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Bratislava, Slovakia, August 21-31, 1998. Databases on the Internet. 4th CEENet Workshop on Network Technology. David Billard. David.Billard@cui.unige.ch. Outline. Classical databases Why should it be different in the Internet? Organizing the data with the Araneus methodology

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slide1

Bratislava, Slovakia, August 21-31, 1998

Databases on the Internet

4th CEENet Workshop on Network Technology

David Billard

David.Billard@cui.unige.ch

slide2
Outline
  • Classical databases
  • Why should it be different in the Internet?
  • Organizing the data with the Araneus methodology
  • Building dynamically a web site with the Target Form Expression
  • Dealing with security
  • Using transactions and workflows
slide3

conceptual level

definition of concepts and relations among them

logical level

database technology applied

DBMS level

data storage, queries, transactions, ...

Classical Databases

Entity-Relationship

(ER) model

Relational model

Oracle DBMS

slide4

request processing

transaction manager

fault-tolerance module

concurrency control

data repository

Classical Database Environment

  • A classical Database Management System (DBMS) is composed of:

interpretation of requests

  • Atomicity (all or nothing)
  • Consistency
  • Isolation
  • Durability

ACID properties

slide5
What is different with the Internet?
  • Hypertext data:
  • relational tables are 2-dimensions:

tuples (lines)

attributes (columns)

  • relational tables do not content navigational data ;
  • hypertext pages implements the third dimension of access path to the data
  • Consequences:
  • Entity-relation scheme must evolve;
  • Relations must be queried with the third dimension in mind.
slide6
What is different with the Internet?
  • Internet technology:
  • no guaranty of service (the RSVP is not fullyimplemented in IP, expected to be in IPng);
  • unsecure channel of communication;
  • lack of the notion of user (only machines);
  • high probability of system crash;
  • very sensible to scale problems.
  • Consequences:
  • we must implement recovery protocols;
  • we must implement security features.
slide7
What is different with the Internet?
  • User behaviour:
  • the user's actions are unknown and unpredictable
  • Strong heterogeneity:
  • a DBMS cannot know every other DBMS technology to interact
  • Consequences:
  • we cannot use tightly coupled integrationof the servers;
  • we must define a minimal set of mandatoryfunctionalities for interoperation.
slide8
Organizing the data for their use via the Web

What we have:

  • Web sites containing valuable pieces of information
  • Web sites containing high volume of data, retrieved from databases
  • Data organized in hypertextual form (access paths are part of the model)
slide9
Organizing the data for their use via the Web

What we need:

  • a methodology for the:
    • Database design process
    • Hypertext design process
  • a tool for:
    • generating web sites from databases
    • maintaining these web sites
slide10

Database Conceptual Design

(Entity-Relationship model)

1

Hypertext Conceptual Design

(Hypertext Conceptual Scheme)

3

Database Logical Design

(Relational model)

Hypertext Logical Design

(Hypertext Logical Scheme)

2

4

Presentation Design

(Page Template)

5

Hypertext to DB mapping, Page Generation

(Web site)

6

The ARANEUS Project (Univ. Roma 3)

slide11

teaching

course

professor

person

researcher

program

place

room

lesson

The ARANEUS Project

  • University ER scheme

1:N

1:1

  • phone
  • name
  • type

1:N

  • name
  • photo
  • e-mail

1:1

1:N

1:1

  • day
  • hour
  • roomNum
slide12
The ARANEUS Project
  • From ER schemes to Hypertext Conceptual schemes

Selecting Macroentities (objects relevant and independent)

Designing Directed Relationships (precise the direction of navigation)

Designing Union Nodes and Aggregations (representation of the IS-A relationship)

slide13

teaching

course

professor

person

researcher

program

place

lesson

room

The ARANEUS Project

  • Selecting Macroentities (objects relevant and independent)

1:N

1:1

  • phone
  • name
  • type

1:N

  • name
  • photo
  • e-mail

1:1

1:N

1:1

  • day
  • hour
  • roomNum
slide14

teaching

course

professor

person

researcher

program

place

lesson

room

The ARANEUS Project

  • Selecting Macroentities (objects relevant and independent)

1:N

1:1

  • phone
  • name
  • type

1:N

  • name
  • photo
  • e-mail

1:1

1:N

1:1

  • day
  • hour
  • roomNum
slide15

teaching

professor

course

person

researcher

program

place

lesson

room

The ARANEUS Project

Designing Directed Relationships (precise the direction of navigation)

1:N

1:1

  • phone
  • name
  • type

1:N

  • name
  • photo
  • e-mail

1:1

1:N

1:1

  • day
  • hour
  • roomNum
slide16

teaching

professor

course

person

researcher

program

place

lesson

room

The ARANEUS Project

Designing Union Nodes and Aggregations (representation of the IS-A relationship)

1:N

1:1

  • phone
  • name
  • type

1:N

  • name
  • photo
  • e-mail

1:1

1:N

1:1

  • day
  • hour
  • roomNum
slide17

department

research

general

education

people

course

student

professor

teaching

The ARANEUS Project

  • Department Hypertext Conceptual Scheme

type =

graduate

type =

undergraduate

name

1:N

type

name

phone

photo

e-mail

day

hour

roomNum

1:1

1:N

slide18
The ARANEUS Project
  • From Hypertext Conceptual schemes to Hypertext Logical Design

Mapping Macroentities (to pages or lists)

Mapping Directed Relationships (to links between pages)

Mapping Aggregations (pages + lists + links)

slide19

name

phone

photo

e-mail

room

...

professor

mapping

The ARANEUS Project

  • Mapping Macroentities to pages

name

phone

photo

e-mail

room

...

slide20

seminar list

title

author

date

hour

room

...

seminar

mapping

The ARANEUS Project

  • Mapping Macroentities to lists

title

author

date

hour

room

...

slide21

professor page

name

phone

photo

e-mail

room

professor

course page

course list

name

type

mapping

name

to course

teacher

time table

toughtby

day

hour

room

course

name

to professor

The ARANEUS Project

  • Mapping Directed relationships to links

name

phone

photo

e-mail

room

...

1:N

name

1:1

type

1:N

day

hour

roomNum

slide22

Database Conceptual Design

(Entity-Relationship model)

Hypertext Conceptual Design

(Hypertext Conceptual Scheme)

Database Logical Design

(Relational model)

Hypertext Logical Design

(Hypertext Logical Scheme)

Presentation Design

(Page Template)

Hypertext to DB mapping, Page Generation

(Web site)

The ARANEUS Project (Univ. Roma 3)

1

3

2

4

5

Dynamic page generation

6

slide23
Querying the databases (browsing and navigating)

What we need:

  • a query language to make DB requests
  • a tool for presenting the result of the request:
    • in HTML form
    • in any form
slide24
The Target Form Expression (TFE) project (Univ. of Keio, Japan)
  • Idea: Extending SQL to add publishing facilities
  • the result of a query is presented in a structured document (HTML, Java, LaTeX, ...)

To give a comparison: Allaire's Cold Fusion does not allow grouping or hyperlink generation (necessary for structuring documents)

slide25
The Target Form Expression project
  • GENERATE keyword

GENERATE <medium> <TFE>

<medium> = HTML, LaTeX, Java, Excel, TCLTK, O2C, SQL

<TFE> = expression

, = tuple connector

! = row connector

% = depth (link) operator

[ and ] = repeaters

[emp.name, emp.salary]!

= list of tuples (names, salary)

[store.name,[dept.name ![emp.name]!,[item.name]!]!]%

slide26

film

id

title

type

year

pict

film, actor

actor

id

name

birth

face

The Target Form Expression project

  • Example of a movie database

cast

slide27

select a category

generate html verb(select a category) !

[f.type %

[f.year, [f.title %

{f.title ! imagefile(f.pict) !

[imagefile(a.face), a.name, a.birth]!}]!]!],

from film f, cast c, actor a

where f.id = c.film and c.actor = a.id

action

comedy

drama

horror

1997 Batman and Robin

Speed 2

1996 Mission impossible 2

Independence day

1997 My best friend's wedding

Out to sea

1996 Dear God

The first wives club

Nutty professor

Tin cup

The first wives club

Diane Keaton 1946

Goldie Hawn 1945

Bette Middler 1945

The Target Form Expression project

slide28

action

comedy

drama

horror

The Target Form Expression project

select a category

generate html verb(select a category) !

[f.type %

[f.year, [f.title %

{f.title ! imagefile(f.pict) !

[imagefile(a.face), a.name, a.birth]!}]!]!],

from film f, cast c, actor a

where f.id = c.film and c.actor = a.id

slide29

select a category

action

comedy

drama

horror

The Target Form Expression project

generate html verb(select a category) !

[f.type %

[f.year, [f.title %

{f.title ! imagefile(f.pict) !

[imagefile(a.face), a.name, a.birth]!}]!]!],

from film f, cast c, actor a

where f.id = c.film and c.actor = a.id

slide30

select a category

action

comedy

drama

horror

1997Batman and Robin

Speed 2

1996Mission impossible 2

Independence day

1997My best friend's wedding

Out to sea

1996Dear God

The first wives club

Nutty professor

Tin cup

The Target Form Expression project

generate html verb(select a category) !

[f.type %

[f.year, [f.title %

{f.title ! imagefile(f.pict) !

[imagefile(a.face), a.name, a.birth]!}]!]!],

from film f, cast c, actor a

where f.id = c.film and c.actor = a.id

slide31

select a category

action

comedy

drama

horror

1997 Batman and Robin

Speed 2

1996 Mission impossible 2

Independence day

1997 My best friend's wedding

Out to sea

1996 Dear God

The first wives club

Nutty professor

Tin cup

The Target Form Expression project

generate html verb(select a category) !

[f.type %

[f.year, [f.title %

{f.title ! imagefile(f.pict) !

[imagefile(a.face), a.name, a.birth]!}]!]!],

from film f, cast c, actor a

where f.id = c.film and c.actor = a.id

slide32

select a category

action

comedy

drama

horror

1997 Batman and Robin

Speed 2

1996 Mission impossible 2

Independence day

1997 My best friend's wedding

Out to sea

1996 Dear God

The first wives club

Nutty professor

Tin cup

The Target Form Expression project

generate html verb(select a category) !

[f.type %

[f.year, [f.title %

{f.title ! imagefile(f.pict) !

[imagefile(a.face), a.name, a.birth]!}]!]!],

from film f, cast c, actor a

where f.id = c.film and c.actor = a.id

The first wives club

slide33

select a category

action

comedy

drama

horror

1997 Batman and Robin

Speed 2

1996 Mission impossible 2

Independence day

1997 My best friend's wedding

Out to sea

1996 Dear God

The first wives club

Nutty professor

Tin cup

The Target Form Expression project

generate html verb(select a category) !

[f.type %

[f.year, [f.title %

{f.title ! imagefile(f.pict) !

[imagefile(a.face), a.name, a.birth]!}]!]!],

from film f, cast c, actor a

where f.id = c.film and c.actor = a.id

The first wives club

slide34

select a category

action

comedy

drama

horror

1997 Batman and Robin

Speed 2

1996 Mission impossible 2

Independence day

1997 My best friend's wedding

Out to sea

1996 Dear God

The first wives club

Nutty professor

Tin cup

Diane Keaton 1946

Goldie Hawn 1945

Bette Middler 1945

The Target Form Expression project

generate html verb(select a category) !

[f.type %

[f.year, [f.title %

{f.title ! imagefile(f.pict) !

[imagefile(a.face), a.name, a.birth]!}]!]!],

from film f, cast c, actor a

where f.id = c.film and c.actor = a.id

The first wives club

slide35

With TFE we have a tool to dynamically create a web site from an existing database, at the whish of the user

The Target Form Expression project

  • INVOKE keyword

allow dynamic queries inside queries

(recursive queries)

slide36

DBMS

DB

Classical Database Environment

  • Environment of a classical DBMS:

secure environment

slide37

DBMS 1

DBMS 2

DB

DB

Classical Database Environment

  • Multidatabases - Federated DBMS
  • Cooperative work, ...
slide38

Normal flow

Sender

receiver

Securing the databases

The Internet introduces threats for the DBMS and the users.

4 attacks among the more frequent

  • Interception
  • Modification
  • Fabrication
  • Interruption
slide39
Confidentiality

Interception

  • Cannot help a message to be intercepted;
  • The message must not be disclosed;
  • Confidentiality of data (Privacy)
  • Encryption (e.g. Secure Socket Layer - SSL)
slide40
Dangerous behaviours

Modification

Fabrication

slide41
Dangerous behaviours
  • A user must really be who he claims to be.
  • Authentication of user
  • Authentication certificates delivered by a "Thrustee"
  • A user cannot deny having received or sent a message.
  • Non-Repudiation schemas, based on the authentication of user.
slide42
Dangerous behaviours

Interruption

  • A user cannot help a communication to being cut.
  • Recovery procedures, based on time-outs and logging.
slide43
Securing the databases
  • The iSaSiLk toolbox (Univ. of Vienna)
  • Written in Java
  • Provides cryptography primitives (possibility to implement SSL sockets)
  • Provides authentication primitives
  • Provides certificate management
  • Free for use for academic partners
  • (not free for industry)
slide44
Transactions in the Internet
  • Transactions are a very common tool in databases
  • They provide isolation of concurrent activities
  • They are fault tolerant processes
  • They have been extensively studied in distributed environment

But

  • They lack security and scalability in the Internet
slide47
Example in Electronic Commerce

the same shirt as

Sandra Bullock's in

"The Net", and...

Internet

slide48
Example in Electronic Commerce

the same hat as

Ingrid Bergman's

in "Casablanca"!

Internet

slide50

Example in Electronic Commerce

  • ACID
  • Atomicity
  • Consistency
  • Isolation
  • Durability

Internet

slide51

Example in Electronic Commerce

  • ACID
  • Atomicity
  • Consistency
  • Isolation
  • Durability

Internet

  • Secure
  • Confidentialty
  • Authentication
  • Non-Repudiation
slide52
Example in Atomic File Transfer Protocol

Sofware update

Server A

Internet

System administrator

Server B

slide53
Example in Atomic File Transfer Protocol

Server A

Internet

System administrator

Server B

slide54

Example in Atomic File Transfer Protocol

Server A

Internet

System administrator

Server B

slide55
Example in Atomic File Transfer Protocol

Server A

Internet

Installation application

Server B

slide56

Example in Internet Aided Manufacturing

Internet

New extension card for PC

slide57

Example in Internet Aided Manufacturing

Printed circuit manufacturer

Internet

New extension card for PC

slide58

Example in Internet Aided Manufacturing

Printed circuit manufacturer

Internet

Electronic component supplier

New extension card for PC

slide59

Example in Internet Aided Manufacturing

Printed circuit manufacturer

Internet

Electronic component supplier

New extension card for PC

slide60

Example in Internet Aided Manufacturing

Towards workflows

Internet

Integrator

slide61
Transactions in the Internet

Related work on transactions:

  • Transaction Internet Protocol (TIP)
  • Corba OTS (Object Transaction Service)
  • X/Open DTP (Distributed Transaction Processing)
slide62

procedures

Workflows on the Internet

  • A workflow business process:
slide63
Workflows on the Internet

3 levels in a workflow:

  • Process (separation of business logic from function logic)
  • Organization (who is doing what)
  • Infrastructure (what has to be done manually, with computer, ...)
slide64
Workflows on the Internet
  • Flowmark
  • Flowman
  • InConcert
  • Staffware
  • ViewStar
  • ...
slide65
Resume of part 1
  • We know how to modelize and represent a database
  • We know how to query the database and visualize the results
  • We are aware of security and fault-tolerance problems