Definition and Explanation of Database Administrator (DBA) and Functions of
Definition and Explanation:
The database administrator (DBA) plays very important role in DBMS environment.
In a database system, the primary resource is the database itself and secondary
resource is the DBMS and related software. Administering these resources and
overall security of the database system is the responsibility of the DBA. The
DBA is also responsible for designing, coordinating and monitoring the database
system. The DBA is an IT professional. He must be technically competent, having
excellent communication and management skills. The management skills (such as
plan and coordinate) have importance for the database development phases, and to
supervise the staff. The technical skill is another most important factor
because DBA has to implement the database system. He must be expert to install
and operate complex hardware and to handle the hardware problems. He must also
have the knowledge of general-purpose programming languages, database languages
and to handle complex software.
The DBA is the central authority for managing a database system. The DBA is also
responsible for creating users and authorizing access to them. The DBA has an
account in the DBMS, sometimes called a system or super-user account.
Functions of the Database Administrator (DBA):
The DBA performs various functions in the database system. The DBA has to
perform many tasks, especially during the database development and maintenance
phases. The major functions or duties of the DBA are described below.
1. Database Planning:
Most of the organizations appoint the DBA before to start work on the
information system project, so that the DBA can participate in the database
planning. The DBA plays main role in the preliminary database planning.
2. Identifying Users Requirements:
The DBA examines the inputs and outputs of current system. He also consults with
different users to determine whether the current system satisfies their information needs and what are the new requirements of the users. The DBA
identifies requirements of the users after studying the current applications.
3. Developing and Maintaining Data Dictionary:
After identifying requirements of the users, the DBA stores data item names,
sources, meanings and usage in the data dictionary. The DBA adds and updates
data items in the data dictionary regularly during the development process of
database system as well as throughout the life of database system.
4. Designing the Logical Model:
The DBA identifies all entities, attributes, and relationships that are to be
represented in the database, and then develops a logical model.
5. Selecting a DBMS:
The DBA selects an appropriate DBMS such as relational, object-oriented etc.
that is suitable for information system and fulfills the requirements of the
organization. For this purpose, the DBA concentrates on the logical model.
6. Developing the Physical Model:
The DBA develops the physical model by mapping the logical model with physical
7. Creating and Loading Database:
Once the physical model is developed, DBA creates the structure of database such
as tables, indexes, relationships between tables etc. He also loads data into
database for testing the database system.
8. Developing User Views:
In DBMS, the users play the vital role to operate the database system. The DBA
develops the user view for each user so that they interact with database system
to access and to update data. The DBA attempts to satisfy the data needs of all
9. Training the Users:
The DBA is also responsible to train the users of DBMS so that they may use the
database system very easily and efficiently.
10. Monitoring Performance:
The major responsibility of the DBA is to monitor the performance of the
database system. Usually, the DBA gets feedback from the end-users to evaluate
the performance of the database system. If there is any problem in the
performance of the database system, the DBA makes adjustments.
11. Tuning and Reorganizing:
Database tuning means maintaining the performance of a database upto the
required level with the passage of time. As more and more data is added to the
database and database system requirements change, the DBA is responsible for
tuning and reorganizing the data structure.
12. Keeping Database System Up-to-Date:
The DBA should be aware of new features and new versions of the selected DBMS.
He should be aware about latest hardware and software technologies that can be
used in the database system for the betterment of the organization.
13. Creating and Maintaining User Accounts:
The DBA is also responsible to create accounts for users so that they can access
the DBMS. He also grants rights to users to access a specific portion of the
database. The DBA can delete the account of any user due to any reason or put
restrictions on him for accessing the database.
14. Maintaining Database Security:
The DBA is responsible for the overall security of the database system. He
grants rights to the users so that the users can access the specific portion of
the database. Most of the users have no rights to update the important data of
database. They can only retrieve the data. Unauthorized person cannot access the
15. Backup and Recovery of Data:
It is the responsibility of the DBA to make backup of important data regularly.
It is a good practice to make backup copy of the data so that it may be
recovered in case of data corruption in the database server (or due to any