This document discusses database models and database systems architecture. It describes hierarchical, network, relational, entity-relationship, and object-relational database models. It also discusses database management systems, how they are used to access and manipulate databases based on different data models, and how database systems are typically architected in mainframe, personal, and client-server configurations.

1. Database ModelsDatabase Models
Database Systems ArchitectureDatabase Systems Architecture
Version 1.0Version 1.0
1Rushdi Shams, Dept of CSE, KUET

2.  Database is structured collection of
records of data stored in a computer
system
 Database Management System (DBMS) is
a computer software designed to
manage (Access/Manipulate/Duplicate)
database based on various Data
Models.
Rushdi Shams, Dept of CSE, KUET
2

3. Rushdi Shams, Dept of CSE, KUET
3
Database

4.  A data model is a formal description of
how data maybe structure, represented,
and accessed
 A database model is a theory or
specification describing how a database
is structured and can be used
Rushdi Shams, Dept of CSE, KUET
4

5. 1. Hierarchical Model
2. Network Model
3. Relational Model
4. Entity-Relationship Model
5. Object Relational Model
Rushdi Shams, Dept of CSE, KUET
5

6.  Organized in Tree Structure
 Allows repeating information using
parent/child relationships
 Each parent can have many children but
a child will have only one parent
Rushdi Shams, Dept of CSE, KUET
6

7. Rushdi Shams, Dept of CSE, KUET
7
Customer Data
Name Address Phone Pointer to Checking
Acct. Data
Pointer to Auto
Loan Data
Maria Chavez 1441 Adams Court 605-777-8992
John Severson 8988 Grover Road 605-898-2314
Harold Brown 3511 Pluto Drive 605-666-3298
Checking Account Data
Acct. Number Current Balance Date Last
Transaction
986-335 445.11 07/11/03
988-310 2988.44 07/01/03
355-822 898.14 06/15/03
Auto Loan Data
Acct. Number Current Balance Date Last Pmt
100988 5676 06/15/03
101732 1545.33 07/01/03
Parent
Data
Child
Data
Pointer

8. Rushdi Shams, Dept of CSE, KUET
8
 Employee has many children
 But a child has only one parent

9. Rushdi Shams, Dept of CSE, KUET
9
 a is boss of b and d
 b is boss of c

10.  Allows each record to have multiple
parent and multiple children records
 More natural modelling than
hierarchical model
 But network model failed-
1. IBM made an improvement on
hierarchical model making it semi-
networked
2. Displaced by relational model, which
offered higher level of interface
Rushdi Shams, Dept of CSE, KUET
10

11.  Based on predicate logic and set theory
 Enforced database integrity
 Data are operated upon by means of
relational algebra
 Designs relations (tables) by
normalization
 Accessing data differs according to the
DBMS
Rushdi Shams, Dept of CSE, KUET
11

12.  The basic building blocks of this model
is-
1. Data type
2. Rows
3. Columns
4. Values
 Rows are called body and columns are
called heading
Rushdi Shams, Dept of CSE, KUET
12

13.  Illustrates logical database
 Commonly aids relational database
design
 End product of the model is Entity
Relation Diagram (ERD)
Rushdi Shams, Dept of CSE, KUET
13

14. Rushdi Shams, Dept of CSE, KUET
14

15.  Relational model but allows user to
integrate a database with their own data
types and methods
 Mostly, external software runs over
traditional DBMS to provide this
functionality
 Polymorphism, inheritance, function
overloading, etc are present
Rushdi Shams, Dept of CSE, KUET
15

16.  Mainframe databases
• Both DBMS and applications run on mainframe
computer
• Users access database and applications using
terminals
 Personal databases
• Both DBMS and applications run on user’s
workstation
 Client/server databases
• DBMS runs on central server
• Applications run on user’s (client) workstation
Rushdi Shams, Dept of CSE, KUET
16

17.  Handling server and client failures
 Processing transactions
 Handling high data volumes
 Providing security
 Servicing multiple simultaneous users
Rushdi Shams, Dept of CSE, KUET
17

18.  Enterprise Edition (on central DB server)
 Express Edition
Or
 Oracle Personal Edition
 Personal database that acts just like a
client/server database
Rushdi Shams, Dept of CSE, KUET
18

19.  SQL*Plus & PL/SQL
 Developer
 Procedure Builder
 Form Builder
 Report Builder
 Graphics Builder
 Project Builder
Rushdi Shams, Dept of CSE, KUET
19