arrivals_departures: move arrival_departure_id into separate view ⚡️💥

For the ID, we use frequencies_it, which we compute using a PARTITION BY. Because the latter is prohibitively slow, we move the entire computation into a separate view.

Co-Authored-By: Holger Bruch <hb@mfdz.de>

lib/stop_times.js

@@ -262,46 +262,13 @@ WITH stop_times_based AS NOT MATERIALIZED (
 )
 -- stop_times-based arrivals/departures
 SELECT
-	(
-		encode(trip_id::bytea, 'base64')
-		|| ':' || encode((
-			extract(ISOYEAR FROM "date")
-			|| '-' || lpad(extract(MONTH FROM "date")::text, 2, '0')
-			|| '-' || lpad(extract(DAY FROM "date")::text, 2, '0')
-		)::bytea, 'base64')
-		|| ':' || encode((stop_sequence::text)::bytea, 'base64')
-		-- frequencies_row
-		|| ':' || encode('-1'::bytea, 'base64')
-		-- frequencies_it
-		|| ':' || encode('-1'::bytea, 'base64')
-	) as arrival_departure_id,
-
 	stop_times_based.*,
 	-- todo: expose local arrival/departure "wall clock time"?
 
-	-1 AS frequencies_row,
-	-1 AS frequencies_it
+	-1 AS frequencies_row
 FROM stop_times_based
 UNION ALL
 -- frequencies-based arrivals/departures
-SELECT
-	(
-		encode(trip_id::bytea, 'base64')
-		|| ':' || encode((
-			extract(ISOYEAR FROM "date")
-			|| '-' || lpad(extract(MONTH FROM "date")::text, 2, '0')
-			|| '-' || lpad(extract(DAY FROM "date")::text, 2, '0')
-		)::bytea, 'base64')
-		|| ':' || encode((stop_sequence::text)::bytea, 'base64')
-		|| ':' || encode((frequencies_row::text)::bytea, 'base64')
-		|| ':' || encode((frequencies_it::text)::bytea, 'base64')
-	) as arrival_departure_id,
-	*
-FROM (
-SELECT
-	*,
-	row_number() OVER (PARTITION BY trip_id, "date", stop_sequence)::integer AS frequencies_it
-FROM (
 SELECT
 	-- stop_times_based.* except t_arrival & t_departure, duh
 	-- todo: find a way to use all columns without explicitly enumerating them here
@@ -341,15 +308,52 @@ FROM (
 	FROM stop_times_based
 	JOIN "${opt.schema}".frequencies ON frequencies.trip_id = stop_times_based.trip_id
 	WHERE frequencies.exact_times = 'schedule_based' -- todo: is this correct?
-) t
-) t
 ) frequencies_based;
 
+${opt.postgraphile ? `\
+-- todo: currently named arrivalsDeparture, should be arrivalDeparture (but allArrivalsDeparturesList!)
+COMMENT ON COLUMN "${opt.schema}".arrivals_departures.route_short_name IS E'@omit';
+COMMENT ON COLUMN "${opt.schema}".arrivals_departures.route_long_name IS E'@omit';
+COMMENT ON COLUMN "${opt.schema}".arrivals_departures.route_type IS E'@omit';
+COMMENT ON COLUMN "${opt.schema}".arrivals_departures.direction_id IS E'@omit';
+COMMENT ON COLUMN "${opt.schema}".arrivals_departures.trip_headsign IS E'@omit';
+COMMENT ON COLUMN "${opt.schema}".arrivals_departures.stop_name IS E'@omit';
+COMMENT ON COLUMN "${opt.schema}".arrivals_departures.station_name IS E'@omit';
+-- > If you want to rename just one field or type, your best bet is to use a [@name] smart comment […].
+-- > NOTE: this still uses the inflectors, but it pretends that the tables name is different, so the input to the inflectors differs.
+-- https://www.graphile.org/postgraphile/inflection/#overriding-naming---one-off
+COMMENT ON VIEW "${opt.schema}".arrivals_departures IS E'@name arrival_departures\\n@primaryKey trip_id,date,stop_sequence,frequencies_row,frequencies_it\\n@foreignKey (route_id) references routes|@fieldName route\\n@foreignKey (trip_id) references trips|@fieldName trip\\n@foreignKey (stop_id) references stops|@fieldName stop\\n@foreignKey (station_id) references stops|@fieldName station';
+` : ''}
+
+CREATE OR REPLACE VIEW "${opt.schema}".arrivals_departures_with_ids AS
+SELECT
+	*,
+	(
+		encode(trip_id::bytea, 'base64')
+		|| ':' || encode((
+			extract(ISOYEAR FROM "date")
+			|| '-' || lpad(extract(MONTH FROM "date")::text, 2, '0')
+			|| '-' || lpad(extract(DAY FROM "date")::text, 2, '0')
+		)::bytea, 'base64')
+		|| ':' || encode((stop_sequence::text)::bytea, 'base64')
+		|| ':' || encode((frequencies_row::text)::bytea, 'base64')
+		|| ':' || encode((frequencies_it::text)::bytea, 'base64')
+	) as arrival_departure_id
+FROM (
+	SELECT
+		*,
+		(CASE WHEN frequencies_row = -1
+			THEN -1
+			ELSE row_number() OVER (PARTITION BY trip_id, "date", stop_sequence)::integer
+		END) AS frequencies_it
+	FROM "${opt.schema}".arrivals_departures
+) t;
+
 CREATE OR REPLACE FUNCTION "${opt.schema}".arrival_departure_by_arrival_departure_id(id TEXT)
-RETURNS "${opt.schema}".arrivals_departures
+RETURNS "${opt.schema}".arrivals_departures_with_ids
 AS $$
 	SELECT *
-	FROM "${opt.schema}".arrivals_departures
+	FROM "${opt.schema}".arrivals_departures_with_ids
 	WHERE trip_id = convert_from(decode(split_part(id, ':', 1), 'base64'), 'UTF-8')::text
 	AND "date" = (convert_from(decode(split_part(id, ':', 2), 'base64'), 'UTF-8')::text)::timestamp
 	AND stop_sequence = (convert_from(decode(split_part(id, ':', 3), 'base64'), 'UTF-8')::text)::integer
@@ -360,18 +364,19 @@ AS $$
 $$ LANGUAGE SQL STABLE STRICT;
 
 ${opt.postgraphile ? `\
--- todo: currently named arrivalsDeparture, should be arrivalDeparture (but allArrivalsDeparturesList!)
-COMMENT ON COLUMN "${opt.schema}".arrivals_departures.route_short_name IS E'@omit';
-COMMENT ON COLUMN "${opt.schema}".arrivals_departures.route_long_name IS E'@omit';
-COMMENT ON COLUMN "${opt.schema}".arrivals_departures.route_type IS E'@omit';
-COMMENT ON COLUMN "${opt.schema}".arrivals_departures.direction_id IS E'@omit';
-COMMENT ON COLUMN "${opt.schema}".arrivals_departures.trip_headsign IS E'@omit';
-COMMENT ON COLUMN "${opt.schema}".arrivals_departures.stop_name IS E'@omit';
-COMMENT ON COLUMN "${opt.schema}".arrivals_departures.station_name IS E'@omit';
+-- todo: DRY with comments on arrivals_departures
+-- todo: what is the graphql field name? postgraphile singularifies most names
+COMMENT ON COLUMN "${opt.schema}".arrivals_departures_with_ids.route_short_name IS E'@omit';
+COMMENT ON COLUMN "${opt.schema}".arrivals_departures_with_ids.route_long_name IS E'@omit';
+COMMENT ON COLUMN "${opt.schema}".arrivals_departures_with_ids.route_type IS E'@omit';
+COMMENT ON COLUMN "${opt.schema}".arrivals_departures_with_ids.direction_id IS E'@omit';
+COMMENT ON COLUMN "${opt.schema}".arrivals_departures_with_ids.trip_headsign IS E'@omit';
+COMMENT ON COLUMN "${opt.schema}".arrivals_departures_with_ids.stop_name IS E'@omit';
+COMMENT ON COLUMN "${opt.schema}".arrivals_departures_with_ids.station_name IS E'@omit';
 -- > If you want to rename just one field or type, your best bet is to use a [@name] smart comment […].
 -- > NOTE: this still uses the inflectors, but it pretends that the tables name is different, so the input to the inflectors differs.
 -- https://www.graphile.org/postgraphile/inflection/#overriding-naming---one-off
-COMMENT ON VIEW "${opt.schema}".arrivals_departures IS E'@name arrival_departures\\n@primaryKey trip_id,date,stop_sequence,frequencies_row,frequencies_it\\n@foreignKey (route_id) references routes|@fieldName route\\n@foreignKey (trip_id) references trips|@fieldName trip\\n@foreignKey (stop_id) references stops|@fieldName stop\\n@foreignKey (station_id) references stops|@fieldName station';
+COMMENT ON VIEW "${opt.schema}".arrivals_departures_with_ids IS E'@name arrivals_departures_with_ids\\n@primaryKey trip_id,date,stop_sequence,frequencies_row,frequencies_it\\n@foreignKey (route_id) references routes|@fieldName route\\n@foreignKey (trip_id) references trips|@fieldName trip\\n@foreignKey (stop_id) references stops|@fieldName stop\\n@foreignKey (station_id) references stops|@fieldName station';
 ` : ''}
 
 CREATE OR REPLACE VIEW "${opt.schema}".connections AS