1.3.2 databases

Question 1

What is database?

Answer 1

database is an organised collection of data that can be accessed, managed and updated easily.

Question 2

field

Answer 2

single piece of data in a record

Question 3

record

Answer 3

a group of related fields

Question 4

table

Answer 4

collection of records

Question 5

primary key

Answer 5

a unique identifier for each record in a table

Question 6

foreign key

Answer 6

is an attribute that links two tables together. It acts as the primary key in one table and as the foreign key in the other.

Question 7

secondary key

Answer 7

used to search for data in a database

Question 8

relational database

Answer 8

a type of database that organises data in multiple tables.
it uses a primary key to link tables together and reduce data redundancy.
making efficient use of storage.

Question 9

what is referential integrity?

Answer 9

• it ensures consistency between related tables in a rational database.
• maintain a valid relationship between the primary key and foreign key.
• a foreign key must only exist if a corresponding primary key is in the related/linked table.

Question 10

benefits and drawbacks of referential integrity.

Answer 10

benefits:
- ensure data consistency and accuracy.
- prevent orphaned records

drawbacks:
- can impact the performance as more checks need to be done (to ensure consistency)
- may require additional planning and designing.

Question 11

how to maintain referential integrity:

Answer 11

• use a DBMS with a built-in support.
• regular checkups and clean data to ensure inconsistency.