1 technology in action chapter 11 behind the scenes: databases and information systems copyright ©...
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Technology in ActionTechnology in Action
Chapter 11Chapter 11
Behind the Scenes: Behind the Scenes: Databases and Information SystemsDatabases and Information Systems
Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall
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Advantages of Using DatabasesAdvantages of Using Databases• Store and retrieve
large quantities of information efficiently and effectively
• Enable information sharing
• Provide data centralization
• Promote data integrity
• Allow for flexible use of data
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Disadvantages of DatabasesDisadvantages of Databases
• Complex to construct
• Time consuming
• Expensive
• Privacy concerns
• Compared to what?
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Database TerminologyDatabase Terminology
• Field: Category of information, displayed in columns
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Database TerminologyDatabase Terminology• Data type: Type of data that can be
stored in a field
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Database TerminologyDatabase Terminology
• Record: A group of related fields
Record
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Database TerminologyDatabase Terminology
• Table: A group of related records
Table
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Database TerminologyDatabase Terminology
• Primary key: A field value unique to a record
Primary Key
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Database TypesDatabase Types
• Relational databases– Organize data in tables– Link tables to each other through their primary
keys (saves disk space, speeds searches)
• Object-oriented databases– Store data in objects– Also store methods for processing data– Handle unstructured data
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Database TypesDatabase Types
• Multidimensional databases– Store data in multiple dimensions (years)– Organize data in a cube format– Can easily be customized– Process data much faster
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Database Management Database Management Systems (DBMS)Systems (DBMS)
• Application software designed to capture and analyze data
• Five main operations of a DBMS:1. Creating databases and entering data
2. Viewing and sorting data
3. Extracting data
4. Outputting data
5. Analyze data (like reorder inventory)
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Creating Databases and Creating Databases and Entering DataEntering Data
• Create field names– Identify
each type of data
– Data dictionary
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Creating Databases and Creating Databases and Entering Data (cont.)Entering Data (cont.)
• Create individual records– Key in– Import– Input form
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Data ValidationData Validation
• Validation – Process of ensuring that data entered into
the database is correct (or at least reasonable) and complete
• Validation rules– Range checks– Completeness checks– Consistency checks– Alphabetic/numeric checks
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Data ValidationData Validation
• Example of a completeness check
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Viewing and Sorting DataViewing and Sorting Data
• Browse through records
• Sort records by field name
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Extracting or Querying DataExtracting or Querying Data
• Query – A question or
inquiry– Provides
records based on criteria
– Structured Query Language (SQL)
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Outputting DataOutputting Data
• Reports– Printed– Summary data reports
• Export data
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Relational Database OperationsRelational Database Operations• Organize data
into tables• Relationships
are links between tables with related data
• Common fields need to exist between fields
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Types of RelationshipsTypes of Relationships
• One-to-one– For each record in a table, only one
corresponding record in a related table
• One-to-many– Only one instance of a record in one table;
many instances in a related table
• Many-to-many– Records in one table related to many records
in another
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Relational Database OperationsRelational Database Operations
• Normalization of data (recording data once) reduces data redundancy.
• Foreign key: The primary key of one table is included in another to establish relationships with that other table.
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Data StorageData Storage
• Data warehouse– Large-scale
repository of data– Organizes all the
data related to an organization
– Data organized by subject
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• Source data– Internal sources
• Company databases, etc.
– External sources • Suppliers, vendors, etc.
– Customers or Web site visitors • Clickstream data (recording visitor clicks for
analysis of web site)
Populating Data WarehousesPopulating Data Warehouses
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• Data staging– Extract data from source– Reformat the data (e.g., for invoice printing)– Store the data
• Software programs/procedures created to extract the data and reformat it for storage
Data StagingData Staging
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• Small slices of data
• Data for a single department
Data MartsData Marts
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Data Warehouse ProcessData Warehouse Process
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OLAP=Online Analytical Processing
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Managing Data: Managing Data: Information SystemsInformation Systems
• Information systems– Software-based solutions used to gather and
analyze information
• Functions performed by information systems include– Acquiring data– Processing data into information– Storing data– Providing output options
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Information Systems CategoriesInformation Systems Categories
• Office support systems
• Transaction processing systems
• Management information systems
• Decision support systems• Each described below
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Office Support Systems (OSSs)Office Support Systems (OSSs)
• Assist employees in day-to-day tasks
• Improve communications
• Example: Microsoft Office
• Include e-mail, word-processing, spreadsheet, database, and presentation programs
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Transaction Processing Transaction Processing Systems (TPSs)Systems (TPSs)
• Keep track of everyday business activities
• Batch processing
• Real-time processing
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Management Information Management Information Systems (MISs)Systems (MISs)
• Provide timely and accurate information for managers in making business decisions
• Detail report:– Transactions that
occur during a period of time
• Summary report:– Consolidated
detailed data
• Exception report:– Unusual conditions
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Decision Support Systems Decision Support Systems (DSSs)(DSSs)
• Help managers develop solutions for specific problems
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Model Management Systems Model Management Systems
• Software that assists in building management models in DSSs
• Can be built to describe any business situation
• Typically contain financial and statistical analysis tools
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Knowledge-Based SystemsKnowledge-Based Systems
• Expert system: Replicates human experts
• Natural language processing (NLP) system: Enables users to communicate with computers using a natural spoken or written language
• Artificial intelligence (AI): Branch of computer science that deals with attempting to create computers that think like humans
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Enterprise Resource Enterprise Resource Planning SystemsPlanning Systems
• Integrate multiple data sources
• Enable smooth flow of information
• Allow information to be used across multiple areas of an enterprise
• Accumulate all information in a central location
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Data MiningData Mining
• Process by which great amounts of data are analyzed and investigated
• Objective is to spot patterns or trends within the data
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Data Mining MethodsData Mining Methods• Classification
– Define data classes
• Estimation– Assign a value to data
• Affinity grouping or association rules– Determine which data goes together
• Clustering– Organize data into subgroups
• Description and visualization– Get a clear picture of what is happening
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