Databases Flashcards
What is a database?
A database is described as “a persistent organised store of data”.
What does it mean to interrogate a database?
Interrogate means to ask questions about the data or to query it.
What does DBMS stand for?
Database Management System
What does a DBMS do?
This is a software system that provides controlled access to the database.
What are the benefits of reducing data redundancy?
Reducing data redundancy has several benefits:
• reduces the risk of data inconsistency
• makes maintaining the database much easier
• reduces the size of the database
What is a primary key?
The field that uniquely identifies each record in a table is called the primary key. The primary key can be a number or text but every record must have a different value for this field.
What is a foreign key?
A field in one table that is the primary key in another table and is used to create a relationship between those two tables.
What is an entity?
A real world object, about which data is stored in a database, corresponds to a table in the relational database.
What is a relational database?
A persistent organised store of data where data is stored as a collection of related tables to minimise data redundancy.
What is a database record?
Data stored about one instance of an entity ie: one particular person or object.
What is persistent storage (of a database)?
Non‐volatile storage on a secondary storage medium such as a hard disk.
What is a database form?
An interactive window used for data entry. Usually includes validation routines.
What is validation?
When the computer software checks that data entered is sensible.
What is verification?
A type of validation where data is entered twice and checked that each
version is the same, to avoid data being entered with typing mistakes.
What is a query?
A feature of a DBMS that allows the database to be interrogated. It selects records from the database based on specified criteria.
