De-duplicate Burst Reviews

SQL practice question · Hard · Data Cleaning · Zomato

Users sometimes submit the same restaurant review several times in quick succession. For the same user and restaurant, a review posted within 10 minutes (600 seconds, inclusive) of that pair's PREVIOUS review belongs to the same burst (bursts chain: 0, 8 and 16 minutes is one burst). Keep only the latest review of every burst (latest `created_at`; if tied, the higher `review_id`). Return the kept `review_id`, `user_id`, `restaurant_id`, `rating`. Order by `review_id`.

Table: reviews

Schema of reviews
ColumnType
review_idINTEGER
user_idINTEGER
restaurant_idINTEGER
ratingINTEGER
created_atTIMESTAMP
Sample rows of reviews
review_iduser_idrestaurant_idratingcreated_at
111042026-09-01 18:00:00
211052026-09-01 18:05:00
311032026-09-01 20:00:00
421022026-09-01 18:01:00
521142026-09-01 18:02:00
621142026-09-01 18:12:00
731152026-09-01 19:00:00
Expected output on the sample data
review_iduser_idrestaurant_idrating
21105
31103
42102
62114
73115

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