Database Design

DB Design

Tables

• users
• sleeps
• followers

users

Column	Data Type	Primary Key	Foreign key	Default Value	Comment
id	Integer	○
name	String
created_at	Time Stamp
updated_at	Time Stamp

sleep_trackings

Column	Data Type	Primary Key	Foreign key	Default Value	Comment
id	Integer	○
user_id	Integer		○		references user(id)
clock_in	Date Time
clock_out	Date Time
sleep_duration	Integer				In seconds
created_at	Time Stamp
updated_at	Time Stamp

followers

Column	Data Type	Primary Key	Foreign key	Default Value	Comment
id	Integer	○
user_id	Integer		○		references user(id)
following_user_id	Integer		○		references user(id)
created_at	Time Stamp
updated_at	Time Stamp

Create a clustered index for ( follower_user_id, following_user_id) to speed up performance.