1. Database Actors

2. 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:

3. 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.

4. 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).

5. 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).

6. 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 ).

7. 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.

8. 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

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

10. 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

11. - 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.

12. 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.

13. 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.

14. 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.

15. 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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