# https://ace.c9.io/ from invoices filter invoice_date >= @1970-01-16 derive { transaction_fees = 0.8, income = total - transaction_fees } filter income > 1 group customer_id ( aggregate { average total, sum_income = sum income, ct = count total, } ) sort {-sum_income} take 10 join c=customers (==customer_id) derive name = f"{c.last_name}, {c.first_name}" select { c.customer_id, name, sum_income } derive db_version = s"version()"