Database Actors

DB limitations The limitations are: The decision to use a DBMS for company’s information needs as critical as decision to introduce computer in the first time. The commission to DBMS is costly because it represents a large commitment in term of money and human resources. The limitations are:

DB limitations 1- Complexity: The DBMS is a complex piece of software, it requires DB experts both to look after it and also to design and develop the database. 2- Cost: Comprehensive DBMS are expensive to purchase and give rise to additional overhead when in operation.

DB limitations 3- Inefficiencies: 4- Rigidity: By no means a database system is inefficient, but what is meant here that in large systems, whenever weakness appear even though it is simple, the maintenance of such weakness will take a considerable time. 4- Rigidity: The most current DBMS, where designed to manage a particular type data (for example, fixed length record).

DB limitations 3- Inefficiencies: 4- Rigidity: By no means a database system is inefficient, but what is meant here that in large systems, whenever weakness appear even though it is simple, the maintenance of such weakness will take a considerable time. 4- Rigidity: The most current DBMS, where designed to manage a particular type data (for example, fixed length record).

Database Actors A primary goal of a database system is to retrieve information from and store new information in the database. People who work with a database can be categorized as database actors ( users ).

Database Actors 1- System Analysts: - System analysts determine the requirements of end users, especially naive and parametric end users, and develop specifications for transactions that meet these requirements.

2- Database Designers: Database Actors - Identifying the data to be stored in the database. - Choosing appropriate structures to represent and store this data undertaken before the database is actually implemented and populated with data. - Communicate with all prospective database users. - Develop a view of the database that meets the data and processing requirements for each group of users

Database Actors 3 - Application Programmers: - Application programmers implement these specifications as programs; then they test, debug, document, and maintain these transactions

4- Database Administrators: - Authorizing access to the database. Database Actors 4- Database Administrators: - Authorizing access to the database. - Coordinating and monitoring its use. - Acquiring software and hardware resources as needed

- Tools are optional packages that are often purchased separately. Database Actors 5- Tool developers: - Tools are optional packages that are often purchased separately. - Include packages for database design, performance monitoring, natural language or graphical interfaces, prototyping, simulation, and test data generation.

Database Actors 6- End Users: - Need different information each time. Access to the database for querying, updating, and generating reports. 6.1- Casual end users: - Occasionally access the database. - Need different information each time. - Learn only a few facilities that they may use repeatedly. - Typically middle-level or high-level managers or other occasional browsers.

Database Actors 6.2- Naive or parametric end users: - Constantly querying and updating the database, using standard types of queries and updates called canned transactions that have been carefully programmed and tested. - Need to learn very little about the facilities provided by the DBMS.

Database Actors 6.3- Sophisticated end users: - Engineers, scientists, business analysts, and others who thoroughly familiarize themselves with the facilities of the DBMS so as to implement their applications to meet their complex requirements. - Try to learn most of the DBMS facilities in order to achieve their complex requirements.

Database Actors 7- Operators and maintenance personnel: - System administration personnel who are responsible for the actual running and maintenance of the hardware and software environment for the database system.

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