Chapter 2. Static Data Dictionary Views
While new views are added with every version of Oracle, the static data dictionary views have existed in their current format since Oracle Version 6. These views, which are owned by SYS and built upon tables owned by SYS, provide the ability to access information about database objects.
Categories of Views
Most of the static data dictionary is constructed in a matrix fashion. The first way to categorize data dictionary views is by the breadth of information they cover. Views can be divided into three groups:
- USER_ views
Views that allow you to see objects you own. These view names begin with USER_, as in USER_TABLES and USER_INDEXES.
- ALL_ views
Views that allow you to see objects that you own or that you have been granted privileges to access. These view names begin with ALL_, as in ALL_TABLES and ALL_INDEXES.
- DBA_ views
Views that allow you to see all objects in the database, regardless of who owns them. Primarily, these views are for use by the DBA, and they begin with DBA_, as in DBA_TABLES and DBA_INDEXES.
There are also a handful of other views that provide information of general interest about the database.
The ALL_ views have the same structure as the DBA_ views. The USER_ views have the same structure as the DBA_ views except that they do not include the OWNER column. The views that exist in multiple forms (i.e., ALL_, DBA_, USER_) are listed in this book in the form *_viewname. So, for example, there are three *_TABLES views: