Lectfffffffffffffffffffffffffure-1 Introduction.ppt

Lectfffffffffffffffffffffffffure-1 Introduction.ppt

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  CSE 209- DatabaseSystems Chapter-1 Farhana Akter Sunny [email protected]
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  Reference Books DATABASE SYSTEMCONCEPTS (6th Edition)- Abraham Silberschatz Fundamentals of Database Systems (5th Edition)- Elmarsri, Navathe
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  Outline  Data andInformation  DB and DBMS  Applications of DBMS  File System  Level of abstraction  Database Language
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  Data & Information 4
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  Data & Information 5 Data:It is raw, unorganized facts that need to be processed. Data can be something simple and seemingly random and useless until it is organized. Example: Each student's test score is one piece of data. Information: When data is processed, organized, structured or presented in a given context so as to make it useful, it is called information. Example: The average score of a class or of the entire school is information that can be derived from the given data.
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  Why Study Databases? Databases are useful  Many computing applications deal with large amounts of information  Database systems give a set of tools for storing, searching and managing this information  Databases in CS  Databases are a ‘core topic’ in computer science  Basic concepts and skills with database systems are part of the skill set you will be assumed to have as a CS graduate
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  What is aDatabase?  “A set of information held in a computer” Oxford English Dictionary  “One or more large structured sets of persistent data, usually associated with software to update and query the data” Free On-Line Dictionary of Computing  “A collection of data arranged for ease and speed of search and retrieval” Dictionary.com
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  Database Systems  Adatabase system consists of  Data (the database)  Software  Hardware  Users  We focus mainly on the software  Database systems allow users to  Store  Update  Retrieve  Organise  Protect their data.
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  Database Management Systems  Adatabase is a collection of information  A database management system (DBMS) is the software than controls that information  Examples:  Oracle  DB2 (IBM)  MS SQL Server  MS Access  Ingres  PostgreSQL  MySQL
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  Database Users  Endusers  Use the database system to achieve some goal  Application developers  Write software to allow end users to interface with the database system  Database Administrator (DBA)  Designs & manages the database system  Database systems programmer  Writes the database software itself
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  11 Database Management System(DBMS)
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  Advantages of DatabaseApproach Advantages of Database Approach Registration Examination Library Applications Library Examination Applications Registration Applications Database Management System University Students Database - Data Sharing - Data Independence - Controlled Redundancy - Better Data Integrity
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  13
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  14 Database Management System(DBMS)  Database Applications:  Banking: transactions  Airlines: reservations, schedules  Universities: registration, grades  Sales: customers, products, purchases  Online retailers: order tracking, customized recommendations  Manufacturing: production, inventory, orders, supply chain  Human resources: employee records, salaries, tax deductions  Databases can be very large.  Databases touch all aspects of our lives.
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  Functions and Servicesof DBMS  Data Storage Management:  Transaction Management:  Integrity Services:  Backup and Recovery Management:  Concurrency Control Services:  Data Manipulation Management:  Data Dictionary/System Catalog Management:  Authorization/Security Management :  Utility Services:  Database Access and Application Programming Interfaces :
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  File Processing System  Acollection of application programs that perform services for the end-users such as production of reports  Each program defines and manages its own data
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  Registration Applications Registration Data Files Registration Examination Applications Examination Data Files Examination Library Applications Library Data Files Library File Processing Systems Programand Data Interdependence
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  Fine Books Issued Father Name Name Reg_Number Library Grade Semester Class Address Name Reg_Number Examination Class Address Phone FatherName Name Reg_Number Registration File Processing Systems
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  Files Based Processing
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  Disadvantages of FileProcessing  Program-Data Dependence  File structure is defined in the program code.  All programs maintain metadata for each file they use  Duplication of Data (Data Redundancy)  Different systems/programs have separate copies of the same data  Same data is held by different programs.  Wasted space and potentially different values and/or different formats for the same item.  Limited Data Sharing  No centralized control of data  Programs are written in different languages, and so cannot easily access each other’s files.
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  Exercise: Sample Question 1.What is data and information? Explain with example. 2. Briefly discuss the application of database management system (DBMS). 3. What are RDBMS and DBMS? List four significant differences between a file processing system and a DBMS. 21