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Users

Users hold privileges to work in the database. Each database designates at least one default super user. The super user enjoys all privileges in the database. The following sections cover the behaviors of super users in Oracle and MySQL databases.

Oracle Users

The Oracle database defines two super users, SYS and SYSTEM, and follows the ANSI-SPARC architecture’s three-tiered model. This architectural model divides the internal, conceptual, and external view of schemas or databases.

The internal view consists of the physical reality of how data is organized, which is specific to any DBMS. The internal view also contains the editable data catalog that maintains all the data about data, or metadata. This metadata contains all the definitions of users, databases, tables, indexes, constraints, sequences, data types, and views. Inside the internal view and with the proper credentials, a super user can alter the contents of the data catalog with Data Manipulation Language (DML) statements. That means an authorized user could use an INSERT, UPDATE, or DELETE statement to change critical metadata outside the administrative barrier of system privileges and Data Definition Language (DDL) statements.


  

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