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

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 Employee has many children
 But a child has only one parent

9. Rushdi Shams, Dept of CSE, KUET
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 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
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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
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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
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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
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14. Rushdi Shams, Dept of CSE, KUET
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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
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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
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17.  Handling server and client failures
 Processing transactions
 Handling high data volumes
 Providing security
 Servicing multiple simultaneous users
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18.  Enterprise Edition (on central DB server)
 Express Edition
Or
 Oracle Personal Edition
 Personal database that acts just like a
client/server database
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19.  SQL*Plus & PL/SQL
 Developer
 Procedure Builder
 Form Builder
 Report Builder
 Graphics Builder
 Project Builder
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