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Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options

SQL> help alter user;

ALTER USER
----------

Use this command to change any of the following characteristics of a
database user:

  *  authentication mechanism of the user
  *  password
  *  default tablespace for object creation
  *  tablespace for temporary segments created for the user
  *  tablespace access and tablespace quotas
  *  limits on database resources
  *  default roles

ALTER USER user
  { IDENTIFIED {BY password | EXTERNALLY
                | GLOBALLY AS 'CN=user'}
  | DEFAULT TABLESPACE tablespace
  | TEMPORARY TABLESPACE tablespace
  | QUOTA { integer [K | M] | UNLIMI