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Database Systems
高海昌
[email protected]
DataBase System
Major Content & Grade
 Introduction
*
 The
***
Relational Model
 SQL
****
 Transaction
Management
***
 Database
Design (E-R)
***
 Database
Design (Normalization)
***
 考核方式
笔试(70%)+平时(课堂/作业/上机) (30%)
Haichang Gao , Software School , Xidian University
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DataBase System
Books
 Book
 Abraham
Silberschatz, Henry F. Korth, S.Sudarshan,
Database System Concepts (5th ed.),
The McGraw-Hill Companies, 2006
 Reference Books
 Thomas
M. Connolly, et al. Database Systems: A practical
approach to Design, Implementation, and Management. 4th
edition, Addison-Wesley, 2008
 萨师煊，王珊
《数据库系统概论》 高等教育出版社
(第4版)
Haichang Gao , Software School , Xidian University
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DataBase System
Unit 1 Introduction
 Data
& Database
 DBMS
 Database
System
 Database
Applications
 Brief
History of Data Management
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DataBase System
Data & Database
 How to management Information (Data)?
data: data are raw facts that describe people, objects,
and events.
Haichang Gao , Software School , Xidian University
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DataBase System
Data & Database
 How to management Information(Data)?
Database
: An integrated collection of related data
constitutes a Database (DB).
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DataBase System
DBMS
 Database Management System (DBMS) : Contains
information about a particular enterprise
 Collection of
interrelated data
 Set
of programs to access the data
 An
environment that is both convenient and efficient to use
Application1
Database
Application2
DBMS
……
Haichang Gao , Software School , Xidian University
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DataBase System
DBMS
 What should A DBMS needed?
 Data
can be shared
 Redundancy(冗余)
can be reduced
 Inconsistency(不一致性) can
 Transaction(事务) support
be avoided
can be provided
 Integrity(完整性) can
be maintained
 Security(安全性) can
be enforced
 Conflicting(冲突) requirements can
 Standards
be balanced
can be enforced
DBMS is less complex than OS.
Haichang Gao , Software School , Xidian University
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DataBase System
DBMS Architecture
成绩单
学号：xxxxx 姓名：xxx
性别：x
离散数据
75
数据库系统
81
……
……
模式（Logical Schema,
Sno Sname Ssex Sage Sdept
Schema，也称逻辑模式）
——数据库中全体数据的逻辑
Sno Cno
结构和特征（型）的描述
外模式（External Schema，
也称子模式或用户模式）
——数据库用户使用的局部数据
的逻辑结构和特征的描述
Cno Cname Cpno Ccredit
Grade
内模式（Physical Schema，
也称存储模式）
——数据物理结构和存储方式
的描述
Haichang Gao , Software School , Xidian University
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DataBase System
DBMS Architecture
 ANSI/SPARC architecture
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DataBase System
Functions of DBMS
1) Data definition(Data Definition Language—DDL)
利用DDL可方便地对数据库中的数据对象进行定义。
2) Data manipulation(Data Manipulation Language—DML)
用户利用DML实现对数据库数据的基本操作，如查询、插入、删
除和修改等。
3) Database running management
在数据库的建立、运行和维护时，由DBMS进行统一管理、统一
控制，以确保数据的安全性、完整性、多用户的并发操作及发生故障
后的系统恢复。
4) Database establish and maintain
数据库初始数据的录入、转换功能、数据库的转储、恢复功能、
数据库的重组织和性能监视、分析功能等。一般由DBMS中的一些实
用程序完成。
Haichang Gao , Software School , Xidian University
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DataBase System
Database System
 Database System: A computerized record-keeping systems,
composed by Data, Hardware, Software and People
User
User
User
Application
Development Tools
DBMS
DBA
OS
DB
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DataBase System
Components of Database System
 Data

Anything that is of significance to the individual or
organization concerned

Two characters
integrated - needn’t include redundant information
shared – a record file should be shared by different user

Multi-views
 Hardware

Secondary storage volume
I/O device, Device controller, I/O channel, etc

Processor and Main memory
Haichang Gao , Software School , Xidian University
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DataBase System
Components of Database System
 Software

OS
Unix，Linux, OS/2, Windows NT …

Database Management System
Oracle, DB2, Sybase, MySQL, PostgreSQL, …

Others software
utilities, application development tools, designs aid,
report writer, transaction manager
Haichang Gao , Software School , Xidian University
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DataBase System
Components of Database System

People



End users—Interactive users.
 Casual users (临时用户):facility with SQL…
 Naive users (初级用户): bank clerks…
Application programmers
 An application programmer, in the sense used with
DBMS, writes the menu applications used by naive
users.
DBA (database administrator)
 A DBA is a computer professional responsible for
the design and maintenance of the database.
Haichang Gao , Software School , Xidian University
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DataBase System
题外：数据库领域的三位图灵奖得主
 Charles W. Bachman(查尔斯 • 巴赫曼) 1973
 主持设计与开发了最早的网状数据库管理系统
IDS，它的设计思想和技术直接影响了后来的
数据库。他还促成了数据库标准的制定，即
DDL和DML规范说明。
 Edgar F. Codd(埃德加 • 科德) 1981
 于1970年6月发表了题为“A Relational Model of
Data for Large Shared Data Banks”一文，首次
明确而清晰地为数据库系统提出了一种崭新的模
型，即关系模型。一经提出迅速商品化。
 James Gray(詹姆斯 • 格雷) 1998
 在事务处理技术上的创造性思维和开拓性工作，
使他成为该技术领域公认的权威。在解决保障
数据的完整性、安全性、并行性，以及从故障
中恢复方面发挥了十分关键的作用。
Haichang Gao , Software School , Xidian University
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DataBase System
Unit 1 Introduction
 Data
& Database
 DBMS
 Database
System
 Database
Applications
 Brief
History of Data Management
Haichang Gao , Software School , Xidian University
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DataBase System
Database Applications
Database contains information about a particular
enterprise.
 Database Applications:
 Banking:
all transactions
 Airlines: reservations,
schedules
 Universities: registration, grades
 Sales:
customers, products, purchases
 Manufacturing:
 Human
production, inventory, orders, supply chain
resources: employee records, salaries, tax deductions
 ……
Databases touch all aspects of our lives
Haichang Gao , Software School , Xidian University
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DataBase System
Database Applications Architecture
 Client/Server architecture
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DataBase System
Database Applications Architecture
 Browser/Server architecture
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DataBase System
Brief History of Data Management
 In the early days(Before 1960s), database applications were
built on top of FILE systems
Prog1
Prog2
Progn
File1
File System
File2
Filen
Haichang Gao , Software School , Xidian University
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DataBase System
Brief History of Data Management
 Drawbacks of using FILE SYSTEMS :
 Data
redundancy and inconsistency(不一致性)
 Difficulty in
 Data
accessing data
isolation
 Integrity
problems
 Atomicity
of updates
 Concurrent
 Security
access by multiple users
problems
It’s impossible to programmers for even ONE solution!
Haichang Gao , Software School , Xidian University
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DataBase System
Brief History of Data Management
 Management using DBMS
 Database systems offer solutions to all the above problems in
using file systems !
Prog1
DB
Prog2
DBMS
Progn
Haichang Gao , Software School , Xidian University
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DataBase System
History of Database System
 Hierarchical system
(1960s)

IBM’s IMS

data represent to user is the form of tree structure

IMS provided the hierarchical data model, where different
kinds of records relate to one another in a hierarchical
form.

data shared by several applications
R1
R2
R4
R3
R5
Haichang Gao , Software School , Xidian University
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DataBase System
Example of Hierarchical system
学院
教研室
D01
通信工程
主楼II区
R0101
信息科学研究所
D02
电子工程
主楼III区
R0102
信息保密研究所
D03
计算机
主楼I区
……
……
……
R0301
应用教研室
R0302
软件实践中心
…… ……
R0303 软件教研室
……
教师
用指针实现记
录间的联系！
E0102
王大明
男
E0103
李明丽
女
……
……
……
E0313
陈芝
女
E0315
孟正堂
男
……
……
……
……
Haichang Gao , Software School , Xidian University
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DataBase System
History of Database System
 Network

System (1960s)
Cullinet Software IDMS (CODASYL DBTG Report)
The network data model, a generalization of the
hierarchical model where a set of record in one layer might
have two different containing hierarchies at the next layer
up.
Bachman
 data represent to user is graph structure


operator similar to hierarchical system
Haichang Gao , Software School , Xidian University
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DataBase System
Example of Network System
S
S001
S002
S003
……
SC
李小明
张娜
王杰
……
CS
CS
CS
…
S001
S001
S002
S002
S003
S003
……
C
C01
C02
C01
C02
C01
C02
…..
80
78
65
84
91
85
…
…
C01 高等数学
3
C02 计算机原理 4
… ……
…
…
Haichang Gao , Software School , Xidian University
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DataBase System
History of Database System
 Relational
system (1970s)
 data representation are table, operator generate new tables
from old tables
 In a relational database, all information is represented in
the form of named tables (relation) with labeled column
(attribute)
 In the relational model, a column of a table must contain a
single, unstructured value(first normal form rule)
 Products : SQL server, Oracle, Sybase, DB2, Informix,
Ingres, etc.
Codd
Haichang Gao , Software School , Xidian University
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DataBase System
Example of Relational System
enrollment (注册)
students
sid
1
2
3
4
lname
Jones
Smith
Brown
White
fname
Allan
John
Harry
Edward
class
2
3
2
3
tel
88201234
88201233
88202255
88201688
courses
cno
101
102
105
108
cname
English I
English II
Math
Chinese
croom
I-101
I-102
II-101
II-202
sid
cno
major
1
1
2
3
3
4
4
101
108
105
101
108
102
105
No
Yes
No
Yes
No
No
No
time
MW2
MW3
MW2
MW4
Haichang Gao , Software School , Xidian University
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DataBase System
History of Database System
 Object-Relational system
(1980s)

In an object-relational database, information is still
represented as in the relational model in the form of
named tables with labeled columns

but the column values are no longer restricted by the First
Normal Form rule (can be STRUCT or SET datatype).
Haichang Gao , Software School , Xidian University
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DataBase System
Example of ORDBMS
students
name
Sid
enrollment
class
lname
tel
fname
cno
1
Jones
Allan
2
88201234
2
3
Smith
Brown
John
Harry
3
2
88201233
88202255
4
White
Edward
3
88201688
101
108
105
101
108
102
105
major
No
Yes
No
Yes
No
No
No
courses
cno
101
102
105
108
cname
English I
English II
Math
Chinese
croom
I-101
I-102
II-101
II-202
time
MW2
MW3
MW2
MW4
Haichang Gao , Software School , Xidian University
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DataBase System
History of Database System
 1990s:
 Large
decision support and data-mining applications
 Large
multi-terabyte data warehouses
 Emergence
of Web commerce
 2000s:
 XML
and XQuery standards
 Automated
database administration
Haichang Gao , Software School , Xidian University
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