Junior — Middle

Have you used window functions in your databases for data analysis?

sobes.tech AI

Answer from AI

Yes, window functions are actively used for data analysis in databases. They allow performing calculations across a set of table rows that are related to the current row, without grouping the data.

An example of using a window function to calculate a cumulative sum of sales over dates:

SELECT
  order_date,
  customer_id,
  amount,
  SUM(amount) OVER (PARTITION BY customer_id ORDER BY order_date) AS cumulative_sum
FROM sales
ORDER BY customer_id, order_date;

Here, a cumulative sum of sales is calculated for each customer by order date. Window functions are useful for trend analysis, ranking, calculating moving averages, and other analytical tasks without losing row-level detail.

Previous Next