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.
What logical operators can be used in database queries?
NOT, AND, OR. Used in complex criteria in queries.
What is a report used for in a database?
Data from a database that has been processed and presented on a page
in a way that makes it information. Designed for hardcopy.
