Topic 3-Database Concepts Flashcards Preview

Digital Technology (GCSE) > Topic 3-Database Concepts > Flashcards

Flashcards in Topic 3-Database Concepts Deck (39):
1

Table

A table consisting of a number of records

2

Record

A record is represented as a row in a table

3

Field

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

4

Key field

A key field uniquely identifies one record

5

Query

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

6

Forms

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

7

Reports

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

8

Macros

-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

9

Database relationships

-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

10

Importing data

-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

11

Text

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

12

Number

Numeric data that requires a mathematical calculation

13

Date/Time

Dates and times

14

Currency

Monetary data;includes 2 decimal places

15

Autonumber

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

16

Yes/No

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

17

OLE object

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

18

Hyperlink

A link to a web address (URL)

19

Attachment

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

20

Calculated

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

21

Lookup wizard

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

22

Data validation

-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

23

Presence check

Ensures data is present;the field cannot be left blank

24

Length check

Ensures data is the correct number of characters

25

Type check

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

26

Format check

Ensures data matches a predetermined pattern

27

Range check

Ensures data is within a lower and upper limit

28

Logical and comparison operators

-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

29

Less than

30

>

More than

31

<=

Less than or equal to

32

>=

More than or equal to

33

=

Equal to

34

<>

Not equal to

35

Big data

-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

36

Volume

-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

37

Variety

-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

38

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 computers to process the data more quickly

39

Need for data analytics to interpret big data

-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