Purpose

Use the ALTER USER statement:

• To change the authentication or database resource characteristics of a database user

• To permit a proxy server to connect as a client without authentication

• In an Oracle Automatic Storage Management (Oracle ASM) cluster, to change the password of a user in the password file that is local to the Oracle ASM instance of the current node

Prerequisites

In general, you must have the ALTER USER system privilege. However, the current user can change his or her own password without this privilege.

To change the password of a SYS user, the password file must exist.

You must be authenticated AS SYSASM to change the password of a user other than yourself in an Oracle ASM instance password file.

To specify the CONTAINER clause, you must be connected to a multitenant container database (CDB). If the current container is the root, then you can specify CONTAINER = ALL or CONTAINER = CURRENT. If the current container is a pluggable database (PDB), then you can specify only CONTAINER = CURRENT.

To set and modify CONTAINER_DATA attributes using the container_data_clause, you must be connected to a CDB and the current container must be the root.

Syntax

alter_user::=

Description of the illustration alter_user.eps

(size_clause::=)

container_data_clause::=

Description of the illustration container_data_clause.eps

proxy_clause::=

Description of the illustration proxy_clause.eps

db_user_proxy_clauses::=

Description of the illustration db_user_proxy_clauses.eps

Semantics

The keywords, parameters, and clauses described in this section are unique to ALTER USER or have different semantics than they have in CREATE USER. Keywords, parameters, and clauses that do not appear here have the same meaning as in the CREATE USER statement.

IDENTIFIED Clause

BY password

Specify BY password to specify a new password for the user. Passwords are case sensitive. Any subsequent CONNECT string used to connect this user to the database must specify the password using the same case (upper, lower, or mixed) that is used in this ALTER USER statement. Passwords can contain single-byte, or multibyte characters, or both from your database character set.

You can omit the REPLACE clause if you are setting your own password or you have the ALTER USER system privilege and you are changing another user's password. However, unless you have the ALTER 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.

In an Oracle ASM cluster, you can use this clause to change the password of a user in the password file that is local to an Oracle ASM instance of the current node. You must be authenticated AS SYSASM to specify IDENTIFIED BY password without the REPLACE old_password clause. If you are not authenticated AS SYSASM, then you can only change your own password by specifying REPLACE old_password.

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.

GLOBALLY

Refer to CREATE USER for more information on this clause.

You can change a user's access verification method from IDENTIFIED GLOBALLY to either IDENTIFIED BY password or IDENTIFIED EXTERNALLY. You can change a user's access verification method to IDENTIFIED GLOBALLY from one of the other methods only if all external roles granted explicitly to the user are revoked.

EXTERNALLY

Refer to CREATE USER for more information on this clause.

NO AUTHENTICATION Clause

Use this clause to change an existing user account with authentication to a schema account without authentication to prevent logins to the account.

DEFAULT COLLATION Clause

Use this clause to change the default collation for the schema owned by the user. The new default collation is assigned to tables, views, and materialized views that are subsequently created in the schema. It does not influence default collations for existing tables views, and materialized views. Refer to the DEFAULT COLLATION Clause clause of CREATE USER for the full semantics of this clause.

DEFAULT TABLESPACE Clause

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.

[LOCAL] TEMPORARY TABLESPACE Clause

Use this clause to assign or reassign a temporary tablespace or tablespace group for the user's temporary segments.

• Specify tablespace to indicate the user's temporary tablespace. Specify TEMPORARY TABLESPACE to indicate a shared temporary tablespace. Specify LOCAL TEMPORARY TABLESPACE to indicate a local temporary tablespace. If you are connected to a CDB, then you can specify CDB$DEFAULT to use the CDB-wide default temporary tablespace.

• Specify tablespace_group_name to indicate that the user can save temporary segments in any tablespace in the tablespace group specified by tablespace_group_name. Local temporary tablespaces cannot be part of a tablespace group.

Restriction on User Temporary Tablespace

Any individual tablespace you assign or reassign as the user's temporary tablespace must be a temporary tablespace and must have a standard block size.

DEFAULT ROLE Clause

Specify the roles enabled by default for the user at logon.This clause can contain only roles that have been granted directly to the user with a GRANT statement, or roles created by the user with the CREATE ROLE privilege. You cannot use the DEFAULT ROLE clause to specify:

• 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

• Roles that are enabled by the SET ROLE statement, such as password-authenticated roles and secure application roles

Assigning Default Roles to Common Users in a CDB

You can modify the default role assigned to a common user both in the current container and across all containers in a CDB.

While assigning a default role to a common user across all containers, role must be a common role that was commonly granted to the common user.

While assigning a default role to a common user in the current container, role must be one of the following:

• A local role that was granted to the common user in the current container

• A common role that was granted to the common user, either commonly or locally in the current container

ENABLE EDITIONS

This clause is not reversible. Specify ENABLE EDITIONS to allow the user to create multiple versions of editionable objects in this schema using editions. Editionable objects in non-editions-enabled schemas cannot be editioned.

Use the FOR clause to specify one or more object types for which the user can create editionable objects. For a list of valid values for object_type, query the V$EDITIONABLE_TYPES dynamic performance view. If you omit the FOR clause, then the user can create editionable objects for all editionable object types.

If the schema to be editions-enabled contains any objects that are not editionable and that depend on editionable type objects in the schema, then you must specify FORCE to enable editions for this schema. In this case, all the objects that are not editionable and that depend on the editionable type objects in the schema being editions-enabled become invalid.

[HTTP] DIGEST Clause

This clause lets you enable or disable HTTP Digest Access Authentication for the user.

• Specify ENABLE to enable HTTP Digest Access Authentication. After you specify this clause, the user’s password must be changed. This causes the database to generate an HTTP Digest verifier for the new password. Only then will HTTP Digest Access Authentication take effect. One way to ensure that the user’s password is changed after you issue this clause is to specify the PASSWORD EXPIRE clause in the same statement with the HTTP DIGEST ENABLE clause, as follows:

  ALTER USER user PASSWORD EXPIRE HTTP DIGEST ENABLE;

  This causes the database to prompt the user for a new password on his or her next attempt to log in to the database. After that, HTTP Digest Access Authentication will take effect for the user.

• Specify DISABLE to disable HTTP Digest Access Authentication for the user. You do not need to change the user’s password in order for this clause to take effect.

Refer to [HTTP] DIGEST Clause in the documentation on CREATE USER for more information on this clause.

CONTAINER Clause

If the current container is a PDB, then you can specify CONTAINER = CURRENT to change the attributes of a local user, or the container-specific attributes (such as the default tablespace) of a common user, in the current container. If the current container is the root, then you can specify CONTAINER = ALL to change the attributes of a common user across the entire CDB. If you omit this clause and the current container is a PDB, then CONTAINER = CURRENT is the default. If you omit this clause and the current container is the root, then CONTAINER = ALL is the default.

Restriction on Modifying Common Users in a CDB

Certain attributes of a common user must be modified for all the containers in a CDB and not for only some containers. Therefore, when you use any of the following clauses to modify a common user, ensure that you modify all of the containers by connecting to the root and specifying CONTAINER=ALL:

• IDENTIFIED clause

• PASSWORD clause

• [HTTP] DIGEST clause

container_data_clause

The container_data_clause allows you the set and modify CONTAINER_DATA attributes for a common user. Use the FOR clause to indicate whether to set or modify the default CONTAINER_DATA attribute or an object-specific CONTAINER_DATA attribute. These attributes determine the set of containers (which can never exclude the root) whose data will be visible via CONTAINER_DATA objects to the specified common user when the current session is the root.

To specify the container_data_clause, the current session must be the root and you must specify CONTAINER = CURRENT.

SET CONTAINER_DATA

Use this clause to set the default CONTAINER_DATA attribute or an object-specific CONTAINER_DATA attribute for a common user. When you specify this clause, you replace the existing value, if any, of the CONTAINER_DATA attribute.

Use container_name to specify one or more containers that will be accessible to the user.

Use ALL to specify that all current and future containers in the CDB will be accessible to the user.

Use DEFAULT to specify the default behavior, which is as follows:

• For a default CONTAINER_DATA attribute, the current container, that is, the root, and the CDB as a whole will be accessible to the user.

• For an object-specific CONTAINER_DATA attribute, the database will use the user's default CONTAINER_DATA attribute.

ADD CONTAINER_DATA

Use this clause to add containers to the default CONTAINER_DATA attribute or an object-specific CONTAINER_DATA attribute for a common user. Use container_name to specify one or more containers to add.

You cannot use this clause if the default CONTAINER_DATA attribute is set to ALL. If you use this clause when the default CONTAINER_DATA attribute is set to DEFAULT, then CDB$ROOT will automatically be added to the set of containers, unless the set already contains CDB$ROOT.

You cannot use this clause if the object-specific CONTAINER_DATA attribute is set to ALL or DEFAULT.

REMOVE CONTAINER_DATA

Use this clause to remove containers from the default CONTAINER_DATA attribute or an object-specific CONTAINER_DATA attribute for a common user. Use container_name to specify one or more containers to remove.

You cannot use this clause if the default CONTAINER_DATA attribute or object-specific CONTAINER_DATA attribute is set to ALL or DEFAULT.

FOR container_data_object

If you specify the FOR clause, then you can set and modify the object-specific CONTAINER_DATA attribute for container_data_object for a common user. container_data_object must be a CONTAINER_DATA table or view. If you omit schema, then Oracle Database assumes that container_data_object is in your own schema.

If you omit the FOR clause, then you can set and modify the default CONTAINER_DATA attribute for a common user.

proxy_clause

The 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.

GRANT CONNECT THROUGH

Specify GRANT CONNECT THROUGH to allow the connection.

REVOKE CONNECT THROUGH

Specify REVOKE CONNECT THROUGH to prohibit the connection.

ENTERPRISE USER

This 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 user.

db_user_proxy

This clause lets you expose user to proxy use by database user db_user_proxy (the proxy).

• The proxy will have all privileges that were directly granted to user.

• The proxy will have all roles associated with user, unless you specify the WITH clauses of db_user_proxy_clauses to limit the proxy to some or none of the roles of user. For each role associated with the proxy, if the role is enabled by default for user at login, then that role will also be enabled by default for the proxy at login.

db_user_proxy_clauses

You can enable password-protected roles in a proxy session. Both secure application role and password-protected roles provide a secure method for enabling a role in a session. Oracle recommends using secure password roles instead of password protected roles in instances where the password has to be maintained and transmitted over insecure channels, or if more than one person needs to know the password. Password-protected roles in a proxy session are suitable for situations where automation is used to set the role.

Proxy users can access password-protected roles. Specify the WITH clauses to limit the proxy to some or none of the roles associated with user, and the AUTHENTICATION REQUIRED clause to specify whether authentication is required.

WITH ROLE

WITH ROLE role_name permits the proxy to connect as the specified user and to activate only the roles that are specified by role_name. This clause can contain only roles that are associated with user. Password protected roles and secure application roles also need to be listed in the WITH ROLE clause if the Proxy user will need to use these secure roles.  These secure roles will be included with the WITH ROLE ALL clause (the default if WITH ROLE is not specified).  If WITH ROLE doesn't specify the secure roles, then those cannot be enabled even with right password.

WITH ROLE ALL EXCEPT

WITH ROLE ALL EXCEPT role_name permits the proxy to connect as the specified user and to activate all roles associated with that user except those specified for role_name. This clause can contain only roles that are associated with user.

WITH NO ROLES

WITH NO ROLES permits the proxy to connect as the specified user, but prohibits the proxy from activating any of that user's roles after connecting, even the secure roles like password protected roles and secure application roles.

AUTHENTICATION REQUIRED

Oracle Database does not expect the proxy to authenticate the user unless you specify the AUTHENTICATION REQUIRED clause. This clause ensures 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

The AUTHENTICATED USING clauses, which appeared in the syntax of earlier releases, have been deprecated and are no longer needed. If you specify the AUTHENTICATED USING PASSWORD clause, then Oracle Database converts it to the AUTHENTICATION REQUIRED clause. Specifying the AUTHENTICATED USING CERTIFICATE clause or the AUTHENTICATED USING DISTINGUISHED NAME clause is equivalent to omitting the AUTHENTICATION REQUIRED clause.

Examples

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 example:

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 sh:

ALTER USER sh 
    PROFILE new_profile; 

In subsequent sessions, sh is restricted by limits in the new_profile profile.

The following statement makes all roles granted directly to sh default roles, except the dw_manager role:

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 dw_manager role.

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 PASSWORD 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 sh:

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 sh:

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, 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 sh:

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;