🗊Презентация Introduction to Database Systems

Категория: Информатика
Нажмите для полного просмотра!
Introduction to Database Systems, слайд №1Introduction to Database Systems, слайд №2Introduction to Database Systems, слайд №3Introduction to Database Systems, слайд №4Introduction to Database Systems, слайд №5Introduction to Database Systems, слайд №6Introduction to Database Systems, слайд №7Introduction to Database Systems, слайд №8Introduction to Database Systems, слайд №9Introduction to Database Systems, слайд №10Introduction to Database Systems, слайд №11Introduction to Database Systems, слайд №12Introduction to Database Systems, слайд №13Introduction to Database Systems, слайд №14Introduction to Database Systems, слайд №15Introduction to Database Systems, слайд №16Introduction to Database Systems, слайд №17Introduction to Database Systems, слайд №18Introduction to Database Systems, слайд №19Introduction to Database Systems, слайд №20Introduction to Database Systems, слайд №21

Вы можете ознакомиться и скачать презентацию на тему Introduction to Database Systems. Доклад-сообщение содержит 21 слайдов. Презентации для любого класса можно скачать бесплатно. Если материал и наш сайт презентаций Mypresentation Вам понравились – поделитесь им с друзьями с помощью социальных кнопок и добавьте в закладки в своем браузере.

Слайды и текст этой презентации


Слайд 1





Introduction to Database Systems
Database Systems Lecture 5
Описание слайда:
Introduction to Database Systems Database Systems Lecture 5

Слайд 2





Textbook
Recommended textbooks:
‘Database Systems: A practical approach to design, implementation and management’ by Connolly and Begg
`A first course in database systems’ by Ullman and Widom.
Описание слайда:
Textbook Recommended textbooks: ‘Database Systems: A practical approach to design, implementation and management’ by Connolly and Begg `A first course in database systems’ by Ullman and Widom.

Слайд 3





Why Study Databases?
Databases are useful
Many computing applications deal with large amounts of information
Database systems give a set of tools for storing, searching and managing this information
Описание слайда:
Why Study Databases? Databases are useful Many computing applications deal with large amounts of information Database systems give a set of tools for storing, searching and managing this information

Слайд 4





What is a Database?
“A set of information held in a computer”
Oxford English Dictionary
“One or more large structured sets of persistent data, usually associated with software to update and query the data”
Free On-Line Dictionary of Computing
“A collection of data arranged for ease and speed of search and retrieval”
Dictionary.com
Описание слайда:
What is a Database? “A set of information held in a computer” Oxford English Dictionary “One or more large structured sets of persistent data, usually associated with software to update and query the data” Free On-Line Dictionary of Computing “A collection of data arranged for ease and speed of search and retrieval” Dictionary.com

Слайд 5





Databases
Web indexes
Library catalogues
Medical records
Bank accounts
Stock control
Personnel systems
Product catalogues
Telephone directories
Описание слайда:
Databases Web indexes Library catalogues Medical records Bank accounts Stock control Personnel systems Product catalogues Telephone directories

Слайд 6





Database Systems
A database system consists of
Data (the database)
Software
Hardware
Users
We focus mainly on the software
Описание слайда:
Database Systems A database system consists of Data (the database) Software Hardware Users We focus mainly on the software

Слайд 7





Database Users
End users 
Use the database system to achieve some goal
Application developers 
Write software to allow end users to interface with the database system
Описание слайда:
Database Users End users Use the database system to achieve some goal Application developers Write software to allow end users to interface with the database system

Слайд 8





Database Management Systems
A database is a collection of information
A database management system (DBMS) is the software than controls that information
Описание слайда:
Database Management Systems A database is a collection of information A database management system (DBMS) is the software than controls that information

Слайд 9





What the DBMS does
Provides users with
Data definition language (DDL)
Data manipulation language (DML)
Data control language (DCL)
Often these are all the same language
Описание слайда:
What the DBMS does Provides users with Data definition language (DDL) Data manipulation language (DML) Data control language (DCL) Often these are all the same language

Слайд 10





Data Dictionary - Metadata
The dictionary or catalog stores information about the database itself
This is data about data or ‘metadata’
Almost every aspect of the DBMS uses the dictionary
Описание слайда:
Data Dictionary - Metadata The dictionary or catalog stores information about the database itself This is data about data or ‘metadata’ Almost every aspect of the DBMS uses the dictionary

Слайд 11





File Based Systems
File based systems
Data is stored in files
Each file has a specific format
Programs that use these files depend on knowledge about that format
Описание слайда:
File Based Systems File based systems Data is stored in files Each file has a specific format Programs that use these files depend on knowledge about that format

Слайд 12





Relational Systems
Problems with early databases
Navigating the records requires complex programs
There is minimal data independence
No theoretical foundations
Описание слайда:
Relational Systems Problems with early databases Navigating the records requires complex programs There is minimal data independence No theoretical foundations

Слайд 13





Relational Systems
Information is stored as tuples or records in relations or tables
There is a sound mathematical theory of relations
Most modern DBMS are based on the relational model
Описание слайда:
Relational Systems Information is stored as tuples or records in relations or tables There is a sound mathematical theory of relations Most modern DBMS are based on the relational model

Слайд 14





ANSI/SPARC Architecture
ANSI - American National Standards Institute
SPARC - Standards Planning and Requirements Committee
1975 - proposed a framework for DBs
Описание слайда:
ANSI/SPARC Architecture ANSI - American National Standards Institute SPARC - Standards Planning and Requirements Committee 1975 - proposed a framework for DBs

Слайд 15





Internal Level
Deals with physical storage of data
Structure of records on disk - files, pages, blocks
Indexes and ordering of records
Used by database system programmers
Описание слайда:
Internal Level Deals with physical storage of data Structure of records on disk - files, pages, blocks Indexes and ordering of records Used by database system programmers

Слайд 16





Conceptual Level
Deals with the organisation of the data as a whole
Abstractions are used to remove unnecessary details of the internal level
Used by DBAs and application programmers
Описание слайда:
Conceptual Level Deals with the organisation of the data as a whole Abstractions are used to remove unnecessary details of the internal level Used by DBAs and application programmers

Слайд 17





External Level
Provides a view of the database tailored to a user
Parts of the data may be hidden
Data is presented in a useful form
Used by end users and application programmers
Описание слайда:
External Level Provides a view of the database tailored to a user Parts of the data may be hidden Data is presented in a useful form Used by end users and application programmers

Слайд 18





Mappings
Mappings translate information from one level to the next
External/Conceptual
Conceptual/Internal
These mappings provide data independence
Описание слайда:
Mappings Mappings translate information from one level to the next External/Conceptual Conceptual/Internal These mappings provide data independence

Слайд 19





ANSI/SPARC Architecture
Описание слайда:
ANSI/SPARC Architecture

Слайд 20





This Lecture in Exams
	Describe the three levels of the ANSI/SPARC model. You should include information about what each level is for, which users might be interested in which levels, and how the levels relate to one another. (2004/05, 7 marks)
Описание слайда:
This Lecture in Exams Describe the three levels of the ANSI/SPARC model. You should include information about what each level is for, which users might be interested in which levels, and how the levels relate to one another. (2004/05, 7 marks)

Слайд 21





Next Lecture
The Relational Model
Relational data structure
Relational data integrity
Relational data manipulation
For more information
Connolly and Begg chapters 3 and 4
Ullman and Widom (2 ed.) Chapter 3.1, 5.1
E.F. Codd’s paper
(there is a link on last year’s G51DBS webpage)
Описание слайда:
Next Lecture The Relational Model Relational data structure Relational data integrity Relational data manipulation For more information Connolly and Begg chapters 3 and 4 Ullman and Widom (2 ed.) Chapter 3.1, 5.1 E.F. Codd’s paper (there is a link on last year’s G51DBS webpage)



Похожие презентации
Mypresentation.ru
Загрузить презентацию