BISM 7406 Information Retrieval and Mana2

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Information Retrieval and Management

• Overview and Architecture
  • Traditional file-based systems
    • The definition of File-Based Approach
    • Limitations of File-Based Approach
      • Separation and isolation of data
      • Duplication of data (data
      • redundancy)
      • Data dependence
      • Incompatible file formats
      • Fixed queries/proliferation of application programs
  • Database Approach
    • The definition of Database Approach
    • Purpose of a Database System
    • Advantages of the Database Approach
      • Control of data redundancy
      • Data consistency
      • More information from the same amount of data
      • Sharing of data
      • Improved data integrity
      • Improved security
      • Enforcement of standards
      • Economy of scale
      • Balance conflicting requirements
      • mproved data accessibility and responsiveness
      • Increased productivity
      • Improved maintenance through data
      • independence
      • Increased concurrency
      • Improved backup and recovery services
    • Disadvantages of the Database Approach
      • Complexity
      • Size
      • Cost of DBMS
      • Additional hardware costs
      • Costs of conversion
      • Performance
      • Impact of failures
  • Database Management Systems (DBMS)
    • The definition of Database Management Systems (DBMS)
    • Components of the DBMS environment
      • Hardware
      • Software
      • Data
      • Procedures
      • People
    • DBMS functions
      • Data Storage, Retrieval, andUpdate
        • Data definition language (DDL)
        • Data manipulation language (DML)
      • A user-accessible catalogue
        • Data Dictionary or System Catalogue
      • Transaction support
        • Create
        • Read
        • Update
        • Delete
      • Concurrency control services.
      • Backup and recovery services
      • Authorization Services
      • Support for Data Communication
      • Integrity Services
      • Services to Promote Data Independence
      • Utility Services.
  • Database Environment
    • The definition of Database Environment
    • Three-level Database Architecture
      • External Level(logical)
      • Conceptual Level(logical)
      • Internal Level(physical)
    • Three Types of Database Schema
      • External schema
      • Conceptual schema
      • Internal schema
    • Data Models
      • The definition of Data Models
      • Various Model Types
        • Object-Based Data Models
          • Entity-Relationship
          • Semantic
          • Functional
          • Object-Oriented
        • Record-Based Data Models
          • Relational Data Model
          • Network Data Model
          • Hierarchical Data Model
        • Physical Data Models
• Entity Relationship Modelling
  • Database System Development Lifecycle
    • Information System (IS)
      • The definition of the Information System
      • Components of an Information System
        • Database
        • Database Software
        • Application Software
        • Computer Hardware including storage media
        • People using
        • Developing the system
    • The relationship between the IS and Database System
      • Database is a fundamental component of IS
    • Database System Development Lifecycle Stages
      • database planning
      • system definition
      • requirements collection and analysis
      • database design
      • DBMS selection (optional)
      • application design
      • prototyping (optional)
      • implementation
      • data conversion and loading
      • testing
      • operational maintenance
    • Mission Objective
      • identify the particular tasks that the database must support
    • Mission Statement
      • defines the major aims of the database system
  • database design
    • The definition of Datebase Design
    • Date Modelling
      • Importance of Data Models
        • Communication tool
        • Give an overall view of the database
        • Organise data for various users
        • Abstraction for the creation of a good database
      • Purposes of data modeling
        • assist in the understanding of the meaning (semantics) of the data and to facilitate communication about the information requirements
      • Various data modelling techniques/model types
        • Entity-Relationship model
        • Hierarchical model
        • Relational model
        • Object-oriented model
      • Criteria for data models
        • 
    • Three phases of database design
      • Conceptual database design
      • Logical database design
      • Physical database design
  • fact-finding
    • The definition of the Fact-Finding
    • Fact-finding Techniques
      • Examining documentation
        • 
      • Interviewing
        • 
      • Observing the organization in operation
        • 
      • Research
        • 
      • Questionnaires
        • 
      • Brainstorming
• DB System Development Lifecycle & DB Analysis
  • Relational Modelling
    • Definition
    • Objectives of the Relational Model
      • o To allow a high degree of data independence. o To provide substantial grounds for dealing with the problems of data semantics, consistency, and redundancy. o To enable the use of set-oriented data manipulation languages.
    • Terminology
      • Degree
      • Domain
      • Tuple
      • Primary Key
      • Alternate Key
      • Foreign Key
      • Attribute
      • Cardinality
      • Composite Key
      • Relation
    • Characteristics of a Relational Table
      • 
    • Relational Database Keys
      • 
  • Mathematical Relations
    • Definition
      • In order to better understand relations, some mathematical concepts are briefly explored here.
    • Relational Algebra
      • -Relational algebra is a theoretical language -It is the theoretical basis of query languages such as SQL -It contains operators that work on one or more relations. -These operators give us the means to construct new relations from given ones.
    • Cartesian Product
  • Integrity Constraints
    • Aims
      • Protect the database from becoming: • Incomplete • Inaccurate •Inconsistent
    • Integrity Constraints Content
      • Required data
        • Nulls
        • How to Ensure Referential Integrity
      • Attribute domain constraints
        • Not null
        • Data type restrictions
        • Limit or range checks
        • Completeness checks
        • Format or template checks
        • Check digit
        • Set membership
        • Master file reference
        • Record checks
      • Multiplicity
      • Entity integrity
        • 
      • Referential integrity
        • 
      • General constraints
        • ➢ Updates to entities may be controlled by general constraints. ➢ General constraints reflect “real world” transactions represented by updates. E.g. DreamHome has a rule that prevents a staff member from managing >100 properties
    • Views
      • 
• Entity Relational Modelling
  • Entity-Relationship Modelling
    • The definition of Entity-Relationship Modelling
    • Main components of ERD
      • Entities
        • Strong Entity
        • Weak Entity
      • Relationships
        • Binary relationship
        • Ternary relationship
        • Quaternary relationship
        • Recursive relationship
        • Strong Relationships
        • Weak Relationships
      • Attributes
        • Attribute domain
        • Simple attribute
        • Composite attribute
        • Single-valued attribute
        • Multi-valued attribute
        • Derived Attributes
      • Constraints
        • Definition
          • Multiplicity consists of two types of restrictions on relationships
        • Multiplicity
          • Cardinality Constraints
          • Participation Constraints
          • ERD Notation/ Multiplicity Constraints – different notations
            •  
      • Other business rules
        •  
        • Cardinality
          • Cardinality 1, A author can have many books 1 to many ( 1, M) But A book has one author 1 to 1 （1，1） 2, A book has one publisher （1，1） But a publisher can publish many books 1 to many (1, M) 3, A warehouse can have many books ( 1 to M ) A book can only store in a warehouse ( 1 to 1)
        • Participation
          • Participation: All books must have an author. (mandatory) An Author must have a book (mandatory) All books have a publisher (mandatory) A publisher can publish many books. (mandatory) A warehouse can have many books . ( mandatory) Books can store in a warehouse ( mandatory)
      • Key
        • Superkey
        • Candidate Key
          • Secondary key
          • Alternate key
        • Primary key
        • Foreign key
        • Composite key
  • Enhanced Entity-Relationship Modelling
    • The reasons of Enhanced Entity-Relationship Modelling
    • Specialisation
      • Definition
      • Superclasses
      • Subclasses
      • Process
    • Generalization
      • Definition
      • Process
    • Attribute inheritance
• ACID
  • Atomicity
  • Consistency
  • Isolation
  • Durability
• Date Independence
  • data independence
  • logical data independence
  • physical data independence
• important reasons for introducing the concepts of superclasses and subclasses into an ER model
  • First, it avoids describing similar concepts more than once, thereby saving time for the designer and making the ER diagram more readable. Second, it adds more semantic information to the design in a form that is familiar to many people. For example, the assertions that “Manager IS-A member of staff” and “flat IS-A type of property,” communicates significant semantic content in a concise form
• Constraints on Specialization/Generalization
  • Two constraints may apply to specialization/generalization: ➢ participation constraints ➢ disjoint constraints. 1. Participation constraint ➢ Shows whether every member in superclass must also participate as a member of a subclass. ➢ May be mandatory or optional. 2. Disjoint constraint ➢ Indicates whether member of a superclass can be a member of one, or more than one, subclass. ➢ May be disjoint (can be member of only one subclass) or nondisjoint (entity may be member of more than one subclass).