1 - - PDF document

1

• !

"! #!$ ! #!

%

• & ''

& & #'()

*'''#

& ''

& '

& #+

& '

,

!" #$

• %.

! / ! '' ! '' 0#'()

1

%"&

2 32! 3

• ('#

& & '45 & '

6

• 7#

8 9+

& &

2

:

• &o1

&o12 &o24 &o29 &o43 &96 &243 &206 &25 “Serge” “Abiteboul” 1997 “Victor” “Vianu” 122 133 paper book paper references references references authortitle year http author author author title publisher author author title page firstname lastname firstname lastname first last Bib

Object Exchange Model (OEM) complex object atomic object

;

!&

#< =''#< => ?( @#<, => ?( ''#<A =#<1 B-C( #<A6 =#<,% BDC( #<E6 BDC?( #<A% BF'59C( #<( #<,( '#<1 =#<6, (#<A %%? ? ?

Observe: Nested tuples, set-values, oids!

A

!&

# =''#=#B-C( #=#BDC( #BDC?( #BF'5>C( '#=#(#%%? ? ?

E

'&

• '

'G

Self-describing, irregular data, no a priori structure

• '()

=9#=#BHC('#%6%,?( 9#=#BC('#6%,%?( 9#=#B@C('#6%6%? ?

name phone John 3634 Sue 6343 Dick 6363

row row row name name name phone phone phone “John” 3634“Sue” “Dick” 6343 6363

• #

HTML describes the presentation

3

%

• IJ'I4J

I'JIJI4J

• ((D

IJ-(AA1 I'JIJI4J

• ((

IJK(AAA

,

• I'J

I@JIJ> I4J IJ- I4J IJI4J IJDI4J I'J-I4'J IJAA1I4J I4@J > I4'J

XML describes the content

1

• %.'

7#LM #

& ' & !

• '#44999N9%N4F4EEE4F0.+L+EEEEE62(

E4EEE3

SGML XML HTML4.0 ⊂ ∈

6

"

# @(((>

& #I@J(#I4@J

0#

I@J>I@J(IJ>I4J

& & '#IJI4J2.N I4J3

! # +! #

• :

$*

I@ ' /B11C /BCJ IJI4J IJ- I4J > IJAA1I4J I4@J Attributes are alternative ways to represent data

;

$ )&

I' /B111CJIJHI4JI4'J I' /B,16CJIJI4J I /B%111C4J I4'J I' /B%C /B,16CJIJHI4J I4'J

• ids and references in XML are just syntax

4

A

$'**

L#IOP.--PNNNNNLNNNQQJ 0L'#

IL'J IOP.--PLI4-JIJQQJ I4L'J

E

$ )&

L#<R 0L'#

IJ<RI4J

#

• <S%;R

B <5R T <'R < <'R J <R I <R

• + "
• G@+ 273
• ,)

,EM 1 A%%) E ,EM 16 ;EE) E

• )*

(

• !"#

$""%& '()*+'( ,-."/+,-

• !"#

011%& '()+'( ,-."/+,-

• %
• !

,

((

<!ELEMENT Book (title, author*) > <!ELEMENT title #PCDATA> <!ELEMENT author (name, address,age?)> <!ATTLIST Book id ID #REQUIRED> <!ATTLIST Book pub IDREF #IMPLIED>

Sort of like a schema but not really.

Inherited from SGML DTD standard BNF grammar establishing constraints on element

structure and content

Definitions of entities

5

1

+ * !(

IUL/VNEVUJ IO0 00*@ 2.W(2-''X73Y3J IO0 00*.0$ZJ IO- 8..--SF0"8F0J IO0 00*-''0$ZJ IO- 8-''.--SF0"8F0J IO0 00*70$ZJ IO- 87T[J ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

+23 ( %45 !# 6 +23 +23 %45 !# (7 !# (7 !# +23

6

• .

IO0 00*@ 2.W(2-''X73Y3J O0 00* (

9

#

& Y \ & W 7

• %8

:

• .*

IO- 8..--SF0"8F0J IO- 87.--SF0"8F0 T[J O- 8

• '(

55( N

• (8
• 9

;

*

'#

.--/ 8/@ 8F0/@ 8F0/@'

'

2XX3/ *7K0*/! *7K0*/'! 0*8Z/[9@9

A

*

K#

SF0"8F0 S8$ 80/' / S8!0/9

%E

"

! 0#

& IO7.Z$00 PNNNNNNNQJ

7#

& IO7.Z$00 Z0 B'#44999NNCJ

7L9NNN2NNL

3

6

%

+-#/

IUL/VNEVUJ IO0 00*@ 2.W3J IO0 00*.0$ZJ IO- 8..--SF0"8F0J ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

:;98 +23 %45 !# +23 :;9 23 %45 23 :;958 < =78,=78 <

%

<!DOCTYPE paper [ <!ELEMENT paper (section*)> <!ELEMENT section ((title,section*) | text)> <!ELEMENT title (#PCDATA)> <!ELEMENT text (#PCDATA)> ]> <!DOCTYPE paper [ <!ELEMENT paper (section*)> <!ELEMENT section ((title,section*) | text)> <!ELEMENT title (#PCDATA)> <!ELEMENT text (#PCDATA)> ]> <paper> <section> <text> </text> </section> <section> <title> </title> <section> … </section> <section> … </section> </section> </paper>

%%

• /
• ! /'
• %,

*9#

'9

IO0 00*' 2('3J

#

IO0 00*' 22X'X3Y3J like an upper bound schema

%1

"&

(#

*''+

& 7G++@[''

*'''

& .[

." @283(#

& *''+@ & *''@2@3 & *8F0 2 3

%6

• 8!

8''2(((

N3

''+2JEE3 +' 82L3 @ 0+'

7

%:

(

<schema version=“1.0” xmlns=“http://www.w3.org/1999/XMLSchema”> <element name=“author” type=“string” /> <element name=“date” type = “date” /> <element name=“abstract”> <type> … </type> </element> <element name=“paper”> <type> <attribute name=“keywords” type=“string”/> <element ref=“author” minOccurs=“0” maxOccurs=“*” /> <element ref=“date” /> <element ref=“abstract” minOccurs=“0” maxOccurs=“1” /> <element ref=“body” /> </type> </element> </schema>

%;

(

! 4! #'

• F#'9@2+

()(N3

!'4!'4!@#@

9

*'# 7#7G

'!

• !#'-$8! '

%A

10(2

book b1 b2 title author author author pcdata Complete... Principles... Chamberlin Bernstein Newcomer pcdata pcdata pcdata pcdata publisher name state CA Morgan... pcdata pcdata pub pub db mkp #1 #2 #3 #4 #5 #6 #7 #0 book title

Issues:

• Distinguish between attributes and sub-elements?
• Should we conserve order?

Think of the labels as names of binary relations.

,E

,

' +(+ ! ( ! LL# I@J@H'' I'@J$ I4'@J I4@J ! #('

(

,

34

!'

& -+B' L'C

& *@L' & 0NN4.4Y4$(4.44$(N !

& !$ ''

!"