To change the authentication or database resource characteristics of a database user
To permit a proxy server to connect as a client without authentication
See Also:Oracle Database Security Guide for detailed information about user authentication methods
You must have the
USER system privilege. However, you can change your own password without this privilege.
The keywords, parameters, and clauses described in this section are unique to
USER or have different semantics than they have in
USER. Keywords, parameters, and clauses that do not appear here have the same meaning as in the
Note:Oracle recommends that user names and passwords be encoded in ASCII or EBCDIC characters only, depending on your platform. Please refer to Oracle Database Administrator's Guide for more information about this recommendation.
See Also:CREATE USER for information on the keywords and parameters and CREATE PROFILE for information on assigning limits on database resources to a user
Note:Oracle Database expects a different timestamp for each resetting of a particular password. If you reset one password multiple times within one second (for example, by cycling through a set of passwords using a script), then the database may return an error message that the password cannot be reused. For this reason, Oracle recommends that you avoid using scripts to reset passwords.
You can omit the
REPLACE clause if you are setting your own password for the first time or you have the
USER system privilege and you are changing another user's password. However, unless you have the
USER system privilege, you must always specify the
REPLACE clause if a password complexity verification function has been enabled, either by running the
UTLPWDMG.SQL script or by specifying such a function in the
PASSWORD_VERIFY_FUNCTION parameter of a profile that has been assigned to the user.
Oracle Database does not check the old password, even if you provide it in the
REPLACE clause, unless you are changing your own existing password. If such a check is important in other cases (for example, when a privileged user changes another user's password), then ensure that the password complexity verification function prohibits password changes in which the old password is null, or use the
OCIPasswordChange() call instead of
USER. For more information, see Oracle Call Interface Programmer's Guide.
See Also:Oracle Database Administrator's Guide for information on the password complexity verification function
GLOBALLY Please refer to CREATE USER for more information on this clause.
You can change a user's access verification method from
GLOBALLY to either
EXTERNALLY. You can change a user's access verification method to
GLOBALLY from one of the other methods only if all external roles granted explicitly to the user are revoked.
EXTERNALLY Please refer to CREATE USER for more information on this clause.
See Also:Oracle Database Identity Management Integration Guide for more information on globally and externally identified users, "Changing User Identification: Example", and "Changing User Authentication: Examples"
Use this clause to assign or reassign a tablespace for the user's permanent segments. This clause overrides any default tablespace that has been specified for the database.
Restriction on Default Tablespaces You cannot specify a locally managed temporary tablespace, including an undo tablespace, or a dictionary-managed temporary tablespace, as a user's default tablespace.
Use this clause to assign or reassign a tablespace or tablespace group for the user's temporary segments.
tablespace to indicate the user's temporary tablespace.
tablespace_group_name to indicate that the user can save temporary segments in any tablespace in the tablespace group specified by
See Also:"Assigning a Tablespace Group: Example"
Specify the roles granted by default to the user at logon. This clause can contain only roles that have been granted directly to the user with a
GRANT statement. You cannot use the
ROLE clause to enable:
Roles not granted to the user
Roles granted through other roles
Roles managed by an external service (such as the operating system), or by the Oracle Internet Directory
Oracle Database enables default roles at logon without requiring the user to specify their passwords or otherwise be authenticated. If you have granted an application role to the user, you should use the
role clause to ensure that, in subsequent logons by the user, the role will not be enabled except by applications using the authorized package.
See Also:CREATE ROLE
proxy_clause lets you control the ability of an enterprise user (a user outside the database) or a database proxy (another database user) to connect as the database user being altered.
USER clause lets you expose
user to proxy use by enterprise users. The administrator working in Oracle Internet Directory must then grant privileges for appropriate enterprise users to act on behalf of
db_user_proxy clause let you expose
user to proxy use by database user
db_user_proxy, activate all, some, or none of the roles of
user, and specify whether authentication is required. For information on proxy authentication of application users, see Oracle Database Application Developer's Guide - Fundamentals.
See Also:Oracle Database Concepts for more information on proxies and their use of the database and "Proxy Users: Examples"
GRANT to allow the connection. Specify
REVOKE to prohibit the connection.
Identify the proxy connecting to Oracle Database. Oracle Database expects the proxy to authenticate the user unless you specify the
If you do not specify any of these
WITH clauses, then Oracle Database activates all roles granted to the specified user automatically.
AUTHENTICATION REQUIRED Clause Specify
REQUIRED to ensure that authentication credentials for the user must be presented when the user is authenticated through the specified proxy. The credential is a password.
AUTHENTICATED USING This clause is no longer needed. It has been deprecated and is ignored if you use it in your code. Please specify the
proxy_clause either with or without the
Oracle Security Overview for an overview of database security
Oracle Database Administrator's Guide and Oracle Database Application Developer's Guide - Fundamentals for information on middle-tier systems and proxy authentication
Changing User Identification: Example The following statement changes the password of the user
sidney (created in "Creating a Database User: Example")
second_2nd_pwd and default tablespace to the tablespace
ALTER USER sidney IDENTIFIED BY second_2nd_pwd DEFAULT TABLESPACE example;
The following statement assigns the
new_profile profile (created in "Creating a Profile: Example") to the sample user
ALTER USER sh PROFILE new_profile;
In subsequent sessions,
sh is restricted by limits in the
The following statement makes all roles granted directly to
sh default roles, except the
ALTER USER sh DEFAULT ROLE ALL EXCEPT dw_manager;
At the beginning of
sh's next session, Oracle Database enables all roles granted directly to
sh except the
Changing User Authentication: Examples The following statement changes the authentication mechanism of user
app_user1 (created in "Creating a Database User: Example"
ALTER USER app_user1 IDENTIFIED GLOBALLY AS 'CN=tom,O=oracle,C=US';
The following statement causes user
sidney's password to expire:
ALTER USER sidney PASSWORD EXPIRE;
If you cause a database user's password to expire with
EXPIRE, then the user (or the DBA) must change the password before attempting to log in to the database following the expiration. However, tools such as SQL*Plus allow the user to change the password on the first attempted login following the expiration.
Assigning a Tablespace Group: Example The following statement assigns
tbs_grp_01 (created in "Adding a Temporary Tablespace to a Tablespace Group: Example") as the tablespace group for user
ALTER USER sh TEMPORARY TABLESPACE tbs_grp_01;
Proxy Users: Examples The following statement alters the user
app_user1. The example permits the
app_user1 to connect through the proxy user
sh. The example also allows
app_user1 to enable its
warehouse_user role (created in "Creating a Role: Example") when connected through the proxy
ALTER USER app_user1 GRANT CONNECT THROUGH sh WITH ROLE warehouse_user;
To show basic syntax, this example uses the sample database Sales History user (
sh) as the proxy. Normally a proxy user would be an application server or middle-tier entity. For information on creating the interface between an application user and a database by way of an application server, please refer to Oracle Call Interface Programmer's Guide.
The following statement takes away the right of user
app_user1 to connect through the proxy user
ALTER USER app_user1 REVOKE CONNECT THROUGH sh;
The following hypothetical examples shows another method of proxy authentication:
ALTER USER sully GRANT CONNECT THROUGH OAS1 AUTHENTICATED USING PASSWORD;
The following example exposes the user
app_user1 to proxy use by enterprise users. The enterprise users cannot act on behalf of
app_user1 until the Oracle Internet Directory administrator has granted them appropriate privileges:
ALTER USER app_user1 GRANT CONNECT THROUGH ENTERPRISE USERS;