tasks/online-compute/FlinkSQL/flinksql_011_en/task.md

metadata

id: online-compute_FlinkSQL_flinksql_011
name: Tumbling Window Product TopN Ranking
category: online-compute/FlinkSQL
timeout_seconds: 600
modality: pure-text
engine: flink-sql

Prompt

I need you to write a Flink SQL that uses the built-in datagen connector to simulate an order data source, aggregates product sales over a 10-minute tumbling window, and then uses the ROW_NUMBER window function to retrieve the top 5 products by sales within each window, outputting the results to the console.

Business Background and Objective: Simulate an order stream using a datagen built-in table, generating massive order data. Group by a 10-minute tumbling window to compute the total sales amount and order count per product within each window, and finally use ROW_NUMBER ranking to retrieve the top 5 products by sales amount within each window.

Source Table Definition:

• order_source (order stream, datagen connector):
  • order_id BIGINT: Order ID, randomly generated in the range 1–10,000,000
  • product_id INT: Product ID, randomly generated in the range 1–200
  • amount DOUBLE: Order amount, randomly generated in the range 0–500
  • event_time: Uses LOCALTIMESTAMP to generate event time, with a WATERMARK delay of 5 seconds
  • Generation rate: rows-per-second = 8000

Output Table Definition:

• console_output (print connector):
  • window_start TIMESTAMP(3): Tumbling window start time
  • product_id INT: Product ID
  • sales DOUBLE: Total sales amount of the product within the window
  • order_cnt BIGINT: Number of orders for the product within the window
  • rn BIGINT: Sales ranking within the window

SQL Logic:

• Apply TUMBLE(event_time, INTERVAL '10' MINUTE) tumbling window on order_source
• Group by window_start, window_end, product_id
• Aggregate SUM(amount) AS sales and COUNT(*) AS order_cnt
• Use ROW_NUMBER() OVER (PARTITION BY window_start, window_end ORDER BY sales DESC) AS rn
• Outer query filter: WHERE rn <= 5
• Final SELECT: window_start, product_id, sales, order_cnt, rn

Output Requirements:

• Use INSERT INTO console_output to output the results.
• Output field order: window_start, product_id, sales, order_cnt, rn