Optimize Large-Scale SQL Aggregation

Optimize a slow-running SQL query that aggregates millions of customer interaction events across multiple sharded tables.

Write a PostgreSQL query that processes the January 2025 event data from both shards, associates events with known customers, and returns only customer and event-type combinations with at least two qualifying events.

Output

1. One row per customer and event type
2. Columns: customer_id, customer_name, event_type, event_count, and total_duration_seconds
3. Include only January events for known customers with at least two events
4. Order by event_count descending, then customer_id ascending and event_type ascending