Oracle® Database 2 Day DBA 11g Release 1 (11.1) Part Number B28301-03 |
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Administrative accounts and privileges enable you to perform administrative functions such as managing users, managing database memory, and starting up and shutting down the database.
This section contains the following topics:
See Also:
The following administrative user accounts are automatically created when you install Oracle Database. They are both created with the password that you supplied upon installation, and they are both automatically granted the DBA
role.
SYSTEM
This account can perform all administrative functions except the following:
Backup and recovery
Database upgrade
It is recommended that you log in with this account to perform day-to-day administrative tasks.
SYS
This account can perform all administrative functions. All base (underlying) tables and views for the database data dictionary are stored in the SYS
schema. These base tables and views are critical for the operation of Oracle Database. To maintain the integrity of the data dictionary, tables in the SYS
schema are manipulated only by the database. They should never be modified by any user or database administrator. You must not create any tables in the SYS
schema.
The SYS
user is granted the SYSDBA
privilege, which enables a user to perform high-level administrative tasks such as backup and recovery.
SYSDBA
and SYSOPER
are administrative privileges required to perform high-level administrative operations such as creating, starting up, shutting down, backing up, or recovering the database. The SYSDBA
system privilege is for fully empowered database administrators and the SYSOPER
system privilege allows a user to perform basic operational tasks, but without the ability to look at user data.
The SYSDBA
and SYSOPER
system privileges allow access to a database instance even when the database is not open. Control of these privileges is therefore completely outside of the database itself. This enables an administrator who is granted one of these privileges to connect to the database instance to start the database.
You can also think of the SYSDBA
and SYSOPER
privileges as types of connections that enable you to perform certain database operations for which privileges cannot be granted in any other way. For example, if you have the SYSDBA
privilege, then you can connect to the database using AS SYSDBA
.
The SYS
user is automatically granted the SYSDBA
privilege upon installation. When you log in as user SYS
, you must connect to the database as SYSDBA
. Connecting as a SYSDBA
user invokes the SYSDBA
privilege. Oracle Enterprise Manager Database Control does not permit you to log in as user SYS
without connecting as SYSDBA
.
When you connect with SYSDBA
or SYSOPER
privileges, you connect with a default schema, not with the schema that is generally associated with your user name. For SYSDBA
this schema is SYS
; for SYSOPER
the schema is PUBLIC
.
Caution:
When you connect as userSYS
, you have unlimited privileges on data dictionary tables. Be certain that you do not modify any data dictionary tables.See Also:
Oracle Database Administrator's Guide for the operations authorized with the SYSDBA
and SYSOPER
privileges