1.3.2 Databases Flashcards
What is a database?
- An organised collection of data
- Allows for easy adding, modification, deletion and searching
Benefits of using electronic databases
- Easier to retrieve, add. delete, update and modify data
- Easier to back up and make copies of the data
- Can be accessed by multiple people at the same time + from different locations
What is a flat file?
- Consists only a single table, can be created easily using either database/spreadsheet software
What are the advantages of a flat file?
- Very simple + quick to set up
- Require little expertise to maintain
- Suitable for storing small amounts of data
Typical uses of flat files
- Storing contact details
- Small product database
- Maintaining a game/music collection
Disadvantage of flat files
Can be inefficient as they include a lot of repetitive data which takes up space
If only flat file databases were used, they would quickly…
- Take up unnecessary space
- Be slow to query
- Become difficult to maintain
What is a relational database?
A database which recognises the difference between entities + uses different tables for each entity
What is an entity?
An item of interest about which information is stored
What is a primary key?
A unique identifier (field) for each record in a table
What is a foreign key?
Attribute which relationally links two tables together
What is a secondary key?
An index other than a primary key used to search and sort through the database with more convenience and speed
What does capturing data mean?
The process of getting the information that will be stored in the database
Different methods of capturing data
- Paper based forms
- Optical character recognition
- Optical mark recognition
- Automated ways e.g. QR codes and barcodes
What methods do banks use to capture data from cheques?
- Magnetic Ink Character Recognition
- Used for all the details apart from the amount which must be entered manually
