Database Basics

ACID

• Atomicity
    All or nothing - each atomic transaction either succeeds or fails as a whole.
• Consistency
    only valid data is written to the database.
• Isolation
    separate, uncommitted transactions do not interfere with each other.
• Durability
    data written to the database will not be lost and can be recovered in the event of a failure.

Normalisation

• 1st Normal Form
  • group data into tables
  • remove repeating groups
  • assign a primary key (PK)
• 2nd Normal Form
  • create tables for data that applies to multiple records
  • relate tables via a Foreign Key (FK)
• 3rd Normal Form
  • eliminate data that does not rely on Primary Key