Database management systems on z/OS
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Who is the database administrator?

Database management systems on z/OS

Database administrators (DBAs) are primarily responsible for specific databases in the subsystem. In some companies, DBAs are given the special group authorization, SYSADM, which gives them the ability to do almost everything in the DB2® subsystem, and gives them jurisdiction over all the databases in the subsystem. In other shops, a DBA's authority is limited to individual databases.

The DBA creates the hierarchy of data objects, beginning with the database, then table spaces, tables, and any indexes or views that are required. This person also sets up the referential integrity definitions and any necessary constraints.

The DBA essentially implements the physical database design. Part of this involves having to do space calculations and determining how large to make the physical data sets for the table spaces and index spaces, and assigning storage groups (also called stogroups).

Many tools are available to help DBAs perform their tasks.

The DBA can be responsible for granting authorizations to the database objects, although sometimes there is a special security administration group that does this.

The centralization of data and control of access to this data is inherent to a database management system. One of the advantages of this centralization is the availability of consistent data to more than one application. As a consequence, this dictates tighter control of that data and its usage.

Responsibility for an accurate implementation of control lies with the DBA. Indeed, to gain the full benefits of using a centralized database, you must have a central point of control for it. Because the actual implementation of the DBA function is dependent on a company's organization, we limit ourselves to a discussion of the roles and responsibilities of a DBA. The group fulfilling the DBA role will need experience in both application and systems programming.

In a typical installation, the DBA is responsible for:
  • Providing the standards for, and the administration of, databases and their use
  • Guiding, reviewing, and approving the design of new databases
  • Determining the rules of access to the data and monitoring its security
  • Ensuring database integrity and availability, and monitoring the necessary activities for reorganization backup and recovery
  • Approving the operation of new programs with existing production databases, based on results of testing with test data.

In general, the DBA is responsible for the maintenance of current information about the data in the database. Initially, this responsibility might be carried out using a manual approach. But it can be expected to grow to a scope and complexity sufficient to justify, or necessitate, the use of a data dictionary program.

The DBA is not responsible for the actual content of databases. This is the responsibility of the user. Rather, the DBA enforces procedures for accurate, complete, and timely update of the databases.

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