Aggregation
Aggregations summarize data. Essential for BI dashboards.
Common Functions
SUM(),AVG(),COUNT(),MIN(),MAX()
Usage
We use aggregations extensively in our Gold layer (dbt marts) to create summary tables like airport_daily_metrics:
SELECT
date_key, departure_airport_key,
COUNT(*) as total_flights,
AVG(delay_minutes) as avg_delay
FROM fact_flights
GROUP BY 1, 2;