94797883-Cs9152-Dbt-Unit-IV-Notes

7/26/2019 94797883-Cs9152-Dbt-Unit-IV-Notes

1/61

CS9152 - DATABASE TECHNOLOGY UNIT IV

CS9152 DATABASETECHNOLOGY

UNIT IV

DATABASE DESIGN ISSUES

TEXT BOOK

1. Elisa Bertino, Barbara Catania, Gian Piero Zarri, Intelligent Database Systems,Addison-esley, !""1.

REFERENCES

1. Carlo Zaniolo, Ste#ano Ceri, C$ristos %alo&stsos, '.(.Snodgrass, ).S.S&bra$manian,

Ad*an+ed Database Systems, organ aman, 1/.!. 0.(amer 2s&, Patri+3 )ald&rie2, Prin+i4les o# Distrib&ted Database Systems,

Prenti+e 5al International In+. , 1.

6. C.S.' Prab$&, b7e+t-riented Database Systems, Prenti+e 5all # India, 18.9. Abd&lla$ :2 (ansel Et Al, (em4oral Databases; ($eory, Design And

Prin+i4les,Ben7amin C&mmings P&blis$ers , 16.

5ill, ($ird Edition, !""9.?. 5enry % ort$, Abra$am Silbers+$at2, S. S&d$ars$an, Database System Con+e4ts,

%o&rt$ Ediion, +Gra> 5ill , !""!.

/. '. Elmasri, S.B. 0a*at$e, %&ndamentals o# Database Systems, Pearson Ed&+ation,!""9.



2/61


Syllab!"

UNIT IV DATABASE DESIGN ISSUES 1#

ER $%&'l N%()al*+a,*% S'.(*,y I,'/(*,y C%!*!,'.y Da,aba!'

T*/ O0,*)*+a,*% a& R'!'a(. I!!'! D'!*/ % T')0%(al Da,aba!'!

S0a,*al Da,aba!'!3

Tabl' % C%,',!

SL N%3 T%0*. 4a/'

1 ER $%&'l 2

2 N%()al*+a,*% 1

S'.(*,y 26

7 I,'/(*,y #

5 C%!*!,'.y 2

8 Da,aba!' T*/

6 O0,*)*+a,*% a& R'!'a(. I!!'! 9

D'!*/ % T')0%(al Da,aba!'! 72

9 S0a,*al Da,aba!'! 76

1# Sa)0l' :'!,*%! 5

11 U*;'(!*,y :'!,*%! 8#

T%0*. 1" ER $%&'l

DATABASE DESIGN ISSUES !


3/61


I,(%&.,*%

A database +an be modeled as;

a +olle+tion o# entities,relations$i4 among entities.

Ste4s in design o# database;-

@ 'e&irements +olle+tion analysis@ Con+e4t&al s+$ema design

@ Im4lementing +on+e4t&al s+$ema into database &sing Im4lementation model

logi+al database design or data model ma44ing

@ P$ysi+al database design

5ig$-le*el +on+e4t&al data model

ER $%&'l C%.'0,!

E,*,*'!< a,,(*b,'! a& ('la,*%!*0!

E,*,*'!are s4e+i#i+ ob7e+ts or t$ings in t$e mini->orld t$at are re4resented in t$e

database.

An entity is an ob7e+t t$at eists and is disting&is$able #rom ot$er

ob7e+ts.Eam4le; s4e+i#i+ 4erson, +om4any, e*ent, 4lant

%or eam4le, t$e EPEE =o$n Smit$, t$e 'esear+$ DEPA'(E0(, t$e

Prod&+tF P'=EC(

E,*,y S',; A +olle+tion o# similar entities. E.g., all em4loyees.

All entities in entity set $a*e same set o# attrib&tes.

Ea+$ entity set $as a key.

Ea+$ attrib&te $as a domain.

A,,(*b,'!"

Attrib&tes are 4ro4erties &sed to des+ribe an entitiy.

%or Eam4le, an EPEE entity may $a*e a 0ame, SS0, Address, Se,

Birt$Date.

A S4e+i#i+ entity >ill $a*e a *al&e #or ea+$ o# its attrib&tes.

DATABASE DESIGN ISSUES 6


4/61


%or eam4le a s4e+i#i+ em4loyee entity may $a*e 0ameH=o$n Smit$,

SS0H1!69


5/61


single *al&ed - age

m&lti *al&ed - &ali#i+ation

stored - dateo#birt$

deri*ed - Age

Nll ;al'!

@ issing

@ A*ailable b&t &n3no>n

@ Ina44li+able 4la+es

@ E,*,y ,y0'!< ;al' !',! = K'y a,,(*b,'!

Entity ty4e entities t$at s$are same attrib&tes or entities >it$ t$e same basi+

attrib&tes are gro&4ed or ty4ed into an entity ty4e

JegK em4loyee

@ des+ribes s+$ema or intension #or a set o# entities

Colle+tion o# indi*id&al entities etension o# entity ty4e or entity set

@ Val' !', >&%)a*? % a,,(*b,'!

@ name, ty4e o# *al&es, #ormat et+.

K'y a,,(*b,' % a ',*,y ,y0' - An attrib&te o# Entity ty4e #or >$i+$ ea+$ entity

m&st $a*e a &ni&e *al&e is +alled a 3ey attrib&te o# t$e entity ty4e.

It doesnt allo> d&4li+ate *al&es

Eam4le, SS0 o# EPEE

An entity ty4e may $a*e more t$an one 3ey.

%or eam4le, t$e CA' entity ty4e may $a*e t>o 3eys;

- )e$i+leIDenti#i+ation0&mber J4o4&larly +alled )I0K and



6/61


- )e$i+le(ag0&mber J 0&mber, stateK, alos 3no>n an li+ense4late

n&mber

-

@ RELATIONSHI4S

Asso+iation among entity ty4es

'elations$i4 ty4e set o# relations$i4s among di##erent entity ty4esE1,E!,L,En entity ty4esQ

r1,r!,L,rn relation instan+es

' relations$i4 ty4e

E.g., Attis$oo >or3s in P$arma+y de4art.

R'la,*%!*0 S'," Colle+tion o# similar relations$i4s.

An n-ary relations$i4 set ' relates n entity sets E1 ... EnQ

ea+$ relations$i4 in ' in*ol*es entities e1 #rom E1, ..., en #rom En

@ Same entity set +o&ld 4arti+i4ate in di##erent relations$i4 sets,or in di##erent roles in same set.

C%!,(a*, % R'la,*%!*0!

- I( is alos 3no>n as ratio +onstraints

- aim&m Cardinality- ne-to-one J1;1K

- ne-to-many J1;0K or many-to-one J0;1K

- any-to-many

- inim&m Cardinality Jalso +alled 4arti+i4ation +onstraint or eisten+e

de4enden+y +onstraintsK

- Zero Jo4tional 4arti+i4ation, not eisten+e-de4endentK

- ne or more Jmandatory, eisten+e-de4endentK

R'la,*%!*0 % H*/'( D'/(''

'elations$i4 o# degree ! are +alled binary

'elations$i4 o# degree 6 are +alled ternary and o# degree n are +alled n-ary.

In genral, an n-ary relations$i4 is not e&i*alent to n binary relations$i4s.

E,*,y !', C%(('!0%&*/ ,% ,' ',*,y Ty0' CAR

CA'

'egistrationJ'Egistration0&mber, StateK, )e$i+leID, a3e, odel, earJColorK

DATABASE DESIGN ISSUES ?


7/61


Car1

JJABC 1!6, (EFASK, (?!, %ord &stang, +on*ertible, 1, Jred,bla+3KK

Car!

JJABC 1!6, 0E 'K, P8/!, 0issan 6""ZF, !-door, !""!, Jbl&eKK

JJ)S /!", (EFASK, (D/!, B&i+3 eSabre, 9-door, !""6, J>$ite,bl&eKK

.

@'a E,*,y Ty0'!

An entity t$at does not $a*e a 3ey attrib&te

A ea3 entity m&st 4arti+i4ate in an identi#ying relations$i4 ty4e >it$ an o>ner

or identi#ying entity ty4e.

A weak entity +an be identi#ied &ni&ely only by +onsidering t$e 4rimary 3ey

o# anot$er JownerK entity.

Eam4le;

>ner entity set and >ea3 entity set m&st 4arti+i4ate in a one-to-manyrelations$i4 set Jone o>ner, many >ea3 entitiesK.

ea3 entity set m&st $a*e total 4arti+i4ation in t$is identifying relations$i4

set.

Entities are identi#ied by t$e +ombination o#;

- A 4artial 3ey o# t$e >ea3 entity ty4e.- ($e 4arti+&lar entity t$ey are related to in t$e identi#ying entity ty4e.

Eam4le;

S&44ose t$at a DEPE0DE0( entity is identi#ied by t$e de4endents #irstname and birt$date, and t$e s4e+i#i+ EPEE t$at t$e de4endent is related to.

DEPE0DE0( is a >ea3 entity ty4e >it$ EPEE as its identi#ying entity ty4e

*ia t$e identi#ying relations$i4 ty4e DEPE0DE0(%


lot

name

agepname

DependentsEmployees

ssn

Policy

cost

/


8/61


A !*)0l' ER &*a/(a)

K'y C%!,(a*,!

Ea)0l'" C%!*&'( @%(!I" * ,' ab%;' !*)0l' ER &*a/(a)"

A ')0l%y'' .a %( * )ay &'0a(,)',! a&

a &'0, .a a;' )ay ')0l%y''!3

Ea. &'0, a! a, )%!, %' )aa/'(< a..%(&*/ ,% ,' key constraint %

$aa/'!3


lot

dname

budgetdid

sincename

Works_In DepartmentsEmployees

ssn

Many-to-Many1-to-1 1-to Many Many-to-1

dname

did

since

ManagesEmployeesDepartmentsR";1R";n

budget

8

lot

name

ssn


9/61


N%,a,*%! %( ER D*a/(a)!

4(%bl') *, ER N%,a,*%($e Entity-'ealtions$i4 model in its original #orm did not s&44ort t$e

s4e+iali2ation T generali2ation abstra+tions.



10/61


DATABASE DESIGN ISSUES 1"


11/61




12/61


DATABASE DESIGN ISSUES 1!


13/61




14/61


T%0*. 2" N%()al*+a,*%

Why Normalization?

R'&&a, I%()a,*% * T0l'! a& U0&a,' A%)al*'!

iing attrib&tes o# m&lti4le entities may +a&se 4roblems

In#ormation is stored red&ndantly >asting storage

Problems >it$ &4date anomalies

Insertion anomalies

Deletion anomalies

odi#i+ation anomalies

Example of an update Anomaly

Consider t$e relation;EPP'= JEm4M, Pro7M, Ename, Pname, 0o$o&rsK

Update Anomaly; C$aing t$e name o# t$e 4ro7e+t n&mber #rom Billing to

C&stomer A++o&nting may +a&se t$is &4date to be made #or all 1"" em4loyees

>or3ing on 4ro7e+t P1.

Insert Anomaly:Cannot insert a 4ro7e+t &nless an em4loyee is assigned to.

In*ersely +annot insert an em4loyee &nless $eTs$e is assigned to a 4ro7e+t.

Delete Anomaly; $en a 4ro7e+t is deleted, it >ill res&lt in deleting all em4loyees

>$o >or3 on t$at 4ro7e+t. Alternati*ely, i# an em4loyee is an sole em4loyee on a

4ro7e+t, deleting t$at em4loyee >o&ld res&lt in deleting t$e +orres4onding 4ro7e+t.

4(a.,*.al U!' % N%()al F%()! N%()al*+a,*%is +arried o&t in 4ra+ti+e so t$at t$e res&lting designs are o#

$ig$ &ality and meet t$e desirable 4ro4erties

($e 4ra+ti+al &tility o# t$ese normal #orms be+omes &estionable >$en t$e

+onstraints on >$i+$ t$ey are based are a(& ,% &'(!,a&or to &','.,

($e database designers need notnormali2e to t$e $ig$est 4ossible normal

#orm. J&s&ally &4 to 60%, BC0% or 90%K

D'%()al*+a,*%" t$e 4ro+ess o# storing t$e 7oin o# $ig$er normal #orm

relations as a base relationU>$i+$ is in a lo>er normal #orm

1st introd&+ed by Codd in 1/!

Database normali2ation relates to t$e le*el o# red&ndan+y in a relational

databases str&+t&re.



15/61


($e 3ey idea is to red&+e t$e +$an+e o# $a*ing m&lti4le di##erent *ersions o#

t$e same data, li3e an address, by storing all 4otentially d&4li+ated data in

di##erent tables and lin3ing to t$em instead o# &sing a +o4y.

N%()al*+a,*% D'**,*%@0ormali2ation is t$e 4ro+ess o# de+om4osing &nsatis#a+tory relation

s+$emas into smaller relation s+$emas >$i+$ +ontain desirable attrib&tes

JorK 4ro4erties

@ %or a good relation s+$ema design, a4art #rom normali2ation it s$o&ld $a*e

additional 4ro4erties li3e

ossless-7oin JorK 0on-additi*e 7oin 4ro4erty - It is more im4ortant +annot be

s+ari#ied

De4enden+y 4reser*ation 4ro4erty - It is less im4ortant +an be s+ari#ied

Functional Dependencies

%&n+tional De4enden+ies J%DsK are &sed to s4e+i#y #ormal meas&res o# a goodness

o# t$e relational design.

%Ds and eys are &sed to de#ine normal #orms #or relations

%Ds are +onstraints t$at are deri*ed #rom t$e meaning#&l and interrelations$i4 o# t$e

data attrib&tes.

A set o# attrib&tes F #&n+tionally determines t$e set o# attrib&tes i# t$e *al&e o# F

determines a &ni&e *al&e o#

F $olds >$ene*er t>o t&4les $a*e t$e same *al&e #or F t$ey m&st $a*e t$e

same *al&e #or .

%or any t>o t&4les t1 and t! in any relation insran+e rJ ' K; i# t1RF H t!RF t$en

t1RHt!R.

F in ' s4e+i#ies a +onstraint on all relation instan+es r J ' K

ritten as F Q +an be dis4layed gra4$i+ally on a relation s+$ema as in %ig&res

J denoted by t$e arro> ; K

%Ds are deri*ed #rom t$e real->orld +onstraints on t$e attrib&tes.



16/61


N%()al F%() Ty0'!@ NF2; non-#irst normal #orm

@ 1NF; ' is in 10%. *all domain *al&es are atomi+.

@ 2NF; ' is in !. 0%.* ' is in 10% and e*ery non3ey attrib&te is #&lly

de4endent on t$e 3ey

@ NF; ' is in 60% *' is !0% and e*ery non3ey attrib&te is non-transiti*ely

de4endent on t$e 3ey

@ BCNF; ' is in BC0% *e*ery determinant is a +andidate 3ey

@ D','()*a,; an attrib&te on >$i+$ some ot$er attrib&te is #&lly #&n+tionally

de4endent.

Fl*/, R'la,*% Ea)0l'"


Overview o !"s NF2

1NF2NF3NF

BCNF

flt#

date

plane#

airline

from

to

miles

1?

l, &a,' 0la' a*(l*' (%) ,% )*l'!

FLT-INSTANCE


17/61


N%()al F%()! % Fl*/, Ea)0l'"


flt#

date

plane#

airline

from

to

miles

flt#

date

plane#flt#

airline

from

to

miles

from

to

miles

flt#

airline

from

to

flt#

date

plane#

1!"#

$!" %&'!"#

(!"#

1/


18/61


F*(!, N%()al F%()>1NF?

Eliminates 'e4eating Gro&4s. a3e a se4arate table #or ea+$ set o# related

attrib&tes, and gi*e ea+$ table a 4rimary 3ey. Based on t$e +on+e4t o# m&lti*al&ed +om4osite attrib&tes.

($e domains o# all attrib&tes o# a relation s+$ema ' are atomi+, >$i+$ is i#

elements o# t$e domain are +onsidered to be indi*isible &nits.

@ D*!all%! ('la,*% !.')a! ,% a;' )l,*;al'& = .%)0%!*,' a,,(*b,'!

Al!% '!,'& ('la,*%! a,,(*b,'! %!' ;al'! %( a *&*;*&al ,0l' a('

%-a,%)*.3

T' &%)a*! % all a,,(*b,'! % a ('la,*% !.')a R a(' a,%)*.< *. *! *

'l')',! % ,' &%)a* a(' .%!*&'('& ,% b' *&*;*!*bl' *,!3

A ('la,*%al !.')a R *! * *(!, %()al %() * ,' &%)a*! % all a,,(*b,'!

% R a(' a,%)*.

0on-atomi+ *al&es +om4li+ate storage and en+o&rage red&ndant Jre4eatedK

storage o# data

E.g. Set o# a++o&nts stored >it$ ea+$ +&stomer, and set o# o>ners stored >it$

ea+$ a++o&nt

e ass&me all relations are in #irst normal #orm

Atomicity is actually a property of ho the elements of the domain are used!

E.g. Strings >o&ld normally be +onsidered indi*isible

S&44ose t$at st&dents are gi*en roll n&mbers >$i+$ are strings o# t$e #orm

CS0012 orEE1127

I# t$e #irst t>o +$ara+ters are etra+ted to #ind t$e de4artment, t$e domain o# roll

n&mbers is not atomi+.

Doing so is a bad idea; leads to en+oding o# in#ormation in a44li+ation 4rogram

rat$er t$an in t$e database.

DE4ART$ENT ('la,*% *, *!,a.'!

DNA$E DNO D$GRSSN DLOCS

'esear+$ ! !"""1"1 JDel$i, &mbai, ol+&ttaK

Administration 6 1"""111 Bangal&r&

5ead V&arters 1 """111 C$ennai

C%!*&'( ,% b' 0a(, % ,' &'**,*% % ('la,*%3

JEg1K

DCS is a m&lti*al&ed attrib&te



19/61


Normalized "a#le $ in I NF ith redundancy

DNA$E DNO D$GRSSN DLOCS

'esear+$ ! !"""1"1 Del$i'esear+$ ! !"""1"1 &mbai

'esear+$ ! !"""1"1 ol+&tta

Administration 6 1"""111 Bangal&r&

5ead V&arters 1 """111 C$ennai

JEg!K

EPP'=

SS0 E0AE P'=EC(S

P0 5:'S

Normalized "a#le $ in I NF ith redundancy

E%&'&()*+

SS0 E0AE

E%&'&()*,

SS0 P0 5:'S

Note:It in*ol*es t$at remo*al o# red&ndant data #rom $ori2ontal ro>s.

e need to ens&re t$at t$ere is no d&4li+ation o# data in a gi*en ro>, and t$at e*ery

+ol&mn stores t$e least amo&nt o# in#ormation 4ossible.

@ S'.%& N%()al F%()>2NF?

Based on #&ll #&n+tional de4enden+y

Eliminate 'ed&ndant Data, i# an attrib&te de4ends on only 4art o# a m&lti-

*al&ed 3ey, remo*e it to a se4arate table.

It &ses t$e +on+e4t o# %DJ%&n+tional De4enden+yK and 4rimary 3ey

F%&ll %D

Prime, non-4rime attrib&tes



20/61


A ('la,*% !.')a R *! * 2NF * ';'(y %0(*)' a,,(*b,' % R *! lly

.,*%ally &'0'&', % ,' 0(*)a(y 'y % R

I# ea+$ attrib&te A in a relation s+$ema ' meets one o# t$e #ollo>ing +riteria;

It m&st be in #irst normal #orm.

It is not 4artially de4endent on a +andidate 3ey.

E*ery non-3ey attrib&te is #&lly de4endent on ea+$ +andidate 3ey o# t$e

relation.

Se+ond 0ormal %orm Jor !0%K deals >it$ red&ndan+y o# data in *erti+al +ol&mns.

' +an be de+om4osed into !0% relations *ia t$e 4ro+ess o# !0% normali2ation.

Prime attrib&te attrib&te t$at is member o# t$e 4rimary 3ey 3.

%&ll %&n+tional De4enden+y A %D Z >$ere remo*al o# any attrib&te #rom means t$e %D does not $old any more.

Ea)0l'"

NSS0 P0 O 5:'S is a #&ll %D

$ere as SS0 5:'S P0 5:'S does not.

($e relation;EPP'=

SS0 E0AE P'=EC(SP0 5:'S

is normali2ed into !0% as;

SS0E0AE

N SS0, P0 O

5:'S

NSS0, E0AE O 5:'S

DATABASE DESIGN ISSUES !"


21/61


T*(& N%()al F%() >NF?

It eliminates +ol&mns not de4endent on 3ey. I# attrib&tes do not +ontrib&te to a

des+ri4tion o# t$e 3ey, remo*e t$em to a se4arate table.

A ('la,*% R *! * T*(& N%()al F%() >NF? * a& %ly * *, *!"

* S'.%& N%()al F%()3

E;'(y %-'y a,,(*b,' *! %-,(a!*,*;'ly &'0'&', % ,'

0(*)a(y 'y3

A a,,(*b,' C *! ,(a!*,*;'ly &'0'&', % a,,(*b,' A * ,'(' '*!,! a

a,,(*b,' B !. ,a, A B a& B C< ,' A C3

T(a!*,*;*,y F.,*%al D'0'&'.y a FD X ,a, .a b' &'(*;'& (%)

,% FD! X Y a& Y

Ea)0l'!"

EPDEP(E0AE SS0 BDA(E ADD'ESS D0 D0AE DG'SS0

SS0DG'SS0 is a (ransiti*e %D sin+e

SS0D0 and D0DG'SS0 $olds.

SS0D0AE is not a (ransiti*e %D sin+e t$ere is no set o# attrib&tes F >$ere

SS0F and FE0AE

A R'la,*% !.')a R *! * NF * *, *! * 2NF a& % %-0(*)' a,,(*b,' A *

R *! ,(a!*,*;'ly &'0'&', % ,' 0(*)a(y 'y.

' +an be de+om4osed into 60% relations *ia t$e 4ro+ess o# 60% normali2ation.

0ote; in F and Z >it$ F as t$e 4rimary 3ey, >e +onsider t$is a 4roblemonly i# is not a +andidate 3ey. $en is a +andidate 3ey, t$ere is no 4roblem

>it$ t$e transiti*e de4enden+y.

Eg. Consider EP JSS0, Em4M, SalaryK

5ere, SS0Em4MSalary and Em4M is a +andidate 3ey.

DATABASE DESIGN ISSUES !1


22/61


T' /''(al %()al %() &'**,*%- %( $l,*0l' 'yA 'elation s+$ema ' is in !0% i# e*ery non-4rime attrib&te A in ' is #&lly

#&n+tionally de4endent on e*ery 3ey o# '.

S&4er 3ey o# relation s+$ema ' a set o# attrib&tes S o# ' t$at +ontains a 3ey o# '.

A 'elation s+$ema ' is in 60% i# >$ene*er a %D F A $olds in ' t$en eit$er;

aK F is a s&4er 3ey o# ' or

bK A is a 4rime attrib&te o# '

E'(.*!'"

Consider a relation +alled s&44lier-4art >it$ t$e #ollo>ing data to be 4ro+essed;

NsM, stat&s, +ity, 4M, ty, +ostO

$ere,

sM -- s&44lier identi#i+ation n&mber Jt$is is t$e 4rimary 3eyK

stat&s -- stat&s +ode assigned to

+ity -- +ity name o# +ity >$ere s&44lier is lo+ated

4M -- 4art n&mber o# 4art s&44lied

ty -- &antity o# 4arts s&44lied to date

Con*ert t$e relation into 10%, !0%, 60%

1NF"

DATABASE DESIGN ISSUES !!


23/61


Eam4le; 1NF b, %, 2NF

#irst JsM, stat&s, +ity, 4M, tyK

%&n+tional De4enden+ies;JsM, 4artnoKty

JsMKstat&s

JsMK+ity

+itystat&s JS&44lierWs stat&s is determined by lo+ationK

Comments;

0on-3ey attrib&tes are not m&t&ally inde4endent J+itystat&sK.

2NF"%&n+tional De4enden+y on %irst 0ormal %orm;

sM UX +ity, stat&s Jt$is *iolated t$e Se+ond 0ormal %ormK

+ity UX stat&s

JsM,4MK UXty

0eed de+om4osition into t>o tables;

NF"%&n+tional De4enden+y o# t$e Se+ond 0ormal %orm;

SEC0D.sM UX SEC0D.stat&s J(ransiti*e de4enden+yK

SEC0D.sM UX SEC0D.+ity

SEC0D.+ity UX SEC0D.stat&s



24/61


SEC0D is +on*erted into S:PPIE'CI( and CI(S(A(:S

B%y.'-C%&& N%()al F%() >BCNF?

A relation ' is in Boy+e-Codd normal #orm JBC0%K i# and only i# e*ery determinant

is a +andidate 3ey

A relation s+$ema ' is in BC0% i# >$ene*er an %D F A $olds in ' t$en F is a

s&4er 3ey o# '.

Ea+$ 0ormal %orm is stri+tly stronger t$an t$e 4re*io&s one;

- E*ery !0% relation is in 10%

- E*ery 60% relation is in !0%

- E*ery BC0% relation is in 60%

($ere eists relations t$at are in 60% b&t not in BC0%.

($e goal is to $a*e ea+$ relation in BC0% J or 60%K

(o be 4re+ise, t$e de#inition o# 60% does not deal >it$ a relation t$at;

$as m&lti4le +andidate 3eys, >$ere

t$ose +andidate 3eys are +om4osite, and

t$e +andidate 3eys o*erla4 Ji.e., $a*e at least one +ommon attrib&teK

Ea)0l'"

1?Consider t$e relation s+$ema ' >$i+$ $as attrib&tes

'HN+o&rseno, se+no,

o##eringde4t, +redit$o&rs, +o&rsele*el, instr+torssn, semester, year,

days$o&rs, roomno, noo#st&dentsO.



25/61


($e #ollo>ing %Ds $old on ';

+o&rseno No##eringde4t, +redit$o&rs, +o&rsele*elO

N+o&rseno, se+no, semester, yearO Ndays$o&rs, roomno, noo#st&dents,instr&+torssnO

Nroomno, days$o&rs, semester, yearONinstr&+torssn, +o&rseno, se+noO

2?A relation (EAC5 t$at is in 60% b&t not in BC0%

0arayanan Database ar3

Smit$ Database 0a*at$e

Smit$ 4erating System Ammar

Smit$ ($eory S+$&lmanalla+e Database ar3

alla+e 4erating System A$amed

ong Database mi+indsZet$ya Database 0a*at$e

A+$ie*ing t$e BC0% by de+om4osition;(>o %Ds eist in t$e relation (EAC5;

%D1; Nst&dent, +o&rse O instr&+tor

%D!; instr&+tor+o&rse

Nst&dent, +o&rseO is a +andidate 3ey #or t$is relation and t$at t$e

de4enden+ies s$o>n.

Sol&tion;

($ree 4ossible de+om4osition #or t$e relation (EAC5;iK N st&dent , instr&+tor O and N st&dent, Co&rse O

iiK N +o&rse, instr&+tor O and N +o&rse, st&dent O

iiiK N instr&+tor, +o&rseO and N instr&+tor, st&dentO


S(:DE0( C:'SE I0S(':C('

(EAC5

!


26/61


Candidate 3eys; NA,BO and NA,CO Determinants; NA,BO and NCO

A de+om4osition;

ossless, b&t not de4enden+y 4reser*ing

$l,*;al'& D'0'&'.*'! = F%(, NF

A single *al&es o# F determines many *al&es o# JJieK F m&ltidetermines KA )D is tri*ial )D i#

J1K is a s&bset o# F, or

J!K F H'

A )D >$i+$ does not satis#y J1K J!K is +alled nontri*ial )D

e &se m&lti*al&ed de4enden+ies in t>o >ays;

1. (o test relations to determine >$et$er t$ey are legal &nder a gi*en set o##&n+tional and m&lti*al&ed de4enden+ies

!. (o s4e+i#y +onstraints on t$e set o# legal relations. e s$all t$&s +on+erno&rsel*es only >it$ relations t$at satis#y a gi*en set o# #&n+tional and m&lti*al&ed

de4enden+ies.

I# a relation r #ails to satis#y a gi*en m&lti*al&ed de4enden+y, >e +an +onstr&+t a

relations rY t$at does

satis#y t$e m&lti*al&ed de4enden+y by adding t&4les to r.


A

BC

A B C

R

C B

R1

A C

R2

!?


27/61


F%(, N%()al F%()>7NF?

Isolates inde4endent m&lti4le relations$i4s. 0o table may +ontain t>o or more 1;n

Jone-to-manyK or n;m Jmany-to-manyK relations$i4s t$at are not dire+tly related.

A ('la,*% !.')a R *! * 7NF *, ('!0'., ,% a !', % .,*%al &'0'&'.*'!

F * %( ';'(y %,(*;*al $VD * F< X *! a !0'( 'y % R

Example:

(rans#orm t$e #ollo>ing BC0% table into a 90% oneJsK.

($e net table is in t$e BC0% #orm, +on*ert it to t$e 9t$ normal #orm.

la/a/'!*llE)0l%y''

%ren+$ele+tri+al=ones

Germanele+tri+al=ones

%ren+$me+$ani+al=ones

Germanme+$ani+al=ones

S4anis$4l&mbingSmit$

($e abo*e table does not +om4ly >it$ t$e 9t$ normal #orm, be+a&se it $as re4etitions li3e

t$is;

AF=ones

B=ones

So t$is data may be already in t$e table, >$i+$ means t$at its re4eated.

FB=ones

A=ones

(o trans#orm t$is into t$e 9t$ normal #orm J90%K >e m&st se4arate t$e original table into

t>o tables li3e t$is;

!*ll')0l%y''

ele+tri+al=ones

me+$ani+al=ones

4l&mbingSmit$

And

la/a/'')0l%y''

%ren+$=ones

DATABASE DESIGN ISSUES !/


28/61


German=ones

S4anis$Smit$

%* &'0'&'.*'! = F*, N%()al F%()

=DJ'1,'!, L, 'nK

E*ery legal relation instan+es r o# ' s$o&ld $a*e a lossless 7oin de+om4osition into

'1,'!, L, 'n

JieK

JJ'1XJrKK, J'!XJrKK, L , J'nXJrKKKHr

F*, N%()al F%()A relation s+$ema ' is in it$ res4e+t to %, a set o# #&n+tional,

m&lti*al&ed and =oin de4enden+ies, i# #or e*ery nontri*ial =D in %[, e*ery 'i is a

s&4er 3ey o# '.

T%0*. " S'.(*,y

Da,aba!' !'.(*,y"

e+$anisms &sed to grant and re*o3e 4ri*ileges in relational database systems.e+$anisms -X Dis+retionary a++ess +ontrol

e+$anisms t$at en#or+e m&lti4le le*els o# se+&rity -X mandatory a++ess +ontrol

S'.(*,y - 4rote+tion #rom mali+io&s attem4ts to steal or modi#y data.

Da,aba!' !y!,') l';'l

A&t$enti+ation and a&t$ori2ation me+$anisms to allo> s4e+i#i+ &sers a++ess only

to re&ired data

Ass&me se+&rity at net>or3, o4erating system, $&man, and

4$ysi+al le*els.

Database s4e+i#i+ iss&es;

ea+$ &ser may $a*e a&t$ority to read only 4art o# t$e data and to>rite only 4art o# t$e data.

:ser a&t$ority may +orres4ond to entire #iles or relations, b&t it may

also +orres4ond only to 4arts o# #iles or relations.

o+al a&tonomy s&ggests site-le*el a&t$ori2ation +ontrol in adistrib&ted database.

Global +ontrol s&ggests +entrali2ed +ontrol

O0'(a,*/ !y!,') l';'l



29/61


4erating system s&4er-&sers +an do anyt$ing t$ey >ant to t$e database\ Good

o4erating system le*el se+&rity is re&ired.

Prote+tion #rom in*alid logins

%ile-le*el a++ess 4rote+tion Jo#ten not *ery $el4#&l #or database

se+&rityKProte+tion #rom im4ro4er &se o# s&4er&ser a&t$ority.

Prote+tion #rom im4ro4er &se o# 4ri*ileged ma+$ine intr&+tions.

N',%( l';'l"m&st &se en+ry4tion to 4re*ent

Ea*esdro44ing J&na&t$ori2ed reading o# messagesK

as&erading J4retending to be an a&t$ori2ed &ser or sending messages

s&44osedly #rom a&t$ori2ed &sersK

Ea+$ site m&st ens&re t$at it +omm&ni+ate >it$ tr&sted sites Jnot

intr&dersK.in3s m&st be 4rote+ted #rom t$e#t or modi#i+ation o# messages

e+$anisms;

Identi#i+ation 4roto+ol J4ass>ord-basedK,

Cry4togra4$y.

4y!*.al l';'l

P$ysi+al a++ess to +om4&ters allo>s destr&+tion o# data by

intr&dersQ traditional lo+3-and-3ey se+&rity is needed

Com4&ters m&st also be 4rote+ted #rom #loods, #ire, et+.Prote+tion o# dis3s #rom t$e#t, eras&re, 4$ysi+al damage, et+.

Prote+tion o# net>or3 and terminal +ables #rom >ireta4s nonin*asi*e

ele+troni+ ea*esdro44ing, 4$ysi+al damage, et+.

Sol&tions;

'e4li+ated $ard>are;

mirrored dis3s, d&al b&sses, et+.

m&lti4le a++ess 4at$s bet>een e*ery 4air o# de*ises

P$ysi+al se+&rity; lo+3s,4oli+e, et+.

So#t>are te+$ni&es to dete+t 4$ysi+al se+&rity brea+$es.

H)a l';'l

:sers m&st be s+reened to ens&re t$at an a&t$ori2ed &sers do

not gi*e a++ess to intr&ders

:sers s$o&ld be trained on 4ass>ord sele+tion and se+re+y

Prote+tion #rom stolen 4ass>ords, sabotage, et+.

DATABASE DESIGN ISSUES !


30/61


Primarily a management 4roblem;

%re&ent +$ange o# 4ass>ords

:se o# non-g&essable 4ass>ords

og all in*alid a++ess attem4ts

Data a&dits

Care#&l $iring 4ra+ti+es

Iss&es;

@ egal et$i+al iss&es

@ Poli+y iss&es

@ System related iss&es@ &lti4le se+&rity le*els - se+ret, to4 se+ret, +on#idential &n+lassi#ied

Database se+&rity and a&t$ori2ation s&bsystem res4onsible #or ens&ring t$e

se+&rity o# 4ortions o# a database against &na&t$ori2ed a++ess.

I,(%&.,*% ,% Da,aba!' S'.(*,y I!!'!

(y4es o# Se+&rity

Database Se+&rity and t$e DBA

A++ess Prote+tion, :ser A++o&nts, and Database A&ditsD*!.(',*%a(y A..'!! C%,(%l Ba!'& % G(a,*/ a& R';%*/ 4(*;*l'/'!

(y4es o# Dis+retionary Pri*ileges

S4e+i#ying Pri*ileges :sing )ie>s

'e*o3ing Pri*ileges

Pro4ogation o# Pri*ileges :sing t$e G'A0( P(I0

An Eam4le

S4e+i#ying imits on Pro4agation o# Pri*ileges

$a&a,%(y A..'!! C%,(%l a& R%l'-Ba!'& A..'!! C%,(%l %( $l,*l';'l

S'.(*,y

Com4aring Dis+retionary A++ess Control and andatory A++ess Control

'ole-Based A++ess Control

A++ess Control Poli+ies #or E-Commer+e and t$e eb

Ty0'! % !'.(*,y )'.a*!)!"Dis+retionary se+&rity me+$anisms

andatory se+&rity me+$anisms

Statisti+al database se+&rity

Data en+ry4tion

Da,aba!' !'.(*,y = DBA:DBA res4onsible #or o*erall se+&rity o# t$e database system

Pri*ileged a++o&nt system a++o&nt

A+tions 4er#ormed by DBA;



31/61


A++o&nt +reation

Pri*ilege granting

Pri*ilege re*o+ation

Se+&rity le*el assignment

Database log - a&dit trail

D*!.(',*%a(y A..'!! C%,(%l"

@ ! le*els o# assigning 4ri*ileges;

Account level

Relation level@ S4e+i#ying A&t$ori2ation by &sing )ie>s

@ 'e*o3ing Pri*ileges

@ Pro4agation o# Pri*ileges and t$e G'A0( P(I0

G'A0( SEEC( 0 EPEE ( A


32/61


5as entries o# t$e a44ro4riate data ty4e

'e#erential Integrity

Con+erned >it$ relations$i4s bet>een tables in t$e database

i.e. t$at t$e data in 1 table does not +ontradi+t t$e data in anot$er

e.g. e*ery %'EIG0 E *al&e in a table m&st $a*e a mat+$ing P'IA'

E *al&e in t$e +orres4onding tableData )alidation

Database anagement System JDBSK 4ro*ides #eat&res to $el4 ens&re data

integrity

:s&ally im4lemented &sing Database Constraints

S4e+i#ied in data di+tionary table de#inition

:s&ally s4e+i#ied on +reation o# table

ay be alteredTaddedTdro44ed later

Constraints

Col&mn Constraints

e.g.0ot 0&ll

S4e+i#ies t$at >$en a ne> ro> is inserted into table

($is +ol&mn m&st not +ontain only n&ll *al&es

De#a&lt

Allo>s a de#a&lt *al&e to be s4e+i#ied

Any time a ro> >it$ a n&ll *al&e #or t$is +ol&mn is entered t$e de#a&lt

*al&e is insertedConstraints

(able Constraints

e.g.Primary ey s4e+i#ies t$at >$en a ne> ro> is inserted t$e *al&e o# t$is +ol&mn

m&st be

0( 0: :0IV:E

DBS +reates an I0DEF on 4rimary 3ey +ol&mns

Constraints

(able Constraints

%oreign ey s4e+i#ies t$at >$en a ne> ro> is inserted t$e *al&e o# t$is +ol&mn

:S( mat+$)A:E o# t$e +orres4onding P'IA' E in t$e master table

0o +orres4onding master table entry

'o> not inserted

Error message

Creating (ables

ea+$ +ol&mn $as a +ol&mn-ty4e indi+ating

t$e si2e o# t$e +ol&mn and

t$e dataty4e o# *al&es t$at are a++e4table



33/61


initially >e >ill &se data ty4es

)A'C5A'! #or Al4$an&meri+

DA(E #or dates and

0:BE' #or n&meri+

Creating (ables

e.g. ($e +&stomer table +o&ld be de#ined asC('a,' Tabl' C!,%)'( >

C!,%)'(N% Va(.a(2>5? NOT NULL8#? NOT NULLill

ta3e it #rom one +onsistent state to anot$er.

($e +onsisten+y 4ro4erty does not say $o> t$e DBS s$o&ld $andle an

in+onsisten+y ot$er t$an ens&re t$e database is +lean at t$e end o# t$e transa+tion. I#,

#or some reason, a transa+tion is ee+&ted t$at *iolates t$e databases +onsisten+y

r&les, t$e entire transa+tion +o&ld be rolled ba+3 to t$e 4re-transa+tional state - or it

>o&ld be e&ally *alid #or t$e DBS to ta3e some 4at+$-&4 a+tion to get t$edatabase in a +onsistent state.

($&s, i# t$e database s+$ema says t$at a 4arti+&lar #ield is #or $olding integern&mbers, t$e DBS +o&ld de+ide to re7e+t attem4ts to 4&t #ra+tional *al&es t$ere, or

it +o&ld ro&nd t$e s&44lied *al&es to t$e nearest >$ole n&mber; bot$ o4tions

maintain +onsisten+y.

http://en.wikipedia.org/wiki/Consistency_(database_systems)http://en.wikipedia.org/wiki/Database_schemahttp://en.wikipedia.org/wiki/Consistency_(database_systems)http://en.wikipedia.org/wiki/Database_schema


34/61


($e +onsisten+y r&le a44lies only to integrity r&les t$at are >it$in its s+o4e. ($&s, i#

a DBS allo>s #ields o# a re+ord to a+t as re#eren+es to anot$er re+ord, t$en

+onsisten+y im4lies t$e DBS m&st en#or+e re#erential integrity; by t$e time any

transa+tion ends, ea+$ and e*ery re#eren+e in t$e database m&st be *alid. I# a

transa+tion +onsisted o# an attem4t to delete a re+ord re#eren+ed by anot$er, ea+$ o#

t$e #ollo>ing me+$anisms >o&ld maintain +onsisten+y;

abort t$e transa+tion, rolling ba+3 to t$e +onsistent, 4rior stateQ

delete all re+ords t$at re#eren+e t$e deleted re+ord Jt$is is 3no>n as cascade

deleteKQ or,

n&lli#y t$e rele*ant #ields in all re+ords t$at 4oint to t$e deleted re+ord.

($ese are eam4les o# 4ro4agation +onstraintsQ some database systems allo> t$e

database designer to s4e+i#y >$i+$ o4tion to +$oose >$en setting &4 t$e s+$ema #ora database.

A44li+ation de*elo4ers are res4onsible #or ens&ring alication level +onsisten+y,

o*er and abo*e t$at o##ered by t$e DBS. ($&s, i# a &ser >it$dra>s #&nds #rom an

a++o&nt and t$e ne> balan+e is lo>er t$an t$e a++o&ntWs minim&m balan+e t$res$old,

as #ar as t$e DBS is +on+erned, t$e database is in a +onsistent state e*en t$o&g$

t$is r&le J&n3no>n to t$e DBSK $as been *iolated.

T%0*. 8" Da,aba!' T*/

$en is t&ning ne+essary] nly i# yo& #eel t$at a44li+ation is not r&nning #ast eno&g$

$at is to be t&ned]

ra+le database

A44li+ation

4erating system

0et>or3

T*/ G%al!

(o o4timi2e t$e 4er#orman+e o# database

(o ma3e database a*ailable to &sers >it$o&t ma3ing t$em >ait #or reso&r+es (o 4er#orm maintenan+e o4erations >it$o&t interr&4ting &sers

T*/ 4a(a)','(!

'es4onse time

Database a*ailability

Database $it 4er+entages

emory &tili2ation

http://en.wikipedia.org/wiki/Referential_integrityhttp://en.wikipedia.org/wiki/Propagation_constrainthttp://en.wikipedia.org/wiki/Referential_integrityhttp://en.wikipedia.org/wiki/Propagation_constraint


35/61


T*/ S,'0!

aK (&ne t$e design

bK (&ne t$e a44li+ation

+K (&ne memorydK (&ne I

eK (&ne +ontention

#K (&ne o4erating system

T*/ C%!*&'(a,*%!

Di##erent #or

(P databases

DSS databases

5ybrid databases &r database

5ybrid database

Data entry and 'e4ort generation done sim&ltaneo&sly

4'(%()a.' T*/

Ad7&sting *ario&s 4arameters and design +$oi+es to im4ro*e system 4er#orman+e #or

a s4e+i#i+ a44li+ation.

(&ning is best done by

identi#ying bottlene+3s, and

eliminating t$em.Can t&ne a database system at 6 le*els;

Ha(&a('-- e.g., add dis3s to s4eed &4 IT, add memory to in+rease b#er $its,

mo*e to a #aster 4ro+essor.Da,aba!' !y!,') 0a(a)','(! -- e.g., set b#er si2e to a*oid 4aging o# b#er,

set +$e+34ointing inter*als to limit log si2e. System may $a*e a&tomati+

t&ning.

H*/'( l';'l &a,aba!' &'!*/, s&+$ as t$e s+$ema, indi+es and transa+tionsB%,,l''.!

Per#orman+e o# most systems Jat least be#ore t$ey are t&nedK &s&ally limited by

4er#orman+e o# one or a #e> +om4onents; t$ese are +alled bottlene+3sE.g. 8"^ o# t$e +ode may ta3e &4 !"^ o# time and !"^ o# +ode ta3es &4 8"^

o# time

ort$ s4ending most time on !"^ o# +ode t$at ta3e 8"^ o# timeBottlene+3s may be in $ard>are Je.g. dis3s are *ery b&sy, CP: is idleK, or in

so#t>are

'emo*ing one bottlene+3 o#ten e4oses anot$er

De-bottlene+3ing +onsists o# re4eatedly #inding bottlene+3s, and remo*ing t$em

($is is a $e&risti+



36/61


I&',*y*/ B%,,l''.!

(ransa+tions re&est a se&en+e o# ser*i+es

e.g. CP:, Dis3 IT, lo+3s

it$ +on+&rrent transa+tions, transa+tions may $a*e to >ait #or a re&ested ser*i+e

>$ile ot$er transa+tions are being ser*ed

Can model database as a ''*/ !y!,')>it$ a &e&e #or ea+$ ser*i+etransa+tions re4eatedly do t$e #ollo>ing

re&est a ser*i+e, >ait in &e&e #or t$e ser*i+e, and get ser*i+ed

Bottlene+3s in a database system ty4i+ally s$o> &4 as *ery $ig$ &tili2ations Jand

+orres4ondingly, *ery long &e&esK o# a 4arti+&lar ser*i+e

E.g. dis3 *s CP: &tili2ation

1""^ &tili2ation leads to *ery long >aiting time;

'&le o# t$&mb; design system #or abo&t /"^ &tili2ation at 4ea3 load

&tili2ation o*er "^ s$o&ld be a*oided

:''! I A Da,aba!' Sy!,')

Tabl' 4a(a)','(!

(&ning o# $ard>are

(&ning o# s+$ema(&ning o# indi+es

(&ning o# materiali2ed *ie>s

(&ning o# transa+tions

T*/ % Ha(&a('

E*en >ell-t&ned transa+tions ty4i+ally re&ire a #e> IT o4erations(y4i+al dis3 s&44orts abo&t 1"" random IT o4erations 4er se+ond

S&44ose ea+$ transa+tion re&ires 7&st ! random IT o4erations. ($en to s&44ort

ntransa+tions 4er se+ond, >e need to stri4e data a+ross nT


37/61


s3e>K

0&mber o# IT o4erations 4er transa+tion +an be red&+ed by 3ee4ing more data in

memory

I# all data is in memory, IT needed only #or >rites

ee4ing #re&ently &sed data in memory red&+es dis3 a++esses, red&+ing n&mber

o# dis3s re&ired, b&t $as a memory +ost

Ha(&a(' T*/" F*;'-$*,' Rl'

V&estion; >$i+$ data to 3ee4 in memory;

I# a 4age is a++essed ntimes 4er se+ond, 3ee4ing it in memory sa*es

n _ 4ri+e-4er-dis3-dri*e

a++esses-4er-se+ond-4er-dis3

Cost o# 3ee4ing 4age in memory

4ri+e-4er-B-o#-memory

ages-4er-B-o#-memory

Brea3-e*en 4oint; *al&e o# n#or >$i+$ abo*e +osts are e&alI# a++esses are more t$en sa*ing is greater t$an +ost

Sol*ing abo*e e&ation >it$ +&rrent dis3 and memory 4ri+es leads to;

5-)*,' (l'"* a 0a/' ,a, *! (a&%)ly a..'!!'& *! !'& )%('

('',ly ,a %.' * 5 )*,'! *, !%l& b' '0, * )')%(y

Jby b&ying s#i+ient memory\K

Ha(&a(' T*/" O'-$*,' Rl'

%or se&entially a++essed data, more 4ages +an be read 4er se+ond. Ass&mingse&ential reads o# 1B o# data at a time;

1-)*,' (l'; !'',*ally a..'!!'& &a,a ,a, *! a..'!!'&

%.' %( )%(' * a )*,' !%l& b' '0, * )')%(yPri+es o# dis3 and memory $a*e +$anged greatly o*er t$e years, b&t t$e ratios $a*e

not +$anged m&+$

so r&les remain as < min&te and 1 min&te r&les, not 1 $o&r or 1 se+ond r&les\

Ha(&a(' T*/" C%*.' % RAID L';'l

(o &se 'AID 1 or 'AID rites

'AID < re&ires ! blo+3 reads and ! blo+3 >rites to >rite o&t one data blo+3I# an a44li+ation re&ires r reads and w>rites 4er se+ond

'AID 1 re&ires r ! 2w IT o4erations 4er se+ond

'AID < re&ires; r ! "w IT o4erations 4er se+ond

%or reasonably large r and >, t$is re&ires lots o# dis3s to $andle >or3load

'AID < may re&ire more dis3s t$an 'AID 1 to $andle load\

A44arent sa*ing o# n&mber o# dis3s by 'AID < Jby &sing 4arity, as o44osed tot$e mirroring done by 'AID 1K may be ill&sory\

($&mb r 'AID < is #ine >$en >rites are rare and data is *ery large, b&t 'AID 1

is 4re#erable ot$er>ise

DATABASE DESIGN ISSUES 6/


38/61


I# yo& need more dis3s to $andle IT load, 7&st mirror t$em sin+e dis3 +a4a+ities

t$ese days are enormo&s\

T*/ ,' Da,aba!' D'!*/

S.')a ,*/

)erti+ally 4artition relations to isolate t$e data t$at is a++essed most o#ten -- only#et+$ needed in#ormation.

E.g., s4lit accountinto t>o, Jaccount#number,branc$#nameK and Jaccount#

number, balanceK.

Bran+$-name need not be #et+$ed &nless re&ired

Im4ro*e 4er#orman+e by storing a &'%()al*+'& ('la,*%

E.g., store 7oin o# accountand deositorQ bran+$-name and balan+e

in#ormation is re4eated #or ea+$ $older o# an a++o&nt, b&t 7oin need not be

+om4&ted re4eatedly.

Pri+e 4aid; more s4a+e and more >or3 #or 4rogrammer to 3ee4 relation

+onsistent on &4datesbetter to &se materiali2ed *ie>s Jmore on t$is later..K

Cl&ster toget$er on t$e same dis3 4age re+ords t$at >o&ld

mat+$ in a #re&ently re&ired 7oin,

+om4&te 7oin *ery e##i+iently >$en re&ired.

I&' ,*/

Create a44ro4riate indi+es to s4eed &4 slo> &eriesT&4datesS4eed &4 slo> &4dates by remo*ing e+ess indi+es Jtradeo## bet>een &eries and

&4datesK

C$oose ty4e o# inde JB-treeT$as$K a44ro4riate #or most #re&ent ty4es o#&eries.

C$oose >$i+$ inde to ma3e +l&stered

Inde t&ning >i2ards loo3 at 4ast $istory o# &eries and &4dates Jt$e %(l%a&Kand re+ommend >$i+$ indi+es >o&ld be best #or t$e >or3load

$a,'(*al*+'& V*'!

ateriali2ed *ie>s +an $el4 s4eed &4 +ertain &eries

Parti+&larly aggregate &eries

*er$eadsS4a+e

(ime #or *ie> maintenan+e

Immediate *ie> maintenan+e;done as 4art o# &4date tn

time o*er$ead 4aid by &4date transa+tion

De#erred *ie> maintenan+e; done only >$en re&ired

&4date transa+tion is not a##e+ted, b&t system time is s4ent on *ie>maintenan+e

,*l 0&a,'&< ,' ;*' )ay b' %,-%-&a,'

Pre#erable to denormali2ed s+$ema sin+e *ie> maintenan+e



39/61


is systems res4onsibility, not 4rogrammers

A*oids in+onsisten+ies +a&sed by errors in &4date 4rograms

5o> to +$oose set o# materiali2ed *ie>s

5el4ing one transa+tion ty4e by introd&+ing a materiali2ed *ie> may $&rt ot$ers

C$oi+e o# materiali2ed *ie>s de4ends on +osts

:sers o#ten $a*e no idea o# a+t&al +ost o# o4erations*erall, man&al sele+tion o# materiali2ed *ie>s is tedio&s

Some database systems 4ro*ide tools to $el4 DBA +$oose *ie>s to materiali2e

ateriali2ed *ie> sele+tion >i2ards

T*/ % T(a!a.,*%!

Basi+ a44roa+$es to t&ning o# transa+tions

Im4ro*e set orientation

'ed&+e lo+3 +ontention

'e>riting o# &eries to im4ro*e 4er#orman+e >as im4ortant in t$e 4ast, b&t smart

o4timi2ers $a*e made t$is less im4ortantComm&ni+ation o*er$ead and &ery $andling o*er$eads signi#i+ant 4art o# +ost o#

ea+$ +all

C%)b*' )l,*0l' ')b'&&'& S:LODBCDBC '(*'! *,% a !*/l' !',-

%(*','& '(y

Set orientation -X #e>er +alls to database

E.g. t&ne 4rogram t$at +om4&tes total salary #or ea+$ de4artment &sing a

se4arate SV &ery by instead &sing a single &ery t$at +om4&tes totalsalaries #or all de4artment at on+e J&sing /(%0 by?

U!' !,%('& 0(%.'&('!; a*oids re-4arsing and re-o4timi2ation

o# &ery'ed&+ing lo+3 +ontention

ong transa+tions Jty4i+ally read-onlyK t$at eamine large 4arts o# a relation res&lt

in lo+3 +ontention >it$ &4date transa+tionsE.g. large &ery to +om4&te ban3 statisti+s and reg&lar ban3 transa+tions

(o red&+e +ontention

:se m&lti-*ersion +on+&rren+y +ontrol

E.g. ra+le sna4s$ots >$i+$ s&44ort m&lti-*ersion !P

:se degree-t>o +onsisten+y J+&rsor-stabilityK #or long transa+tions

Dra>ba+3; res&lt may be a44roimateong &4date transa+tions +a&se se*eral 4roblems

E$a&st lo+3 s4a+e

E$a&st log s4a+e

and also greatly in+rease re+o*ery time a#ter a +ras$, and may e*en e$a&st log

s4a+e d&ring re+o*ery i# re+o*ery algorit$m is badly designed\

:se )**-ba,.transa+tions to limit n&mber o# &4dates t$at a single transa+tion +an+arry o&t. E.g., i# a single large transa+tion &4dates e*ery re+ord o# a *ery large

relation, log may gro> too big.

_ S4lit large transa+tion into bat+$ o# `mini-transa+tions,WW ea+$ 4er#orming 4art



40/61


o# t$e &4dates

5old lo+3s a+ross transa+tions in a mini-bat+$ to ens&re seriali2ability

I# lo+3 table si2e is a 4roblem +an release lo+3s, b&t at t$e +ost o#

seriali2ability

_ In +ase o# #ail&re d&ring a mini-bat+$, m&st +om4lete its

remaining 4ortion on re+o*ery, to ens&re atomi+ity.

4'(%()a.' S*)la,*%

4'(%()a.' !*)la,*%&sing &e&ing model &se#&l to 4redi+t bottlene+3s as >ell

as t$e e##e+ts o# t&ning +$anges, e*en >it$o&t a++ess to real system

V&e&ing model as >e sa> earlier

odels a+ti*ities t$at go on in 4arallel

Sim&lation model is &ite detailed, b&t &s&ally omits some lo> le*el details

odel !'(;*.' ,*)', b&t disregard details o# ser*i+e

E.g. a44roimate dis3 read time by &sing an a*erage dis3 read time

E4eriments +an be r&n on model, and 4ro*ide an estimate o# meas&res s&+$ asa*erage t$ro&g$4&tTres4onse time

Parameters +an be t&ned in model and t$en re4li+ated in real system

E.g. n&mber o# dis3s, memory, algorit$ms, et+

T%0*. 6" O0,*)*+a,*% a& R'!'a(. I!!'!

U&'(!,a&*/ ,' :'(y O0,*)*+'(

A SV statement +an be ee+&ted in many di##erent >ays, s&+$ as #&ll table s+ans,inde s+ans, nested loo4s, and $as$ 7oins.

($e o&t4&t #rom t$e o4timi2er is a 4lan t$at des+ribes an o4tim&m met$od o#

ee+&tion.

($e &ery o4timi2er determines t$e most e##i+ient >ay to ee+&te a SV statement

a#ter +onsidering many #a+tors related to t$e ob7e+ts re#eren+ed and t$e +onditions

s4e+i#ied in t$e &ery.

($is determination is an im4ortant ste4 in t$e 4ro+essing o# any SV statement and+an greatly a##e+t ee+&tion time.

($e &ery o4timi2er determines >$i+$ ee+&tion 4lan is most e##i+ient by+onsidering a*ailable a++ess 4at$s and by #a+toring in in#ormation based on statisti+s

#or t$e s+$ema ob7e+ts Jtables or indeesK a++essed by t$e SV statement.

($e &ery o4timi2er also +onsiders $ints, >$i+$ are o4timi2ation s&ggestions 4la+ed

in a +omment in t$e statement.



41/61


($e &ery o4timi2er 4er#orms t$e #ollo>ing ste4s;

1. ($e o4timi2er generates a set o# 4otential 4lans #or t$e SV statement based

on a*ailable a++ess 4at$s and $ints.

!. ($e o4timi2er estimates t$e +ost o# ea+$ 4lan based on statisti+s in t$e data

di+tionary #or t$e data distrib&tion and storage +$ara+teristi+s o# t$e tables,

indees, and 4artitions a++essed by t$e statement.

($e .%!,is an estimated *al&e 4ro4ortional to t$e e4e+ted reso&r+e &se

needed to ee+&te t$e statement >it$ a 4arti+&lar 4lan. ($e o4timi2er

+al+&lates t$e +ost o# a++ess 4at$s and 7oin orders based on t$e estimated+om4&ter reso&r+es, >$i+$ in+l&des IT, CP:, and memory.

Serial 4lans >it$ $ig$er +osts ta3e more time to ee+&te t$an t$ose >it$

smaller +osts. $en &sing a 4arallel 4lan, $o>e*er, reso&r+e &se is not

dire+tly related to ela4sed time.

6. ($e o4timi2er +om4ares t$e +osts o# t$e 4lans and +$ooses t$e one >it$ t$e

lo>est +ost.

V&ery o4timi2er +om4onents are ill&strated in



42/61


/omponents of the 0uery )ptimizer

($e &ery o4timi2er o4erations in+l&de;

(rans#orming V&eries

Estimating

Generating Plans

"ransformin. 0ueries

($e in4&t to t$e &ery trans#ormer is a 4arsed &ery, >$i+$ is re4resented by a set o#

&ery blo+3s. ($e &ery blo+3s are nested or interrelated to ea+$ ot$er. ($e #orm o#t$e &ery determines $o> t$e &ery blo+3s are interrelated to ea+$ ot$er. ($e main

ob7e+ti*e o# t$e &ery trans#ormer is to determine i# it is ad*antageo&s to +$ange t$e

#orm o# t$e &ery so t$at it enables generation o# a better &ery 4lan.

Estimatin.

($e end goal o# t$e estimator is to estimate t$e o*erall +ost o# a gi*en 4lan. I#

statisti+s are a*ailable, t$en t$e estimator &ses t$em to +om4&te t$e meas&res. ($e

statisti+s im4ro*e t$e degree o# a++&ra+y o# t$e meas&res.

($e estimator generates t$ree di##erent ty4es o# meas&res;

Sele+ti*ity

Cardinality

http://www.sc.ehu.es/siwebso/KZCC/Oracle_10g_Documentacion/server.101/b10752/optimops.htm#37241http://www.sc.ehu.es/siwebso/KZCC/Oracle_10g_Documentacion/server.101/b10752/optimops.htm#37300http://www.sc.ehu.es/siwebso/KZCC/Oracle_10g_Documentacion/server.101/b10752/optimops.htm#37012http://www.sc.ehu.es/siwebso/KZCC/Oracle_10g_Documentacion/server.101/b10752/optimops.htm#37309http://www.sc.ehu.es/siwebso/KZCC/Oracle_10g_Documentacion/server.101/b10752/optimops.htm#37340http://www.sc.ehu.es/siwebso/KZCC/Oracle_10g_Documentacion/server.101/b10752/optimops.htm#37241http://www.sc.ehu.es/siwebso/KZCC/Oracle_10g_Documentacion/server.101/b10752/optimops.htm#37300http://www.sc.ehu.es/siwebso/KZCC/Oracle_10g_Documentacion/server.101/b10752/optimops.htm#37012http://www.sc.ehu.es/siwebso/KZCC/Oracle_10g_Documentacion/server.101/b10752/optimops.htm#37309http://www.sc.ehu.es/siwebso/KZCC/Oracle_10g_Documentacion/server.101/b10752/optimops.htm#37340


43/61


Cost

($ese meas&res are related to ea+$ ot$er, and one is deri*ed #rom anot$er.

1eneratin. &lans

($e main #&n+tion o# t$e 4lan generator is to try o&t di##erent 4ossible 4lans #or a

gi*en &ery and 4i+3 t$e one t$at $as t$e lo>est +ost. any di##erent 4lans are

4ossible be+a&se o# t$e *ario&s +ombinations o# di##erent a++ess 4at$s, 7oin met$ods,

and 7oin orders t$at +an be &sed to a++ess and 4ro+ess data in di##erent >ays and

4rod&+e t$e same res&lt.

R'!'a(. I!!'!%ulti20uery )ptimization

S+enario; &lti4le related, b&t slig$tly di##erent &eries

Goal; Sa*e 4o>er and +omm&ni+ationC$allenge; Combining m&lti4le &eries, #inding +ommon &ery 4arts

(>o a44roa+$es;

ateriali2ation

Pi4elining

3syntactic4 optimizer 5s syntactic optimizer

SV &ery tet is #irst semanti+ally o4timi2ed t$en 4assed to t$e +on*entional

Jsynta+ti+K o4timi2er.

Any ad*antage besto>ed by t$e semanti+ o4timi2er +an only be mani#ested by t$esynta+ti+ o4timi2er.

($e synta+ti+ o4timi2er >ill ty4i+ally loo3 to indees to en$an+e &ery e##i+ien+y.

T%0*. " D'!*/ % T')0%(al Da,aba!'!

@a, a(' ,')0%(al &a,aba!'!M

T')0%(al Da,aba!'!

(em4oral DBS manages time-re#eren+ed data, and times are asso+iated >it$database entities.

It en+om4asses database a44li+ations t$at re&ire some as4e+t o# time >$en

organi2ing t$eir in#ormation.

$%!, a00l*.a,*%! % &a,aba!' ,'.%l%/y a(' ,')0%(al * a,('"

%inan+ial a44s.; 4ort#olio management, a++o&nting ban3ing

'e+ord-3ee4ing a44s.; 4ersonnel, medi+al re+ord and in*entory management

http://www.sc.ehu.es/siwebso/KZCC/Oracle_10g_Documentacion/server.101/b10752/optimops.htm#37379http://www.sc.ehu.es/siwebso/KZCC/Oracle_10g_Documentacion/server.101/b10752/optimops.htm#37379


44/61


S+$ed&ling a44s.; airline, +ar, $otel reser*ations and 4ro7e+t management

S+ienti#i+ a44s.; >eat$er monitoring

De#inition;

A00l*.a,*%!"$ealt$-+are system ins&ran+e reser*ation systems, s+ienti#i+ databases

@ (ime 'e4resentation, (ime Dimensions

time- ordered se&en+e o# 0%*,! in some gran&larity t$at is determined bya44li+ation

Calendar- organi2es time into di##erent time &nits

JegK ?" se+s. -X 1 min et+.

N% T')0%(al

store only a single state o# t$e real >orld, &s&ally t$e most re+entstate

+lassi#ied as sna4s$ot databases

a44li+ation de*elo4ers and database designers need to +ode #or time

*arying data re&irements eg $istory tables, #ore+ast re4orts et+

T')0%(al

stores &4to t>o dimensions o# time i.e )AID JstatedK time and

('A0SAC(I0 JloggedK time

Classi#ied as $istori+al, rollba+3 or bi-tem4oral

0o need #or a44li+ation de*elo4ers or database designers to +ode #or

time *arying data re&irements i.e time is in$erently s&44orted

T')0%(al Da,a ,y0'!;

1K DA(E !K (IE 6K (IES(AP 9K I0(E')A


45/61


e +an &se t$ese t>o dimensions to disting&is$ bet>een di##erent #orms o#

tem4oral database

A rollba+3 database stores data >it$ res4e+t to transa+tion time e.g. ra+le1"g $as #las$ba+3 &ery

A $istori+al database stores data >it$ res4e+t to *alid time

A bi-tem4oral database stores data >it$ res4e+t to bot$ *alid time and

transa+tion time.

@a, *! ,*)' ;a(y*/ &a,aM

o& >ant a re4rint o# a +&stomerWs in*oi+e o# A&g&st 1!, 1.

$at >as t$e sto+3 *al&e o# t$e ra+le s$ares on =&ne 1as t$e lo>est sto+3 &antity #or e*ery 4rod&+t last year] 5o> m&+$

money >ill yo& sa*e, i# yo& 3ee4 t$e sto+3s at t$ose le*els]

$ere do yo& enter t$e ne> address o# t$is +&stomer as #rom t$e #irst o#

net mont$]

$at >ill yo&r 4ro#its be net mont$, gi*en t$e 4ri+e list and +ost 4ri+es by

t$en]

A& .%)b*a,*%! % ,' !*,a,*%! .a b' ;'(y .%)0l'

o& o##ered t$ese goods to t$e +&stomer on =an&ary 1" t$is year. $at

>ere t$e billing 4ri+es and >$at >as $is dis+o&nt le*el >$en yo& sent $im

t$is o##er] 5e $as not a++e4ted yet. Is it smart to o##er $im an a+t&ali2eddis+o&nt no>]

DATABASE DESIGN ISSUES 9$en >ere t$e 4oli+ies in e##e+tK

'eser*ation Systems Je.g. >$en is >$i+$ room in a $otel boo3edK

edi+al In#ormation anagement Systems Je.g. 4atient re+ordsK

De+ision S&44ort Systems Je.g. 4lanning #&t&re +ontigen+iesK

C' a44li+ations Jeg +&stomer $istory T #&t&reK

5' a44li+ations Je.g Date tra+3ed 4ositions in $ierar+$iesK

In #a+t, time *arying data $as AAS been in b&siness re&irements b&t

eisting te+$nology does not deal >it$ it elegantly\

E;', I%()a,*% V'(!! D(a,*% >%( S,a,'? I%()a,*%"

Point e*ents or #a+ts

single time 4oint

time series data

D&ration e*ents or #a+ts

time 4eriod Rstart-time, endtime

Val*& T*)' a& T(a!a.,*% T*)' D*)'!*%!"

Inter4retation o# e*ents a*ailable in tem4oral databases

*alid time

transa+tion time

*alid time database, transa+tion time databaseBitem4oral database

:ser-de#ined time

"

(ime dimensions

(ime, semanti+s 4rogram

a44li+ations

In+or4orating (ime in 'elational DatabasesVal*& T*)' R'la,*%!

Gran&larity Day, data ty4e

)alid Start (imeJ)S(K, )alid End (imeJ)E(K

(em4oral *ariableno>

DATABASE DESIGN ISSUES 9?


47/61


:4date o4erations in tem4oral relations;

+&rrent *ersion, old *ersion

4roa+ti*e &4date J&4dation be#ore im4lementationK

rea+ti*e &4date J&4dation a#ter im4lementationK

sim&ltaneo&s &4date

EPB(

SS0 E0AE D0 )S( )E( (S( (E(

In+or4orating (ime in 'elational Databases

T(a!a.,*% T*)' R'la,*%!

(ransa+tion Start (imeJ(S(K, (ransa+tion End (imeJ(E(K

(ransa+tion time relations

'ollba+3 database

B*,')0%(al T*)' R'la,*%!

)S(,)E(,(S(,(E(X

T*)' S'(*'! Da,a

Data *al&es re+orded a++ording to a s4e+i#i+ 4rede#ined se&en+e o# time 4oints.U!a/';

#inan+ial, sales e+onomi+s a44li+ations

(y4i+al &eries in*ol*e tem4oral aggregation(ime series management systems

I)0l')',a,*% A00(%a.'!

Se*eral im4lementation strategies are a*ailable

:se a date ty4e s&44lied in a non-tem4oral DBS and b&ild tem4oral

s&44ort into a44li+ations JtraditionalK

Im4lement an abstra+t data ty4e #or time Job7e+t orientedK

Pro*ide a 4rogram layer Ja4iK abo*e a non-tem4oral data model Jstrat&mK

Generalise a non-tem4oral data model into a tem4oral data modelJ(em4oral 0ormal %ormK

'e-design +ore database 3ernel J(em4oral DatabaseK

DATABASE DESIGN ISSUES 9/


48/61


T%0*. 9" S0a,*al Da,aba!'!

I,(%&.,*%

any a44li+ations in *ario&s #ields re&ire management o#geometric% geogra$icor satial data Jdata related to s4a+eK

A geogra4$i+ s4a+e; s&r#a+e o# t$e eart$

an-made s4a+e; layo&t o# )SI design

odel o# t$e $&man brain

6-D s4a+e re4resentation o# t$e +$ains o# 4rotein mole+&les

($e Common +$allenge;

Dealing >it$ large +olle+tions o# relati*ely sim4le geometri+ ob7e+ts; e.g.,

1"",""" 4olygons

S0a,*al Da,aba!'

What is a -D6%- ?

A SDBS is a so#t>are mod&le t$at

+an >or3 >it$ an &nderlying DBS

s&44orts s4atial data models, s4atial abstra+t data ty4es JAD(sK and a

&ery lang&age #rom >$i+$ t$ese AD(s are +allable

s&44orts s4atial indeing, e##i+ient algorit$ms #or 4ro+essing s4atial

o4erations, and domain s4e+i#i+ r&les #or &ery o4timi2ation

Eam4le; ra+le S4atial data +artridge, ES'I SDE +an >or3 >it$ ra+le 8i DBS

5as s4atial data ty4es Je.g. 4olygonK, o4erations Je.g. o*erla4K +allable

#rom SV6 &ery lang&age

5as s4atial indi+es, e.g. '-trees

A !0a,*al &a,aba!' !y!,')"

Is a database system J>it$ additional +a4abilities #or $andling s4atial dataK

##ers s4atial data ty4es JSD(sK in its data model and &ery lang&age

Str&+t&re in s4a+e; e.g., PI0(, I0E, 'EGI0

'elations$i4s among t$em; e.g., a interse+ts b

S&44orts SD( in its im4lementation

S4atial indeing; retrie*ing ob7e+ts in 4arti+&lar area >it$o&t s+anning t$e >$ole

s4a+e

E##i+ient algorit$m #or s4atial 7oins

Ea)0l'"

Ass&me !-D GIS a44li+ation, t>o basi+ t$ings need to be re4resented;



49/61


b7e+ts in s4a+e; +ities, #orests, or ri*ers

distin+t entities arranged in s4a+e, ea+$ o# >$i+$ $as its o>n geometri+ des+ri4tion

HXmodeling single ob7e+ts

S4a+e; des+ribe t$e s4a+e itsel# say somet$ing abo&t e*ery 4oint in s4a+e

HXmodeling s4atially related +olle+tions o# ob7e+ts

-D6%- Example

Consider a s4atial dataset >it$;

Co&nty bo&ndary Jdas$ed >$ite lineK

Cens&s blo+3 - name, area, 4o4&lation, bo&ndary Jdar3 lineK

ater bodies Jdar3 4olygonsK

Satellite Imagery Jgray s+ale 4ielsK

Storage in a SDBS table;

+reate table +ens&sblo+3s J

name string, area #loat,

4o4&lation n&mber,

bo&ndary 4olygon KQ

S0a,*al Da,aba!'!

Con+e4ts abo&t ob7e+ts in a m&ltidimensional s4a+e.n-dimensional s4a+e.

JegK ma4s

Poli+e *e$i+les, amb&lan+es

(e+$ni&es #or s4atial indeing;

1K R-,(''!

'e+tangle areas

ea# node

Internal nodes-Xre+tangles >$ose area +o*ers all t$e re+tangles in its s&btree

!K :a&,(''!

di*ides ea+$ s4a+e or s&bs4a+e into e&ally si2ed areas 4ro+eed >it$ t$e

s&bdi*isions o# ea+$ s&bs4a+e to identi#y t$e 4ositions o# *ario&s ob7e+ts.

-patial Data "ypes and "raditional Data#ases

(raditional relational DBS

S&44ort sim4le data ty4es, e.g. n&mber, strings, date

odeling S4atial data ty4es is tedio&s

Eam4le; modeling o# 4olygon &sing n&mbers

($ree ne> tables; 4olygon, edge, 4oints



50/61


@ 0ote; Polygon is a 4olyline >$ere last 4oint and #irst 4oint are

same

A sim4le &nit sa&re re4resented as 1? ro>s a+ross 6 tables

Sim4le s4atial o4erators, e.g. areaJK, re&ire 7oining tables

(edio&s and +om4&tationally ine##i+ient

V&estion. 0ame 4ost-relational database management systems >$i+$ #a+ilitate

modeling o# s4atial data ty4es, e.g. 4olygon

-patial Data "ypes and &ost2relational Data#ases

&ost#relational '()S

Suort user defined abstract data tyes

Satial data tyes *e.g. olygon+ can be added

C$oice of ost#relational '()S

,b-ect oriented *,,+ '()S

,b-ect relational *,R+ '()S A satial database is a collection of satial data tyes% oerators% indices%

rocessing strategies% etc. and can work wit$ many ost#relational '()S aswell as rogramming languages like ava% /isual (asic etc.

7o is a -D6%- different from a 1I-?

S is a software to visualie and analye satial data using satial analysis

functions suc$ as

Searc$ 3$ematic searc$% searc$ by region% *re#+classification

4ocation analysis (uffer% corridor% overlay

3errain analysis Sloe5asect% catc$ment% drainage network 6low analysis Connectivity% s$ortest at$

'istribution C$ange detection% roimity% nearest neig$bor

Satial analysis5Statistics &attern% centrality% autocorrelation% indices

of similarity% toology8 $ole descrition

)easurements 'istance% erimeter% s$ae% ad-acency% direction

S uses S'()S

to store% searc$% 9uery% s$are large satial data sets

SDB$S %.!'! %

E##i+ient storage, &erying, s$aring o# large s4atial datasets Pro*ides sim4ler set based &ery o4erations

Eam4le o4erations; sear+$ by region, o*erlay, nearest neig$bor,

distan+e, ad7a+en+y, 4erimeter et+.

:ses s4atial indi+es and &ery o4timi2ation to s4eed&4 &eries o*er

large s4atial datasets.

SDBS may be &sed by a44li+ations ot$er t$an GIS

Astronomy, Genomi+s, &ltimedia in#ormation systems, ...



51/61


ill one &se a GIS or a SDB to ans>er t$e #ollo>ing;

5o> many neig$boring +o&ntries does :SA $a*e]

$i+$ +o&ntry $as $ig$est n&mber o# neig$bors]

/omponents of a -D6%-

'e+all; a SDBS is a so#t>are mod&le t$at

+an >or3 >it$ an &nderlying DBS

s&44orts s4atial data models, s4atial AD(s and a &ery lang&age #rom

>$i+$ t$ese AD(s are +allable

s&44orts s4atial indeing, algorit$ms #or 4ro+essing s4atial o4erations,

and domain s4e+i#i+ r&les #or &ery o4timi2ation

Com4onents in+l&de

s4atial data model, &ery lang&age, &ery 4ro+essing, #ile organi2ation

and indi+es, &ery o4timi2ation, et+.

%ig&re 1.? s$o>s t$ese +om4onents e dis+&ss ea+$ +om4onent brie#ly in +$a4ter 1.? and in more detail

in later +$a4ters.

T('' Lay'( A(.*,'.,('

S4atial A44li+ations S4atial DB DBS

-patial "axonomy8 Data %odels

S4atial (aonomy; m&ltit&de o# des+ri4tions a*ailable to organi2e s4a+e.

(o4ology models $omeomor4$i+ relations$i4s, e.g. o*erla4

E&+lidean s4a+e models distan+e and dire+tion in a 4lane

Gra4$s models +onne+ti*ity, S$ortest-Pat$

S4atial data models

r&les to identi#y identi#iable ob7e+ts and 4ro4erties o# s4a+e

b7e+t model $el4 manage identi#iable t$ings, e.g. mo&ntains, +ities,

land-4ar+els et+.

%ield model $el4 manage +ontin&o&s and amor4$o&s 4$enomenon,

e.g. >etlands, satellite imagery, sno>#all et+.-patial 0uery 9an.ua.e

(y4es o# s4atial &eries;

1K 'ange &ery !K 0earest neig$bor &ery 6K S4atial =oins

@ S4atial &ery lang&age

@ S4atial data ty4es, e.g. 4oint, linestring, 4olygon, L

@ S4atial o4erations, e.g. o*erla4, distan+e, nearest neig$bor, L



52/61


@ Callable #rom a &ery lang&age Je.g. SV6K o# &nderlying DBS

SEEC( S.name

%' Senator S

5E'E S.distri+t.AreaJK X 6""

@ Standards

@ SV6 Ja.3.a. SV 1K is a standard #or &ery lang&ages@ GIS is a standard #or s4atial data ty4es and o4erators

@ Bot$ standards en7oy >ide s&44ort in ind&stry

(>o main iss&es;

1. Conne+ting t$e o4erations o# a s4atial algebra to t$e #a+ilities o# a DBS

&ery lang&age.

!. Pro*iding gra4$i+al 4resentation o# s4atial data Ji.e. res&lts o# &eriesK, and

gra4$i+al in4&t o# SD( *al&es &sed in &eries.

F&a)',al !0a,*al al/'b(a %0'(a,*%!"

S0a,*al !'l'.,*%; ret&rning t$ose ob7e+ts satis#ying a s4atial 4redi+ate >it$ t$e

&ery ob7e+t

Eam4le; All big +ities no more t$an 6""ms #rom a&sanne

SEEC( +name %' +ities + 5E'E distJ+.+enter,

a&sanne.+enterK 6"" and +.4o4 X it2erland.,area and

distJr.ro&te, +.areaK


53/61


S+ale Sele+tion

S&barea #or &eries

&lti-s+an V&ery

S4atial 7oin Eam4le

SEEC( S.name %' Senator S, B&siness B 5E'E S.dsitin+t.AreaJK X 6""A0D it$inJB.lo+ation, S.distin+tK0on-S4atial =oin Eam4le;

SEEC( S.name %' Senator S, B&siness B 5E'E S.so+.Se+ A0D S.gender

H%emale A0D it$inJB.lo+ation, S.distin+tK


0AE SEC-SEC GE0DE' DIS(I0C(JPG0K

B-0AE 0E' SC-SEC CA(I0JPI0(K

SE0A('

B:SI0ESS

=I0SPA(IA=I0


54/61


Sa)0l' :'!,*%!

T%0*. 1"

1K $at are t$e t>o >ays o# modeling a Database] J!K

!K $at are t$e ste4s in designing database] J!K

6K $at are entities] Des+ribe abo&t Entity set J!K

9K $at are attrib&tes] J!K

E' odel diagram #or t$e #ollo>ing 4roblem statement;($e 4roblem area is Com4any en*ironment.

aK Ea+$ em4loyee data s&+$ em4M, name, date-o#-birt$, address,

+ity, state, +o&ntry s$o&ld be stored.

bK Em4loyee m&st >or3 in 4arti+&lar de4artment.

+K Ea+$ de4artment in#ormation s&+$ de4tM, name, lo+ation

s$o&ld be stored.

T%0*. 2"

1K $at is 0ormali2ation] J!K

!K $y >e need to sele+t and a44ly 0ormali2ation] J!K6K $at are red&ndant data ] 5o> t$ey in#l&en+es di##erent anomalies and

e4lain t$em >it$ an eam4le. J8K

9K Com4are and +ontrast 0ormali2ation >it$ Denormali2ation. J!K

it$ an eam4le #or ea+$. J8K

/K ist and des+ribe t$e basi+ r&leJsK be$ind %irst 0ormal %ormJ10%K. E4lain

>it$ an eam4le.



55/61


8K ist and des+ribe t$e basi+ r&leJsK be$ind %irst 0ormal %ormJ10%K. E4lain

>it$ an eam4le.

K ist and des+ribe t$e basi+ r&leJsK be$ind Se+ond 0ormal %ormJ!0%K.

E4lain >it$ an eam4le.

1"Kist and des+ribe t$e basi+ r&leJsK be$ind %irst 0ormal %ormJ60%K. E4lain

>it$ an eam4le.11K ist and des+ribe t$e basi+ r&leJsK be$ind Boy+e-Codd 0ormal

%ormJBC0%K. E4lain >it$ an eam4le.

1!K ist and des+ribe t$e basi+ r&leJsK be$ind %o&rt$ 0ormal %ormJ90%K.

E4lain >it$ an eam4le.

16Kist and des+ribe t$e basi+ r&leJsK be$ind %i#t$ 0ormal %ormJit$ an eam4le.

19K All 60% relations need not be BC0% E4lain >it$ an eam4le. J!K

1it$ an eam4le. J!K

1?K $at are =oin de4enden+ies] E4lain >it$ an eam4le. J!K

1/K$at is 0ormali2ation] E4lain t$e *ario&s normali2ation te+$ni&es >it$s&itable eam4les. J1?K

18KGi*en t$e Com4arison bet>een BC0% and 60%. J8K

1K C$oose a 3ey and >rite t$e de4enden+ies #or t$e #ollo>ing Grades;

relation;G'ADESJSt&dentID, Co&rseM, SemesterM, GradeK

A!'("

ey is ;

St&dentID, Co&rseM, SemesterM,

De4enden+y is;

St&dentID, Co&rseM, SemesterM -X Grade

2#?C$oose a 3ey and >rite t$e de4enden+ies #or t$e I0EI(ES relation;

I0EI(ES JP0&mber, Item0&m, Part0&m, Des+ri4tion, Pri+e, VtyK

A!'("

ey +an be; P0&mber, Item0&mDe4enden+ies are;

P0&mber, Item0&m -X Part0&m, Des+ri4tion, Pri+e, Vty

Part0&m -X Des+ri4tion, Pri+e

21? $at normal #orm is t$e abo*e I0EI(ES relation in]

A!'(;

%irst o##, I0EI(ES +o&ld not be in BCNFbe+a&se; not all determinants are 3eys.

net; it +o&ld not be in NFbe+a&se t$ere is a transiti*e de4enden+y;



56/61


P0&mber, Item0&m -X Part0&m

and

Part0&m -X Des+ri4tion

($ere#ore, it m&st be in 2NF, >e +an +$e+3 t$is is tr&e be+a&se;

t$e 3ey o# P0&mber, Item0&m determines all o# t$e non-3ey attrib&tes $o>e*er,P0&mber by itsel# and Item0&m by itsel# +an not determine any ot$er attrib&tes.

22? $at normal #orm is t$e #ollo>ing relation in]

S('EI(EJ S:, PromotionID, )endor, Style, Pri+e K S:;% &romotion' #< /endor% Style% &rice

S:; #< /endor% Style

A!'(;

S('EI(E is in 1NFJnon-3ey attrib&te J*endorK is de4endent on only 4art o#

t$e 3ey.

2?0ormali2e t$e abo*e JV9K relation into t$e net $ig$er normal #orm.

A!'(;

S('EI(E JS:, PromotionID, Pri+eK

)E0D' I(E JS:, )endor, StyleK

27?C$oose a 3ey and >rite t$e de4enden+ies #or t$e #ollo>ing S%(A'E relationJass&me all o# t$e *endors 4rod&+ts $a*e t$e same >arrantyK.

S%(A'E JSo#t>are)endor, Prod&+t, 'elease, System'e, Pri+e, arrantyK

Software/endor% &roduct% Release #< SystemRe9% &rice% =arranty

A!'(;

3ey is; So#t>are)endor, Prod&+t, 'elease

Software/endor% &roduct% Release #< SystemRe9% &rice% =arranty

Software/endor #< =arranty.;. S%(A'E is in 10%

25?0ormali2e t$e abo*e So#t>are relation into 90%.

A!'(;

S%(A'E JSo#t>are)endor, Prod&+t, 'elease, System'e, Pri+eKA''A0( JSo#t>are)endor, arrantyK

28? $at normal #orm is t$e #ollo>ing relation in]

only 5,I +an a+t as t$e 3ey.

S(:%% J5, I, =, , , , 0, K 5, I -X =, ,

= -X

-X 0 -X



57/61


A!'(;

!0% J(ransiti*e de4enden+ies eistK

25?$at normal #orm t$e #ollo>ing relation in]

S(:%%! JD, , 0, (, C, ', K

D, -X 0, (, C, ', C, ' -X D

D -X 0

A!'(;10% JPartial ey De4enden+y eistK

!?K Is t$is relation in 10%] !0%] 60%]

Con*ert t$e relation to 60%.

I;%*.' ('la,*%

In*M date +&stID 0ame PartM Des+ Pri+e M:sed EtPri+e

(arate

(a (otal

19 1!T?6 9! ee A68 0&t ".6! 1" 6.!" ".1" 1.!! 16.9!

19 1!T?6 9! ee A9" Sa> 9.6 because- it +ontains deri*ed *al&es

EF( P'ICEJHPri+e F M &sedK

6.! H ".6! F 1"

- (a JHs&m o# Et 4ri+e o# same In*M F (a rateK1.!! H J6.! [ .""K F ".1"

- (otal JHs&m o# Et 4ri+e [ (aK

16.9! H J6.!" [ .""K [ 1.!!

(o get 10%, identi#y P and remo*e deri*ed attrib&tes

I; date +&stID 0ame 4a(, Des+ Pri+e M:sed (a rate

19 1!T?6 9! ee A68 0&t ".6! 1" ".1"

19 1!T?6 9! ee A9" Sa> 9.


58/61


- Partial %Ds >it$ 3ey attrib&tes.

- In*M -X Date, C&stID, 0ame, (a 'ate

- PartM -X Des+, Pri+e

R')%;' 4a(,*al FD!

1-UUUUUUUD1UUUUUUUUUUUU!UUU-D!UUU

I; date +&stID 0ame (a rate 4a(, Des+ Pri+e M:sed

19 1!T?6 9! ee ".1" A68 0&t ".6! 1"

19 1!T?6 9! ee ".1" A9" Sa> 9.


59/61


H

I; date +&stID (a rate

19 1!T?6 9! ".1"

1< 1T?9 99 ".1"

[.!,ID 0ame

9! ee

99 Pat

All relations in NF

I; 4a(, M:sed

19 A68 1"

19 A9" !1< A68 !"

4a(, Des+ Pri+e

A68 0&t ".6!

A9" Sa> 9.


60/61


3ennel lo+ation

tri+3 ID

tri+3 name

tri+3 >$ere learned

s3ill le*el

Con*ert t$e relation #rom 00% to \0%, !0%, 60%.

T%0*. "

1. De#ine Database se+&rity. J!K

!. E4lain Database system le*el se+&rity. J!K

6. E4lain 4erating system le*el se+&rity. J!K

9. E4lain 0et>or3 le*el se+&rity. J!K

(&ning t$e Database Design is a+$ie*ed] E4lain. J8K

T%0*. 6"

1. E4lain V&ery 4timi2ation in detail. J8K!. 5o> do yo& &nderstand t$e V&ery 4timi2er] J!K

6. $at are t$e ste4s 4er#ormed in t$e &ery o4timi2er] Des+ribe. J8K

9. Ill&strate V&ery o4timi2er +om4onents >it$ a neat diagram. J8K

DATABASE DESIGN ISSUES ?"


61/61


94797883-Cs9152-Dbt-Unit-IV-Notes

Documents

Transcript of 94797883-Cs9152-Dbt-Unit-IV-Notes