It is important to develop a security policy for every database. The security policy establishes methods for protecting your database from accidental or malicious destruction of data or damage to the database infrastructure.

Each database can have an administrator, referred to as the security administrator, who is responsible for implementing and maintaining the database security policy If the database system is small, the database administrator can have the responsibilities of the security administrator. However, if the database system is large, a designated person or group of people may have sole responsibility as security administrator.

For information about establishing security policies for your database, see Oracle Database Security Guide.

To connect to the database, each user must specify a valid user name that has been previously defined to the database. An account must have been established for the user, with information about the user being stored in the data dictionary.

When you create a database user (account), you specify the following attributes of the user:

• User name

• Authentication method

• Default tablespace

• Temporary tablespace

• Other tablespaces and quotas

• User profile

To learn how to create and manage users, see Oracle Database Security Guide.

Privileges and roles are used to control user access to data and the types of SQL statements that can be executed.

The table that follows describes the three types of privileges and roles:

Privileges and roles can be granted to other users by users who have been granted the privilege to do so. The granting of roles and privileges starts at the administrator level. At database creation, the administrative user SYS is created and granted all system privileges and predefined Oracle Database roles. User SYS can then grant privileges and roles to other users, and also grant those users the right to grant specific privileges to others.

To learn how to administer privileges and roles for users, see Oracle Database Security Guide.

You can monitor and record selected user database actions, including those performed by administrators. You can monitor system-wide actions as well as actions performed on individual database objects. This type of monitoring is called database auditing.

You can create unified audit policies and manage these audit policies using SQL statements. Oracle Database provides default unified audit policies that contain the standard audit settings, and you can create custom unified audit policies. You can also create fine-grained audit policies using the DBMS_FGA PL/SQL package.

Oracle Database includes several predefined user accounts.

The three types of predefined accounts are:

• Administrative accounts (SYS, SYSTEM, SYSBACKUP, SYSDG, SYSKM, SYSRAC, SYSMAN, and DBSNMP)

  SYS, SYSTEM, SYSBACKUP, SYSDG, SYSKM, and SYSRAC are described in "About Database Administrator Security and Privileges". SYSMAN is used to perform Oracle Enterprise Manager Cloud Control (Cloud Control) administration tasks. The management agent of Cloud Control uses the DBSNMP account to monitor and manage the database. You must not delete these accounts.

• Sample schema accounts

  These optional accounts are used for examples in Oracle Database documentation and instructional materials. The sample schema accounts are – HR, SH, and OE.

• Internal accounts

  These accounts are created so that individual Oracle Database features or components can have their own schemas. You must not delete internal accounts, and you must not attempt to log in with them.