Managing Users参考.pptVIP

Managing Users Objectives After completing this lesson, you should be able to do the following: Create new database users Alter and drop existing database users Monitor information about existing users Users and Security Database Schema Creating a New User: Database Authentication Set the initial password: Creating a New User: Operating System Authentication OS_AUTHENT_PREFIX initialization parameter specifies the format of the usernames Defaults to OPS$ Changing User Quota on Tablespace Dropping a User Use the CASCADE clause to drop all objects in the schema if the schema contains objects. Users currently connected to the Oracle server cannot be dropped Obtaining User Information Information about users can be obtained by querying the data dictionary. DBA_USERS DBA_TS_QUOTAS Summary In this lesson, you should have learned how to: Create users specifying the appropriate password mechanism Control usage of space by users Practice 15 Overview This practice covers the following topics: Creating users Displaying data dictionary information about users Removing user quotas Managing Privileges Objectives After completing this lesson, you should be able to do the following: Identify system and object privileges Grant and revoke privileges Identify auditing capabilities Managing Privileges Two types of Oracle user privileges: System: Enables users to perform particular actions in the database Object: Enables users to access and manipulate a specific object System Privileges There are over 100 distinct system privileges The ANY keyword in the privileges signifies that users have the privilege in any schema The GRANT command adds a privilege to a user or a group of users The REVOKE command deletes the privileges System Privileges: Examples Granting System Privileges SYSDBA and SYSOPERPrivileges System Privilege Restrictions O7_DICTIONARY_ACCESSIBILITY parameter Controls restrictions on SYSTEM privileges If set to TRUE, access to objects in SYS schema is allowed