Principles of Information Systems Eighth Edition Chapter 5 Organizing Data and Information

Principles and Learning Objectives Data management and modeling are key aspects of organizing data and information Define general data management concepts and terms, highlighting the advantages of the database approach to data management Describe the relational database model and outline its basic features Principles of Information Systems, Eighth Edition

Principles and Learning Objectives (continued) A well-designed and well-managed database is an extremely valuable tool in supporting decision making Identify the common functions performed by all database management systems and identify popular user database management systems Principles of Information Systems, Eighth Edition

Principles and Learning Objectives (continued) The number and types of database applications will continue to evolve and yield real business benefits Identify and briefly discuss current database applications Principles of Information Systems, Eighth Edition

Why Learn About Database Systems? Database systems process and organize large amounts of data Examples: Marketing manager can access customer data Corporate lawyer can access past cases and opinions Principles of Information Systems, Eighth Edition

Introduction Database: an organized collection of data Database management system (DBMS): group of programs to manage database Manipulates database Provides an interface between database and the user of the database and other application programs Database administrator (DBA): skilled IS professional who directs all activities related to an organization’s database Principles of Information Systems, Eighth Edition

Data Management Without data and the ability to process it, an organization could not successfully complete most business activities Data consists of raw facts To transform data into useful information, it must first be organized in a meaningful way Principles of Information Systems, Eighth Edition

The Hierarchy of Data Bit (a binary digit): represents a circuit that is either on or off Byte: typically made up of eight bits Character: a byte represents a character; the basic building block of information Can be an uppercase letter, lowercase letter, numeric digit, or special symbol Field: typically a name, number, or combination of characters that describes an aspect of a business object or activity Principles of Information Systems, Eighth Edition

The Hierarchy of Data (continued) Record: collection of related data fields File: collection of related records Database: collection of integrated and related files Hierarchy of data Bits, characters, fields, records, files, and databases Principles of Information Systems, Eighth Edition

The Hierarchy of Data (continued) Figure 5.1: The Hierarchy of Data Principles of Information Systems, Eighth Edition

Data Entities, Attributes, and Keys Entity: generalized class of people, places, or things (objects) for which data is collected, stored, and maintained Attribute: characteristic of an entity Data item: specific value of an attribute Key: field or set of fields in a record that is used to identify the record Primary key: field or set of fields that uniquely identifies the record Principles of Information Systems, Eighth Edition

Data Entities, Attributes, and Keys (continued) Figure 5.2: Keys and Attributes Principles of Information Systems, Eighth Edition

The Database Approach Traditional approach to data management: separate data files are created and stored for each application program Database approach to data management: a pool of related data is shared by multiple application programs Offers significant advantages over the traditional file-based approach Principles of Information Systems, Eighth Edition

The Database Approach (continued) Figure 5.3: The Database Approach to Data Management Principles of Information Systems, Eighth Edition

The Database Approach (continued) Table 5.1: Advantages of the Database Approach Principles of Information Systems, Eighth Edition

The Database Approach (continued) Table 5.1: Advantages of the Database Approach (continued) Principles of Information Systems, Eighth Edition

The Database Approach (continued) Table 5.2: Disadvantages of the Database Approach Principles of Information Systems, Eighth Edition

Data Modeling and the Relational Database Model When building a database, an organization must consider: Content: What data should be collected and at what cost? Access: What data should be provided to which users and when? Logical structure: How should data be arranged so that it makes sense to a given user? Physical organization: Where should data be physically located? Principles of Information Systems, Eighth Edition

Data Modeling Building a database requires two types of designs Logical design: abstract model of how the data should be structured and arranged to meet an organization’s information needs Physical design: starts from the logical database design and fine-tunes it for performance and cost considerations Principles of Information Systems, Eighth Edition

Data Modeling (continued) Data model: diagram of data entities and their relationships Entity-relationship (ER) diagrams: data models that use basic graphical symbols to show the organization of and relationships between data Principles of Information Systems, Eighth Edition

Data Modeling (continued) Figure 5.4: An Entity-Relationship (ER) Diagram for a Customer Order Database Principles of Information Systems, Eighth Edition

The Relational Database Model Relational model: describes data in which all data elements are placed in two-dimensional tables, called relations, that are the logical equivalent of files Each row of a table represents a data entity Columns of the table represent attributes Domain: allowable values for data attributes Principles of Information Systems, Eighth Edition

The Relational Database Model (continued) Figure 5.5: A Relational Database Model Principles of Information Systems, Eighth Edition

The Relational Database Model (continued) Selecting: eliminates rows according to certain criteria Projecting: eliminates columns in a table Joining: combines two or more tables Linking: manipulating two or more tables that share at least one common data attribute to provide useful information and reports Principles of Information Systems, Eighth Edition

The Relational Database Model (continued) Figure 5.6: A Simplified ER Diagram Showing the Relationship Between the Manager, Department, and Project Tables Principles of Information Systems, Eighth Edition

The Relational Database Model (continued) Figure 5.7: Linking Data Tables to Answer an Inquiry Principles of Information Systems, Eighth Edition

The Relational Database Model (continued) Data cleanup: process of looking for and fixing inconsistencies to ensure that data is accurate and complete Eliminate redundancies and anomalies Principles of Information Systems, Eighth Edition

The Relational Database Model (continued) Table 5.3: Fitness Center Dues Principles of Information Systems, Eighth Edition

The Relational Database Model (continued) Table 5.4: Fitness Center Members Table 5.5: Dues Paid Principles of Information Systems, Eighth Edition

Database Management Systems (DBMSs) Creating and implementing the right database system ensures that the database will support both business activities and goals DBMS: a group of programs used as an interface between a database and application programs or a database and the user Principles of Information Systems, Eighth Edition

Overview of Database Types Flat file Simple database program whose records have no relationship to one another Single user Only one person can use the database at a time Examples: Access, FileMaker, and InfoPath Multiple user Allows dozens or hundreds of people to access the same database system at the same time Examples: Oracle, Sybase, and IBM Principles of Information Systems, Eighth Edition

Providing a User View Schema: description of the entire database Typically used by large database systems to define tables and other database features associated with a person or user A DBMS can reference a schema to find where to access the requested data in relation to another piece of data Principles of Information Systems, Eighth Edition

Creating and Modifying the Database Data definition language (DDL): collection of instructions and commands used to define and describe data and relationships in a specific database Allows the database’s creator to describe the data and relationships that are to be contained in the schema Data dictionary: detailed description of all the data used in the database Principles of Information Systems, Eighth Edition

Creating and Modifying the Database (continued) Figure 5.10: Using a Data Definition Language to Define a Schema Principles of Information Systems, Eighth Edition

Creating and Modifying the Database (continued) Figure 5.11: A Typical Data Dictionary Entry Principles of Information Systems, Eighth Edition

Storing and Retrieving Data When an application program requests data from the DBMS, the application program follows a logical access path When the DBMS goes to a storage device to retrieve the requested data, it follows a path to the physical location (physical access path) where the data is stored Principles of Information Systems, Eighth Edition

Storing and Retrieving Data (continued) Figure 5.12: Logical and Physical Access Paths Principles of Information Systems, Eighth Edition

Manipulating Data and Generating Reports Data manipulation language (DML): commands that manipulate the data in a database Structured Query Language (SQL) Adopted by the American National Standards Institute (ANSI) as the standard query language for relational databases Once a database has been set up and loaded with data, it can produce reports, documents, and other outputs Principles of Information Systems, Eighth Edition

Manipulating Data and Generating Reports (continued) Table 5.6: Examples of SQL Commands Principles of Information Systems, Eighth Edition

Database Administration Role of the database administrator (DBA): plan, design, create, operate, secure, monitor, and maintain databases DBA works with both users and programmers A data administrator is responsible for defining and implementing consistent principles for a variety of data issues, including setting data standards and data definitions; a nontechnical position Principles of Information Systems, Eighth Edition

Popular Database Management Systems Popular DBMSs for end users include Microsoft’s Access and FileMaker Pro Complete database management software market includes: Software for professional programmers Databases for midrange, mainframe, and supercomputers Examples of open-source database systems: PostgreSQL and MySQL Many traditional database programs are now available on open-source operating systems Principles of Information Systems, Eighth Edition

Special-Purpose Database Systems Some specialized database packages are used for specific purposes or in specific industries Israeli Holocaust Database (www.yadvashem.org) Hazmat database Art and Antique Organizer Deluxe Special-purpose database by Tableau can be used to store and process visual images Principles of Information Systems, Eighth Edition

Selecting a Database Management System Important characteristics of databases to consider Database size Database cost Concurrent users Performance Integration Vendor Principles of Information Systems, Eighth Edition

Using Databases with Other Software DBMSs can act as front-end or back-end applications Front-end applications interact directly with people or users Back-end applications interact with other programs or applications Principles of Information Systems, Eighth Edition

Database Applications Today’s database applications manipulate the content of a database to produce useful information Common manipulations are searching, filtering, synthesizing, and assimilating the data contained in a database using a number of database applications Principles of Information Systems, Eighth Edition

Linking Databases to the Internet Linking databases to the Internet is important for many organizations and people Semantic Web Developing a seamless integration of traditional databases with the Internet Allows people to access and manipulate a number of traditional databases at the same time through the Internet Principles of Information Systems, Eighth Edition

Data Warehouses, Data Marts, and Data Mining Data warehouse: database that collects business information from many sources in the enterprise, covering all aspects of the company’s processes, products, and customers Data mart: subset of a data warehouse Data mining: information-analysis tool that involves the automated discovery of patterns and relationships in a data warehouse Principles of Information Systems, Eighth Edition

Data Warehouses, Data Marts, and Data Mining (continued) Figure 5.17: Elements of a Data Warehouse Principles of Information Systems, Eighth Edition

Data Warehouses, Data Marts, and Data Mining (continued) Table 5.8: Common Data-Mining Applications Principles of Information Systems, Eighth Edition

Business Intelligence Business intelligence (BI): process of gathering enough of the right information in a timely manner and usable form and analyzing it to have a positive impact on business strategy, tactics, or operations Turns data into useful information that is then distributed throughout an enterprise Principles of Information Systems, Eighth Edition

Business Intelligence (continued) Competitive intelligence: aspect of business intelligence limited to information about competitors and the ways that knowledge affects strategy, tactics, and operations Counterintelligence: steps an organization takes to protect information sought by “hostile” intelligence gatherers Principles of Information Systems, Eighth Edition

Distributed Databases Database in which the data may be spread across several smaller databases connected via telecommunications devices Gives corporations more flexibility in how databases are organized and used Replicated database Database that holds a duplicate set of frequently used data Principles of Information Systems, Eighth Edition

Online Analytical Processing (OLAP) Software that allows users to explore data from a number of different perspectives Principles of Information Systems, Eighth Edition

Online Analytical Processing (OLAP) (continued) Table 5.9: Comparison of OLAP and Data Mining Principles of Information Systems, Eighth Edition

Object-Oriented and Object-Relational Database Management Systems Object-oriented database: database that stores both data and its processing instructions Method: procedure or action Message: request to execute or run a method Principles of Information Systems, Eighth Edition

Object-Oriented and Object-Relational Database Management Systems (continued) Object-oriented database management system (OODBMS): group of programs that manipulate an object-oriented database and provide a user interface and connections to other application programs Object-relational database management system (ORDBMS): DBMS capable of manipulating audio, video, and graphical data Principles of Information Systems, Eighth Edition

Visual, Audio, and Other Database Systems Databases for storing images Databases for storing sound Virtual database systems: allow different databases to work together as a unified database system Other special-purpose database systems Spatial data technology: stores and accesses data according to the locations it describes and permits spatial queries and analysis Principles of Information Systems, Eighth Edition

Summary Database: a collection of integrated and related files Hierarchy of data: bits, characters, fields, records, files, and databases Key: a field or set of fields in a record that is used to identify the record Database approach to data management: a pool of related data is shared by multiple application programs Data model: diagram of entities and relationships Principles of Information Systems, Eighth Edition

Summary (continued) Relational model: describes data in which all elements are placed in two-dimensional tables called relations Database management system (DBMS): group of programs used as an interface between a database and application programs or a database and the user Role of the database administrator (DBA): plan, design, create, operate, secure, monitor, and maintain databases Principles of Information Systems, Eighth Edition

Summary (continued) Data warehouse: database that collects business information from all aspects of a company’s processes, products, and customers Data mining: information-analysis tool for the automated discovery of patterns and relationships in a data warehouse Object-oriented database: database that stores both data and its processing instructions Principles of Information Systems, Eighth Edition