Creating static Datacontext() or Creating whenever its needed. Which is Better, and Why?

I have a function, and inside that I am creating a DataContext() everytime the function is called. What is the cost of creating a new DataContext(). Can I create a static DataContext() and use开发者_开发技巧 it everywhere. Because The DataContext has a full recording of all the changes when SubmitChanges() fails, is there a way I can remove those specific changes from the DataContext when SubmitChanges() fails. My Question is which is better Creating static Datacontext() or Creating whenever its needed?

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This topic has been discussed quite a bit and you should read this article about DataContext lifetime management. The short answer is that DataContext is meant to be used for a unit of work, typically a single request. DataContext objects are cheap to construct and there is no database overhead to creating one.

The main reason to avoid a shared instance of DataContext is because of thread safety and change tracking. Each modification you make to a repository object is captured and translated into update/insert/delete operations when you call SubmitChanges(). This feature breaks down when using a single DataContext object.