Updating views in oracle
The SQL syntax to create a materialized view includes many options for when it is first to be run, how often it is to be re-run, and so on.
This requires an advanced reference manual for your specific system, and is beyond the scope of this tutorial.
As a very simple example, suppose that you have a table of employee information on the scheme Employees = .
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).
In turn, you can grant table-level or view-level permissions to a role as well as to a specific user.
Rather than sorting records on the field or fields during query execution, the system can simply access the rows in order of the index.
For this reason, a view is sometimes called a named query or a stored query.• The syntax to remove a view from your schema is exactly what you would expect: A view name may be used in exactly the same way as a table name in any SELECT query.Once stored, the view can be used again and again, rather than re-writing the same query many times.The scheme of this table is given by the SELECT clause of the view definition.• This technique is most useful when the query involves many joins of large tables, or any other SQL feature that could contribute to long execution times.
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What I think you're saying is that table 2 is a duplicate of table 1.