Course Notes 01

8/3/2019 Course Notes 01

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DataBase course notes - Intro.

DataBase

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DataBase people

Me - Calin CENAN

You

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DataBase Courses GOAL

to present introduction to database anddatabase management systems

organize information in DBMS

retrieve it efficiently

concentrates on relationalsystems, whichare by far the dominant type of DBMS

today

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DataBase Practice GOAL

usea database management system forapplication

MySQL

Structured Query Language SQL

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Course Textbooks

R. Ramakrishnan, J. Gerhrke, DatabaseManagement Systems, McGraw Hill, 2002

J. Ullman, H.G. Molina, J. Widom,Database Systems, Prentice Hall, 2001

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Course Textbooks

R. Dollinger, Ed. Albastra 2001

Baze de date

Baze de date i gestiunea tranzaciilor Utilizarea sistemului SQL Server (SQL 7.0,

SQL 2000)

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Database from Wikipedia

In computer science, a database is astructured collection of records or data thatis stored in a computer system so that a

computer program or person using a querylanguage can consult it to answer queries

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Database

Database Management Systems (DBMS)

Database applications

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Database management system(DBMS)

computer program used to manage andquery a database

usually categorized according to the datamodel that they support: hierarchical,network, relational, object

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Database management system(DBMS) Data Model

data model will tend to determine the querylanguages that are available to access thedatabase

great deal of the internal engineering of a DBMSis independent of the data model, and isconcerned with managing factors such asperformance, concurrency, integrity, and

recovery from hardware failures

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Data Model

Tyler Farrar

1100100011001010100110101100100110100110

10010 .. Tyler Farrar

June 2, 1984 (age 27)

U.S.A.

1.83 m (6 ft 0 in)

74 kg (160 lb)

Sprinter

Tyler Farrar

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Database Need

amount of information available exploding

value of data as organizational asset iswidely recognized

ability to manage this vast amount of data

quickly find information relevant

need for increasingly powerful and flexibledata management systems

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Database Definition

database - collection of data, typicallydescribing the activities of one or more relatedorganizations

database management system, orDBMS, software designed to assist inmaintaining and utilizing large collections

of data need for such systems, as well as their

use, is growing rapidly

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Database Importance

there is not real application without a kindof database

great number of DBMS packages can befound on software market, for all types ofcomputers and processing technologies

DBMS can be found at the top 3 of mostneeded, requested, sold and usedproducts

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Database: Functional Definition

Database is a stored data collectionhaving the following characteristics:

assures data independence

assures accesses (possibly shared access)to large volumes of data

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All DBMS performs 3 main functions

data definition

data manipulation

user interface many other functions that can be carried out

data security

data integrity

data access sharing; data acces control

data recovery

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Database

collection of data, typically describing theactivities of one or more related organizations

university database might contain information

about: Entities such as students, faculty, courses, and

classrooms

Relationships between entities, such as students'

enrollment in courses, faculty teaching courses, andthe use of rooms for courses

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DataBase ManagementSystem, or DBMS

software designed to assist in maintaining andutilizing large collections of data

alternative to using a DBMS is to use ad hoc

approaches that do not carry over from oneapplication to another

store data in files and write application-specific codeto manage it

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Database application

Common interface between language,technology and database SQL Structured Query Language

Architecture Client Server

Web application

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Database Web application

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Server-side script

web server technology in which a user's request isfulfilled by running a script directly on the web server togenerate dynamic HTML pages

provide interactive web sites that interface to databases

different from client-side scripting where scripts are runby the viewing web browser, usually in JavaScript or anJava applet

primary advantage - ability to highly customize theresponse based on the user's requirements, accessrights, or queries into data stores.

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PHP

recursive acronym for "PHP: HypertextPreprocessor

reflective programming language originallydesigned for producing dynamic webpages

used mainly in server-side scripting

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PHP

generally runs on a web server

taking PHP code as its input and

creating Web pages as output

acts as a filter

takes input from a file or stream containingtext and special PHP instructions and

outputs another stream of data for display

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PHP

can be deployed on most web servers and onalmost every operating system and platform

can be used with a large number of relational

database management systems

over 19 million Internet domains are currently

hosted on servers with PHP installed

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LAMP architecture

popular in the Web industry as a way ofdeploying inexpensive, reliable, scalable,secure web applications

PHP is commonly used as the P in thisbundle alongside Linux, Apache andMySQL, although the P can also refer to

Python or Perl

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LAMP architecture

solution stack of software

usually free software / open-source software

used to run dynamic Web sites or servers

the original expansion is as follows:

Linux, referring to the operating system;

Apache, the Web server;

MySQL, the database management system PHP, the programming language

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LAMP / WAMP architecture

Linux, GNU/Linux a Unix-like computer operating system/ Microsoft Windows families of software operatingsystems

Apache HTTP Serve (http://httpd.apache.org) - free

software/open source web server, the most popular inuse; serves as the de facto reference platform againstwhich other web servers are designed and judged

MySQL (mysql.com) - multithreaded, multi-user, SQLDatabase Management System (DBMS) with more than

ten million installations

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LAMP / WAMP architecture

Microsoft Windows-based variant of aLAMP (software bundle)

WAMP5

www.en.wampserver.com

WOS Portable

www.chsoftware.net/en/useware/wos/wos.htm

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Portable

mowes portable MySQL, Apache Web Server, PHP

MySQL WorkBench

front-end, client, manage MySQL database



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Old Time Rock and Roll

Examples based on

Garmin - Cervlo Pro Cycling Team

A Song of Ice and Fire, George RR Martin



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Garmin - Cervlo

Tyler Farrar, June 2, 1984, U.S.A., 1.83,74, Sprinter

David Zabriskie, January 12, 1979,U.S.A.,1.83, 67, Time-trialist

David Millar January 4, 1977, UnitedKingdom, 1.92, 76, Time-trialist

Thor Hushovd, 18 January 1978, Norway,1.83, 83, Classics Specialist



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Game of Thrones

Bran Stark, House Stark, Westeros

Catelyn Tully, House Stark, Westeros

Daenerys Targaryen, House Targaryen,Valyria

Eddard Stark, House Stark, Westeros

Jon Snow, , The North

Tyrion Lannister, House Lannister, Westeros

Arya Stark, House Stark, Westeros



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Game of Thrones

Sansa Stark, House Stark, Westeros

Davos Seaworth, House Seaworth, Westeros

Theon Greyjoy, House Greyjoy, Ironmen

Jaime Lannister, House Lannister, Westeros

Samwell Tarly , , Westeros

Cersei Lannister House Lannister, Westeros

Brienne of Tarth, House Tarth, Westeros



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Historical perspective filesystems vs DBMS

have to write special programs toanswer each question a user may wantto ask

must protect data from inconsistentchanges made by different conccurentusers

Restore

Security



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Advantage of DBMS

DBMS software designed to make thepreceding tasks easier

Data Independence

Efficient Data Access

Reduced Application Development Time



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Advantage of DBMS

Data Integrity and Security

Data Administration

Concurrent Access Crash Recovery



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Data Independence

Application programs should not, ideally,be exposed to details of datarepresentation and storage, DBMS

provides an abstract view of the data thathides such details

immunity of user applications to make

changes in the definition and organizationof data



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Historical perspective

Integrated Data Store first general-purpose DBMS, designed by CharlesBachman at General Electric in the early

1960s

network data model, standardized byConference on Data Systems Languages

(CODASYL)



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Information Management System (IMS) inthe late 1960s, developed by IBM, usedeven today in many major installations

hierarchical data model



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In 1970, Edgar Codd, at IBM's San JoseResearch Laboratory, proposed

relational data model



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Mathematics

always strive for elegance and orthogonality -dislike exceptions

system is said to be designed in an orthogonal

way if its set of components that together makeup whole system capability are non-overlappingand mutually independent

each capability should be implemented by only one

component one component should only implement one capability

of system



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Mathematics

well-separated and independent componentsensure that there are no side effects: using oreven changing one component does not cause

side effects in another area of system

formal disciplines, most relevant ones inapplication of mathematics to field of

databases Set theory



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Mathematics

Everything should be made as simple aspossible, but not simpler.

Albert Einstein (18791955)



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Relational model

Professionals in any discipline need toknow the foundations of their field

Database Professional - need to knowtheory of relations

is not product-specific;

rather, it is concerned with principles



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Principles, not Products

principle

source, root, origin; which is fundamental;essential nature; theoretical basis

principles endure

by contrast, products and technologies,change all the time



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E. F. Codd, at the time researcher at IBM;late in 1968 that Codd, a mathematician,first realized that discipline of mathematics

could be used to inject some solidprinciples and rigor into field of database


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original definition ofrelational model

E. F. Codd

Derivability, Redundancy, and Consistency ofRelations Stored in Large Data Banks, IBM ResearchReport RJ599, 1969.

A Relational Model of Data for Large Shared DataBanks, CACM 13, No. 6, 1970.

C. J. Date

An Introduction to Database Systems, 8th

Ed. Boston,Mass.: Addison-Wesley, 2004.

first edition of book was published in 1975


R l ti l d l


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Relational modelthree major components

structure

integrity

manipulation



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Set theory

branch of mathematics

studies sets - collections of objects

probably remember your math teacherdrawing pictures on blackboard whileexplaining sets (Venn diagrams)



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Set theory

branch of mathematics

studies sets - collections of objects

probably remember your math teacherdrawing pictures on blackboard whileexplaining sets (Venn diagrams)



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Set

primitive terms

collection of objects, those objects arecalled elements of set

fully characterized by its distinct elements,and nothing else but these elements



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Set

elements of set dont have any ordering

dont contain duplicate elements

x S



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Methods to specify sets

Enumerative Method

Predicative Method



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Cartesian Product

A x B { (a;b) | a A b B }



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Relation

Relative

Catelyn Tully is the mother of Bran Stark

Eddard Stark is the father of Bran Stark

x Rel y

catelyn Mother bran

eddard Father bran

bran Child catelyn

bran Child eddardDataBase course notes - Intro. 55


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Relation

1 Square 1

2 Square 4

3 Square 9

4 Square 16

16 Square 256

1.41 Square 2



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Binary Relation

from set A to set B is defined as subset ofCartesian product A x B

A := {X,Y,Z}, B := {1,2}

R1 := { (X;1), (X;2), (Y;1), (Z;2) }



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Function

binary relation that doesnt have two

elements that have the same firstcoordinate



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Relation

subset of generalized Cartesian product

set of tuples (N-Tuples)

tuple ordered list of elements

{(e1; e2; ; en) | ei Si}



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(Father, Mother, Child)

eddard, catelyn, bran

eddard, catelyn, arya

eddard, catelyn, sansa

eddard, catelyn, robb

tywin, joanna, jaime

tywin, joanna, tyrion tywin, joanna, cersei

hoster, minisa, catelynDataBase course notes - Intro. 60


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Sets

Name

Date of Born

Country

Height

Weight

Rider type {Sprinter, Time-trialist, ClassicsSpecialist}



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Tuple (N-Tuple) element of relation

Name - Tyler Farrar

Date of Born - June 2, 1984

Country U.S.A.

Height - 1.83

Weight - 74

Rider type - Sprinter



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Tuple (N-Tuple) element of relation

(Tyler Farrar; June 2, 1984; U.S.A.; 1.83;74; Sprinter)

Name - Tyler Farrar

Date of Born - June 2, 1984

Country U.S.A.

Height - 1.83 Weight - 74

Rider type SprinterDataBase course notes - Intro. 63


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Relation

{

(Tyler Farrar; June 2, 1984; U.S.A.; 1.83; 74; Sprinter),

(David Zabriskie; January 12, 1979; U.S.A.; 1.83; 67;Time-trialist),

(David Millar; January 4, 1977; United Kingdom; 1.92;76; Time-trialist),

(Thor Hushovd; 18 January 1978; Norway; 1.83; 83;Classics Specialist),

(Andrei Nechita; 29 May 1988; Romania; NULL; NULL;NULL)

}



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Relation subset - set

Elements

elements of set dont

have any ordering

dont contain duplicateelements

Specify sets

Enumerative Method

Predicative Method



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Relation

are defined over domains, (data types)

domain set of values from which actualattributes in actual relations take their

actual values

n-ary relations can be pictured as tablewith ncolumns

columns correspond to attributes of relation

rows correspond to tuples



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Relational Algebra



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Properties of Relations

every relation has headingand body

heading is set of attributes (name, typepair)

body is set of tuples that conform to thatheading

relation doesn't really contain tuples, itcontains body, and that body in turncontains tuples



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number of attributes in heading is thedegree(arity), and number of tuples inbody is the cardinality

tuples of relation are unordered; followsbecause body is set, and sets inmathematics have no ordering to their

elements attributes of relation are also unordered

because heading too is mathematical setDataBase course notes - Intro. 69


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relations never contain duplicate tuples;follows because body is set of tuples, andsets in mathematics do not contain

duplicate elements relational operations always produce result

without duplicate tuples

SQL results are allowed to containduplicate rows



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Tuple

Let T1, T2, ... , Tn, (n> 0) be type names, not necessarilyall distinct.

Associate with each Ti a distinct attribute name, Ai; eachof the nattribute-name : type-name combinations that

results is an attribute. Associate with each attribute a value vi of type Ti; each

of the nattribute : value combinations that results iscomponent.

set of all ncomponents thus defined, tsay, is tuple value(or just tuple for short) over the attributes A1, A2, ... , An

value n is the degree of t; set of all nattributes isheading of t



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Relation

Let {H} be a tuple heading and let t1, t2, ... , tn, (n> 0) be distinct tuples with heading {H}.

The combination, rsay, of {H} and the set of

tuples {t1, t2, ... , tn} is a relation value (or justrelation for short) over attributes A1, A2, ... , An,where A1, A2, ... , An are the attributes in {H}.

heading of r is {H}

rhas same attributes that heading does

body of ris set of tuples {t1, t2, ... , tn}



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Thank you for your kindly attention!

Course Notes 01

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