Classification of DBMS users
There are two classes of DBMS users:
Actor on the Scene:person whose job involves daily use of a large database are:
Workers behind the scene
Persons whose job involves design, development, operation and maintenance of the DBMS software are 1 DBMS designers and implementers
2 Tool developers
3 Operator and maintenance personnel
Database Administrator (DBA)
Database Administrator or DBA is a person or group of persons responsible for over all control of database system. Intact all the activities in a database system are controlled by DBA.
Hence, Database Administrators (DBA) are responsible for:
1. authorizing access to the database,
2.coordinating and monitoring its use,
3.acquiring software and hardware resources as needed,
4. Defining security and Integrity checks,
5. Monitoring performance and responding to changing requirements,
6. Liaising with users.
Database designers task is undertaken before the database is actually implemented. Responsibilities of database designers are:
1. Schema definition i.e. the creation of the original database schema.
2. Storage Structure and Access Method definitioni.e. writing a set of definitions translated by the data storage and definition language compiler.
3. Schema and Physical Organization Modification i.e. writing a set of definitions to generate modifications to appropriate internal system tables (e.g. data dictionary).
Hence, Database Designers are responsible for:
1.identifying the data to be stored in the database, and
2. choosing appropriate structures to represent and store this data.
The term end-user is used to describe the person who accesses the database in the course of their day-to-day work.
There are three types of end-users :
1. Sophisticated end-users
Sophisticated end-users interact with the system without writing programs. They form requests by writing queries in a database query language. This category of users are very familiar with the system and can use the database to meet their requirements.
2. Specialized end-users
Specialized end-users interact with the system with writing special database application programs.
Specialized users can write a specialized program like CAD (Computer Aided Design), CASE (Computer Aided Software Engineering) or Multimedia Database Programs. This specialized programmer is called specialized user.
3. Naive User
Naive users access data through application programs that have been written for them. They do not need to know any details of the structure of language of the database system. They are totally unsophisticated users who never know writing programs or even small queries.
System Analysts determine the requirements of end users, especially naive end-users, and develop pacification's for canned transactions that meet these requirements. Not only this he also analyses the user requirement so that the DBMS data fields can be selected appropriately to fulfill the user needs. This requirement includes the number of fields, size, type, constraints etc. Once analyzing all these requirement he also uses the skill for coding so that codes can be decided for efficient use of DBMS. After complete analysis he hands it over to the database designer, who proceeds with the actual designing of the database.
The application programmer, responsible for writing application programs that use the database, typically in a language such as COBOL or PL/1 to meet the user requirement. These application programs operate on the data in all the usual ways: retrieving information, creating new information, deleting or changing existing information. They actually make use of DMA (data manipulation language) calls which are embedded in the programs written by them. These programs are known as application programs. For example programs written for credit accounts and debit account in a banking system, a pay bill generator program or a hospital management system program etc.
DBMS Designers and implementers
They perform tough and responsible jobs. The DBMS system designer knows the hardware requirements of the system and through his . analyzing and designing capability, he produces an efficient system design for the DBMS. The DBMS system implementer are those who help for hardware implementation of the entire system. They do not play any role in the software implementation as it is the job of DBA and application/system programmers.
Tool developers help to develop the software tools for DBMS. It is their job to provide complete management, help and other database creation and maintenance tools for the DBMS.
Operator and Maintenance Personal
The operators, who know how to operate the entire system, are fully responsible for proper running and operation of the hardware parts of complete system.
The final job is the maintenance of machinery for the entire system. The maintenance not only includes repair and proper working, it also includes the up gradation of the equipment's/peripherals as and when required. All of them are technical people and they know how to maintain, operate and upgrade the system.