Predefined User Accounts
In addition to the user accounts that you create, the database includes several user
accounts that are automatically created upon installation.
All databases include the administrative accounts SYS, SYSTEM, SYSMAN, and DBSNMP.
Administrative accounts are highly privileged accounts, and are needed only by
individuals authorized to perform administrative tasks such as starting and stopping
the database, managing database memory and storage, creating and managing
database users, and so on. You log in to Oracle Enterprise Manager Database Express
(EM Express) with SYS, SYSTEM, or SYSMAN. You assign the passwords for these
accounts when you create the database with Oracle Database Configuration Assistant
(DBCA). You must not delete these accounts.
All databases also include internal accounts, which are automatically created so that
individual Oracle Database features or components such as Oracle Application
Express can have their own schemas. To protect these accounts from unauthorized
access, they are initially locked and their passwords are expired. (A locked account is
an account for which login is disabled.) You must not delete internal accounts, and
you must not use them to log in to the database.
Your database may also include sample schemas, if you chose the option to create the
sample schemas in your database when the database was installed. The sample
schemas are a set of interlinked schemas that enable Oracle documentation and Oracle
instructional materials to illustrate common database tasks. These schemas also
provide a way for you to experiment without endangering production data.
Each sample schema has a user account associated with it. For example, the hr user
account owns the hr schema, which contains a set of simple tables for a human
resources application. The sample schema accounts are also initially locked and have
an expired password. As the database administrator, you are responsible for
unlocking these accounts and assigning passwords to these accounts.
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