Introduction to database management

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Introduction to Database

MtM

anagemen

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Outline

Database characteristicsDatabase characteristics

DBMS features

Architectures

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Initial Vocabulary

Data: raw facts about things and eventsData: raw facts about things and events

Information: transformed data that has value for decision making

value for decision making

Essential to organize data for retrieval and maintenance

maintenance

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Database Characteristics

Persistent : stable storagePersistent : stable storage

Shared : multiple users and uses

Interrelated : data stored as entities and

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University Database

Registration Faculty Registration Assignment Entities:

students, faculty, courses, offerings, enrollments Relationships: Grade Recording Course Scheduling Relationships:

faculty teach offerings, students enroll in

offerings, offerings made

University Database

g

of courses, ...

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Water Utility Database

Billing _ProcessingPayment

E titi

g _Processing

Entities:

customers, meters, bills, payments, meter readings

Relationships:

Meter Reading

Service Start/ Stop

Relationships:

bills sent to customers,

customers make payments, customers use meters, ...

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Database Management

System (DBMS)

Collection of components that supportCollection of components that support data acquisition, dissemination, storage, maintenance, retrieval, and formatting

maintenance, retrieval, and formatting

Enterprise DBMSs

Desktop DBMSs

Embedded DBMSs

Major part of information technology infrastructure

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Database Definition

Define database structure before using aDefine database structure before using a database

Tables and relationships

SQL CREATE TABLE statement G

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University

Database

University

Database

R

elatio

n

sh

ip

s

Ta

b

le

s

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University Database (ERD)

Student Offering Faculty

StdSSN StdClass StdMajor Student OfferNo OffLocation OffTime Offering FacSSN FacSalary FacRank Faculty Teaches j StdGPA Accepts FacHireDate Has Supervises

E ll t

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Nonprocedural Access

Query: request for data to answer aQuery: request for data to answer a question

Indicate what parts of database to retrieve

Indicate what parts of database to retrieve not the procedural details

Improve productivity and improve

Improve productivity and improve accessibility

SQL SELECT d hi l

SQL SELECT statement and graphical tools

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Application Development

Form: formatted document for data entryForm: formatted document for data entry and display

Report: formatted document for display

Use nonprocedural access to specify data requirements of forms and reports

requirements of forms and reports

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Data

Entry

Form

Data

Entry

Form

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Sample

Report

Sample

Report

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Procedural Language Interface

Combine procedural language withCombine procedural language with nonprocedural access

Why

Batch processing

Customization and automation

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Transaction Processing

Transaction: unit of work that should beTransaction: unit of work that should be reliably processed

Control simultaneous users

Recover from failures

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Database Technology Evolution

Era Generation Orientation Major Features

1960s 1st Generation File File structures and proprietary program interfaces

1970 2nd G ti N t k N t k d hi hi

1970s 2nd Generation Network Navigation

Networks and hierarchies of related records,

standard program interfaces

1980s 3rd Generation Relational Non-procedural

languages, optimization, transaction processing

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DBMS Marketplace

Enterprise DBMSEnterprise DBMS

Oracle: dominates in Unix; strong in Windows

SQL Server: strong in WindowsSQL Server: strong in Windows

DB2: strong in mainframe environment

Significant open source DBMSs: MySQL, g p y , Firebird, PostgreSQL

Desktop DBMS

Access: dominates

FoxPro, Paradox, Approach, FileMaker Pro

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Data Independence

Software maintenance is a large partSoftware maintenance is a large part (50%) of information system budgets

Reduce impact of changes by separating

Reduce impact of changes by separating database description from applications

Change database definition with minimal

Change database definition with minimal effect on applications that use the

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Three Schema Architecture

View 1 View 2 View n External_L _l

View 1 View 2 View n _Level

External to Conceptual

Conceptual Schema

Conceptual Level

Conceptual Mappings

Conceptual

Internal Internal_Level

to Internal Mappings

Schema Level

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Differences among Levels

External Forms

Reports

Conceptual Tables

Internal

Files needed to store the tables

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Client-Server Architecture

Client Server Architecture

a) Client, server, and

d t b th

b) Mulitple clients and 1 server

diff t t

database on the same computer

on different computers

Client Server Client Server Database Server Client Client Database

c) Multiple servers and databases on different computers

Client Server Server

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Organizational Roles

Specialization

Functional User Information Systems

Specialization

Indirect Parametric Power

Functional User

DBA Analyst/Programmer Management

Information Systems

Indirect Parametric Power

Technical Non Technical

DBA Analyst/Programmer Management

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Database Specialists

Database administrator (DBA)Database administrator (DBA) More technical

DBMS specific skillsDBMS specific skills

Data administrator

Less technical

Planning role

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Summary

Databases and database technology vitalDatabases and database technology vital to modern organizations

Database technology supports daily

Database technology supports daily operations and decision making

Nonprocedural access is a crucial feature