tasks/online-compute/FlinkSQL/flinksql_003_en/task.md

---
id: online-compute_FlinkSQL_flinksql_003
name: Word Frequency Tumbling Window Statistics
category: online-compute/FlinkSQL
timeout_seconds: 600
modality: pure-text
engine: flink-sql
---
## Prompt
I need you to write a Flink SQL that uses a datagen built-in table to simulate a word frequency data stream, groups by `word` and opens a 1-minute tumbling window to count the occurrences of each word, and outputs the results to the console.

**Business Background and Objective**: Simulate a word frequency data stream using a datagen built-in table, generating 1 billion records in the `word` field. Use `LOCALTIMESTAMP` as the event time and set a 5-second watermark delay. Group by `word` and count the occurrences of each word over a 1-minute tumbling window, then output `word` and `cnt` to the console table.

**Source Table Definition**:
- `word_source` (word frequency stream, datagen connector):
  - `word VARCHAR`: Word, randomly generated (value range 1–1000 to simulate distinct words)
  - `event_time`: Uses `LOCALTIMESTAMP` to generate event time, with a WATERMARK delay of 5 seconds
  - Generation rate: `rows-per-second = 1000`

**Output Table Definition**:
- `console_output` (print connector):
  - `word VARCHAR`: Word
  - `cnt BIGINT`: Number of occurrences of the word within the current window

**Aggregation Logic**:
- Group by `word`, using a 1-minute tumbling window
- Aggregation metric: `COUNT(*) AS cnt`
- The window is defined by the `TUMBLE` function

**Output Requirements**:
- Use `INSERT INTO console_output` to output the results.
- Output field order: `word`, `cnt`