionSK = @TeamProjectCollectionSK                 AND cwi.[System_WorkItemType] NOT IN (@DeliverableCategory) Added AssignedTo and FinishDate columns to the @Rollups table Added two columns to the table used for column headers <Tablix Name="ProgressTable">         <TablixBody>           <TablixColumns>             <TablixColumn>               <Width>2.7625in</Width>             </TablixColumn>             <TablixColumn>               <Width>0.5125in</Width>             </TablixColumn>             <TablixColumn>               <Width>3.4625in</Width>             </TablixColumn>             <TablixColumn>               <Width>0.7625in</Width>             </TablixColumn>             <TablixColumn>               <Width>1.25in</Width>             </TablixColumn>             <TablixColumn>               <Width>1.25in</Width>             </TablixColumn>           </TablixColumns> Added Cells for the two new headers Added Cells to the data table to include the two new values (Assigned to & Finish Date) Changed a bunch of widths that would change the format of the report to display landscape and have room for the two additional columns Set the Value of the IncludeTasks Parameter to 1 <ReportParameter Name="IncludeTasks">       <DataType>Integer</DataType>       <DefaultValue>         <Values>           <Value>=1</Value>         </Values>       </DefaultValue>       <Prompt>IncludeTasks</Prompt>       <Hidden>true</Hidden>     </ReportParameter> Change a few descriptions on how the report should be used This is the resulting report I have attached the final rdl. Step 7: Update ReportTasks.xml Last step before the template is ready for use is to update the reportTasks.xml file in the reports folder.  This file defines the reports that are available in the template.           <report name="Task Progress Breakdown" filename="Reports\Task Progress Breakdown.rdl" folder="Project Management" cacheExpiration="30">             <parameters>               <parameter name="ExplicitProject" value="" />             </parameters>             <datasources>               <reference name="/Tfs2010ReportDS" dsname="TfsReportDS" />             </datasources>           </report> Step 8: Upload the template Open the process Template Manager just like Step 1.  And upload the new template. Thats it.  One other note, if you want to add this report to existing team project you will have to go into reportmanager (the reporting services portal) and upload the rdl to that projects directory.Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • how do you document your development process?

    - by David
    My current state is a mixture of spreadsheets, wikis, documents, and dated folders for my input/configuration and output files and bzr version control for code. I am relatively new to programming that requires this level of documentation, and I would like to find a better, more coherent approach. update (for clarity): My inputs are data used to generate configuration files with parameter values and my outputs are analyses of model predictions. I would really like to have an approach that allows me to associate particular configuration(s) with particular outputs, so that I can ask questions of my documentation such as "what causes over/under estimates?" or "what causes error 'X'"?

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  • ANTS CLR and Memory Profiler In Depth Review (Part 1 of 2 &ndash; CLR Profiler)

    - by ToStringTheory
    One of the things that people might not know about me, is my obsession to make my code as efficient as possible.  Many people might not realize how much of a task or undertaking that this might be, but it is surely a task as monumental as climbing Mount Everest, except this time it is a challenge for the mind…  In trying to make code efficient, there are many different factors that play a part – size of project or solution, tiers, language used, experience and training of the programmer, technologies used, maintainability of the code – the list can go on for quite some time. I spend quite a bit of time when developing trying to determine what is the best way to implement a feature to accomplish the efficiency that I look to achieve.  One program that I have recently come to learn about – Red Gate ANTS Performance (CLR) and Memory profiler gives me tools to accomplish that job more efficiently as well.  In this review, I am going to cover some of the features of the ANTS profiler set by compiling some hideous example code to test against. Notice As a member of the Geeks With Blogs Influencers program, one of the perks is the ability to review products, in exchange for a free license to the program.  I have not let this affect my opinions of the product in any way, and Red Gate nor Geeks With Blogs has tried to influence my opinion regarding this product in any way. Introduction The ANTS Profiler pack provided by Red Gate was something that I had not heard of before receiving an email regarding an offer to review it for a license.  Since I look to make my code efficient, it was a no brainer for me to try it out!  One thing that I have to say took me by surprise is that upon downloading the program and installing it you fill out a form for your usual contact information.  Sure enough within 2 hours, I received an email from a sales representative at Red Gate asking if she could help me to achieve the most out of my trial time so it wouldn’t go to waste.  After replying to her and explaining that I was looking to review its feature set, she put me in contact with someone that setup a demo session to give me a quick rundown of its features via an online meeting.  After having dealt with a massive ordeal with one of my utility companies and their complete lack of customer service, Red Gates friendly and helpful representatives were a breath of fresh air, and something I was thankful for. ANTS CLR Profiler The ANTS CLR profiler is the thing I want to focus on the most in this post, so I am going to dive right in now. Install was simple and took no time at all.  It installed both the profiler for the CLR and Memory, but also visual studio extensions to facilitate the usage of the profilers (click any images for full size images): The Visual Studio menu options (under ANTS menu) Starting the CLR Performance Profiler from the start menu yields this window If you follow the instructions after launching the program from the start menu (Click File > New Profiling Session to start a new project), you are given a dialog with plenty of options for profiling: The New Session dialog.  Lots of options.  One thing I noticed is that the buttons in the lower right were half-covered by the panel of the application.  If I had to guess, I would imagine that this is caused by my DPI settings being set to 125%.  This is a problem I have seen in other applications as well that don’t scale well to different dpi scales. The profiler options give you the ability to profile: .NET Executable ASP.NET web application (hosted in IIS) ASP.NET web application (hosted in IIS express) ASP.NET web application (hosted in Cassini Web Development Server) SharePoint web application (hosted in IIS) Silverlight 4+ application Windows Service COM+ server XBAP (local XAML browser application) Attach to an already running .NET 4 process Choosing each option provides a varying set of other variables/options that one can set including options such as application arguments, operating path, record I/O performance performance counters to record (43 counters in all!), etc…  All in all, they give you the ability to profile many different .Net project types, and make it simple to do so.  In most cases of my using this application, I would be using the built in Visual Studio extensions, as they automatically start a new profiling project in ANTS with the options setup, and start your program, however RedGate has made it easy enough to profile outside of Visual Studio as well. On the flip side of this, as someone who lives most of their work life in Visual Studio, one thing I do wish is that instead of opening an entirely separate application/gui to perform profiling after launching, that instead they would provide a Visual Studio panel with the information, and integrate more of the profiling project information into Visual Studio.  So, now that we have an idea of what options that the profiler gives us, its time to test its abilities and features. Horrendous Example Code – Prime Number Generator One of my interests besides development, is Physics and Math – what I went to college for.  I have especially always been interested in prime numbers, as they are something of a mystery…  So, I decided that I would go ahead and to test the abilities of the profiler, I would write a small program, website, and library to generate prime numbers in the quantity that you ask for.  I am going to start off with some terrible code, and show how I would see the profiler being used as a development tool. First off, the IPrimes interface (all code is downloadable at the end of the post): interface IPrimes { IEnumerable<int> GetPrimes(int retrieve); } Simple enough, right?  Anything that implements the interface will (hopefully) provide an IEnumerable of int, with the quantity specified in the parameter argument.  Next, I am going to implement this interface in the most basic way: public class DumbPrimes : IPrimes { public IEnumerable<int> GetPrimes(int retrieve) { //store a list of primes already found var _foundPrimes = new List<int>() { 2, 3 }; //if i ask for 1 or two primes, return what asked for if (retrieve <= _foundPrimes.Count()) return _foundPrimes.Take(retrieve); //the next number to look at int _analyzing = 4; //since I already determined I don't have enough //execute at least once, and until quantity is sufficed do { //assume prime until otherwise determined bool isPrime = true; //start dividing at 2 //divide until number is reached, or determined not prime for (int i = 2; i < _analyzing && isPrime; i++) { //if (i) goes into _analyzing without a remainder, //_analyzing is NOT prime if (_analyzing % i == 0) isPrime = false; } //if it is prime, add to found list if (isPrime) _foundPrimes.Add(_analyzing); //increment number to analyze next _analyzing++; } while (_foundPrimes.Count() < retrieve); return _foundPrimes; } } This is the simplest way to get primes in my opinion.  Checking each number by the straight definition of a prime – is it divisible by anything besides 1 and itself. I have included this code in a base class library for my solution, as I am going to use it to demonstrate a couple of features of ANTS.  This class library is consumed by a simple non-MVVM WPF application, and a simple MVC4 website.  I will not post the WPF code here inline, as it is simply an ObservableCollection<int>, a label, two textbox’s, and a button. Starting a new Profiling Session So, in Visual Studio, I have just completed my first stint developing the GUI and DumbPrimes IPrimes class, so now I want to check my codes efficiency by profiling it.  All I have to do is build the solution (surprised initiating a profiling session doesn’t do this, but I suppose I can understand it), and then click the ANTS menu, followed by Profile Performance.  I am then greeted by the profiler starting up and already monitoring my program live: You are provided with a realtime graph at the top, and a pane at the bottom giving you information on how to proceed.  I am going to start by asking my program to show me the first 15000 primes: After the program finally began responding again (I did all the work on the main UI thread – how bad!), I stopped the profiler, which did kill the process of my program too.  One important thing to note, is that the profiler by default wants to give you a lot of detail about the operation – line hit counts, time per line, percent time per line, etc…  The important thing to remember is that this itself takes a lot of time.  When running my program without the profiler attached, it can generate the 15000 primes in 5.18 seconds, compared to 74.5 seconds – almost a 1500 percent increase.  While this may seem like a lot, remember that there is a trade off.  It may be WAY more inefficient, however, I am able to drill down and make improvements to specific problem areas, and then decrease execution time all around. Analyzing the Profiling Session After clicking ‘Stop Profiling’, the process running my application stopped, and the entire execution time was automatically selected by ANTS, and the results shown below: Now there are a number of interesting things going on here, I am going to cover each in a section of its own: Real Time Performance Counter Bar (top of screen) At the top of the screen, is the real time performance bar.  As your application is running, this will constantly update with the currently selected performance counters status.  A couple of cool things to note are the fact that you can drag a selection around specific time periods to drill down the detail views in the lower 2 panels to information pertaining to only that period. After selecting a time period, you can bookmark a section and name it, so that it is easy to find later, or after reloaded at a later time.  You can also zoom in, out, or fit the graph to the space provided – useful for drilling down. It may be hard to see, but at the top of the processor time graph below the time ticks, but above the red usage graph, there is a green bar. This bar shows at what times a method that is selected in the ‘Call tree’ panel is called. Very cool to be able to click on a method and see at what times it made an impact. As I said before, ANTS provides 43 different performance counters you can hook into.  Click the arrow next to the Performance tab at the top will allow you to change between different counters if you have them selected: Method Call Tree, ADO.Net Database Calls, File IO – Detail Panel Red Gate really hit the mark here I think. When you select a section of the run with the graph, the call tree populates to fill a hierarchical tree of method calls, with information regarding each of the methods.   By default, methods are hidden where the source is not provided (framework type code), however, Red Gate has integrated Reflector into ANTS, so even if you don’t have source for something, you can select a method and get the source if you want.  Methods are also hidden where the impact is seen as insignificant – methods that are only executed for 1% of the time of the overall calling methods time; in other words, working on making them better is not where your efforts should be focused. – Smart! Source Panel – Detail Panel The source panel is where you can see line level information on your code, showing the code for the currently selected method from the Method Call Tree.  If the code is not available, Reflector takes care of it and shows the code anyways! As you can notice, there does seem to be a problem with how ANTS determines what line is the actual line that a call is completed on.  I have suspicions that this may be due to some of the inline code optimizations that the CLR applies upon compilation of the assembly.  In a method with comments, the problem is much more severe: As you can see here, apparently the most offending code in my base library was a comment – *gasp*!  Removing the comments does help quite a bit, however I hope that Red Gate works on their counter algorithm soon to improve the logic on positioning for statistics: I did a small test just to demonstrate the lines are correct without comments. For me, it isn’t a deal breaker, as I can usually determine the correct placements by looking at the application code in the region and determining what makes sense, but it is something that would probably build up some irritation with time. Feature – Suggest Method for Optimization A neat feature to really help those in need of a pointer, is the menu option under tools to automatically suggest methods to optimize/improve: Nice feature – clicking it filters the call tree and stars methods that it thinks are good candidates for optimization.  I do wish that they would have made it more visible for those of use who aren’t great on sight: Process Integration I do think that this could have a place in my process.  After experimenting with the profiler, I do think it would be a great benefit to do some development, testing, and then after all the bugs are worked out, use the profiler to check on things to make sure nothing seems like it is hogging more than its fair share.  For example, with this program, I would have developed it, ran it, tested it – it works, but slowly. After looking at the profiler, and seeing the massive amount of time spent in 1 method, I might go ahead and try to re-implement IPrimes (I actually would probably rewrite the offending code, but so that I can distribute both sets of code easily, I’m just going to make another implementation of IPrimes).  Using two pieces of knowledge about prime numbers can make this method MUCH more efficient – prime numbers fall into two buckets 6k+/-1 , and a number is prime if it is not divisible by any other primes before it: public class SmartPrimes : IPrimes { public IEnumerable<int> GetPrimes(int retrieve) { //store a list of primes already found var _foundPrimes = new List<int>() { 2, 3 }; //if i ask for 1 or two primes, return what asked for if (retrieve <= _foundPrimes.Count()) return _foundPrimes.Take(retrieve); //the next number to look at int _k = 1; //since I already determined I don't have enough //execute at least once, and until quantity is sufficed do { //assume prime until otherwise determined bool isPrime = true; int potentialPrime; //analyze 6k-1 //assign the value to potential potentialPrime = 6 * _k - 1; //if there are any primes that divise this, it is NOT a prime number //using PLINQ for quick boost isPrime = !_foundPrimes.AsParallel() .Any(prime => potentialPrime % prime == 0); //if it is prime, add to found list if (isPrime) _foundPrimes.Add(potentialPrime); if (_foundPrimes.Count() == retrieve) break; //analyze 6k+1 //assign the value to potential potentialPrime = 6 * _k + 1; //if there are any primes that divise this, it is NOT a prime number //using PLINQ for quick boost isPrime = !_foundPrimes.AsParallel() .Any(prime => potentialPrime % prime == 0); //if it is prime, add to found list if (isPrime) _foundPrimes.Add(potentialPrime); //increment k to analyze next _k++; } while (_foundPrimes.Count() < retrieve); return _foundPrimes; } } Now there are definitely more things I can do to help make this more efficient, but for the scope of this example, I think this is fine (but still hideous)! Profiling this now yields a happy surprise 27 seconds to generate the 15000 primes with the profiler attached, and only 1.43 seconds without.  One important thing I wanted to call out though was the performance graph now: Notice anything odd?  The %Processor time is above 100%.  This is because there is now more than 1 core in the operation.  A better label for the chart in my mind would have been %Core time, but to each their own. Another odd thing I noticed was that the profiler seemed to be spot on this time in my DumbPrimes class with line details in source, even with comments..  Odd. Profiling Web Applications The last thing that I wanted to cover, that means a lot to me as a web developer, is the great amount of work that Red Gate put into the profiler when profiling web applications.  In my solution, I have a simple MVC4 application setup with 1 page, a single input form, that will output prime values as my WPF app did.  Launching the profiler from Visual Studio as before, nothing is really different in the profiler window, however I did receive a UAC prompt for a Red Gate helper app to integrate with the web server without notification. After requesting 500, 1000, 2000, and 5000 primes, and looking at the profiler session, things are slightly different from before: As you can see, there are 4 spikes of activity in the processor time graph, but there is also something new in the call tree: That’s right – ANTS will actually group method calls by get/post operations, so it is easier to find out what action/page is giving the largest problems…  Pretty cool in my mind! Overview Overall, I think that Red Gate ANTS CLR Profiler has a lot to offer, however I think it also has a long ways to go.  3 Biggest Pros: Ability to easily drill down from time graph, to method calls, to source code Wide variety of counters to choose from when profiling your application Excellent integration/grouping of methods being called from web applications by request – BRILLIANT! 3 Biggest Cons: Issue regarding line details in source view Nit pick – Processor time vs. Core time Nit pick – Lack of full integration with Visual Studio Ratings Ease of Use (7/10) – I marked down here because of the problems with the line level details and the extra work that that entails, and the lack of better integration with Visual Studio. Effectiveness (10/10) – I believe that the profiler does EXACTLY what it purports to do.  Especially with its large variety of performance counters, a definite plus! Features (9/10) – Besides the real time performance monitoring, and the drill downs that I’ve shown here, ANTS also has great integration with ADO.Net, with the ability to show database queries run by your application in the profiler.  This, with the line level details, the web request grouping, reflector integration, and various options to customize your profiling session I think create a great set of features! Customer Service (10/10) – My entire experience with Red Gate personnel has been nothing but good.  their people are friendly, helpful, and happy! UI / UX (8/10) – The interface is very easy to get around, and all of the options are easy to find.  With a little bit of poking around, you’ll be optimizing Hello World in no time flat! Overall (8/10) – Overall, I am happy with the Performance Profiler and its features, as well as with the service I received when working with the Red Gate personnel.  I WOULD recommend you trying the application and seeing if it would fit into your process, BUT, remember there are still some kinks in it to hopefully be worked out. My next post will definitely be shorter (hopefully), but thank you for reading up to here, or skipping ahead!  Please, if you do try the product, drop me a message and let me know what you think!  I would love to hear any opinions you may have on the product. Code Feel free to download the code I used above – download via DropBox

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  • Looking into Entity Framework Code First Migrations

    - by nikolaosk
    In this post I will introduce you to Code First Migrations, an Entity Framework feature introduced in version 4.3 back in February of 2012.I have extensively covered Entity Framework in this blog. Please find my other Entity Framework posts here .   Before the addition of Code First Migrations (4.1,4.2 versions), Code First database initialisation meant that Code First would create the database if it does not exist (the default behaviour - CreateDatabaseIfNotExists). The other pattern we could use is DropCreateDatabaseIfModelChanges which means that Entity Framework, will drop the database if it realises that model has changes since the last time it created the database.The final pattern is DropCreateDatabaseAlways which means that Code First will recreate the database every time one runs the application.That is of course fine for the development database but totally unacceptable and catastrophic when you have a production database. We cannot lose our data because of the work that Code First works.Migrations solve this problem.With migrations we can modify the database without completely dropping it.We can modify the database schema to reflect the changes to the model without losing data.In version EF 5.0 migrations are fully included and supported. I will demonstrate migrations with a hands-on example.Let me say a few words first about Entity Framework first. The .Net framework provides support for Object Relational Mappingthrough EF. So EF is a an ORM tool and it is now the main data access technology that microsoft works on. I use it quite extensively in my projects. Through EF we have many things out of the box provided for us. We have the automatic generation of SQL code.It maps relational data to strongly types objects.All the changes made to the objects in the memory are persisted in a transactional way back to the data store. You can find in this post an example on how to use the Entity Framework to retrieve data from an SQL Server Database using the "Database/Schema First" approach.In this approach we make all the changes at the database level and then we update the model with those changes. In this post you can see an example on how to use the "Model First" approach when working with ASP.Net and the Entity Framework.This model was firstly introduced in EF version 4.0 and we could start with a blank model and then create a database from that model.When we made changes to the model , we could recreate the database from the new model. The Code First approach is the more code-centric than the other two. Basically we write POCO classes and then we persist to a database using something called DBContext.Code First relies on DbContext. We create 2,3 classes (e.g Person,Product) with properties and then these classes interact with the DbContext class we can create a new database based upon our POCOS classes and have tables generated from those classes.We do not have an .edmx file in this approach.By using this approach we can write much easier unit tests.DbContext is a new context class and is smaller,lightweight wrapper for the main context class which is ObjectContext (Schema First and Model First).Let's move on to our hands-on example.I have installed VS 2012 Ultimate edition in my Windows 8 machine. 1)  Create an empty asp.net web application. Give your application a suitable name. Choose C# as the development language2) Add a new web form item in your application. Leave the default name.3) Create a new folder. Name it CodeFirst .4) Add a new item in your application, a class file. Name it Footballer.cs. This is going to be a simple POCO class.Place this class file in the CodeFirst folder.The code follows    public class Footballer     {         public int FootballerID { get; set; }         public string FirstName { get; set; }         public string LastName { get; set; }         public double Weight { get; set; }         public double Height { get; set; }              }5) We will have to add EF 5.0 to our project. Right-click on the project in the Solution Explorer and select Manage NuGet Packages... for it.In the window that will pop up search for Entity Framework and install it.Have a look at the picture below   If you want to find out if indeed EF version is 5.0 version is installed have a look at the References. Have a look at the picture below to see what you will see if you have installed everything correctly.Have a look at the picture below 6) Then we need to create a context class that inherits from DbContext.Add a new class to the CodeFirst folder.Name it FootballerDBContext.Now that we have the entity classes created, we must let the model know.I will have to use the DbSet<T> property.The code for this class follows     public class FootballerDBContext:DbContext     {         public DbSet<Footballer> Footballers { get; set; }             }    Do not forget to add  (using System.Data.Entity;) in the beginning of the class file 7) We must take care of the connection string. It is very easy to create one in the web.config.It does not matter that we do not have a database yet.When we run the DbContext and query against it , it will use a connection string in the web.config and will create the database based on the classes.I will use the name "FootballTraining" for the database.In my case the connection string inside the web.config, looks like this    <connectionStrings>    <add name="CodeFirstDBContext" connectionString="server=.;integrated security=true; database=FootballTraining" providerName="System.Data.SqlClient"/>                       </connectionStrings>8) Now it is time to create Linq to Entities queries to retrieve data from the database . Add a new class to your application in the CodeFirst folder.Name the file DALfootballer.csWe will create a simple public method to retrieve the footballers. The code for the class followspublic class DALfootballer     {         FootballerDBContext ctx = new FootballerDBContext();         public List<Footballer> GetFootballers()         {             var query = from player in ctx.Footballers select player;             return query.ToList();         }     } 9) Place a GridView control on the Default.aspx page and leave the default name.Add an ObjectDataSource control on the Default.aspx page and leave the default name. Set the DatasourceID property of the GridView control to the ID of the ObjectDataSource control.(DataSourceID="ObjectDataSource1" ). Let's configure the ObjectDataSource control. Click on the smart tag item of the ObjectDataSource control and select Configure Data Source. In the Wizzard that pops up select the DALFootballer class and then in the next step choose the GetFootballers() method.Click Finish to complete the steps of the wizzard.Build and Run your application.  10) Obviously you will not see any records coming back from your database, because we have not inserted anything. The database is created, though.Have a look at the picture below.  11) Now let's change the POCO class. Let's add a new property to the Footballer.cs class.        public int Age { get; set; } Build and run your application again. You will receive an error. Have a look at the picture below 12) That was to be expected.EF Code First Migrations is not activated by default. We have to activate them manually and configure them according to your needs. We will open the Package Manager Console from the Tools menu within Visual Studio 2012.Then we will activate the EF Code First Migration Features by writing the command “Enable-Migrations”.  Have a look at the picture below. This adds a new folder Migrations in our project. A new auto-generated class Configuration.cs is created.Another class is also created [CURRENTDATE]_InitialCreate.cs and added to our project.The Configuration.cs  is shown in the picture below. The [CURRENTDATE]_InitialCreate.cs is shown in the picture below  13) ??w we are ready to migrate the changes in the database. We need to run the Add-Migration Age command in Package Manager ConsoleAdd-Migration will scaffold the next migration based on changes you have made to your model since the last migration was created.In the Migrations folder, the file 201211201231066_Age.cs is created.Have a look at the picture below to see the newly generated file and its contents. Now we can run the Update-Database command in Package Manager Console .See the picture above.Code First Migrations will compare the migrations in our Migrations folder with the ones that have been applied to the database. It will see that the Age migration needs to be applied, and run it.The EFMigrations.CodeFirst.FootballeDBContext database is now updated to include the Age column in the Footballers table.Build and run your application.Everything will work fine now.Have a look at the picture below to see the migrations applied to our table. 14) We may want it to automatically upgrade the database (by applying any pending migrations) when the application launches.Let's add another property to our Poco class.          public string TShirtNo { get; set; }We want this change to migrate automatically to the database.We go to the Configuration.cs we enable automatic migrations.     public Configuration()        {            AutomaticMigrationsEnabled = true;        } In the Page_Load event handling routine we have to register the MigrateDatabaseToLatestVersion database initializer. A database initializer simply contains some logic that is used to make sure the database is setup correctly.   protected void Page_Load(object sender, EventArgs e)        {            Database.SetInitializer(new MigrateDatabaseToLatestVersion<FootballerDBContext, Configuration>());        } Build and run your application. It will work fine. Have a look at the picture below to see the migrations applied to our table in the database. Hope it helps!!!  

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  • Book Review - Programming Windows Azure by Siriram Krishnan

    - by BuckWoody
    As part of my professional development, I’ve created a list of books to read throughout the year, starting in June of 2011. This a review of the first one, called Programming Windows Azure by Siriram Krishnan. You can find my entire list of books I’m reading for my career here: http://blogs.msdn.com/b/buckwoody/archive/2011/06/07/head-in-the-clouds-eyes-on-the-books.aspx  Why I Chose This Book: As part of my learning style, I try to read multiple books about a single subject. I’ve found that at least 3 books are necessary to get the right amount of information to me. This is a “technical” work, meaning that it deals with technology and not business, writing or other facets of my career. I’ll have a mix of all of those as I read along. I chose this work in addition to others I’ve read since it covers everything from an introduction to more advanced topics in a single book. It also has some practical examples of actually working with the product, particularly on storage. Although it’s dated, many examples normally translate. I also saw that it had pretty good reviews. What I learned: I learned a great deal about storage, and many useful code snippets. I do think that there could have been more of a focus on the application fabric - but of course that wasn’t as mature a feature when this book was written. I learned some great architecture examples, and in one section I learned more about encryption. In that example, however, I would rather have seen the examples go the other way - the book focused on moving data from on-premise to Azure storage in an encrypted fashion. Using the Application Fabric I would rather see sensitive data left in a hybrid fashion on premise, and connect to for the Azure application. Even so, the examples were very useful. If you’re looking for a good “starter” Azure book, this is a good choice. I also recommend the last chapter as a quick read for a DBA, or Database Administrator. It’s not very long, but useful. Note that the limits described are incorrect - which is one of the dangers of reading a book about any cloud offering. The services offered are updated so quickly that the information is in constant danger of being “stale”. Even so, I found this a useful book, which I believe will help me work with Azure better. Raw Notes: I take notes as I read, calling that process “reading with a pencil”. I find that when I do that I pay attention better, and record some things that I need to know later. I’ll take these notes, categorize them into a OneNote notebook that I synchronize in my Live.com account, and that way I can search them from anywhere. I can even read them on the web, since the Live.com has a OneNote program built in. Note that these are the raw notes, so they might not make a lot of sense out of context - I include them here so you can watch my though process. Programming Windows Azure by Siriram Krishnan: Learning about how to select applications suitable for Distributed Technology. Application Fabric gets the least attention; probably because it was newer at the time. Very clear (Chapter One) Good foundation Background and history, but not too much I normally arrange my descriptions differently, starting with the use-cases and moving to physicality, but this difference helps me. Interesting that I am reading this using Safari Books Online, which uses many of these concepts. Taught me some new aspects of a Hypervisor – very low-level information about the Azure Fabric (not to be confused with the Application Fabric feature) (Chapter Two) Good detail of what is included in the SDK. Even more is available now. CS = Cloud Service (Chapter 3) Place Storage info in the configuration file, since it can be streamed in-line with a running app. Ditto for logging, and keep separated configs for staging and testing. Easy-switch in and switch out.  (Chapter 4) There are two Runtime API’s, one of external and one for internal. Realizing how powerful this paradigm really is. Some places seem light, and to drop off but perhaps that’s best. Managing API is not charged, which is nice. I don’t often think about the price, until it comes to an actual deployment (Chapter 5) Csmanage is something I want to dig into deeper. API requires package moves to Blob storage first, so it needs a URL. Csmanage equivalent can be written in Unix scripting using openssl. Upgrades are possible, and you use the upgradeDomainCount attribute in the Service-Definition.csdef file  Always use a low-privileged account to test on the dev fabric, since Windows Azure runs in partial trust. Full trust is available, but can be dangerous and must be well-thought out. (Chapter 6) Learned how to run full CMD commands in a web window – not that you would ever do that, but it was an interesting view into those links. This leads to a discussion on hosting other runtimes (such as Java or PHP) in Windows Azure. I got an expanded view on this process, although this is where the book shows its age a little. Books can be a problem for Cloud Computing for this reason – things just change too quickly. Windows Azure storage is not eventually consistent – it is instantly consistent with multi-phase commit. Plumbing for this is internal, not required to code that. (Chapter 7) REST API makes the service interoperable, hybrid, and consistent across code architectures. Nicely done. Use affinity groups to keep data and code together. Side note: e-book readers need a common “notes” feature. There’s a decent quick description of REST in this chapter. Learned about CloudDrive code – PowerShell sample that mounts Blob storage as a local provider. Works against Dev fabric by default, can be switched to Account. Good treatment in the storage chapters on the differences between using Dev storage and Azure storage. These can be mitigated. No, blobs are not of any size or number. Not a good statement (Chapter 8) Blob storage is probably Azure’s closest play to Infrastructure as a Service (Iaas). Blob change operations must be authenticated, even when public. Chapters on storage are pretty in-depth. Queue Messages are base-64 encoded (Chapter 9) The visibility timeout ensures processing of message in a disconnected system. Order is not guaranteed for a message, so if you need that set an increasing number in the queue mechanism. While Queues are accessible via REST, they are not public and are secured by default. Interesting – the header for a queue request includes an estimated count. This can be useful to create more worker roles in a dynamic system. Each Entity (row) in the Azure Table service is atomic – all or nothing. (Chapter 10) An entity can have up to 255 Properties  Use “ID” for the class to indicate the key value, or use the [DataServiceKey] Attribute.  LINQ makes working with the Azure Table Service much easier, although Interop is certainly possible. Good description on the process of selecting the Partition and Row Key.  When checking for continuation tokens for pagination, include logic that falls out of the check in case you are at the last page.  On deleting a storage object, it is instantly unavailable, however a background process is dispatched to perform the physical deletion. So if you want to re-create a storage object with the same name, add retry logic into the code. Interesting approach to deleting an index entity without having to read it first – create a local entity with the same keys and apply it to the Azure system regardless of change-state.  Although the “Indexes” description is a little vague, it’s interesting to see a Folding and Stemming discussion a-la the Porter Stemming Algorithm. (Chapter 11)  Presents a better discussion of indexes (at least inverted indexes) later in the chapter. Great treatment for DBA’s in Chapter 11. We need to work on getting secondary indexes in Table storage. There is a limited form of transactions called “Entity Group Transactions” that, although they have conditions, makes a transactional system more possible. Concurrency also becomes an issue, but is handled well if you’re using Data Services in .NET. It watches the Etag and allows you to take action appropriately. I do not recommend using Azure as a location for secure backups. In fact, I would rather have seen the examples in (Chapter 12) go the other way, showing how data could be brought back to a local store as a DR or HA strategy. Good information on cryptography and so on even so. Chapter seems out of place, and should be combined with the Blob chapter.  (Chapter 13) on SQL Azure is dated, although the base concepts are OK.  Nice example of simple ADO.NET access to a SQL Azure (or any SQL Server Really) database.  

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  • Commit in SQL

    - by PRajkumar
    SQL Transaction Control Language Commands (TCL)                                           (COMMIT) Commit Transaction As a SQL language we use transaction control language very frequently. Committing a transaction means making permanent the changes performed by the SQL statements within the transaction. A transaction is a sequence of SQL statements that Oracle Database treats as a single unit. This statement also erases all save points in the transaction and releases transaction locks. Oracle Database issues an implicit COMMIT before and after any data definition language (DDL) statement. Oracle recommends that you explicitly end every transaction in your application programs with a COMMIT or ROLLBACK statement, including the last transaction, before disconnecting from Oracle Database. If you do not explicitly commit the transaction and the program terminates abnormally, then the last uncommitted transaction is automatically rolled back.   Until you commit a transaction: ·         You can see any changes you have made during the transaction by querying the modified tables, but other users cannot see the changes. After you commit the transaction, the changes are visible to other users' statements that execute after the commit ·         You can roll back (undo) any changes made during the transaction with the ROLLBACK statement   Note: Most of the people think that when we type commit data or changes of what you have made has been written to data files, but this is wrong when you type commit it means that you are saying that your job has been completed and respective verification will be done by oracle engine that means it checks whether your transaction achieved consistency when it finds ok it sends a commit message to the user from log buffer but not from data buffer, so after writing data in log buffer it insists data buffer to write data in to data files, this is how it works.   Before a transaction that modifies data is committed, the following has occurred: ·         Oracle has generated undo information. The undo information contains the old data values changed by the SQL statements of the transaction ·         Oracle has generated redo log entries in the redo log buffer of the System Global Area (SGA). The redo log record contains the change to the data block and the change to the rollback block. These changes may go to disk before a transaction is committed ·         The changes have been made to the database buffers of the SGA. These changes may go to disk before a transaction is committed   Note:   The data changes for a committed transaction, stored in the database buffers of the SGA, are not necessarily written immediately to the data files by the database writer (DBWn) background process. This writing takes place when it is most efficient for the database to do so. It can happen before the transaction commits or, alternatively, it can happen some times after the transaction commits.   When a transaction is committed, the following occurs: 1.      The internal transaction table for the associated undo table space records that the transaction has committed, and the corresponding unique system change number (SCN) of the transaction is assigned and recorded in the table 2.      The log writer process (LGWR) writes redo log entries in the SGA's redo log buffers to the redo log file. It also writes the transaction's SCN to the redo log file. This atomic event constitutes the commit of the transaction 3.      Oracle releases locks held on rows and tables 4.      Oracle marks the transaction complete   Note:   The default behavior is for LGWR to write redo to the online redo log files synchronously and for transactions to wait for the redo to go to disk before returning a commit to the user. However, for lower transaction commit latency application developers can specify that redo be written asynchronously and that transaction do not need to wait for the redo to be on disk.   The syntax of Commit Statement is   COMMIT [WORK] [COMMENT ‘your comment’]; ·         WORK is optional. The WORK keyword is supported for compliance with standard SQL. The statements COMMIT and COMMIT WORK are equivalent. Examples Committing an Insert INSERT INTO table_name VALUES (val1, val2); COMMIT WORK; ·         COMMENT Comment is also optional. This clause is supported for backward compatibility. Oracle recommends that you used named transactions instead of commit comments. Specify a comment to be associated with the current transaction. The 'text' is a quoted literal of up to 255 bytes that Oracle Database stores in the data dictionary view DBA_2PC_PENDING along with the transaction ID if a distributed transaction becomes in doubt. This comment can help you diagnose the failure of a distributed transaction. Examples The following statement commits the current transaction and associates a comment with it: COMMIT     COMMENT 'In-doubt transaction Code 36, Call (415) 555-2637'; ·         WRITE Clause Use this clause to specify the priority with which the redo information generated by the commit operation is written to the redo log. This clause can improve performance by reducing latency, thus eliminating the wait for an I/O to the redo log. Use this clause to improve response time in environments with stringent response time requirements where the following conditions apply: The volume of update transactions is large, requiring that the redo log be written to disk frequently. The application can tolerate the loss of an asynchronously committed transaction. The latency contributed by waiting for the redo log write to occur contributes significantly to overall response time. You can specify the WAIT | NOWAIT and IMMEDIATE | BATCH clauses in any order. Examples To commit the same insert operation and instruct the database to buffer the change to the redo log, without initiating disk I/O, use the following COMMIT statement: COMMIT WRITE BATCH; Note: If you omit this clause, then the behavior of the commit operation is controlled by the COMMIT_WRITE initialization parameter, if it has been set. The default value of the parameter is the same as the default for this clause. Therefore, if the parameter has not been set and you omit this clause, then commit records are written to disk before control is returned to the user. WAIT | NOWAIT Use these clauses to specify when control returns to the user. The WAIT parameter ensures that the commit will return only after the corresponding redo is persistent in the online redo log. Whether in BATCH or IMMEDIATE mode, when the client receives a successful return from this COMMIT statement, the transaction has been committed to durable media. A crash occurring after a successful write to the log can prevent the success message from returning to the client. In this case the client cannot tell whether or not the transaction committed. The NOWAIT parameter causes the commit to return to the client whether or not the write to the redo log has completed. This behavior can increase transaction throughput. With the WAIT parameter, if the commit message is received, then you can be sure that no data has been lost. Caution: With NOWAIT, a crash occurring after the commit message is received, but before the redo log record(s) are written, can falsely indicate to a transaction that its changes are persistent. If you omit this clause, then the transaction commits with the WAIT behavior. IMMEDIATE | BATCH Use these clauses to specify when the redo is written to the log. The IMMEDIATE parameter causes the log writer process (LGWR) to write the transaction's redo information to the log. This operation option forces a disk I/O, so it can reduce transaction throughput. The BATCH parameter causes the redo to be buffered to the redo log, along with other concurrently executing transactions. When sufficient redo information is collected, a disk write of the redo log is initiated. This behavior is called "group commit", as redo for multiple transactions is written to the log in a single I/O operation. If you omit this clause, then the transaction commits with the IMMEDIATE behavior. ·         FORCE Clause Use this clause to manually commit an in-doubt distributed transaction or a corrupt transaction. ·         In a distributed database system, the FORCE string [, integer] clause lets you manually commit an in-doubt distributed transaction. The transaction is identified by the 'string' containing its local or global transaction ID. To find the IDs of such transactions, query the data dictionary view DBA_2PC_PENDING. You can use integer to specifically assign the transaction a system change number (SCN). If you omit integer, then the transaction is committed using the current SCN. ·         The FORCE CORRUPT_XID 'string' clause lets you manually commit a single corrupt transaction, where string is the ID of the corrupt transaction. Query the V$CORRUPT_XID_LIST data dictionary view to find the transaction IDs of corrupt transactions. You must have DBA privileges to view the V$CORRUPT_XID_LIST and to specify this clause. ·         Specify FORCE CORRUPT_XID_ALL to manually commit all corrupt transactions. You must have DBA privileges to specify this clause. Examples Forcing an in doubt transaction. Example The following statement manually commits a hypothetical in-doubt distributed transaction. Query the V$CORRUPT_XID_LIST data dictionary view to find the transaction IDs of corrupt transactions. You must have DBA privileges to view the V$CORRUPT_XID_LIST and to issue this statement. COMMIT FORCE '22.57.53';

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