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Uber · Data Engineering
Move from trip grain to fact constellation and dimensions.
Grain: 1 row per trip request, including cancelled and expired outcomes
Keys
PK · trip_keyFK · rider_keyFK · driver_keyFK · city_keyFK · service_keyFK · vehicle_keyFK · pickup_geo_keyFK · dropoff_geo_keyFK · trip_status_keyFK · request_date_keyImportant columns
trip_id · requested_at · matched_at · started_at · completed_at · cancelled_at · quoted_fare · surge_multiplier · final_fare · request_to_match_sec · trip_duration_sec · gps_derived_distance_km · is_reconciled · record_versionAccumulating snapshot. Milestones update as the trip progresses; fact_trip_event preserves immutable history.
Explore every atomic fact and conformed dimension by domain. Dashed relationships point from fact foreign keys to shared dimensions.
A fact table exists only when the business process has a distinct grain.
The same historical definitions support marketplace, finance, safety, support, and experimentation facts.