GROUPING_ID
APPROX_COUNT_DISTINCT
ROW_NUMBER
個別値数の近似値を高速に返します。
APPROX_COUNT_DISTINCT(expr)
下記の値を入力するとサンプルに即時反映されます。
customer_id
approx_customers
orders
SELECT APPROX_COUNT_DISTINCT(customer_id) AS approx_customers FROM orders;