Views
A view is an Oracle data structure defined through a SQL statement. The SQL statement
is stored in the database. When you use a view in a query, the stored query is
executed and the base table data is returned to the user. Views do not contain data,
but represent ways to look at the base table data in the way the query specifies.
You can use a view for several purposes:
??? To simplify access to data stored in multiple tables.
??? To implement specific security for the data in a table (e.g., by creating a view that
includes a WHERE clause that limits the data you can access through the view).
Starting with Oracle9i, youcan use fine-grained access control to accomplish the
same purpose. Fine-grained access control gives you the ability to automatically
limit data access based on the value of data in a row.
??? To isolate an application from the specific structure of the underlying tables.
A view is built on a collection of base tables, which can be either actual tables in an
Oracle database or other views. If youmodify any of the base tables for a view so
that they no longer can be used for a view, that view itself can no longer be used.
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