Databases & Database Management System (DBMS) PDF

Databases & Database management system (DBMS)  Plan 1.What is a Database (DB)? 2.What is a database management system (DBMS)? 3.Levels of data representation 4.Objective of DBMS 5.Design phase of databases  History... File usage limits  The user must write a progra...

Databases & Database management system (DBMS)  Plan 1.What is a Database (DB)? 2.What is a database management system (DBMS)? 3.Levels of data representation 4.Objective of DBMS 5.Design phase of databases  History... File usage limits  The user must write a program that is often complex!!!  Application: long, complex  Data: redundant, unreliable, and hard to  History... File usage limits Users are increasingly demanding that they do not write complex (or rather complicated!) to have quick answers to the questions they ask, to have up-to-date data,... DBMS  Comprehensive  Interrogate  Non-redundant  Modify  Structured DB  Describe  Persistent 1. What is a Database (DB)? A database is a structured set of persistent data that can be easily accessed by multiple programs that use it simultaneously for different purposes. A comic book is made to record facts, operations within an organization Examples: (administration, bank, university, hospital,...) University: Student, Module, Grade...  Application example (1) Schooling management Various activities Enrolment of new bachelor's degree. Establishment of timetables Entry and display of students' grades... Data Information on new baccalaureate holders Number of rooms Number of sections and groups List of teachers List of modules, etc.  Application example (2) Management of bank accounts Various activities Account creation Account operations (withdrawal, deposit, loan management) Transfer between branches Data Customer information Balances Agency information (name, city, etc.)  Application example (3) Management of a hospital Various activities Patient management (consultation, hospitalization) Management of doctors (working hours, on-call duty, etc.) Management of services (interventions, etc.) Data Patient information (surname, first name, date of admission, date of discharge, etc.) Doctor Information (surname, first name, specialty, etc.) Service Information (director, number of rooms, number of beds,  2. What is a database management system (DBMS)? Definition: All the programs that structure, store, maintain, update and search the data of a database + interfaces necessary for the different forms of use of the database. DB DB DB DBMS Examples of PC DBMSs: Access, Foxpro, Paradox... Mainframes: Oracle, DB2, Sybase, SQL Server,... Freeware and Shareware: MySQL, MSQL,...  3. Levels of data representation Internal Level: Actual PHYSICAL storage structure and access paths. Conceptual : Structure and constraints for the entire database External or View level: Describes various user views  4. Objective of DBMS A DBMS must solve certain problems and meet specific needs:  Data independence from programs  Non-redundancy  Easy data handling  Easy data administration  Efficient access to data  Consistency (or integrity)  Data security  Data sharing 5. Design phase of databases How did you find this course