Lecture 1 Database Systems - Walailak 2015-01-13آ  Lecture 1 Database Systems ITM661...

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  • DATABASE SYSTEMS Lecture 1: Introduction to DBs 1

    Lecture 1

    Database Systems

    ITM661 – Database Systems

    • T. Connolly, and C. Begg, “Database Systems: A Practical Approach to Design, Implementation, and Management”, 5th edition,

    Addison-Wesley, 2009. 6th edition, Addison-Wesley, 2014, ISBN: 0-132-94326-3, (International Edition).

    • R. Elmasri and S. B. Navathe, “Fundamentals of Database Systems”, 5th ed., Pearson, 2007, ISBN: 0-321-41506-X.

  • DATABASE SYSTEMS Lecture 1: Introduction to DBs 2

    Textbooks Database Systems: A Practical Approach to Design,

    Implementation, and Management

    By T. Connolly, and C. Begg,

    6th edition, Addison-Wesley, 2014

    ISBN: 0-132-94326-3

    OR

    5th edition, Addison-Wesley, 2009

    ISBN-10: 0-321-60110-6,

    ISBN-13: 978-0-321-60110-0

    Fundamentals of Database Systems

    By R. Elmasri and S. B. Navathe,

    6th edition, Pearson (Addison & Wesley), 2010,

    ISBN: 0-136-08620-9

    http://wps.pearsoned.co.uk/ema_uk_he_connolly_datasys_4

  • DATABASE SYSTEMS Lecture 1: Introduction to DBs 3

    Office Hours and Grading  Content

     Database and applications;

     Database system development lifecycle;

     Data modeling;

     Relational model;

     Database languages;

     Design methodology;

     Normalization;

     Monitoring and tuning the operational systems.

     Grading: Attendance 8%

    Assignment/project 20% (TT)

    Project 12% (SB)

    Class activities 10% (SB)

    Midterm 25% (TT)

    Final 25% (SB)

  • ITS322 - DBMSs Lecture 1: Introduction to DBs and DB Env. 4

    Course Outline

    DATABASE SYSTEMS 4Lecture 1: Introduction to DBs

  • DATABASE SYSTEMS Lecture 1: Introduction to DBs 5

    Lecture 1 Introduction to

    Databases Systems

    ITM661 – Database Systems

    • T. Connolly, and C. Begg, “Database Systems: A Practical Approach to Design, Implementation, and Management”, 5th edition,

    Addison-Wesley, 2009. 6th edition, Addison-Wesley, 2014, ISBN: 0-132-94326-3, (International Edition).

    • R. Elmasri and S. B. Navathe, “Fundamentals of Database Systems”, 5th ed., Pearson, 2007, ISBN: 0-321-41506-X.

  • DATABASE SYSTEMS Lecture 1: Introduction to DBs 6

    Objectives

     Some common uses of database systems

     The characteristics of file-based systems

     The problems with the file-based approach

     The benefits of database approach

     The meaning of the terms database, database

    systems, database management system (DBMS)

     The typical functions of a DBMS

     The advantages and disadvantages of DBMSs

  • DATABASE SYSTEMS Lecture 1: Introduction to DBs 7

    Objectives

     The major components of the DBMS environment

     The personnel involved in the DBMS environment

     Difference between data administration and database administration

     Types of database systems

     System Catalog and Information Resource Dictionary System (IRDS)

     Purposes and the origin of the 3-level database architecture

     Concepts and types of data models

     Functions and components of a DBMS

  • DATABASE SYSTEMS Lecture 1: Introduction to DBs 8

    Data Versus Information

     Data constitute building blocks of information

     Information produced by processing data

     Information reveals meaning of data

     Good, timely, relevant information key to

    decision making

     Good decision making key to organizational

    survival

  • DATABASE SYSTEMS Lecture 1: Introduction to DBs 9

    Where is Database?

     The database (DB) is now such an integral part our day-to-day life that often we are not aware we are using one.

     Ex: supermarket, credit card, travel agent, library, insurance, security systems, university. First applications focused on clerical tasks

     Requests for information quickly followed

     File systems developed to address needs

     Data organized according to expected use

     Data Processing (DP) specialists computerized manual file systems

  • DATABASE SYSTEMS Lecture 1: Introduction to DBs 10

    Types of Databases and DB Applications

     Traditional Applications:

     Numeric and Textual Databases

     More Recent Applications:

     Multimedia Databases

     Geographic Information Systems (GIS)

     Data Warehouses

     Real-time and Active Databases

     Many other applications

  • DATABASE SYSTEMS Lecture 1: Introduction to DBs 11

    File-based Systems

     The file-based system is the predecessor of the

    database system.  Decentralized

     A collection of application programs that perform

    services for the end users (e.g. reports).

     Each program defines and manages its own data.

     File-based systems were an early attempt to

    computerize the manual filing system.

     The related topics: storage, security, indexing,

    cross-reference, processing

  • DATABASE SYSTEMS Lecture 1: Introduction to DBs 12

    Simple File-based System

  • DATABASE SYSTEMS Lecture 1: Introduction to DBs 13

    File-based Processing

  • DATABASE SYSTEMS Lecture 1: Introduction to DBs 14

    File-based System Critique (I)

     File-based System Data Management

     Requires extensive programming in third-generation

    language (3GL)

     Time consuming

     Makes ad hoc queries impossible

     Leads to islands of information

    Data Raw Facts

    Field Group of characters with specific meaning

    Record Logically connected fields that describe a person, place, or thing

    File Collection of related records

  • DATABASE SYSTEMS Lecture 1: Introduction to DBs 15

    File-based System Critique (II)

     Data Dependence

     File structure is defined in the program code.

     Change in file‟s data characteristics requires

    modification of data access programs

     Must tell program what to do and how

     Makes file systems cumbersome from programming

    and data management views

     Structural Dependence

     Change in file structure requires modification of related

    programs

  • DATABASE SYSTEMS Lecture 1: Introduction to DBs 16

    File-based System Critique (III)

     Field Definitions and Naming Conventions

     Flexible record definition anticipates reporting requirements

     Selection of proper field names important

     Attention to length of field names

     Use of unique record identifiers

     Data Redundancy

     Different and conflicting versions of same data

     Results of uncontrolled data redundancy

     Data anomalies

     Data inconsistency

  • DATABASE SYSTEMS Lecture 1: Introduction to DBs 17

    File-based System Critique (IV)

     Separation and isolation of data

     Each program maintains its own set of data. Users of

    one program may be unaware of potentially useful data

    held by other programs.

     Incompatible file formats

     Programs are written in different languages, and so

    cannot easily access each others files.

     Fixed Queries/Proliferation of application

    programs

     Programs are written to satisfy particular functions.

    Any new requirement needs a new program.

  • DATABASE SYSTEMS Lecture 1: Introduction to DBs 18

    Database Approach

     Arose because:

     Definition of data was embedded in application

    programs, rather than being stored separately and

    independently.

     No control over access and manipulation of data

    beyond that imposed by application programs.

     Result - the database and Database Management

    System (DBMS).

  • DATABASE SYSTEMS Lecture 1: Introduction to DBs 19

    Database Management

     Database is shared, integrated computer structure

    housing:

     End user data

     Metadata

     Database Management System (DBMS)

     Manages Database structure

     Controls access to data

     Contains query language

  • DATABASE SYSTEMS Lecture 1: Introduction to DBs 20

    Database

     A shared collection of logically related data (and

    a description of this data), designed to meet the

    information needs of an organization.

     System catalog (data dictionary or metadata)

    provides the description of the data to enable

    program–data independence.

     Logically related data comprises entities,

    attributes, and relationships of an organization's

    information.

  • DATABASE SYSTEMS Lecture 1: Introduction to DBs 21

    Database Systems & DBMS

     Database System

     A system that occupies a database as a basic storage

     Provides the following advantages over file-based

    systems

     Eliminates inconsistency, data anoma