Databases and Information Management Information Systems Managing the
Databases and Information Management Information Systems: Managing the Digital Firm, 12 e Authors: Kenneth C. Laudon and Jane P. Laudon Copyright © 2013 Dorling Kindersley (India) Pvt. Ltd. Chapter 6
File Organization Terms & Concepts Record: Group of related fields File: Group of records of same type i. e. entity Entity: Person, place, thing on which we store information. Example: Course, Student, Attribute: Each characteristic, or quality describing entity ○ E. g. , Attributes “Student_ID, Grade” belong to entity “COURSE” Database: Group of related files Management Information Systems: Managing the Digital Firm, 12 e Authors: Kenneth C. Laudon and Jane P. Laudon Copyright © 2013 Dorling Kindersley (India) Pvt. Ltd. Field: Group of characters as word(s) or number e. g. a person’s name, age
FIGURE 6 -2 The use of a traditional approach to file processing encourages each functional area in a corporation to develop specialized applications. Each application requires a unique data file that is likely to be a subset of the master file. These subsets of the master file lead to data redundancy and inconsistency, processing inflexibility, and wasted storage resources. Management Information Systems: Managing the Digital Firm, 12 e Authors: Kenneth C. Laudon and Jane P. Laudon Copyright © 2013 Dorling Kindersley (India) Pvt. Ltd. Traditional File Processing
Problems With The Traditional File Environment • Files maintained separately by different departments cause many problems § Presence of duplicate data in multiple files Data inconsistency: § § Same attribute has different values Same attribute may have different names Application Program-Data Dependence: – Every traditional computer program describes the location and the nature of data – Changes in program requires changes to data accessed by program or vice versa – Programmers have to perform modifications if changes happen Management Information Systems: Managing the Digital Firm, 12 e Authors: Kenneth C. Laudon and Jane P. Laudon Copyright © 2013 Dorling Kindersley (India) Pvt. Ltd. Data redundancy:
Problems With The Traditional File Environment Lack of flexibility - There can be report requirements that must include data from several departments. Poor security - Not possible to track if anyone changes data. Lack of data sharing and availability - Since the software not related in a traditional file environment it is impossible to share data very easily - This situation hinders data availability in a timely manner ØMore on traditional file processing system: http: //ecomputernotes. com/fundamental/what-is-adatabase/traditional-file-processing-system Management Information Systems: Managing the Digital Firm, 12 e Authors: Kenneth C. Laudon and Jane P. Laudon Copyright © 2013 Dorling Kindersley (India) Pvt. Ltd. - A traditional application program can generate report designed for each department.
Database & Database Management Systems (DBMS) • Database Serves many applications by centralizing data and controlling redundant data • Database management system (DBMS) A DBMS is a software that allows an organization to centralize data, manage them efficiently, and provide access to the stored data by application programs Acts as an interface among applications and data files Solves problems of traditional file environment § § § Controls redundancy Eliminates inconsistency Enables organization to centrally manage data and data security Management Information Systems: Managing the Digital Firm, 12 e Authors: Kenneth C. Laudon and Jane P. Laudon Copyright © 2013 Dorling Kindersley (India) Pvt. Ltd. Database technology helps to eliminate many of the problems of the traditional file systems
FIGURE 6 -3 A single human resources database provides many different views of data, depending on the information requirements of the user. Illustrated here are two possible views, one of interest to a benefits specialist and one of interest to a member of the company’s payroll department. Management Information Systems: Managing the Digital Firm, 12 e Authors: Kenneth C. Laudon and Jane P. Laudon Copyright © 2013 Dorling Kindersley (India) Pvt. Ltd. Human Resources Database With Different Views
Relational DBMS Represent data as two-dimensional tables called relations or files Relationships are established among related tables Each table contains data on entity and attributes • Table: grid of columns and rows Rows: Records for different entities Fields (columns): Represents attribute for entity Key field: Field used to uniquely identify each record Primary key: Field in table used for key fields Foreign key: Primary key used in second table as look-up field to identify records from original table Management Information Systems: Managing the Digital Firm, 12 e Authors: Kenneth C. Laudon and Jane P. Laudon Copyright © 2013 Dorling Kindersley (India) Pvt. Ltd. •
FIGURE 6 -4 A relational database organizes data in the form of two-dimensional tables. Illustrated here are tables for the entities SUPPLIER and PART showing how they represent each entity and its attributes. Supplier Number is a primary key for the SUPPLIER table and a foreign key for the PART table. Management Information Systems: Managing the Digital Firm, 12 e Authors: Kenneth C. Laudon and Jane P. Laudon Copyright © 2013 Dorling Kindersley (India) Pvt. Ltd. Relational Database Table
FIGURE 6 -4 (cont. ) A relational database organizes data in the form of two-dimensional tables. Illustrated here are tables for the entities SUPPLIER and PART showing how they represent each entity and its attributes. Supplier Number is a primary key for the SUPPLIER table and a foreign key for the PART table. Management Information Systems: Managing the Digital Firm, 12 e Authors: Kenneth C. Laudon and Jane P. Laudon Copyright © 2013 Dorling Kindersley (India) Pvt. Ltd. Relational Database Table
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