Consider a table 'customer_orderS with columns 'order_id' (INT), 'customer_id' (INT), 'order_date' (DATE), and 'order_total' (NUMBER). The table is partitioned by 'order_date'. You need to create a materialized view that summarizes the total order value per customer, per month. Which of the following materialized view definitions will both achieve the desired summarization and effectively leverage partition pruning for efficient refreshes?

Correct Answer: A
Option A is the best choice. It groups by and 'DATE TRUNC('month', order_datey , which creates a monthly aggregation. Since the base table is partitioned by 'order_date' , the materialized view refresh can efficiently use partition pruning based on the monthly date truncations. Option B groups by the full 'order_date' , leading to daily aggregations instead of monthly. Option C uses , which is less efficient and doesn't preserve the year information for partition pruning. Option D uses "CONVERT_TIMEZONE' , which is incorrect for the purpose and will not efficiently leverage partition pruning.Option E using CAST(order_date AS VARCHAR(7)) as it change the date data type.