Topic 3-Database Concepts

Question 1

Table

Answer 1

A table consisting of a number of records

Question 2

Record

Answer 2

A record is represented as a row in a table

Question 3

Field

Answer 3

A field is part of a record that stores a single data item,represented by a column

Question 4

Key field

Answer 4

A key field uniquely identifies one record

Question 5

Query

Answer 5

A query searches snd filters data in a database that satisfies the query criteria

Question 6

Forms

Answer 6

Forms are used to collect data to create a new record,modify an existing record or view records already stored in a table

Question 7

Reports

Answer 7

Reports are used to present results from queries in an efficient manner

The layout of reports can be customised,such sd grouping similar data or presenting data in ascending or descending order

Question 8

Macros

Answer 8

• Macros are small programs that are written to preform a repetitive database task automatically
• They are used to add functionality to forms and reports
• Running a macro will result in instructions stored within the macro being executed with a single click of a button

Question 9

Database relationships

Answer 9

• Database relationships link two or more tables in a database using a relationship type
• For this to happen,a common field must be stored in each table;the key field from one table as a non-key field (also called a ‘foreign key’)
• Relationships are defined as one-to-one, one-to-many or many-to-many

Question 10

Importing data

Answer 10

• It is possible to import a number of worksheets from a spreadsheet to a database package or vice versa
• This gives organisations more flexibility in handling their data

Question 11

Text

Answer 11

Text and data that is a mixture of text and numbers,e.g. as a postcode

Question 12

Number

Answer 12

Numeric data that requires a mathematical calculation

Question 13

Date/Time

Answer 13

Dates and times

Question 14

Currency

Answer 14

Monetary data;includes 2 decimal places

Question 15

Autonumber

Answer 15

To create a key field,the computer generates sequential numbers that are automatically inserted for each new record created

Question 16

Yes/No

Answer 16

Data that has two possible values,e.g. Yes/No or True/False;this is called a ‘Boolean value’

Question 17

OLE object

Answer 17

Object linking and embedding;objects created using a software package other than a database

Question 18

Hyperlink

Answer 18

A link to a web address (URL)

Question 19

Attachment

Answer 19

A file attached to a record,e.g. a digital image

Question 20

Calculated

Answer 20

The result pf a calculation produced from another field in the record

Question 21

Lookup wizard

Answer 21

A value can be selected from a predefined list and entered into the field

Question 22

Data validation

Answer 22

• Data validation involves checking of data at the input stage to ensure it is reasonable,sensible and within acceptable limits
• It guarantees that is present,and of the correct type,range or length
• The computer checks data and either accepts the data,or rejects it and displays an error message
• A number of data validation checks exsist

Question 23

Presence check

Answer 23

Ensures data is present;the field cannot be left blank

Question 24

Length check

Answer 24

Ensures data is the correct number of characters

Question 25

Type check

Answer 25

Ensures data is of the correct type, e.g. Numeric/text

Question 26

Format check

Answer 26

Ensures data matches a predetermined pattern

Question 27

Range check

Answer 27

Ensures data is within a lower and upper limit

Question 28

Logical and comparison operators

Answer 28

• Comparing a value against other data is a typical operation when data is queried in a database
• Logical operators analyse 2 values and return either a true or false result
• Operators are denoted by the words AND,OR and BETWEEN

Answer 29

Less than

Question 30

>

Answer 30

More than

Question 31

<=

Answer 31

Less than or equal to

Question 32

> =

Answer 32

More than or equal to

Question 33

=

Answer 33

Equal to

Question 34

<>

Answer 34

Not equal to

Question 35

Big data

Answer 35

• Big data refers to large amounts of data that have the potential to be mined for information
• It can be described as the 3Vs:volume,variety and velocity

Question 36

Volume

Answer 36

• Refers to the amount of data stored by organisations
• Data is raw facts and figures that is unprocessed
• Organisations now store large amounts of data from different sources,requiring large storage capacity hardware
• Data storage is now measured in terabytes

Question 37

Variety

Answer 37

• Refers to the different types and varieties of data
• Data is now stored in many formats,e.g. video and images;not just text
• Data can be structured,semi-structured or unstructured

Question 38

Velocity

Answer 38

• Refers to the speed at which data can be processed

- Due to large volumes of data,there is a need to use more powerful computers to process the data more quickly

Question 39

Need for data analytics to interpret big data

Answer 39

• Data analytics involves analysing large volumes of data to produce useful information
• This is beneficial to organisations for making decisions and planning for future growth
• Specialised software such as data mining and statistical analysis are designed to process vast quantities of data
• When data is in different formats (e.g. Structured/unstructured) it makes preparing snd processing the data more challenging for data analytics