Unit 8.1 Basic Database Concepts

Flashcards for Basic Database Concepts

Database

Collection of data/info held together in an organised way.

File-based Database

Database that stores data in a single table, separated by commas, spaces etc. often in a plain text file,

Pro’s of File-based Database

1. Easy setup

2. All data in one place so finding data is easier

Con’s of File-based Database

1. Lots of redundant data as it is repeated.

2. Difficult to manage/maintain/expand in future.

3. Data access is slower due to more to search through.

Relational Database

Stores data in multiple tables and links them together using relationships.

Pro’s of Relational Database

1. Less redundant data leading to smaller file size.

2. Easier to manage/maintain/expand in future.

3. Access data faster as less to search through.

Con’s of Relational Database

1. More complex structure

2. Data spread out in multiple tables.

3. Harder set up so more technical knowledge and skills needed.

Entity

Person/Place/thing/object/concept about which data can be collected and stored.

Attribute

Single part of an entity

Table

Contains info about an entity, made up of records and fields

Record (Tuple)

Single row within a table, collection of fields about single item/event also must contain one Primary Key.

Field

Column within a table, separate part of a record

Candidate Key

Set of field(s) that can uniquely identify each record in a table

Primary Key

Field in a table that uniquely identifies each record.

Secondary Key

Key fields used in addition to Primary Key to locate specific info.

Foreign Key

Field in one table that links to a Primary Key in another table.

Relationships

Links between tables in a relational database, commonly joining Primary & Foreign Keys.

Referential Integrity

Ensures data consistency by preventing invalid references into tables and maintaining data changes across tables.