L7 data model and dbms architecture

Database ModelsDatabase ModelsDatabase Systems ArchitectureDatabase Systems Architecture

Version 1.0Version 1.0

1Rushdi Shams, Dept of CSE, KUET

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, KUET2

Teacher

PK Teacher_ID

Title Name Department

Student

PK Roll

Name Year Semester

Staff

PK Staff_ID

Title Name Department

ORACLE DBMS


Database

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


1. Hierarchical Model2. Network Model3. Relational Model4. Entity-Relationship Model5. Object Relational Model


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



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

ParentData

ChildData

Pointer

Employee

First Name Last Name Job Salary

Children

First Name Last Name Date of Birth


Employee has many children But a child has only one parent


a is boss of b and d b is boss of c

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


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


The basic building blocks of this model is-

1. Data type2. Rows3. Columns4. Values

Rows are called body and columns are called heading


Illustrates logical database Commonly aids relational database

design End product of the model is Entity

Relation Diagram (ERD)


Artist

PK Artist_ID

Name Band

Song

PK Song_IDPK Artist_ID

Song_Name Album_Name


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


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


Handling server and client failures Processing transactions Handling high data volumes Providing security Servicing multiple simultaneous users


Enterprise Edition (on central DB server)

Express EditionOr Oracle Personal Edition

Personal database that acts just like a client/server database


SQL*Plus & PL/SQL Developer

Procedure Builder Form Builder Report Builder Graphics Builder Project Builder


Technology

L7 data model and dbms architecture