The SYSD BA System Privilege

SYSDBA is a system privilege that is assigned only to user SYS. It enables SYS to perform high-level administrative tasks such as starting up and shutting down the database.

Although under typical circumstances it is not necessary to log in to the database as user SYS, if you want to log in as SYS with SQL Command Line (SQL*Plus), you must connect to the database "AS SYSDBA." Connecting AS SYSDBA invokes the SYSDBA privilege. If you omit the AS SYSDBA clause when logging in as user SYS, SQL Command Line rejects the login attempt.

The following example illustrates how to connect to the database with the SYSDBA privilege from SQL Command Line:

SQL > connect sys/password as sysdba

password is the password for the SYS user account.

Caution:

When you connect as user SYS, you have unlimited privileges on data dictionary tables. Be certain that you do not modify any data dictionary tables.

The SYSDBA System Privilege

The SYSD BA System Privilege