Information Systems and Databases

Question 1

Relationship types (list)

Answer 1

1. one-to-one
2. one-to-many
3. many-to-one
4. many-to-many

Question 2

One-to-one (example)

Answer 2

each individual has one passport

Question 3

One-to-many (example)

Answer 3

one customer can have many sales orders (the most common one in RD !!)

Question 4

Many-to-one (example)

Answer 4

many individuals can be part of one group project

Question 5

Many-to-many (example)

Answer 5

many different students can be part of many different classes

Question 6

Metadata

Answer 6

data that describes data, one example are data dictionaries !!

Question 7

Data types (list)

Answer 7

1. text
2. short integer
3. long integer
4. decimal/fixed point
5. real/float
6. money/currency
7. date/time
8. binary/BLOB

Question 8

Data validation

Answer 8

maintaining the correct format and correctness of data as soon as it is entered

Question 9

Data verification

Answer 9

maintaining the relevancy and correctness of data after it has been entered (this includes regularly checking that the current data is up to date)

Question 10

Data mining

Answer 10

the process of discovering non-obvious patterns within large collections of data

Question 11

Data warehousing

Answer 11

compiling and organising data into one common database

Question 12

BYODs, using from home (issues)

Answer 12

data security:
1. confidential information about individuals in database can be leaked to family members

Other:
1. Lack of effective communication with others.

Question 13

Database security measures

Answer 13

1. encryption
2. managing access to data
3. firewalls

Question 14

Data Dictionary (list fields)

Answer 14

1. Field name
2. Data type
3. Data format
4. Field size
5. Special conditions
6. Description
7. Example

Question 15

Pilot conversion

Answer 15

A selected group of participants/users trials the new system. This is effective to gain user feedback and see if any errors or bugs occur before sending it to everyone.

Question 16

Phased conversion

Answer 16

Features of the new system are gradually implemented to the old system until the old system becomes the new system. This is effective to allow users and participants to gradually get used to the system’s features without getting overwhelmed.

Question 17

Parallel conversion

Answer 17

Both the new system and the old system operate at the same time, i.e. users and participants can choose which system they prefer to use. This is effective if the system’s features are completely new and may require more technical skills to operate. However, this system conversion is very costly and employees have to do double the amount of work as they need to manage both systems.

Question 18

Direct Conversion

Answer 18

Completely getting rid of the old system and implementing the new system. This is effective in saving implementation costs, resources and time as there no need to manage the old system once the new system is implemented. However, this is the most riskiest method of conversion as data from the old system will be lost and may not be able to recover again. Additionally, users may get unsatisfied with the new system as well as technical skills may be required so this system conversion can actually make organisations lose their customers.

Question 19

Features of Live Data

Answer 19

actual data that is processed by the operational system
1. makes sure that all installed parts of the system are working as intended and meeting system requirements
2. different types of IT are likely to be present within the final operational environment

Question 20

Storyboards (define)

Answer 20

Tool used for designing the user interface within software

Question 21

Schema

Answer 21

organised plan of the entire database, describes the structure of the database

Question 22

Attribute

Answer 22

a defined property about an entity, can also, in some cases, be known as a field

Question 23

Entity

Answer 23

specific thing about which information is collected

Question 24

Flat-file database

Answer 24

databases where related records are organised in a simple single table

Question 25

Benefits of flat-file database

Answer 25

• all records are stored in one place
• they are easier to understand and configure
• requires less hardware and software

Question 26

Disadvantages of flat-file databases

Answer 26

• increased potential for data redundancy and inconsistencies
• flat-file databases are harder to update
• harder to change format
• harder to perform complex queries

Question 27

Relational Databases

Answer 27

stores data in a series of related tables where every table includes a primary key and all of the data is stored into tables

Question 28

Relational databases benefits

Answer 28

• minimises data redundancy which allows for more efficient searching, sorting, querying and updating in a database
• data input errors can be reduced by data validation

Question 29

Relational databases disadvantages

Answer 29

• requires a lot of structure and planning to develop
• lack of scalability
• maintenance problem

Question 30

Total file size of a database (calc)

Answer 30

(total of field sizes) * no of records
- for kb put over 1024
- for Mb put over 1024 * 1024

Question 31

Data validation techniques (list)

Answer 31

• list check
• range check
• input mask
• type check
• check digit