1、2 Required:A First Course in Database Systems,by Jeffrey D.Ullman Jennifer Widom.Recommended:萨师煊,王珊.数据库系统概论(第三版).高等教育出版社,2000 年 Books on SQL Server 2000 You may also want:Books on design and programming:Powerbuilder,PowerDesigner,UML,VB,Delphi,VC,JAVA,C#,ASP,PHP,JSP etc.3 More computer English words
2、 More advanced and newest information Better information retrieval capability More international communication chance4 Basic theories(basic)System and database design(designer)Application Programming(programmer)Database management and maintenance(database manager)5 Background and history of database
3、 management systems Fundamentals of using a database management systems:SQL 2000.(*extracurricular)Database modeling Relational model:theoretical background and operations Database Language SQL Fundamentals of database management systems:transactions and security etc.Database system design and pract
4、iceEvolution of Database SystemsArchitecture of DBMS and DBSFuture of Database Systems71.1.1 Some Basic notions Data Database(DB)Database Management System(DBMS)Database System(DBS).Database Administrator(DBA)8 Data Distinct pieces of information represented in a form suitable for processing by comp
5、uter.Data can exist in a variety of forms-as digital numbers,text,image,sound,video and etc.Database(DB)In essence,its nothing more than a collection of information that exists over a long period of time.In common parlance,it refers to a collection of data managed by a database management system(DBM
6、S)or just database system(DBS).910 Database Management System(DBMS)A collection of programs that enables you to store,modify,and extract information from a database.There are many different types of DBMSs,ranging from small systems that run on personal computers to huge systems that run on mainframe
7、s.11 Data definition Allow creating new databases and specify their schema(logical structure of the data),via data definition language(DDL).Data manipulation Allow efficient access to the data,such as querying and modifying the data,via query language or data manipulation language(DML).Operation man
8、agement of DB Support the storage of very large amounts of data over a long period of time,assuring data integrity,keeping data secure from accident or unauthorized use.Support concurrent,atomic access to data.Creation and maintenance of DB Such as inputting and transferring of Data,DB backup and re
9、covery,performance monitoring,audit and analysis etc.12 Database System(DBS).DB,DBMS,Development Tools,DB applications,DB Administrator(DBA)and usersDBOSDBMSDeveloping ToolsDB applicationsUserUserDBAHardwareOperating SystemDBMS,Compiling SystemDeveloping ToolsApplication SystemsDBMS in Computer Syst
10、em13 DBA Person who is responsible for management and maintenance of DB.Tasks Database contents and structures Storage structure and access methods Database security and integration Monitor and improve database performance 14 File systems Problems:limited support to definition of data schema,no dire
11、ctly support to DML(Data Manipulate Language),no support to efficient concurrent,secure access etc.Early DBMS The first commercial DBMS appeared in the late 1960s,evolved from file systems.The early DBMSs used several data models for describing structure of DB:hierarchical model and network model.Pr
12、oblems:no support to high-level query languages.15 Relational DBMS A famous paper by Ted Codd in 1970,“A relational model for large shared data banks”in Comm.ACM.Data organized as tables called relations.Unlike the user of early DBS,user of a relational system wont be concerned with the storage stru
13、cture,and queries are expressed in a very high-level language(SQL).Today used in most DBMSs.16 Based on tables,such as:acct#namebalance12345Sally1000.2134567Sue285.48 Attributes(column headers)Tuples(rows)17EmployeeNameDeptDepartmentDeptManagerSELECT ManagerFROM Employee,DepartmentWHERE Employee.nam
14、e=Clark Kent”AND Employee.Dept=Department.Dept;18 Data model:abstraction of data features in real world into computer world.Hierarchical model 60s70s80s90snowRelational modelChoice for most new applicationsObject Bases modelKnowledge Bases modelNetwork model19 Relational model is good for:Large amou
15、nts of data simple operations Navigate among small number of relations Difficult Applications for relational model:VLSI Design(CAD in general)CASE:Computer-Aided Software Engineering Graphical Data Where number of relations is large,relationships are complex Object Data Model Logic Data Model20 Obje
16、ct data model Usually find objects via explicit navigation,also query language in some systems Complex Objects Nested Structure(pointers or references)Encapsulation,set of Methods/Access functions Object Identity Inheritance Defining new classes like old classes Logic data model Prolog,Datalog More
17、power than relational21 Relational DBMS companies are among the largest software companies in the world.IBM offers its relational system.With IMS,a nonrelational system,IBM is by some accounts the largest DBMS vendor in the world.Microsoft offers,plus for the cheap DBMS on the desktop,answered by“li
18、te”systems from other competitors.Relational companies also challenged by“object-oriented DB”companies.But countered with“object-relational”systems,which retain the relational core while allowing type extension as in OO systems.22 Major components of a DBMSDataMetadataStorage ManagerQuery ProcessorT
19、ransactionManagerSchemaModificationsQueriesModificationsSchema(logical structure of the data);Metadata(data of data)23Three Schema Architecture of DBS External Schema:user schema or subschema Defines one view of the data as seen by a specific set of application or end users.There may be many externa
20、l schemas in a DB.Schema:conceptual schema,logical schema Defines data from perspective systems designer;Independent of end users&data storage mechanism There is only one conceptual schema in a DB.Internal Schema:storage schema Defines how data is organized,stored and manipulated inside the system.T
21、otally dependent on particular implementation.There is only one internal schema in a DB.24ApplicationAExternal Schema 1SchemaInternal SchemaDBApplicationBApplicationDApplicationEApplicationCExternal Schema 2External Schema 325 Logical Independence Via Reflection of External Schema/Schema One Schema
22、corresponds to many External schemas;every Ex-Schema has an Ex-Schema/Schema Reflection.When Schema changes,DBA changes the Ex-Schema/Schema reflections,so application programs neednt been changed.Physical Independence Via Reflection of Schema/Internal Schema Schema/Internal Schema Reflection is uni
23、que.When Internal Schema changes,DBA changes the Schema/Internal Schema Reflection,so application programs neednt been changed.26 Modeling and design of databases Allows exploration of issues before committing to an implementation.Application programming SQL:queries and DB operations like update.Hos
24、t language and Embedded SQL DBMS implementation Storage,query processing,transaction,27 A First Course in Database Systems:Required:1.1 Recommended:1.2,1.5 数据库系统概论 推荐：第一章28(Required,in English)Explain the following notions and give an example to show them clearly.DB,DBMS,DBS 以下选做：以下选做：(推荐作业，中文完成推荐作业，中文完成)逻辑独立性和物理独立性是什么含逻辑独立性和物理独立性是什么含义？在数据库系统架构中是如何保证这两个独立性的？义？在数据库系统架构中是如何保证这两个独立性的？(建议作业，中文完成建议作业，中文完成)对数据库技术发展趋势、主流数据对数据库技术发展趋势、主流数据库产品、流行数据库开发和设计技术进行调研，撰写小论库产品、流行数据库开发和设计技术进行调研，撰写小论文，和同学分组讨论。文，和同学分组讨论。
