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Views
A view is like a window by which data from tables can be changed or viewed. The table on which a view is based is known as Base table. The view is stored as a SELECT statement in the data dictionary. When the user needs to retrieve data, using view. Then the following steps are defined.
1) View definition is finding from data dictionary table. For example, the view definitions in oracle are to be finding from table name USER-VIEWS.
2) Checks access privileges for the view base table.
3) Changes the view query into an equivalent operation on the underlying base table
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