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New Database Applications. Properties of Conventional Databases - Fixed size record oriented - Small data item (ex) 1 record size < 80 bytes - Atomic value in a field - Static schema - Fast transaction ( < 2 ~ 3 sec) New Applications CAD (Computer-Aided Design),
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New Database Applications • Properties of Conventional Databases • - Fixed size record oriented • - Small data item • (ex) 1 record size < 80 bytes • - Atomic value in a field • - Static schema • - Fast transaction ( < 2 ~ 3 sec) • New Applications • CAD (Computer-Aided Design), • CASE (Computer-Aided Software Engineering), • Multimedia Databases, • Office Information System, • Expert Database System (including rules)
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
New Database Applications • Properties of Conventional Databases • - Fixed size record oriented • - Small data item • (ex) 1 record size < 80 bytes • - Atomic value in a field • - Static schema • - Fast transaction ( < 2 ~ 3 sec) • New Applications • CAD (Computer-Aided Design), • CASE (Computer-Aided Software Engineering), • Multimedia Databases, • Office Information System, • Expert Database System (including rules)
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.
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
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)
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));
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.
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
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.
Properties of Object-Oriented Databases • III : Classes can have methods checking_plus account_# amount interest_% overdraft_amt last_check_# open() deposit() withdraw() checking account_# amount overdraft last_check_# open() deposit() withdraw() savings account_# amount interest_% open() deposit() withdraw() create class savings (account_# string not null unique, amount monetary, interest_% float) method open (string, monetary) savings function open, deposit(monetary) monetary function deposit, withdraw(monetary) monetary function withdraw file '$METHODS/accounts.o';
Properties of Object-Oriented Databases (IV) • IV : Hierarchical organization of classes • Inheritance is the sharing of properties (attributes and operations) • among classes. Inheritance is based on a hierarchical relationship • between classes, such that a child class, or subclass, inherits • properties from its class, or superclass. • - A superclass can have one or more subclass. • - A subclass can have one or more superclass. • - A subclass may inherit (reuse) the attributes and methods of the • superclass(es). • - Attributes and methods may be specialized in subclasses.
Properties of Object-Oriented Databases • IV : Hierarchical organization of classes account account_# amount open() transfer() withdraw() client client_# client_name address city state zip Multipicity checking overdraft last_check_# savings interest_% only one zero or more zero or one checking_plus
create class address (street string, city string, state char(2)); create class account (account_# string not null unique, amount monetary) method open (string, monetary) account function open, deposit(monetary) monetary function deposit, withdraw(monetary) monetary function withdraw file '$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 set account);
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
Future Directions • Standardization • Performance • Database Design Tool • Deductive Facility
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
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
The End 나는 에레베스트 산을 정복하겠다는 목표를 세운 다음 등산을 한 결과, 어느 날 나는 산꼭대기를 정복한 나를 발견하게 되었다. 애드먼드 힐래리 에레베스트산 최초로 오른 사람
파커와 만년필 파커는 만년필 가게의 점원이었다. 그가 다른 사람과 달랐던 점은 언제나 보기 좋고 편리한 만년필을 만들 수 없을 까하고 궁리하는 일 이었다. 자력으로 조그만 가게를 낸 그는 만년필 개량에 몰두했다. 마침 그무렵 자동차의 스피드가 증가함에 따라 그 모양도 유선형으로 바뀌어 갔다. 이것이다! 파커는 막대기 모양을 유선형으로 바꾸기로 했다. 주위에서는 모두 반대했다. 이 아이디어가 관심을 끌어 만년필은 무섭게 팔려나갔고, 파커는 만년필계의 왕자로 큰 부자가 되었다. 이 이야기는 우리에게 끊임없는 생각으로 새로운 아이디어와 점원 시절의 노력이 그를 성공 시켰음을 알 수 있다. 파커 세셰적인 만년필 파커 창업자