CH.5- Data base systems, data centers, business intelligence Flashcards Preview

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Flashcards in CH.5- Data base systems, data centers, business intelligence Deck (38):
1

Database


-Database: organized collection of data.

- Helps organization achieve its goals.

2

Database Management Systems (DBMS)

-Database management systems (DBMS):

-group of programs that manipulate database
- interface between the database -->users-->programs

3

Database administrator (DBA)

- skilled IS professional
-directs all activities related to database.----> a person
-Like a security guard

4

Character

basic building block of most information, consisting of :
○ upper case letters,
○ lower case letters,
○ numeric digits,
○ special symbols

Characters put together = field

5

Field

-Collection of characters with meaning.
○ a name, number or combination of characters

6

Record

-collection of related data fields all related to one object, activity, individual.

7

File

-Collection of related records.
I.e employee file is a collection of all company employee records

8

Hierarchy of data

(at bottom) bits => characters => fields =>records,
=>files, => databases (at top)

9

Entity

Grouping similar items.
○ general class of ppl, places, things for which data collected, stored, maintained.
○ i.e employees, investory, customers

10

Attribute

• Attribute: Characteristic of an entity.
○ Employee 1st name, last name, hire date,department number are attributes for an employee

11

Data Item

specific value of an attribute

12

Key

field or set of fields in a record used to identify the record

13

Primary Key

field or set of fields that uniquely identifies the record (I.e an item number)
• No other record can have the same primary key

14

Traditional approach to data mgmt
Database approach to data mgmt

traditional: used data files dedicated to that system

Database approach: pool of related data shared by variety of information systems

15

Data Centre
-Traditional
-Modular

climate controlled building/set of bldgs that keep database servers and systems
- Traditional- rows
-Modular- shipping Containers

16

Planned database redundancy

way of organizing data so that logical database design altered so that certain data entities combined, summary totals carried in the data record instead of calculated from elemental data, some data attributes repeated in more than one data entity to improve database performance.

17

Data Model

diagram of entities and their relationships

18

Entity relationship diagram (ER)

Data model ,uses graphical symbols to show organization of + relationships between data

○ Boxes = data items or entities
○ Diamonds = relationships betwen data items and entities
○ ER diagrams show data items in tables (entities ) and how they are related

19

Relational Model

-database model that describes data,
-all data placed in 2 dimensional tables (relations) -->logical equivalent of files

20

Domain

Allowable values for data attributes

21

Querying relational data model:

-SELECTING
-PROJECTING
-JOINING
-LINKING

22

Querying relational data model: Selecting

Manipulating data to eliminate rows according to certain data (i.e eliminate all rows except the one with the data u need)

23

Querying relational data model: Projecting

Manipulating data to eliminate columns in a table (i.e eliminate all columns except the one with the data u need)

24

Querying relational data model: Joining

combining 2 or more tables

25

Querying relational data model: Linking

Linking tables with common attributes

26

Data clean up

process of looking for and fixing inconsistencies to ensure data is accurate and complete

27

Flat File

Simple data base program whose records have no relationship to one another
-store and manipulate single table or file

28

Single User

database installed on personal computer for single user

29

Multiple Users

Allows dozens or hundreds of ppl to access the same database system at same time

30

Schema

description of entire database

31

Data definition Language

instructions + commands to define and describe data and relationships in database

32

Data dictionary

detailed description of all the data used in the database

33

Concurrency Controls

2 or more users or applications need to access same record at same time

34

Data manipulation language (DML)

language provided with DBMS that allows users to: -access and modify the data,
-make querries, a
-generate

35

Structured query language (SQL)

STANDARD QUERY LANGUAGE FOR RELATIONAL DATABASES

36

DATABASE OUTPUT

a database application that offers sophisticated formatting and optimization options to produce the right information in the right format.

37

database administrator (DBA)

role is to plan, design, create, operate, secure, monitor, and maintain databases

38

DATA ADMINISTRATOR

-non technical position responsible for defining and implementing consistent principles for a variety of data issues
- Incl setting data standards and data definitions that apply across all databases in org.

- Work with business managers to identify who should have read or update access to certain databases.