CompSci - Databases

Question 1

Database

Answer 1

Contains individual attributes about entities structued in various data structures.

Question 2

Data Consistency

Answer 2

Ensures data is correct by controlling all occurences of the same data item to be updated dynamically.

Question 3

Referential Integrity

Answer 3

Ensuring that foreign keys in tables refer to valid records/tables.

Question 4

Data Redundancy

Answer 4

Ensures that data isn’t duplicated, wasting storage

Question 5

Data Independence

Answer 5

Ensures the database is a separate system from its application so that changes are simpler to make.

Question 6

Atomic Data

Answer 6

Attributes that are broken down into their fundamental parts to maximise flexibility.

Question 7

DBMS

Answer 7

Database Management System

Question 8

DBMS Tools

Answer 8

IQRAMS DUM

Integrity
Queries
Report generation
Access levels
Maintenance
Security

Dictionaires
User interface
Manipulation

Question 9

Primary Key

Answer 9

Unique identifier for an entity

Question 10

Compound Key

Answer 10

Unique identifier with >1 fields for an entity

Question 11

Candidate Key

Answer 11

Any field other than a dedicated ID that can be used as a primary key.

Question 12

Foreign Key

Answer 12

A primary key from another table to represent a relationship between the objects

Question 13

Secondary Key

Answer 13

A second primary key, allowing users to access the data in some other order

Question 14

Validation Techniques

Answer 14

Presence
Format
Length
Range
Lookup
Type

Question 15

Verification Techniques

Answer 15

Double-Entry
Proof-reading

Question 16

Big Data

Answer 16

A large & complex set of data collected from various sources that can be analysed using dedicated systems to find trends and patterns.

Question 17

Predictive Analysis

Answer 17

An active process that relates past patterns and trends with potential future behaviour using modelling and machine learning to inform business risks or opportunities.

Question 18

Data Warehousing

Answer 18

Storing big data sets in a centralised location from several sources that support analysis.

Question 19

Data Mining

Answer 19

A passive process that uses automated software to find patterns and relationships in large data sets.

Question 20

0NF

Answer 20

Flat file (contains a number of single tables w no links between them)

Question 21

1NF

Answer 21

• Primary Key
• Fields are atomic
• No repeating rows / columns

Question 22

2NF

Answer 22

Attributes are dependent on only one primary key (split into tables).

Question 23

3NF

Answer 23

No transitive partial dependency (no composite keys).

Question 24

SQL - TABLE

Answer 24

CREATE TABLE [name] (
[var1] Int PRIMARY KEY
[var2] Varchar(n)
[var3] Varchar(n) NOT NULL
)

Question 25

SQL - SELECT

Answer 25

SELECT */### FROM [table_name] WHERE [condition]

Question 26

SQL - INSERT

Answer 26

INSERT INTO [table_name] VALUES [vars]

Question 27

SQL - DELETE

Answer 27

DELETE FROM [table_name] WHERE [condition]

Question 28

Purpose of SQL (Data Operations)

Answer 28

CSS TRIM but on databases Copying Searching Sorting Traversing Removing Inserting Merging

Question 29

Normalisation Format

Answer 29

TABLE_NAME ([underscore]PK[underscore], extras, [overscore]FK[overscore])

Question 30

IQRAMS DUM - Integrity

Answer 30

If any data is updated, linked data in other tables is updated

Question 31

IQRAMS DUM - Queries

Answer 31

Can use code to perform commands to manipulate the database

Question 32

IQRAMS DUM - Report gen.

Answer 32

Generate a visual represntation of database contents

Question 33

IQRAMS DUM - Access lvls.

Answer 33

Users can only view the data they are granted to see

Question 34

IQRAMS DUM - Maintenance

Answer 34

Ensures that data is stored properly in memory

Question 35

IQRAMS DUM - Security

Answer 35

Data is protected with passwords or other methods

Question 36

IQRAMS DUM - Dictionaries

Answer 36

Allows users to specify the structure of data and the metadata of each attribute (length, type...)

Question 37

IQRAMS DUM - User Interface

Answer 37

Provides a visual representation of the database that users can interact with

Question 38

IQRAMS DUM - Manipulation

Answer 38

CSS TRIM Copying Searching Sorting Traversing Removing Inserting Merging

Question 39

Distributed Database Benefits

Answer 39

NASCRHp Network bottleneck Access can be limited Scalable Cost Resilient High performance

Question 40

SQL - UPDATE

Answer 40

UPDATE [table_name] SET [table_var = var]

Question 41

SQL - JOIN

Answer 41

SELECT */### FROM [table_name] JOIN [other_table] WHERE [condition]

Question 42

Data Normalisation

Answer 42

Reorganising data in a database to make it more convenient, simple and flexible.

Question 43

Distributed Processing

Answer 43

Loading programs and processes onto several devices that can be run independently and the output is compiled for the overall result

Question 44

Distributed Processing Factors

Answer 44

Availability of equipment Availability of wide/local area network with high enough bandwidth Consideration of other tasks needed with network Security