module 3

Question 1

database

Answer 1

collection of related data that is stored ina central location or in multiple locations

Question 2

data hierarchy

Answer 2

structure and organization of data, which involves fields, records and files

Question 3

database management system (DBMS)

Answer 3

software for creating, sorting, maintaining and accessing database files

Question 4

internal data

Answer 4

stored in the organizations internal databases and can be used by functional info systems
ex: transactions, sales, personnel records

Question 5

external data

Answer 5

stored in a data warehouse
ex: competitors, cxs, tax records

Question 6

sequential access file structure

Answer 6

records are organized and processed in a numerical or sequential order
records are organized based on a primary key
used for backup and archive files
typically stored on magnetic tape

Question 7

random access file structure

Answer 7

records can be accessed in any order, regardless of their physical locations in storage media
fast and very effective when a small number or records need to be processed daily or weekly
records are stored on magnetic disks to achieve speed

Question 8

indexed sequential access method (ISAM)

Answer 8

records accessed sequentially or randomly, depending on the amount
- random access: small numbers of records
- sequential access: large number of records

uses an index structure with two parts
- indexed value
-pointer to the desk location of the record matching the indexed value

Question 9

physical view

Answer 9

how data is stored on and retrieved from storage media (hard disks and magnetic tapes)

Question 10

logical view

Answer 10

how info appears, and is organized and retrieved

Question 11

data model

Answer 11

determines how data is created, represetned, organized and maintained

• data structure
• operations
• integrity rules

Question 12

hierarchical model

Answer 12

relationships (or branches) between records (or nodes)

Question 13

network model

Answer 13

similar to hierarchical model but organized differently
each record can have multiple parent and child records

Question 14

relation model

Answer 14

uses a 2d table table or rows and columns of data

rows are records
columns are fields

Question 15

data dictionary

Answer 15

stores definitions

field name, field data type, default value and validation rule

Question 16

primary key

Answer 16

uniquely identifies every record

Question 17

foreign key

Answer 17

a key of a child table that links to primary key of parent table
used to establish relationship between tables

Question 18

normalization

Answer 18

eliminates redundant data
ensures only related data is stored in a table
first normal form (1NF) to fifth normal form (5NF)

Question 19

operations

Answer 19

process in which data is retrieved from tables
common operations: select, project, join, intersect, union, and difference

Question 20

DBMS software components

Answer 20

database engine
data definition
data manipulation
application generation
data administration

Question 21

database engine

Answer 21

responsible for data storage, manipulation and retrieval

Question 22

data definition

Answer 22

creates and maintains the data dictionary
defines the structure of files in a database

Question 23

data manipulation

Answer 23

used to add, delete, modify and retrieve records
query languages like structured query language (SQL)a

Question 24

application generation

Answer 24

used to create designs elements of an application

Question 25

data administration

Answer 25

used for backup and recovery, secuirty, and change management
used to determine permissions to create, read, update and delete (CRUD)

Question 26

database administrators (DBAs)

Answer 26

handle db design and mgmt
est security measures
develop recvoery procedures
evaluate db performance
add and fine tune db functions

Question 27

distributed database management system (DDBMS)

Answer 27

stores data on multiple servers throughout an org

Question 28

setting up a DDBMS

Answer 28

fragmentation: how tables are divided among multiple locations
replication: each site stores a copy of the data
allocation: combines fragmentation and replication

Question 29

object oriented databases

Answer 29

data and thier relationships are contained in a single object

encapsulation: grouping objects withing their attributes and ethofs
inheritance: new objects can be created faster and more easily by entering new data in attributes

Question 30

data warehouse

Answer 30

collection of data from a variety of sources

used to support decision-making applications
used to generate BIc

Question 31

characteristics of data in a data warehouse

Answer 31

subjected oriented - focused on specific area
integrated - comes from a variety of sources
time variant - categorized based on time
type of data - captures aggreted data
purpose - used for analytical purposes

Question 32

collection of info stored as:

Answer 32

• raw data: info given in itd original form
• summary data: gives users subtotals of various vategories

Question 33

data warehouses use these to generate reports

Answer 33

• online transactiom processing (OLTP)
• online analytical processing
  (OLAP)

Question 34

data mining analysis

Answer 34

used to discover patterns and relationships

Question 35

text mining

Answer 35

used to analyze vast amounts of textual info

Question 36

data mart

Answer 36

smaller versions of data warehouse

Question 37

data lake

Answer 37

gather and stores data in its original format in a central location

Question 38

business analytics

Answer 38

descriptive, predictive, prescriptive

Question 39

five dimensions

Answer 39

volume, varietym veloctiy, varacity and value