Data dictionary view names typically have prefixes that suggest the existence of four main categories.
Note that not all data dictionary views have one of these prefixes.
By using the appropriate views, you suppress information that is not of interest to you.
Depending on your database privileges, you cannot use certain categories of data dictionary views.
The following table lists the most common data dictionary view name prefixes.
| Prefix | Description |
|---|---|
| USER_... | Information about your own objects |
| ALL_... | Information about all objects you can access |
| DBA_... | All information in the database; for database administrators only |
| [G]V$... | Dynamic performance views; for database administrators only |
The dynamic performance views, with V$ or GV$ name prefix, are a special category.
These views are not based on database tables, but on information from other sources such as internal memory structures.
They are mainly relevant for database administrators.
The most popular data dictionary views also have alternative (shorter) synonyms, such as CAT, OBJ, IND, TABS, and COLS.