CS403 Highlighted Handouts Lectures 1-18 by Masters

Introduction to the course ............................................................................................................. 9 Database definitions.................................................................................................................... 10 Importance of the Databases ..................................................................................................... 12 Databases and Traditional File Processing Systems ............................................................. 12 Advantages of Databases .......................................................................................................... 15

Difference between Data and Information ............................................................................... 17 Further Advantages of Database Systems .............................................................................. 19 Cost Involved ............................................................................................................................... 21 Importance of Data ...................................................................................................................... 22 Levels of Data .............................................................................................................................. 22 Users of Database Systems ...................................................................................................... 24

Database Architecture ................................................................................................................ 31 The Architecture .......................................................................................................................... 33 External View (Level, Schema or Model) ................................................................................. 35 Conceptual or Logical View ....................................................................................................... 37

Internal or Physical View / Schema ......................................................... 40 Data Independence ................................................................................ 43 Functions of DBMS ................................................................................... 45

Database Development Process ............................................................................................... 51 Preliminary Study ........................................................................................................................ 51 Database Development Process: Approach 2 ........................................................................ 54 Tools Used for Database System Development: .................................................................... 56 Data Flow Diagrams .................................................................................................................... 56 Types of DFD ............................................................................................................................... 60

Detailed Data Flow Diagram ...................................................................................................... 63 Data Dictionary ............................................................................................................................ 64 Database Design Phase ............................................................................................................. 67 Data Model ................................................................................................................................... 68 Types of Data Models ................................................................................................................. 68 Types of Database Design ......................................................................................................... 69

Entity-Relationship Data Model ................................................................................................. 70 The Entity ...................................................................................................................................... 71 Classification of entity types....................................................................................................... 74 Attribute ......................................................................................................................................... 75 Types of Attributes ...................................................................................................................... 77 Summary....................................................................................................................................... 79 Exercises ...................................................................................................................................... 79

Attributes ....................................................................................................................................... 80 The Keys ....................................................................................................................................... 80

Relationships ................................................................................................................................ 85 Types of Relationships ............................................................................................................... 87

Roles in Relationships ................................................................................................................ 95 Dependencies .............................................................................................................................. 97 Enhancements in E-R Data Model ........................................................................................... 98 Super-type and Subtypes ........................................................................................................... 98 Summary....................................................................................................................................... 99

Inheritance Is .............................................................................................................................. 100 Super types and Subtypes ....................................................................................................... 101 Specifying Constraints .............................................................................................................. 103 Completeness Constraint ......................................................................................................... 103 Disjointness Constraint ............................................................................................................. 104 Subtype Discriminator ............................................................................................................... 108

Steps in the Study of system ................................................................................................... 110 Identification of Entity Types of the Examination System .................................................... 118 Relationships and Cardinalities in between Entities ............................................................ 120 Conceptual Database Design .................................................................................................. 122 Logical Database Design ......................................................................................................... 122 Conclusion .................................................................................................................................. 123

Relational Data Model .............................................................................................................. 125 Introduction to the Relational Data model .............................................................................. 126 Mathematical Relations ............................................................................................................ 129 Database Relations ................................................................................................................... 130 Summary..................................................................................................................................... 130 Exercise ...................................................................................................................................... 131

Database and Math Relations ................................................................................................. 132 Degree of a Relation ................................................................................................................. 133

Mapping Relationships ............................................................................................................. 140 Binary Relationships ................................................................................................................. 140 Unary Relationship .................................................................................................................... 144 Data Manipulation Languages ................................................................................................. 146 Relational Algebra ..................................................................................................................... 147 Exercise ...................................................................................................................................... 147

The Project Operator................................................................................................................. 150

Types of Joins ............................................................................................................................ 157 Theta Join ................................................................................................................................... 157 Equi–Join ....................................................................................................................................159 Natural Join ................................................................................................................................ 159

Semi Join .................................................................................................................................... 161 Relational Calculus ................................................................................................................... 162 Tuple Oriented Relational Calculus ........................................................................................ 162 Domain Oriented Relational Calculus .................................................................................... 162 Normalization ............................................................................................................................. 162