2 - Data Management Techniques Flashcards
What is a relational database?
Data that is contained in more than one table. Tables are linked by connecting a primary key in one table to a foreign key in another table.
What is a primary key?
A unique identifier, e.g. code number, that identifies records in a database.
What is a foreign key?
A field in a table that is linked with a primary key to form a relationship.
How are relational databases managed?
Relational databases are managed by a relational database management system (RDBMS) which joins the tables via the keys.
What is autonumber data type?
A number generator that ensures that a unique identifier is defined.
What is a flexible query?
Allows a user to make requirements without many limitations to what they ask.
What are some data validation methods?
- Input Mask = makes sure that the correct amount of numbers are entered & no letters
- Presence check
- Range check
- List check
What are some data verification methods?
- Proofreading to make sure data entered matches original source
- Double entry
What is data cleansing?
A method for the detection and correction of corrupt records/irrelevant data. The data is cleaned by replacing, modifying or deleting it. This improves organisation, productivity & frees data storage.
