Create User in Oracle

CREATE USER user in Oracle

Controlling User Access

In a multiple-user environment, you want to maintain security of the database access and use. With Oracle server database security, you can do the following:
Control database access.
Give access to specific objects in the database.
Confirm given and received privileges with the Oracle data dictionary.
Create synonyms for database objects.
Database security can be classified into two categories: system security and data security. System security covers access and use of the database at the system level such as the username and password, the disk space allocated to users, and the system operations that users can perform. Database security covers access and use of the database objects and the actions that those users can have on the objects.

Privileges
Privileges are the right to execute particular SQL statements. The database administrator (DBA) is a high-level user with the ability to create users and grant users access to the database and its objects. Users require system privileges to gain access to the database and object privileges to manipulate the content of the objects in the database. Users can also be given the privilege to grant additional privileges to other users or to roles, which are named groups of related privileges.
Schemas
A schema is a collection of objects such as tables, views, and sequences. The schema is owned by a database user and has the same name as that user.

System Privileges
More than 100 distinct system privileges are available for users and roles. System privileges typically are provided by the database administrator.
Typical DBA Privileges

CREATE USER user              
IDENTIFIED BY   password;

Creating a User
The DBA creates a user by executing the CREATE USER statement. The user does not have any privileges at this point. The DBA can then grant privileges to that user. These privileges determine what the user can do at the database level

CREATE USER hema
IDENTIFIED BY   hema