Unit 8-databases

Question 1

File based approach

Answer 1

Data stored in files with separate data items stored in different places for certain topics

Question 2

Field

Answer 2

One item/column about one thing, E.G.one column for student names

Question 3

Primary key

Answer 3

Unique identifier

Question 5

Table/relation

Answer 5

All the data about one entity

Question 7

Record/tuple

Answer 7

Data in one row of the table

Question 8

Relational database

Answer 8

Similar to file base structure but recorded into tables

Question 9

Attribute

Answer 9

Column/field in the table

Question 12

Data item

Answer 12

Individual data thing

Question 13

Candidate Key

Answer 13

Unique Identifier

Question 14

Secondary key

Answer 14

Alternative primary key that wasn’t chosen for some reason

Question 15

Foreign key

Answer 15

Attributes of one table that link to the primary key of another table

Question 16

Composite key

Answer 16

Made up of two un-unique attributes to make a new, unique attribute

Question 17

Advantages of a relational database

Answer 17

Data redundancy reduced
Data only changed once and is automatically updated everywhere
Data independent of the app.s, so doesn’t affect them and makes it more easily available

Question 18

Data management

Answer 18

Organising and managing the DBs data

Question 19

Data dictionary

Answer 19

Contains the DB metadata

Question 20

Logical schema

Answer 20

Specific database model used to build DB and independent from the DBMS

Question 21

Data modelling

Answer 21

Way of showing DB structure like E-R diagrams

Question 22

DBMS

Answer 22

Provides security like:
Access rights that’s limited based on user
Automatic audit trail
Usernames and (strong) passwords
Data encryption
Regular backup
Also uses query processors and developer interface (using SQL)