Normalization

What is Normalization?

Breaking data into related tables to:

• Reduce redundancy
• Maintain data integrity
• Make updates easier

Example: Our Dataset

Normalized structure:

• users (id, username, email)
• sessions (id, user_id, started_at)
• events (id, session_id, user_id, event_type)

Each piece of information stored once, linked by foreign keys.

Your Task

Query the normalized structure to get user activity:

• username
• session count
• total events across all sessions

Group by user, order by event count descending, limit 5.