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Island Length Classification
Extend gaps-and-islands: find consecutive date ranges (islands) in orders and classify each island by length. Show island_start, island_end, island_length (days), and island_type: 'flash' (1 day), 'burst' (2-3 days), 'streak' (4-7 days), 'marathon' (8+ days). Sort by island_start. This classification of consecutive patterns is asked at Meta and Uber for engagement analysis.
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Schema
orders
| order_id | customer_id | product | category | quantity | price | total | order_date | country | status |
|---|---|---|---|---|---|---|---|---|---|
| 1 | 1 | Laptop Pro | Electronics | 1 | 1299.99 | 1299.99 | 2024-01-15 | USA | completed |
| 2 | 2 | Wireless Mouse | Electronics | 2 | 49.99 | 99.98 | 2024-01-16 | Canada | completed |
| 3 | 3 | Office Chair | Furniture | 1 | 349.99 | 349.99 | 2024-01-17 | USA | completed |
Expected output: Jan 1-3: burst (3 days), Jan 10-15: streak (6 days)
Hint
Concepts
SELECT CTE Window Functions ROW_NUMBER GROUP BY CASE DISTINCT Gaps and Islands + CASE
Practise the topic: SQL practice questions · CTE practice · Window function practice · GROUP BY exercises · CASE WHEN practice · Ranking function practice · Advanced SQL interview questions
In these company practice sets
Airbnb · Amazon · Databricks · Meta · Revolut · Snowflake · Uber
A SQL Quest challenge matched to patterns reported for these companies — not a question any of them has published.
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