DBMS LEC-1PDF.pdf
- 2. What is database? A database is an integrated and logical collection of related records and files. It is a collection of tables, schedules, reports, queries and other objects. A database can be made manually and also can be computerized. The size of database may vary according to the nature and amount of information. It provides an easy access to the user to review the information. • Database is a set of information and facts. Database Files/tables records characters Collection of Contains Formed of
- 3. Examples of database • Attendance sheets of our classes. • Our report cards or mark sheets. • A payroll prepared on Microsoft Excel. • Student records with the college/university. • Bank statements etc.
- 4. Traditional File System •Each file is independent of other file and data in the different file can be integrated only by writing an individual program for each application. •The data and application program that uses the data are arranged that any change to data requires modification of all the programs that use the data. •All functional areas in the organization create, processes its own files.
- 6. Problems with the Traditional File System • Data redundancy: The presence of duplicate data in multiple data files so that the same data are stored in more than one place or location • Data inconsistency: The same attribute may have different values.
- 7. Problems with the Traditional File System (Continued) •Poor security: Because there is little control or management of data, management will have no knowledge of who is accessing or even making changes to the organization’s data. • Lack of data sharing and availability: Information cannot flow freely across different functional areas or different parts of the organization. Users find different values of the same piece of information in two different systems, and hence they may not use these systems because they cannot trust the accuracy of the data.
- 8. Database Management System The database management system or DMBS is a general purpose software system which facilitates the process of defining, constructing, arranging and maintaining databases for various applications. In other words it is managing the databases. ** one can also easily alter or update databases easily with the help of DMBS software. DBMS = database + DBMS software
- 10. IMPORTANCE OF DBMS •It makes data management more efficient and effective. •It provides easy access to better managed data. •It helps in maintaining centralized control over data. •It maintains accuracy and consistency of data among different units of organisation. •DBMS is independent program, therefore , it supports many programs and there is no need to collect different data for different programs.
- 11. DBMS SOFTWARE Some of the DMBS software are: • Ocrale database • Microsoft SQL server • Microsoft Access • SQLite • MySQL • PostgreSQL • IBM Informix • Microsoft Excel • Ingres
- 12. Advantages of DBMS ✓ EASY TO ACCESS: Presenting data in the easiest form is the motive of DBMS. It is done with the help of various kinds of tables, charts, diagrams and reports. ✓ DATA SHARING: with the help of DBMS any kind of data can be easily shared to all the authorized users. Furthermore new applications can be used to share the data. ✓ IMPROVED SECURITY: the database administrator ensures that proper access procedure is followed, including proper authentications schemes for access of the database.
- 13. ✓ EASY TO REPRESENT : since the data is available in the form of tables and diagrams, it becomes easy for the user to represent the data to other people. ✓ ECONOMICAL : centralizing all the organizational data into one database results in saving a lot of cost. It also saves the time of the user due to very easy access. ✓ IMPROVED BACKUP AND DATA QUALITY : DMBS facilitates for recovery of damaged hardware and software failure with the help of restore and backup subsystem.
- 14. Disadvantages of DBMS ✓ OVERHEAD COST : when the size of the database is huge, it requires a powerful hardware platform and a software for database management which is quite expensive. ✓ OWNERSHIP PROBLEMS: for any change in the database a user needs to seek permission from the managers of the company which makes it a individual resource but it should be a corporate resource which can be used by any of the member of the organization.
- 15. ✓ COMPLEXITY: The functionality of the DBMS is expected to be very good which makes it quite complex to use. Failure to understand the functions properly can lead to bad decisions, which can have serious consequences to the organization. ✓ SIZE : the complexity and breadth of functionality makes the DMBS an extremely large piece of software which requires a substantial amounts of memory to run efficiently.
- 16. Traditional File System vs. Database Management System
- 18. Thank you