CompSci - Databases Flashcards
Database
Contains individual data about entities in linked tables.
Data Consistency
Ensures data is correct, done using validation & verification.
Referential Integrity
Ensuring that foreign keys in tables refer to valid records/tables.
Data Redundancy
Ensures that data isn’t duplicated, wasting storage
Data Independence
Ensures the database is a separate system from its application.
Atomic Data
Attributes that are broken down into their fundamental parts to maximise flexibility.
DBMS
Database Management System
DBMS Tools
IQRAMS DUM
Integrity
Queries
Report generation
Access levels
Maintenance
Security
Dictionaires
User interface
Manipulation
Primary Key
Unique identifier for an entity
Compound Key
Unique identifier with >1 fields for an entity
Candidate Key
Any field other than a dedicated ID that can be used as a primary key.
Foreign Key
A primary key from another table to represent a relationship between the objects
Secondary Key
A second primary key, allowing users to access the data in some other order
Validation Techniques
Presence
Format
Length
Range
Lookup
Type
Verification Techniques
Double-Entry
Proof-reading
Big Data
A large & complex set of data collected from various sources that can be analysed using dedicated systems to find trends and patterns.