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Learn about managing files, database management systems, models, data mining, digital economy impact, and artificial intelligence. Explore key concepts, components, models, data mining techniques, e-commerce trends, and AI applications.
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DATABASES 6 Chapter
Chapter Topics 8.1 Managing Files 8.2 Database Management Systems 8.3 Database Models 8.4 Data Mining 8.5 Databases & the Digital Economy 8.6Artificial Intelligence
8.1 Managing Files Basic Concepts
A database is a logically organized collection of related data designed and built for a specific purpose • File (table): collection of related records • Records (row): collections of related fields • Field (column): unit of data containing 1 or more characters • Character [Byte]: a letter number or special character made of bits • Bit: 0 or 1
Key Field (primary key) – the field that uniquely identifies a record • Often an identifying number, such as social security number or a student ID number • Keys are used to sort records in different ways • Primary keys must be unique make records distinguishable from one another • Foreign keys appear in other tables and usually refer to primary keys in particular tables; they are used to relate one table to another (to cross-reference data)
Database Management System (DBMS) • Software written specifically to control the structure of a database and access to the data • DBMS benefits: • Reduced data redundancy (redundant data is stored in multiple places, which causes problems keeping all the copies current) • Speed—Modern DBMSs are much faster than manual data-organization systems • Improved data integrity—The data is accurate, consistent, and up to date • Timeliness—The data can be supplied in a timely fashion—when people need it. • Ease of sharing—The data in a database is usually shared over a network by an entire organization.
Ease of data maintenance—DBMS offers backup utilities, and standard procedures for data inserting, updating, and deletion. • Forecasting capabilities—DBMSs can hold massive amounts of data that can be studied, and compared in order to forecast behaviors in markets and to support the decision making process. • Increased security—Although various departments may share data, access to specific information can be limited to selected users—called authorization control.
3 Principal Database Components • Data Dictionary • Repository that stores the data definitions and descriptions of the structure of the data and the database • DBMS Utilities • Programs that allow you to maintain the database by creating, editing, deleting data, records, and files • Report Generator • Program for producing on-screen or printed readable documents from all or part of a database
Hierarchical Database • Fields or records are arranged in related groups resembling a family tree with child (low-level) records subordinate to parent (high-level) records • Network Database • Similar to a hierarchical database but more flexible-- each child record can have more than one parent record • Object-Oriented Database • An object consists of: • Data in any form, including audio, graphics, and video • Instructions on the action to be taken with the data
Relational Database • Data stored in tables (relations, or files) of rows (tuples, or records) and columns (attributes, or fields) • More flexible than previous models; built with SQL • Example for large systems is Oracle • Example for microcomputers is Microsoft Access • Users employ SQL (structured query language) to create, modify, maintain, and query the database
Data mining is the computer-assisted process of sifting through and analyzing vast amounts of data to extract hidden patterns and meaning and to discover new knowledge • Data and meta-data (data about the data) are transported to a data warehouse after some data fusion and data cleansing processes • Data warehouse is a special database of cleaned-up data and meta-data
E-Commerce (Electronic Commerce) • The buying and selling of products and services through computer networks • Examples of some e-tailers (electronic retailers): • amazon.com sells books and almost everything else • priceline.com sells airline tickets and hotel rooms • dell.com sells computers and other electronic items
Innovative e-tailer technologies make online shopping easier • 360-degree images • Allow you to see all sides of an item • Order tracking • Codes are assigned to items being shipped that allow customers to track shipping progress via the internet • Shop bots • Programs that help users search for a particular product or service and then provide price comparisons
Types of E-Commerce • Business-to-Business (B2B) • A business sells to other businesses using the internet or a private network • Business-to-Consumer (B2C) • A business sells goods or services directly to consumers • Consumer-to-Consumer (C2C) • Consumers sell goods or services directly to other consumers with the help of a third party, such as eBay
AI is a group of related technologies used to develop software and machines that emulate human qualities such as learning, reasoning, communicating, seeing, and hearing • Areas include: • Expert systems • Natural language processing • Pattern recognition • Robotics
Expert Systems • Also called knowledge-based system • Three components of an expert system: • Knowledge base: an expert system’s database of knowledge about a particular subject • Inference engine: the software that controls the search of the expert system’s knowledge base and produces conclusions • User interface: the display screen for the user to interact with the expert system
Natural language processing • Allows users to interact with a system using normal language • The study of ways for computers to recognize and understand human language • Pattern recognition • Involves a camera and software that identify visual patterns by mapping them against similar patterns stored in a database
Robotics • The development and study of machines that can perform work that is normally done by people • Commonly found in factories and also in situations where people would be in danger • Nuclear inspections • Checking for land mines and bombs
Turing Test • In 1950 Allen Turing predicted computers would eventually be able to mimic human thinking • Turing test determines whether the computer is human • Judge is in another location and doesn’t see the computer • Judge converses via a computer terminal with two entities: one a person and one a computer • Judge must determine who is the person and who is the computer • If the computer can fool the judge, it is said to be intelligent • No computer system has yet passed the Turing test