Oracle updating through view dating old fender amps
Base tables might in turn be actual tables or might be views themselves.
All operations performed on a view actually affect the base table of the view.
If conditions later change so that the query of an invalid view can be executed, the view can be recompiled and be made valid (usable).
For information changing conditions and their impact on views, see "Managing Object Dependencies".
Views are very powerful because they allow you to tailor the presentation of data to different types of users.When a view is created, Oracle Database expands any wildcard (*) in a top-level view query into a column list.The resulting query is stored in the data dictionary; any subqueries are left intact.SELECT COLUMN_NAME, UPDATABLE FROM USER_UPDATABLE_COLUMNS WHERE TABLE_NAME = 'EMP_DEPT'; COLUMN_NAME UPD ------------------------------ --- EMPNO YES ENAME YES DEPTNO YES SAL YES DNAME NO LOC NO 6 rows selected.statement lets you locate recompilation errors before run time.