How Views Work
What actually happens in the database when you create a view, and what happens when you use it?
Creating a view means defining it in terms of its base tables. The definition of the view is stored in the system catalogs without any data. When you query or perform data modification commands through the view, you are accessing the data that is stored in association with the underlying tables. In other words, creating a view does not generate a copy of the data, neither at the time the view is defined nor at the time the view is accessed.
When you query a view, it looks exactly like any other database table. You can display it in much the same way as you can any other table, with few restrictions.
Changing data through a view has some ...
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