From the earliest releases of the Oracle database, a mechanism has been provided to let users connect to the database in order to perform tasks via user accounts. There are several different types of Oracle user accounts—both operating system and database—that a company might implement:
Although they are created with the CREATE USER command, some accounts are used to house application schemas. These accounts own objects like tables, views, indexes, triggers, procedures, etc.
Another type of account is used by Oracle itself to enable the database engine work to be performed; these accounts are sys and system.
In later versions of the RDBMS, an account to enable the intelligent agent to connect to each database is automatically created during database creation. This account is dbsnmp and carries full DBA privileges.
Each application might need one or more accounts to enable work to be performed.
Each user in your system may require an individual Oracle account with specific privileges to enable the user to work with an application.
One or more accounts may be needed to enable one or more DBAs to perform database maintenance and duties.
Each account type must be considered and a decision reached on whether that account type will be used and how it will be set up and administered. In smaller organizations, there may be little need for some types of accounts discussed in this section. In very large organizations, there may be a need for more extensive divisions of database ...