Chapter 1 Introduction
Chapter 1 Introduction
Contents The history of Database System Overview of a database Management System(DBMS) Three aspects of database-system studies
Contents The history of Database System Overview of a database Management System (DBMS) Three aspects of database-system studies
Introduction to Database Systems What is a Database System? Database (data metadata) Hardware (disks) Software (DBMS) People (users,database designers and database administrators DBA)
Introduction to Database Systems What is a Database System? Database (data , metadata) Hardware (disks) Software (DBMS) People (users, database designers and database administrators DBA)
The history of Database Systems Early database management systems evolved from file system Network DBMS,Hierarchical DBMS Relational database Systems (in 1970, Ted Codd proposed tables called relations as a view of data in database) Object-oriented database Web database and XML
The history of Database Systems Early database management systems evolved from file system Network DBMS, Hierarchical DBMS Relational database Systems (in 1970, Ted Codd proposed tables called relations as a view of data in database) Object-oriented database Web database and XML
Drawbacks of using file systems to store data Data redundancy and inconsistency Multiple file formats,duplication of information in different files Database Difficulty in accessing data systems Need to write a new program to carry out each new task provide solutions to Data isolation-multiple files and formats all these problems ■Integrity problems Integrity constraints (e.g.account balance 0)become part of program code,Hard to add new constraints or change existing ones ■ Concurrent access by multiple users ■ Security problem
Data redundancy and inconsistency Multiple file formats, duplication of information in different files Difficulty in accessing data Need to write a new program to carry out each new task Data isolation — multiple files and formats Integrity problems Integrity constraints (e.g. account balance > 0) become part of program code, Hard to add new constraints or change existing ones Concurrent access by multiple users Security problem … Drawbacks of using file systems to store data Database systems provide solutions to all these problems
More detailed History (From Database Concepts 6th edition) 1950s and early 1960s: Data processing using magnetic tapes for storage Tapes provided only sequential access Punched cards for input ■ Late 1960s and 1970s: Hard disks allowed direct access to data Network and hierarchical data models in widespread use Ted Codd defines the relational data model he won the ACM Turing Award for this work IBM Research begins System R prototype UC Berkeley begins Ingres prototype High-performance(for the era)transaction processing
More detailed History More detailed History (From Database Concepts 6 (From Database Concepts 6th e dition) 1950s and early 1960s: Data processing using magnetic tapes for storage • Tapes provided only sequential access Punched cards for input Late 1960s and 1970s: Hard disks allowed direct access to data Network and hierarchical data models in widespread use Ted C odd defines the relational data model • he won the ACM Turing Award for this wor k • IBM Researc h begins System R prototype • UC Berkeley begins Ingres prototype High-performance (for the era) trans action processing
More detailed History (cont. 1980s: Research relational prototypes evolve into commercial systems SQL becomes industrial standard Parallel and distributed database systems Object-oriented database systems ■1990s: Large decision support and data-mining applications Large multi-terabyte data warehouses Emergence of Web commerce Early 2000s: XML and XQuery standards Automated database administration Later 2000s: ■( Giant data storage systems ■？？？
More detailed History (cont.) 1980s: Research relational prototypes evolve into commercial systems • SQL becomes industrial standard Parallel and distributed database systems Object-oriented database systems 1990s: Large decision support and data-mining applications Large multi-terabyte data warehouses Emergence of Web commerce Early 2000s: XML and XQuery standards Automated database administration Later 2000s: Giant data storage systems ???
Overview of a Database System ■ Database applications Database Database application Management System DBMS Operating System 个 (not in this course) Operating system 个 computer
Overview of a Database System Database applications Database Management System Operating System (not in this course) computer Operating system DBMS Database application
Some applications of database systems ■ Databases touch all aspects of our lives Banking:all transactions Airlines:reservations,schedules s Universities:course registration,grades Sales:customers,products,purchases Manufacturing:production,inventory,orders, supply chain ■ Human resources:employee records, salaries,tax deductions
Some applications of database systems Databases touch all aspects of our lives Banking: all transactions Airlines: reservations, schedules Universities: course registration, grades Sales: customers, products, purchases Manufacturing: production, inventory, orders, supply chain Human resources: employee records, salaries, tax deductions …
What is a DBMS(database management system)? From Commercial Market: Oracle,Sybase are among the largest software companies in the world. IBM offers its DB2 system Microsoft offers SQL-Server Microsoft Access for DBMS on desktop
What is a DBMS (database management system) ? From Commercial Market: Oracle, Sybase are among the largest software companies in the world. IBM offers its DB2 system Microsoft offers SQL-Server & Microsoft Access for DBMS on desktop