Chapter 12: Databases McGraw-Hill Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved mputing Essentials 2012: Making IT Work for You Competencies (Page of 2) • Distinguish between the physical and logical views of data • Describe how data is organized: characters, fields, records, tables, and databases • Define key fields and compare batch versus real-time processing • Describe databases, including the need for databases, and database management systems (DBMS) McGraw-Hill Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 12-2 mputing Essentials 2012: Making IT Work for You Competencies (Page of 2) • Describe the five common database models: hierarchical, network, relational, multidimensional, and object-oriented • Distinguish among individual, company, distributed, and commercial databases • Discuss strategic database uses and security concerns McGraw-Hill Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 12-3 mputing Essentials 2012: Making IT Work for You Introduction to Databases • Like a 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 – The different types of databases and structures • Competent end users need to be able to find information that is stored in databases McGraw-Hill Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 12-4 mputing Essentials 2012: Making IT Work for You Data • Examples of data include – Facts or observations about people, places, things, and events – Audio, music, photographs, and video • Two ways to view data – Physical view – Logical view McGraw-Hill Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 12-5 mputing Essentials 2012: Making IT Work for You Data Organization • • • • • • • • Character Field Record File Table Database Key Field Batch Versus Real-Time Processing McGraw-Hill Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 12-6 mputing Essentials 2012: Making IT Work for You Key Field • Unique identifier also known as primary field • Common examples – – – – – McGraw-Hill Social Security Number Student Identification Numbers Employee Identification Numbers Part Numbers Inventory Numbers Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 12-7 mputing Essentials 2012: Making IT Work for You Batch Processing • Batch processing – Data is collected over a period of time and the processing happens later all at one time McGraw-Hill Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 12-8 mputing Essentials 2012: Making IT Work for You Real-Time Processing • Real-time processing – Also known as online processing because it happens immediately during the transaction McGraw-Hill Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 12-9 mputing Essentials 2012: Making IT Work for You Databases • Collection of integrated data – Logically related files and records • Databases address data redundancy and data integrity • Need for databases • Database management McGraw-Hill Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 12-10 mputing Essentials 2012: Making IT Work for You Hierarchical Database • Fields or records are structured in nodes • Nodes are points connected like branches • One parent per node; a parent has several child nodes (one-to-many relationship) McGraw-Hill Return Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 12-14 mputing Essentials 2012: Making IT Work for You Network Database • Hierarchical node arrangement • Each child node may have more than one parent node (many-to-many relationship) • Additional nodes are called pointers • Nodes can be reached through multiple paths McGraw-Hill Return Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 12-15 mputing Essentials 2012: Making IT Work for You Relational Database • • • Data stored in table called a relation Tables consist of rows and columns Tables related via a common data item McGraw-Hill Return Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 12-16 mputing Essentials 2012: Making IT Work for You Multidimensional Database • A variation and an extension of the relational model to include additional dimensions, sometimes called a data cube • Good for representing complex relationships • Advantages over relational – Conceptualization – Processing speed McGraw-Hill Return Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 12-17 mputing Essentials 2012: Making IT Work for You Object-Oriented Database • Works with unstructured data – – – Photographs Audio Video • Objects contain both data and instructions • Organize using objects, classes, entities, attributes, and methods McGraw-Hill Return Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 12-18 mputing Essentials 2012: Making IT Work for You Types of Databases • Individual • Company or shared • Distributed • Commercial McGraw-Hill Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 12-19 mputing Essentials 2012: Making IT Work for You Individual Databases • Also called a microcomputer database • Integrated file collection for one person usually under the person’s direct control • Generally stored on the user’s hard-disk drive or on a LAN file server McGraw-Hill Return Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 12-20