1. IT 5433 LM1

2. Learning Objectives Understand key terms in database Explain file processing systems List parts of a database environment Explain types of database develop approaches

3. Database Management System A database management system is the software system that allows users to define, create and maintain a database and provides controlled access to the data. A Database Management System (DBMS) is basically a collection of programs that enables users to store, modify, and extract information from a database as per the requirements. http://ecomputernotes.com/fundamental/what-is-a- database/advantages-and-disadvantages-of-dbms

4. Traditional File Storage Method http://ecomputernotes.com/fundamental/what-is-a- database/traditional-file-processing-system The File Storage Method is a group of files storing data of an organization.

5. Important Characteristics of File Processing System Each file is independent from one another. Each file is called a flat file. Each file contained and processed information for one specific function, such as accounting or inventory. Files are designed by using programs written in programming languages such as COBOL, C, C++. The physical implementation and access procedures are written into database application; therefore, physical changes resulted in intensive rework on the part of the programmer. As systems became more complex, file processing systems offered little flexibility, presented many limitations, and were difficult to maintain. http://ecomputernotes.com/fundamental/what-is-a- database/traditional-file-processing-system

6. Limitations of the File Processing System I File-Based Approach 1. Separated and Isolated Data 2. Duplication of data 3. Data Dependence 4. Difficulty in representing data from the user's view 5. Data Inflexibility 6. Incompatible file formats 7. Data Security 8. Transactional Problems 9. Concurrency problems 10. Poor data modeling of real world http://ecomputernotes.com/fundamental/what-is-a- database/traditional-file-processing-system

7. Components of the Database System Environment There are five major components in the database system environment Hardware Software Data Users Procedures http://ecomputernotes.com/fundamental/what-is-a- database/advantages-and-disadvantages-of-dbms

8. Components in the Database System Environment Hardware - the actual computer system used for keeping and accessing the database. Software - the actual DBMS. Data - the most important component of DBMS environment from the end users point of view http://ecomputernotes.com/fundamental/what-is-a- database/advantages-and-disadvantages-of-dbms

9. Components in the Database System Environment Users – individuals who can access or retrieve data on demand using the applications and interfaces provided by the DBMS. The users can be:  Naive Users - users who need not be aware of the presence of the database system or any other system supporting their usage.  Online Users - those who may communicate with the database directly via an online terminal or indirectly via a user interface and application program.  Application Programmers - those who are responsible for developing application programs or user interface.  Sophisticated Users - users who interact with the system without,writing programs. Instead, they form their requests in database query language.  Data Base Administrator (DBA) - the person or group in charge for implementing the database system,within an organization. Procedures - the instructions and rules that govern the design and use of the database. http://ecomputernotes.com/fundamental/what-is-a- database/advantages-and-disadvantages-of-dbms

10. Type of Database Systems On the basis of the number of users: Single-user DBMS Multi-user DBMS On the basis of the site location Centralized DBMS Parallel DBMS Distributed DBMS Client/server DBMS http://ecomputernotes.com/fundamental/what-is-a- database/type-of-database-system

11. Users Single-user DBMS - the database resides on one computer and is only accessed by one user at a time. This one user may design, maintain, and write database programs. Multi-user DBMS - the data are both integrated and shared. A database is integrated when the same information is not recorded in two places. http://ecomputernotes.com/fundamental/what-is-a- database/type-of-database-system

12. Site Location The centralized database system consists of a single processor together with its associated data storage devices and other peripherals. Parallel database system architecture consists of a multiple Central Processing Units (CPUs) and data storage disk in parallel. http://ecomputernotes.com/fundamental/what-is-a- database/type-of-database-system

13. Site Location A logically interrelated collection of shared data physically distributed over a computer network is called a distributed database and the software system that permits the management of the distributed database and makes the distribution transparent to users is called a Distributed DBMS. Client/Server architecture of database system has two logical components namely client, and server. Clients are generally personal computers or workstations whereas server is large workstations, mini range computer system or a mainframe computer system. The applications and tools of DBMS run on one or more client platforms, while the DBMS soft wares reside on the server. The server computer is caned backend and the client's computer is called front end. http://ecomputernotes.com/fundamental/what-is-a- database/type-of-database-system