Mis Lecture 6

Front 1

Bit

Back 1

smallest unit of data; binary digit (0,1)

Front 2

byte

Back 2

group of bits that represent a single character, 8 bits = 1 byte

Front 3

field

Back 3

a group of words or a complete number

Front 4

record

Back 4

group of related fields

Front 5

file

Back 5

group of records of the same type

Front 6

database

Back 6

group of related files

Front 7

entity

Back 7

person, place, thing, event about which information is maintained

Front 8

attribute

Back 8

description of a particlar entity

Front 9

key field

Back 9

indentifier field used to retrieve , update, sort a record

Front 10

data hierarchy

Back 10

bit, byte, field, record, file, database

Front 11

problems with traditional file environment

Back 11

- data redundancy
- data inconsistency
- program-data dependence
- lack of flexibility
- poor security
- lack of data sharing and availablity

Front 12

data redundancy

Back 12

the presence of duplicate data in multiple data files so that the same data are stored in more than one place or location

Front 13

data inconsistency

Back 13

the same attribute may have different values

Front 14

program-data dependence

Back 14

the coupling of data stored in files and the specific programs required to update and maintain those files such that changes in programs require changes to the data

Front 15

lack of flexibility

Back 15

a traditional file system can deliver routine scheduled reports after extensive programming efforts, but it cannot devliver ad-hoc reports or respond to unanticipated information requirements in a timely fashion

Front 16

poor security

Back 16

because there is little control or management of data, management will have no knowledge of who is accessing or even making changes to the organization's data

Front 17

lack of data sharing and availablity

Back 17

information cannot flow freely across different functional area of different parts of the organization. users find different values of teh same piece of information in two different systems, and hece, they may not use these systems because they cannot trust the accuracy of the data

Front 18

Database Management System (DBMS)

Back 18

- software for creating and maintaining databases
- permits firms to rationally manage data for the entire firm
- acts as interface between application programs and physical data files
- separates logical and design views of data
- solves many problems of the traditional data file approach

Front 19

Data definition language (component of DBMS)

Back 19

specifies content and structure of the database and defines each data element

Front 20

data manipulation language
(component of DBMS)

Back 20

used to process data in a database

Front 21

data dictionary
(component of DBMS)

Back 21

stores definitions of data elements and data characteristics

Front 22

types of databases

Back 22

- relational DBMS
- hierarchal and network DBMS
- orbject-oriented databases

Front 23

Relational DBMS

Back 23

- represents data as two-dimensional tables called relations
- relates data across tables based on common data element

Front 24

Three basic operations in a relational database

Back 24

- select
- join
- project

Front 25

select

Back 25

in a relational database, it creates subset of rows that meet specific criteria

Front 26

join

Back 26

in a relational database, combines relational tables to provide users with information

Front 27

project

Back 27

in a relational database,enables users to create new tables containing only relevent information

Front 28

Hierarchical DBMS

Back 28

- organizes data in tree-like structure
- supports one-to-many parent-child relationships
- prevalent in large legacy systems

Front 29

Network DBMS

Back 29

depicts data logically as many-to-many relationships

Front 30

Disadvantages to Hierarchical and Network DBMS

Back 30

- outdated
- less flexible compared to RDBMS
- lack support for ad-hoc and English language-like queries

Front 31

Object-Oriented Databases

Back 31

stores data and procedures as objects that can be retrieved and shared automatically

Front 32

object-relational databases

Back 32

provides capabilities of both object-oriented and relational DBMS

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conceptual design (in designing databases)

Back 33

abstract model of database from a business perspective

Front 34

physical design (in designing databases)

Back 34

detailed description of business information needs

Front 35

entity-relationship diagram (in designing databases)

Back 35

methodology for documenting databases illustrating relationships between database entities

Front 36

normalization

Back 36

process of creating small stable data structures from complex groups of data

Front 37

centralized database

Back 37

used by a single central processor or multiple processors in a client/server network

all corporate data is in one location

security is higher in central environments, risks lower

if data demands are highly decentralized, than a decentralized design is less costly and more flexible

Front 38

distributed database

Back 38

databases can be decentralized either by partitioning or by replicating

Front 39

partitioned database

Back 39

database is divided into segments or regions (i.e. eastern customers and western customers - two separate databases maintained in the two regions)

Front 40

duplicated databses

Back 40

database is completely duplicated at two or more locations - the separate databases are synchronized in off hours on a batch basis

Front 41

online analytical processing (OLAP)

Back 41

multidimensional data analysis

supports manipulation and analysis of large volumes of data from multiple dimensions/perspectives

Front 42

database warehouse

Back 42

supports reporting and query tools

stores current and historical data

consolidates data for management analysis and decision making

Front 43

data mart

Back 43

subset of data warehouse

contains summarized or highly focused portion of data for a specified function or group of users

Front 44

data mining

Back 44

tools for analyzing large pools of data

find hidden patterns and infer rules to predict trends

Front 45

benefits of data warehouses

Back 45

imporved and easy accessibility of information

ability to model and remodel the data

Front 46

the web and hypermedia database

Back 46

organizes data as a network of nodes

links nodes in pattern specified by user

supports text, graphic, sound, video, and executable programs

Front 47

database server

Back 47

computer in a client/server environment runs a DBMS to process SQL statements and perform database management tasks

Front 48

application server

Back 48

software handling all application operations