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Database Management System (DBMS) Brenda Castro 07-June 2012 1st Semester AY 2012-2013

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Chapter Objectives

Establish an understanding of database

principles and the technologies and theory underlying database management systems.

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1. Topics:

Data vs. Information Database Database Management System (DBMS) File System vs. DBMS Data Models Entities Relationships Relational Database

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Data vs. Information

- Are values of qualitative (description of a certain type

of information) or quantitative (measured or identifies on

a numerical scale) variables, belonging to a set of items.

-Data that have been processed in such a way that the

knowledge of the person who uses the data is

increased

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Bayani, Jeffrey Joseph 2010019922

Torres, Gladyse Faye 2010019340

Estaris, Alain 2010018273

Sanchez, Jessica 2010000001

Aquino, Simeon 2011000002

Corona, Renato 2011000010

Enrile, Johnny 2011000100

Belmonte, Sonny 2011000030

Santiago, Defensor 2010101010

Philips, Philip 2010000002

Data or Information ?

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Course: IM201-Database Management System Semester: 1st, 2012-13

Class Roster

Student ID Student Name Section GPA

2010019922 Bayani, Jeffrey Joseph 3ISA 2.9

2010019340 Torres, Gladyse Faye 3ISA 3.4

2010018273 Estaris, Alain 3ISA 2.8

2011000002 Aquino, Simeon 3-PH 2.9

2011000010 Corona, Renato 3-PH 3.3

2011000100 Enrile, Johnny 3-PH 3.1

2011000030 Belmonte, Sonny 3-PH 2.9

2010101010 Santiago, Defensor 3-PH 3.2

2010000001 Sanchez, Jessica 3-AI 3.7

2010000002 Philips, Philip 3-AI 3.5

Data or Information ?

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Data or Information ?

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Metadata Data that describe the properties or characteristics of end-user

data, and the context of that data.

Describes how data is formatted to essentially understand the

information/records stored in a database.

Data about data

Name Type Length Min Max Description Source

Course Alphanumeric 30 Course ID and Name Academic

Units

Semester Alphanumeric 15 Semester and Year Registrar

Section Alphanumeric 4 Section Registrar

Student

ID.

Integer 10 Student Number Student File

Name Alphanumeric 50 Student’s Full Name Student File

GPA Decimal 3 0.0 5.0 Grade Point Average Academic

Units

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What is DBMS?

Is an organized collection of data that exists over a long

period of time, typically in digital form. The data are

organized to model relevant aspects of reality (for

example, the availability of rooms in hotels), in a way

that supports processes requiring this information (for

example, finding a hotel with vacancies).

Is a collection of programs that allows storage,

modification and extraction of information from a

database.

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File System vs. DBMS

A system for organizing directories and files, generally in terms of how it is implemented in the disk operating system

Computers use particular kinds of file systems to store and organize data on media, such as a hard drive, the CDs and DVDs, or on a flash drive.

DBMS evolved from file systems DBMS enables: data independence and efficient

access reduced application development

time data integrity and security uniform data administration concurrent access, recovery from

crashes

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Data Models

A collection of tools for describing • data • data relationships • data semantics • data constraints

A set of concepts to describe the structure of a

database, and certain constraints that the database

should obey.

Entity-Relationship model

Relational model

Other models:

• object-oriented model • semi-structured data models • Older models: network model and hierarchical

model

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REALITY

• structures

• processes

DATABASE SYSTEM

MODEL data modeling

The model represents a perception of structures of

reality

The data modeling process is to fix a perception of

structures of reality and represent this perception

In the data modeling process we select features and

then, we conceptualize

Data Modelling

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Entity - Relationship

deposit

Entities (objects)

• E.g. customers, accounts, bank branch

Relationships between entities

• E.g. Account A-101 is held by customer John Luna

• Relationship set depositor associates customers with

accounts

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Relational Model

Database design in E-R model usually

converted to design in the relational model

which is used for storage and processing

customer-

name customer-id

customer-

street

customer-

city

account-

number

John Luna

Pepe Rizal

Andy Buena

Greg Diaz

Marie Yu

192-83-7465

019-28-3746

192-83-7465

321-12-3123

019-28-3746

V. Mapa

Tordesillas

Castilla

Esteban

Valencia

Manila

Makati

Quezon

Makati

Manila

A-101

A-215

A-201

A-217

A-210

Attributes

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Relational Database Customer-id Customer-name Customer-street Customer-city

192-83-7465 John Luna V. Mapa Manila

019-28-3746 Pepe Rizal Tordesillas Makati

192-83-7465 Andy Buena Castilla Quezon

321-12-3123 Greg Diaz Esteban Makati

019-28-374 Marie Yu Valencia Manila

account-no account-balance

A-101 25,000.00

A-215 42,785.23

A-201 56,987.58

A-217 167,926.89

A-210 89,937.19

Customer-id Account-no

192-83-7465 A-101

019-28-3746 A-215

192-83-7465 A-201

321-12-3123 A-217

019-28-374 A-210

tblCustomers

tblAccounts tblDepositor

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Questions?

Consultation Hours:

Thursdays, 1:00PM to 3:00PM

Email: bccwork2012@yahoo.com

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2. Topics:

File Processing System vs. DB Approach Range of DB Applications Applications of DBMS DBMS Users