DBMS Models and DBMS Users

DATABASE MODELS

It is representation of sealed down version of a system in form of presentable and understandable format. A data model is the representation of an actual system created to understand the behavior of system so that processes in system can be planned and defined to extract the max benefit out of the system or to use system in the best possible way.

THERE ARE 3 TYPES OF MODELS:

•     NETWORK MODEL (NDBMS)
•     HIERARCHICAL MODEL (HDBMS)
•     OBJECT ORIENTED MODEL (E-R model)

RDBMS (Relational dbms):

Developed by Dr. E. F. Codd (Set.), 1960, for data representation.

Data should be stored in the form of relations called as tables and each table consist of set of rows and columns.

It generally contains the information with the sub division or components and, is defined into the system. The information may be in one or multiple tables.

So basically, the developer has to set out a relation between information stored in tables.

DATABASE USERS:

•  Naive Users: those who need not be aware of the presence of the db system or other system supporting their usage.
• Online Users: those who may communicate with the db directly via an online terminal or indirectly via a user interface and application program.
•  Sophisticated Users: they interact with the system without writing programs. They form their requests in db query language.
•  Specialized Users: they write specialized db application that do not fit into the fractional data-processing framework eg-> CAD systems
•  Application programmer: are professionals who are responsible for developing application programs or user interface.
•  Database Administrator: DBA is a person or group in-charge for implementing db system within an organization. DBA have all the privileges allowed by the dbms.