1212 CHAPTER DATABASES

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved Competencies Distinguish between the physical and logical view of data Describe how data is organized Describe databases Describe the five data models Distinguish among the different databases Recognize strategic database uses & security concerns

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved Data Facts or observations about people, places, things, and events Two ways to view data Physical view Logical view

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved Data Organization Character Field Record File Database

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved Key Field Unique identifier Common examples Social security number Driver’s license Credit card account

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved Batch Versus Real-Time Processing Batch processing -- later Real-time processing -- now Batch Processing

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved Real-Time Processing

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved Databases Sharing – one department to another Security – passwords to access Less data redundancy Data integrity

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved Database Management DBMS engine Data definition subsystem Data manipulation subsystem Query-by-example Structured query language (SQL) Application generation subsystem Data administration subsystem

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved DBMS Structure Hierarchical database Network database Relational database Multidimensional database Object-oriented database

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved Hierarchical Database Fields or records are structured in nodes Nodes are point connected like branches One parent per node Parent has several child nodes Airlines may use a hierarchical database

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved Network Database Hierarchical node arrangement Many-to-many relationship

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved Relational Database Most flexible Data stored in table or relation Tables related via a common data item Easy to use

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved 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

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved Object-Oriented Database Works with unstructured data Photographs Graphics Audio Video Objects contain both data and instructions

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved Types of Databases Individual or microcomputer database Company or shared Operational User Distributed Proprietary Web database

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved 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

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved A Look to the Future Xperanto Enhancement to searching for data Access to structured (relational databases) and unstructured data (word processing and spreadsheet files)

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved Key Terms application generation subsystem (334) attribute (329) batch processing (330) CGI (Common Gateway Interface) (341) character (329) child node (335) class (338) common data item (337) common operational database (340) common user database (340) company database (339) data (328) data administration subsystem (334) data bank (340)

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved Key Terms database (330) database administrator (DBA) (334) database management system (DBMS) (333) data definition subsystem (333) data dictionary (333) data integrity (332) data maintenance (334) data manipulation subsystem (333) data mining (342) data model (334) data redundancy (332) data warehouse (342) DBMS engine (333)

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved Key Terms distributed database (340) entity (329) field (329) file (330) firewall (343) hierarchical database (335) hyper cube (337) individual database (339) information utility (340) key field (330) logical view (328) many-to-many relationship (335) method (338) microcomputer database (339)

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved Key Terms multidimensional database (337) network database (335) node (335) object (338) object-oriented database (335) one-to-many relationship (335) online processing (331) parent node (335) physical view (328) pointer (335) primary field (330) processing rights (334) proprietary database (340) query-by-example (334)

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved Key Terms real-time processing (331) record (330) relation (336) relational database (336) shared database (336) structured query language (SQL) (334) Web database (341)

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved FAQs What is data? Name the different types of data. What is the difference between a physical and a logical view? What is a key field? What is a relational database? What are the five classifications of databases? What is data mining?

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved Discussion Questions Explain how data is organized. Discuss the difference between batch and real- time processing. Discuss the advantages of using a database. Describe the five DBMS models.