Database Applications - Chapter 3

Question 1

What is a query ?

Answer 1

Used to search and extract data from a database to find the answer to a question.

Question 2

What is a form ?

Answer 2

A form is used to enter a new record , modify an existing record and view
Records already stored in a table.

Question 3

What is a report ?

Answer 3

Allows tables and results of queries to be presented in a user friendly way

Question 4

What is a macro ?

Answer 4

A small program written to preform a repetitive task automatically.

Question 5

What is a data type ?

Answer 5

When a database is created , each field is allocated a data type ; different data types are used for different fields , e.g. text or numeric ; the data type defines the type of data associated with the field.

Question 6

What is the purpose of database relationships ?

Answer 6

To link two or more tables in a database using a relationship type. For this to happen a common field must be stored.

Question 7

What is data validation ?

Answer 7

Carried out by a computer automatically when data is input, it ensures that data is reasonable, sensible and within acceptable limits.
E.g presence check , length check , type check , format check , range check.

Question 8

What is a primary key ?

Answer 8

The key field from one table

Question 9

What is a foreign key ?

Answer 9

When a primary key in a table is stored as a non-key field in another table.

Question 10

Give examples of different data types

Answer 10

Text , number , date/time , currency , autonumber , yes/no , OLE object , hyperlink , attachment , calculated and lookup wizard.

Question 11

What are the three different types of data-base relationships ?

Answer 11

-One to one - means each records in one table can relate to one and only one record in another table
-One to many - meant a record in one table can relate to zero one or many records in another table
-many to many - both tables on either side of the relationship can contain multiple rows.

Question 12

What is meant by big data ?

Answer 12

-Refers to the large amount of data that have potential to be mined for information.
-It can be described as the 3vs : volume , variety and velocity.

Question 13

Explain the 3vs with big data

Answer 13

VOLUME
- 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 software.
VARIETY
- refers to the different types and
Varieties of data.
- data I’d now stored in many formats e.g video and images ( not just text ).
- data can be structured, semi structured or unstructured.
VELOCITY
- refers to the speed at which data can be processed.
- due to large volumes of data there is a need to use more powerful computer to process the data more quickly

Question 14

What is the need for data analytics to interpret big data

Answer 14

• Data analytics involves organisations analysing large amounts of data to produce useful information
• This is beneficial 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 it makes preparing and processing the data more
challenging for data analytics