Chapter 6 Flashcards
Bit
Smallest unit of data a computer can handle
Byte
Group of bit. Single charactere: letter, number, etc..
Field
Grouping of charactere into a word, a group of words, or a complete number / Columns in a relational DBMS
Record
A group of related fields, such as the student’s name, the course taken, the date, and the grade, it is a row in a relational DBMS
File
A Group of related records / A talbe in a relational DBMS
Database
Def 1: Group of related files Def 2: A collection of data organized to serve many applications efficiently by centralizing the data and managing redundant data
Entity
A person, place, thing, or event about which we store and maintain information
Attribute
Characteristic or quality describing a particular entity
Problems with traditional file environment
- Data redundancy and Inconsistency - Program Data dependance - Lack of flexibility - Poor security - Lack of Data Sharing and Availability
Data Redundancy
The presence of duplicate data in multiple data files so that the same data are stored in more than one place or location
Data Inconsistency
The same attribute may have different values
Program–Data Dependence
The coupling of data stored in files and the specific programs required to update and maintain those files so that changes in programs require changes to the data
Lack of flexibility
A traditional file system can deliver routine scheduled reports after extensive programming efforts, but it cannot deliver ad hoc reports or respond to unanticipated information requirements in a timely fashion
Poor security
Because there is little control or management of data, access to and dissemination of information may be out of control
Database Management System (DBMS)
Software that permits an organization to centralize data, manage them efficiently, and provide access to the stored data by application programs It relieves the programmer or end user from the task of understanding where and how the data are actually stored by separating the logical and physical views of the data
Logical View
Presents data as they would be perceived by end users or business specialists
Physical View
Shows how data are actualy organized and structured on physical storage media
Relational DBMS
Represents data as a 2 dimentiona table called relations
Key Field / Primary Key
A field in a record that uniquely identifies instances of that record so that it can be retrieved, updated, or sorted
Foreign Key
a lookup fi eld to look up data about another relational database
3 Operations of the relational database
- Select - Joint - Project
Select operation of a relational database
Creates a subset consisting of all records in the file that meet stated criteria
Join operation of the relational database
Combines relational tables to provide the user with more information than is available in individual tables
Project operation of a relational database
Creates a subset consisting of columns in a table, permitting the user to create new tables that contain only the information required
Multimedia
The integration of two or more types of media such as text, graphics, sound, voice, full-motion video, or animation into a computer-based application
object-oriented DBMS (OODBMS)
Better suited than simple DBSM to handle graphics-based or multimedia applications.It stores the data and procedures that act on those data as objects that can be automatically retrieved and shared
object-relational DBMS
provide capabilities of both object-oriented and relational DBMS
Data Definition
The component of a database management system that defines each data element as it appears in the database
Data Dictionary
an automated or manual file that stores definitions of data elements and their characteristics
data Manipulation Language
A language associated with a database management system that end users and programmers use to manipulate data in the database
Structured Query Language (SQL)
The most prominent data manipulation language today
Normalization
process of creating small, stable, yet flexible and adaptive data structures from complex groups of data
Referential Integrity Rules
ensure that relationships between coupled tables remain consistent
Entity-Relationship Diagram
A methodology for documenting databases illustrating the relationship between various entities in the database
Data Warehouse
Database that stores current and historical data of potential interest to decision makers throughout the company. It consolidates and standardize information which can be easily accessed, but can no longer be altered. Also provides a range of ad hoc and standardized query tools, analytical tools, and graphical reporting facilities
Data Mart
A subset of the data warehouse in which a summarized or highly focused portion of the organization’s data is put in a separate database for a specific population of users
Online aAnalytical Processing (OLAP)
Supports multidimensional data analysis, enabling users to view the same data in different ways using multiple dimensions. Each aspect of information—product, pricing, cost, region, or time period—represents a different dimension
Data mining
Data mining provides insights into corporate data that cannot be obtained with OLAP by finding hidden patterns and relationships in large databases and inferring rules from them to predict future behaviour. The types of information obtainable from data mining include associations, sequences, classifications, clusters, and forecasts
Data mining Association
Occurrences linked to a single event
Data mining Sequences
Findes relationships between events that are linked over time
Data mining Classification
Recognizes patterns that describe the group to which an item belongs by examining existing items that have been classified and by inferring a set of rules
Data Mining Clustering
Can discover different groupings within data
Data Mining Forecasting
It uses a series of existing values to forecast what other values will be
Predctive analytics
Use data mining techniques, historical data, and assumptions about future conditions to predict outcomes of events, such as the probability that a customer will respond to an offer or purchase a specific product
Text Mining
extract key elements from large unstructured data sets, discover patterns and relationships, and summarize the information
Web Mining
The discovery and analysis of useful patterns and information from the World Wide Web
Database server
In a client/ server environment, the DBMS resides on a dedicated computer
Information Policy
specifies the organization’s rules for sharing, disseminating, acquiring, standardizing, classifying, and inventorying information
Data Administration
Is responsible for the specific policies and procedures through which data can be managed as an organizational resource
Data Governance
Deals with the policies and processes for managing the availability, usability, integrity, and security of the data employed in an enterprise, with special emphasis on promoting privacy, security, data quality, and compliance with government regulations
Database Administration
Refers to the more technical and operational aspects of managing data, including physical database design and maintenance
Data Quality Audit
a structured survey of the accuracy and level of completeness of the data in an information system
Data Cleansing
consists of activities for detecting and correcting data in a database that are incorrect, incomplete, improperly formatted, or redundant. It not only corrects errors but also enforces consistency
