Databases

Question 1

Components of a database?

Answer 1

Tables, queries, reports, forms

fields (and key field) , records, auto numbers, data types (number, text, date, currency)

Question 2

What are queries used for?

Answer 2

To search for specific records

Question 3

What is validation?

Answer 3

Acts as a limit on what can be entered into a field/cell eg price > £10 < £50

Question 4

Validation: range check -what it does and an example?

Answer 4

Minimum and maximun value

eg price > £10 < £50

Question 5

Validation: Type check -what it does and an example?

Answer 5

**Sets type of data **

eg prices, currency, quantity

Question 6

Validation: **Prescence check **-what it does and an example?

Answer 6

Checks that the field has been completed

eg email, password

Question 7

Validation: **Length check **-what it does and an example?

Answer 7

Checks the number of characters

eg a moble phone number (11 numbers)

Question 8

Validation: **List/look up **-what it does and an example?

Answer 8

Lists options

eg Mrs, Mr, Miss etc, gender

Question 9

Validation: **Input mask **-what it does and an example?

Answer 9

Sets format

eg post code, product code

Question 10

What is a data redundancy?

Answer 10

Duplication of data in a database eg 2x adress

Question 11

Why might data be inaccurate and what fafcts may this have?

Answer 11

• Wrong orders
• Human errors
• May be difficult to contact someone if their data is wrong
• Incorrect procedures may take place

Question 12

What is a simultation?

Answer 12

Simulators replican real life scenarios using variables and mathematical rules

eg variables for turbulance - wind speed, no of passengers, type of plane, plane size

Question 13

Benefits of simulators?

Answer 13

• Less risk to peeople (eg passengers)
• Prapares for different scenarios
• Less expensive in the ong run

Question 14

Limitations of simulators?

Answer 14

• Doesn’t simulare the real pressure of a situation
• Can’t replicate every single situation and its not always accurate anyay
• Can be very expensive in the short term eg Sydney plane simulators are $30 million

Question 15

Whats an expert system?

Answer 15

Replicates the knowlage from an expert eg NHS symptom checker

User enters information, they recieve a response based on their input eg if their wifi wasnt working, they’d be told to switch it on and off

Question 16

Whats the main limitation of an expert system?

Answer 16

It can only cope with certain inputs and doesn’t provide much detail