Knowledge of the authorities needed to access data in an application

[Note]
  • [INFOCENTER_V9] Authorization, privileges, and object ownership

Users (identified by an authorization ID) can successfully execute SQL or XQuery statements only if they have the authority to perform the specified function. To create a table, a user must be authorized to create tables; to alter a table, a user must be authorized to alter the table; and so forth.

There are two forms of authorization, administrative authority and privileges.

The database manager requires that each user be specifically authorized, either implicitly or explicitly, to use each database function needed to perform a specific task. Explicit authorities or privileges are granted to the user (GRANTEETYPE of U in the database catalogs). Implicit authorities or privileges are granted to a group to which the user belongs (GRANTEETYPE of G in the database catalogs).

Administrative authority

The person or persons holding administrative authority are charged with the task of controlling the database manager and are responsible for the safety and integrity of the data. Those with administrative authority levels of SYSADM and DBADM implicitly have all privileges on all objects except objects pertaining to database security and control who will have access to the database manager and the extent of this access.

Authority levels provide a method of grouping privileges and higher-level database manager maintenance and utility operations. Database authorities enable users to perform activities at the database level. A user or group can have one or more of the following authorities:

Figure 1.2, “Hierarchy of Authorities” illustrates the relationship between authorities and their span of control (database, database manager):

Figure 1.2. Hierarchy of Authorities

Hierarchy of Authorities

Privileges

Privileges are those activities that a user is allowed to perform. Authorized users can create objects, have access to objects they own, and can pass on privileges on their own objects to other users by using the GRANT statement.

Privileges may be granted to individual users, to groups, or to PUBLIC. PUBLIC is a special group that consists of all users, including future users. Users that are members of a group will indirectly take advantage of the privileges granted to the group, where groups are supported.

Possessing the CONTROL privilege on an object allows a user to access that database object, and to grant and revoke privileges to or from other users on that object. The CONTROL privilege only apples to tables, views, nicknames, indexes, and packages.

If a different user requires the CONTROL privilege to that object, a user with SYSADM or DBADM authority could grant the CONTROL privilege to that object. The CONTROL privilege cannot be revoked from the object owner, however, the object owner can be changed by using the TRANSFER OWNERSHIP statement.

Individual privileges can be granted to allow a user to carry out specific tasks on specific objects. Users with administrative authority (SYSADM or DBADM) or the CONTROL privilege can grant and revoke privileges to and from users.

Individual privileges and database authorities allow a specific function, but do not include the right to grant the same privileges or authorities to other users. The right to grant table, view, schema, package, routine, and sequence privileges to others can be extended to other users through the WITH GRANT OPTION on the GRANT statement. However, the WITH GRANT OPTION does not allow the person granting the privilege to revoke the privilege once granted. You must have SYSADM authority, DBADM authority, or the CONTROL privilege to revoke the privilege.

Figure 1.3. Object Privileges

Object Privileges

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