queryScheduleStopTimes(): use subquery instead of join when querying trip stop_times ⚡️

Decreasing the query p50 query time from ~2 minutes to ~150ms. 🚀

Author: derhuerst

lib/query-schedule-stop-times.js

@@ -64,10 +64,8 @@ SELECT
 	ad.stop_sequence,
 	ad.t_arrival, ad.t_departure
 FROM arrivals_departures ad
-JOIN st ON (
-	st."date" = ad."date"
-	AND st.trip_id = ad.trip_id
-)
+WHERE ad."date" = (SELECT "date" FROM st)
+AND ad.trip_id = (SELECT trip_id FROM st)
 LIMIT $7
 `
 		values.push(