Lessons

Ensuring that all the necessary information is stored in the database Ensuring the possibility of obtaining data for all necessary requests Reducing redundancy and duplication of data Ensuring the integrity of the database Optimizing the speed of data access

Defining entities Defining tables and fields Defining dependencies Physical design

first normal form second normal form third normal form

one to one relationship one to many relationship many to many relationship

Primary key Foreign key Custom Key

Indexes Denormalizing Tables Query Optimization Examples Caching

DB-side caching Current caching status Caching efficiency Where cache is not used

Why is denormalization necessary? Denormalization example When is denormalization needed? Pros and cons of denormalization How to correctly implement denormalization