Tales From A Lazy Fat DBA

What are SYS and SYSTEM users ?

SYS:

•automatically created when Oracle database is installed
•automatically granted the DBA role
•has a default password: CHANGE_ON_INSTALL
•owns the base tables and views for the database data dictionary

SYSTEM:

•automatically created when Oracle database is installed
•automatically granted the DBA role
•has a default password: MANAGER (make sure you change it)

When you create an Oracle Database, the user SYSTEM is also automatically created and granted the DBA role.
The SYSTEM username is used to create additional tables and views that display administrative information, and internal tables and views used by various Oracle Database options and tools. Never use the SYSTEM schema to store tables of interest to non-administrative users.

What are SYSDBA & SYSOPER Privileges?

SYSDBA role permissions:

CREATE DATABASE
CREATE SPFILE
STARTUP and SHUTDOWN
ALTER DATABASE: open, mount, back up, or change character set.
ARCHIVELOG and RECOVERY
Includes the RESTRICTED SESSION privilege

SYSOPER role permissions:

CREATE SPFILE
STARTUP and SHUTDOWN
ALTER DATABASE: open, mount, back up
ARCHIVELOG and RECOVERY
Includes the RESTRICTED SESSION privilege