The difference between simple and complex views in Oracle ____oracle

A view is a logical table that is based on a table or multiple tables or views, and does not contain data, which allows you to query and modify the data in the table. The table on which the view is based is called the base table, and Oracle's database objects are grouped into five categories: tables, views, sequences, indexes, and synonyms.

A view is a SELECT statement stored in a data dictionary. You can extract a logical collection or combination of data by creating a view.

Benefits of view:

1. Access to the database because the view can selectively select a portion of the database.

2. Users can get results from complex queries through simple queries.

3. Maintaining the independence of the data, attempting to retrieve data from multiple tables.

4. Different views can be generated for the same data.

views are divided into simple views and complex views:

1, simple view from the single table to obtain data, complex view from multiple tables;

2, the simple view does not contain functions and data sets, complex view contains;

3. A simple view can implement DML operations, and complex views are not available.

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