1、Chapter 12,Databases,12-2,Competencies (Page 1 of 2),Distinguish between the physical and logical view of data Describe how data is organized: characters, fields, records, files, and databases Describe databases, database issues, and database management systems (DBMS),Page 344,12-3,Competencies (Pag
2、e 2 of 2),Describe five data models: hierarchical, network, relational, multidimensional, and object-oriented Distinguish among individual, company, distributed, proprietary, and Web databases Recognize strategic database uses and security concerns,Page 344,12-4,Introduction to Databases,Much like a
3、 library, secondary storage is designed to store information. End users need to understand how such stored information is organized using data field, records, files and databases. There are different types of databases and structures. To be a competent user of information in the information age end
4、users need to be able to find information that is stored in databases.,Page 345,12-5,Data,Examples of data include: Facts or observations about people, places, things, and events Audio captured, music captured, photographs and video Two ways to view data Physical view Logical view,Page 346,12-6,Data
5、 Organization,Character Field Record File Table Database Key Field Batch Versus Real-Time Processing,Page 346,12-7,Key Field,Unique identifier also known as primary field Common examples Social security number Student Identification Numbers Employee Identification Numbers Part Numbers Inventory Numb
6、ers,Page 347,Return,12-8,Batch Versus Real-time Processing (Page 1 of 2),Batch processing - data is collected over a period of time and the processing happens later all at one time,Page 348,12-9,Batch Versus Real-Time Processing (Page 2 of 2),Real-time processing - happens immediately when the trans
7、action occurs,Page 348,12-10,Databases,Collection of integrated data logically related files and records Databases address data redundancy and data integrity Need for databases Database Management,Page 349,12-11,Need for Databases,Sharing Security Less data redundancy Data integrity,Page 350,Access
8、data entry form,Return,12-12,Database Management,DBMS engine Data definition subsystem Data manipulation subsystem Query-by-example Structured query language (SQL) Application generation subsystem Data administration subsystem,Page 350,12-13,DBMS Structure,DBMS programs are designed to work with dat
9、a that is logically structured or arranged Data models define rules and standards for data in a database the five widely used data models are: Hierarchical database Network database Relational database Multidimensional database Object-oriented database,Page 352,12-14,Hierarchical Database,Fields or
10、records are structured in nodesNodes are points connected like branches One parent per nodeParent has several child nodes (one-to-many relationship),Page 352,Return,Airline reservation system,12-15,Network Database,Hierarchical node arrangement Each child node may have more than one parent node (Man
11、y-to-many relationship) Additional nodes are called pointers Nodes can be reached through more than one path,Page 353,University Student System,Return,12-16,Relational Database,More flexible Data stored in table called a relation Tables consist of rows and columns Tables related via a common data it
12、em Easy to use,Page 353,Return,12-17,Multidimensional Database,A variation and an extension of the relational model Includes a hyper cube Good for representing complex relationships Advantages over relational Conceptualization Processing speed,Page 354,Return,12-18,Object-Oriented Database,Works wit
13、h unstructured data Photographs Audio Video Objects contain both data and instructions Organize using objects, classes, entities, attributes, and methods,Page 355,12-19,Types of Databases,Individual Company or shared Distributed Proprietary Web,Page 356,12-20,Individual Databases,Also called a micro
14、computer database Integrated file collection for one person usually under the persons direct control Generally stored on the users hard-disk drive or on a LAN file server,Return,Page 368,12-21,Company or Shared Databases,May be stored on a mainframe and managed by a database administrator Provides a
15、ccess to users throughout a company 2 Types of company or shared databases Common operational database Common user database,Return,Page 356,12-22,Distributed Databases,Database is located in a place or places other than where users are located Typically database servers on a client/server network pr
16、ovide the link between users and the distant data,Return,Page 357,12-23,Proprietary Databases,Generally an enormous database developed by an organization to cover particular subjects Access is offered to the public or selected outside individuals for a fee Most proprietary databases are designed for
17、 organizational and individual use Also referred to as information utilities or data banks,Return,Page 357,12-24,Web Databases,Distinguishing feature is that the database is available over the web Web search engines interact with databases Web databases incorporate special interface programs that cr
18、eate input forms, accept input, and send the data to the Web database,Page 357,12-25,Database Uses and Issues,Strategic uses Special type of database called data warehouse Data mining used to search database Security Databases are valuable Protection necessary,Page 358,Electronic fingerprint pads,12
19、-26,Careers In IT,Database administrators determine the most efficient ways to organize and access a companys data Typically responsible for maintaining database security and backing up the system Employers look for individuals with a bachelors degree in computer science and technical experience Dat
20、abase administrators can expect to earn $44K - $81K annually,Page 359,12-27,A Look to the Future Xperanto,Enhancement to searching for data Access to structured (relational databases) and unstructured data (word processing and spreadsheet files),Page 360,12-28,Discussion Questions (Page 1 of 2),Desc
21、ribe the five logical data groups or categories.What is the difference between batch processing and real-time processing?Identify and define the five part of DBMS programs.,Page 369,12-29,Discussion Questions (Page 2 of 2),What are the five types of databases? Why does more than one kind of database exist?What are some of the benefits and limitations of databases? Why is security a concern?,Page 369,
