March 2022
Intermediate to advanced
682 pages
22h 58m
English
Views are an important tool for providing users with a simple, customized environment and for hiding data. As explained in Section 5.2, a relational view does not correspond exactly to the general external view but can be either a window into a base table or a virtual table derived from one or more underlying base tables. It usually does not exist in storage in the same way as base tables but is created by selecting specified rows and columns from the base tables and possibly performing operations on them.
A view is dynamically produced as the user works with it. To make up a view, the DBA decides which data the user needs to access, determines what base tables contain the data, and creates one or more views to display ...