DATABASE SYSTEMS

1
New Database Applications

• Properties of Conventional Databases
• - Fixed size record oriented
• - Small data item
• (ex) 1 record size lt 80 bytes
• - Atomic value in a field
• - Static schema
• - Fast transaction ( lt 2 3 sec)
• New Applications
• CAD (Computer-Aided Design),
• CASE (Computer-Aided Software Engineering),
• Multimedia Databases,
• Office Information System,
• Expert Database System (including rules)

2
9. Object-Oriented Databases and Multimedia
Databases

• Object-Oriented Databases
• New Database Applications
• Properties of OODB
• Advantages and Disadvantages
• Future Directions
• Multimedia Databases
• Implementation Approaches
• Properties

3
New Database Applications

• Properties of Conventional Databases
• - Fixed size record oriented
• - Small data item
• (ex) 1 record size lt 80 bytes
• - Atomic value in a field
• - Static schema
• - Fast transaction ( lt 2 3 sec)
• New Applications
• CAD (Computer-Aided Design),
• CASE (Computer-Aided Software Engineering),
• Multimedia Databases,
• Office Information System,
• Expert Database System (including rules)

4
Properties of Object-Oriented Databases

• Object-Oriented Concepts
• (1) The fundamental construct is an object
  which includes properties
• (attributes) and behavior (operations).
• (2) An object has its own inherent, unique
  identity (OID).
• (3) Objects with the same data structure
  (attributes) and behavior
• (operations) are grouped into a class.
• (4) Inheritance is the sharing of properties
  (attributes and operations)
• among classes.
• (5) A specific implementation of an operation
  is called a method.
• It update attribute values.

5
Properties of Object-Oriented Databases

• I Classes can be valid domain
• II A class cell can contain more than 1
  values
• III Classes can have methods
• IV Hierarchical organization of classes

6
Properties of Object-Oriented Databases (I)

• I Classes can be valid domain
• A class is an abstraction of a set of objects
  that describes their data
• structure (attributes) and behavior (operations).
• - The domain of an attribute can be expressed as
  an existing
• class in the database.
• - Arbitrary domain can be defined and managed.
• - Complex nested data can be modeled and accessed
  directly by
• application.
• - Allows common information to be stored only
  once.
• - Data residing in multiple classes can be
  accessed directly and
• more efficiently without an explicit join.
• (already included address class in client)

7
Properties of Object-Oriented Databases

• I Classes can be valid domain

Multipicity
address street city state
client client_ client_name
zero or one
create class client (client_ string not null
unique, client_name string, address address)
create class address (street string,
city string, state char(2))
8
Properties of Object-Oriented Databases (II)

• II A class cell can contain more than 1 values
• OODB supports various types of collections
  sets, multisets,
• and sequences.
• - The domain of a field can be specified as a set
  of values.
• - The set can be consist of either a
  system-defined domain,
• a user-defined domain, a group of
  system-defined domains
• and /or user-defined domaines.
• - Simplifies the creation of one-to-many and
  many-to-many
• data relationships.

9
Properties of Object-Oriented Databases

• II A class cell can contain more than 1 values

client_account account_ account_type
client client_ client_name
address street city state
Multipicity
create class client (client_ string not null
unique, client_name string, address address
account set client_account)
only one
zero or more
zero or one
10
Properties of Object-Oriented Databases (III)

• III Classes can have methods
• An operation is an abstraction of comparable
  behavior associated
• with different kinds of objects. A specific
  implementation of an
• operation is called a method.
• - User-written C programs can be registered with
  specific class
• to be invoked by database engine.
• - Methods can be reused within a database to
  transparently support
• class-specific behavior.
• - Class-specific behavior can be hidden from
  calling applications,
• providing true application independence from
  procedural data.

11
Properties of Object-Oriented Databases

• III Classes can have methods

checking_plus account_ amount interest_ overdra
ft_amt last_check_ open() deposit() withdraw()
checking account_ amount overdraft last_check_
open() deposit() withdraw()
savings account_ amount interest_ open() depos
it() withdraw()
create class savings (account_ string not null
unique, amount monetary, interest_ float) met
hod open (string, monetary) savings function
open, deposit(monetary) monetary function
deposit, withdraw(monetary) monetary function
withdraw file 'METHODS/accounts.o'
12
Properties of Object-Oriented Databases (IV)

• IV Hierarchical organization of classes
• Inheritance is the sharing of properties
  (attributes and operations)
• among classes. Inheritance is based on a
  hierarchical relationship
• between classes, such that a child class, or
  subclass, inherits
• properties from its class, or superclass.
• - A superclass can have one or more subclass.
• - A subclass can have one or more superclass.
• - A subclass may inherit (reuse) the attributes
  and methods of the
• superclass(es).
• - Attributes and methods may be specialized in
  subclasses.

13
Properties of Object-Oriented Databases

• IV Hierarchical organization of classes

account account_ amount open() transfer() withd
raw()
client client_ client_name
address city state zip
Multipicity
checking overdraft last_check_
savings interest_
only one
zero or more
zero or one
checking_plus
14
create class address (street string,
city string, state char(2)) create class
account (account_ string not null unique,
amount monetary) method open (string, monetary)
account function open, deposit(monetary)
monetary function deposit, withdraw(monetary)
monetary function withdraw file
'METHODS/accounts.o' create class checking
under account (overdraft_amt monetary,
last_check_ integer) create class saving under
account (interest_ float) create class
checking_plus under checking, saving create
class client (client_ string not null unique,
client_name string, address address, accounts s
et account)
15
Advantages and Disadvantages

• Advantages
• (1) Powerful expressive facilities
• (2) Reusability and extensibility
• (3) Impedance match
• (4) Complex Object
• Disadvantages
• (1) Weakness of theoretical background
• cf) Relational model is based on mathematics
• (2) Complexity implementation or usability
• (3) Difficulty on query optimization

16
Future Directions

• Standardization
• Performance
• Database Design Tool
• Deductive Facility

17
Multimedia Databases

• What ?
• Database system that handle unformatted data
  such as text, graphics,
• images, audio, video, etc.
• Implementation Approaches
• (1) RDBMS file system
• - can not support database facilities
  (concurrency control, recovery)
• on multimedia data.
• (2) Extension of RDBMS
• - store on the long field or several tuples.
• - can not handle multimedia data accurately.
• (3) OODBMS or MMDBMS
• - can handle multimedia data accurately.
• (ex) store video as set of frames

18
Properties

• Properties of Multimedia Databases
• (1) Mass data
• (ex) 512 x 480 color still image 750
  KB
• (ex) 30 frame animation 22MB
• (2) Various storage protocol
• (ex) still image JPEG, X11 bitmap,
  TIFF ...
• (3) Difficulty of media retrieval
• - (ex) "Dunk shot of Michael Jordon", "Sorak
  Mt."
• - sequential browsing
• - abstract description (character searching)
• (4) Time synchronization
• - (ex) "scene with ringing the bell"
• - relationship of video frame information
  audio data information

19
The End
?? ????? ?? ?????? ??? ?? ?? ??? ? ??, ?? ? ??
????? ??? ?? ???? ???.
???? ??? ?????? ??? ?? ??
20
??? ???
??? ??? ??? ?????. ?? ?? ??? ??? ?? ??? ??
?? ??? ???? ?? ? ?? ??? ???? ? ???. ???? ???
??? ? ?? ??? ??? ????. ?? ??? ???? ???? ???? ?? ?
??? ????? ??? ??. ????! ??? ??? ??? ????? ????
??. ????? ?? ????. ? ????? ??? ?? ???? ??? ?????,
??? ????? ??? ? ??? ???. ? ???? ???? ???? ????
??? ????? ?? ??? ??? ?? ?? ???? ? ? ??.
?? ???? ??? ?? ???