Postgres Database Schema

users

column name	data type	details
id	integer	primary key
username	string	not null, unique, indexed
session_token	string	not null, indexed, unique
password_digest	string	not null
created_at	datetime	not null
updated_at	datetime	not null

• index on username, unique: true
• index on session_token, unique: true

photos

column name	data type	details
id	integer	primary key
title	string	not null, unique, indexed
user_id	integer	foreign key, not null, indexed
description	text	not null
created_at	datetime	not null
updated_at	datetime	not null

• user_id references users
• index on user_id

likes

column name	data type	details
id	integer	primary key
user_id	integer	foreign key, not null, indexed
photo_id	integer	foreign key, not null, indexed
created_at	datetime	not null
updated_at	datetime	not null

• user_id references users
• photo_id references photos
• index on [:photo_id, :user_id], unique: true

follows

column name	data type	details
id	integer	primary key
follower_id	integer	foreign key, not null, indexed
followee_id	integer	foreign key, not null, indexed
created_at	datetime	not null
updated_at	datetime	not null

• follower_id references users
• followee_id references users
• index on [:follower_id, :followee_id], unique: true