• One of the most important uses of views is in large multi-user systems, where they make it easy to control access to data for different types of users.
As a very simple example, suppose that you have a table of employee information on the scheme Employees = .
For this reason, the view does not take up any disk space for data storage, and it does not create any redundant copies of data that is already stored in the tables that it references (which are sometimes called the base tables of the view).
In this article, we shall see how to specify INDEX hints and what the advantages of the same are.The Hints are enclosed in comment, /* comment */, in an SQL statement, and can only be specified with SELECT, DELETE and UPDATE keyword.• In many systems, views are stored in a pre-compiled form.This might save some execution time for the query, but usually not enough for a human user to notice.By using Hints, you can improve certain SQL statements that might otherwise be inefficient.
A view is simply any SELECT query that has been given a name and saved in the database.Obviously, you can’t let everyone in the company look at all of this information, let alone make changes to it.• Your database administrator (DBA) can define roles to represent different groups of users, and then grant membership in one or more roles to any specific user account (schema).Hints are used to give specific information that we know about our data and application, to Oracle.This further improves the performance of our system.This is the same as a NO_INDEX hint that specifies a list of all available indexes for the table.