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12 DATABASES McGraw-Hill Technology Education © 2006 by the McGraw-Hill Companies, Inc. All rights reserved. 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 332 CE06_PP12-2 Competencies (Page 2 of 2) Describe the 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 332 CE06_PP12-3 Data Facts or observations about people, places, things, and events Two ways to view data Physical view Logical view Page 334 CE06_PP12-4 Data Organization Field Record File Database Page 334 CE06_PP12-5 Key Field Unique identifier also known as primary field or primary key Common examples Social security number Driver’s license Credit card account Page 336 CE06_PP12-6 Batch Versus Real-time Processing (Page 1 of 2) Batch processing – data is collected over hours, days, etc. Processed all at once as a “batch” Batch Processing Page 336 CE06_PP12-7 Batch Versus Real-Time Processing (Page 2 of 2) Real-time processing -- now Page 338 CE06_PP12-8 Need for Database Management Systems Efficient data access, processing. Less data redundancy Data integrity Sharing – one department to another Security – passwords to access Access data entry form Page 339 CE06_PP12-9 Subsystems of a Database Management System DBMS engine MS Access, MS SQL Server, Oracle Bridge between the logical view and physical view Data definition subsystem Data dictionary: defines types of data in each field Data manipulation subsystem Provides tools for analyzing and maintaining data Query-by-example Structured query language (SQL) Application generation subsystem Create data entry forms interface with common programming languages e.g. visual basic Data administration subsystem Manage the database system: security, backup, recovery, performance monitoring Page 339 CE06_PP12-10 DBMS Structure Data models define rules and standards for data in a database – the five data models are: Hierarchical database Network database Relational database Multidimensional database Object-oriented database Page 340 CE06_PP12-11 Hierarchical Database Fields or records are structured in nodes Nodes are point connected like branches One parent per node Parent has several child nodes (one-to-many relationship) Airline reservation system Return Page 341 CE06_PP12-12 Network Database Hierarchical node arrangement Each child node may have more than one parent node (Many-tomany relationship) Additional nodes are called pointers University Student System Return Page 341 CE06_PP12-13 Relational Database Most flexible Data stored in table called a relation Tables consist of rows and columns Tables related via a common data item Easy to use Return Page 342 CE06_PP12-14 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 Return Page 343 CE06_PP12-15 Object-Oriented Database Works with unstructured data Photographs Graphics Audio Video Objects contain both data and instructions Organize using objects, classes, entities, attributes, and methods Page 344 Return CE06_PP12-16 Types of Databases The five classifications of databases include: Individual or microcomputer database Company or shared Operational User Distributed Web database Page 345 CE06_PP12-17 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 Electronic fingerprint pads Page 348 CE06_PP12-18 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 350 CE06_PP12-19 Discussion Questions (Page 1 of 2) Describe 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. What are the five types of databases? Why does more than one kind of database exist? Page 359 CE06_PP12-20 Discussion Questions (Page 2 of 2) What are some of the benefits and limitations of databases? Why is security a concern? Page 359 CE06_PP12-21 Example— Simple Banking Business Bank has many customers who open and maintain one or more accounts. For each customer Name, address, unique ID, account(s) example For each account Account number, CustomerID, account type, balance example CE06_PP12-22