Slide 5.13: Oracle data dictionary (cont.)

Oracle Data Dictionary (Cont.)

Some Useful Commands

To display the names of objects created by users:
```
 SQL> SELECT object_name FROM user_objects; 
```
ALL_TAB_COLUMNS contains information about columns of all tables and views. Table name such as inventory has to use capital letters. Oracle is a case-insensitive system, but is with few exceptions.
```
 SQL> SELECT column_name, data_type FROM all_tab_columns 
   2    WHERE table_name = 'INVENTORY'; 
```

TABLE_PRIVILEGES and COLUMN_PRIVILEGES list privileges granted:

 SQL> SELECT grantor, delete_priv FROM table_privileges 
   2    WHERE table_name = 'USER_TABLES';

USER_VIEWS contains information about views:

 SQL> SELECT view_name FROM user_views;

USER_TYPES provides a top-level view of each object type:
```
 SQL> SELECT type_name FROM user_types; 
```

USER_DEPENDENCIES contains information about dependencies:

 SQL> SELECT referenced_name FROM user_dependencies 
   2    WHERE name = 'INVENTORY';

Schemata
A schema is a collection of tables, indexes, and other related database objects. The full name of a table is schemaname.tablename, e.g., the following two commands are the same for the user/schema wenchen:

 SQL> SELECT title FROM inventory; 
 SQL> SELECT title FROM wenchen.inventory;