Approximate statistical functions
GoogleSQL provides four different approximate aggregate functions which provide better performance on large datasets: APPROX_COUNT_DISTINCT, APPROX_QUANTILES, APPROX_TOP_COUNT, APPROX_TOP_SUM. This exercise will take you through the same query using each function.
Este exercício faz parte do curso
Introduction to BigQuery
Exercício interativo prático
Experimente este exercício completando este código de exemplo.
-- Complete the query to approximate the number of customers that have ordered each product
SELECT
items.product_id,
-- Add the correct syntax for the approximate distinct count
___ AS estimated_unique_customers
FROM ecommerce.ecomm_orders o, UNNEST(o.order_items) items
JOIN ecommerce.ecomm_order_details od USING (order_id)
GROUP BY items.product_id;