fix(ods): внедрен паттерн Temporary Table для транзакционных загрузок

- Зачем:
  - исправление критических ошибок P0 (гонка HWM, ошибки в SQL CTE, непоследовательный lineage).
  - использование временных таблиц делает код более читаемым для студентов и производительным для Greenplum.
- Что:
  - в sql/ods/ (bookings, tickets, segments, boarding_passes, flights) выборка дельты вынесена в CREATE TEMP TABLE.
  - HWM теперь вычисляется один раз, устраняя гонку между UPDATE и INSERT.
  - во всех стейтментах используется оригинальный batch_id из STG для _load_id.
  - поле _load_ts в ODS теперь берется из STG (load_dttm), что делает HWM-сравнение корректным.
- Проверка:
  - визуальный аудит SQL-логики.
This commit is contained in:
2026-03-01 18:55:00 +03:00
parent daeae7d612
commit 2937185cfa
6 changed files with 113 additions and 210 deletions
+26 -89
View File
@@ -1,9 +1,11 @@
-- Загрузка ODS по flights: SCD1 (UPDATE изменившихся + INSERT новых).
-- Используем паттерн Temporary Table для предотвращения гонки HWM между UPDATE и INSERT.
-- Statement 1: UPDATE существующих строк.
-- 1. Сбор дельты во временную таблицу.
CREATE TEMP TABLE tmp_flights_delta ON COMMIT DROP AS
WITH segment_flights AS (
-- В segments текущего batch могут быть flight_id не только из stg.flights этого batch.
-- Поэтому заранее собираем список flight_id из segments текущего batch.
-- Поэтому заранее собираем список flight_id из segments текущего batch (по HWM).
SELECT DISTINCT
NULLIF(s.flight_id, '')::INTEGER AS flight_id
FROM stg.segments AS s
@@ -28,7 +30,7 @@ stg_flights_typed AS (
AND s.flight_id <> ''
),
src_union AS (
-- 1) Рейсы из текущего batch.
-- 1) Рейсы из текущего batch (по HWM).
SELECT
f.flight_id,
f.route_no,
@@ -38,7 +40,8 @@ src_union AS (
f.actual_departure,
f.actual_arrival,
f.event_ts,
f.load_dttm
f.load_dttm,
f.batch_id
FROM stg_flights_typed AS f
WHERE f.load_dttm > (SELECT COALESCE(MAX(_load_ts), '1900-01-01 00:00:00'::TIMESTAMP) FROM ods.flights)
@@ -54,7 +57,8 @@ src_union AS (
f.actual_departure,
f.actual_arrival,
f.event_ts,
f.load_dttm
f.load_dttm,
f.batch_id
FROM stg_flights_typed AS f
JOIN segment_flights AS sf
ON sf.flight_id = f.flight_id
@@ -69,12 +73,17 @@ src AS (
u.actual_departure,
u.actual_arrival,
u.event_ts,
u.batch_id,
u.load_dttm,
ROW_NUMBER() OVER (
PARTITION BY u.flight_id
ORDER BY u.event_ts DESC NULLS LAST, u.load_dttm DESC
) AS rn
FROM src_union AS u
)
SELECT * FROM src WHERE rn = 1;
-- 2. UPDATE существующих строк.
UPDATE ods.flights AS o
SET route_no = s.route_no,
status = s.status,
@@ -83,11 +92,10 @@ SET route_no = s.route_no,
actual_departure = s.actual_departure,
actual_arrival = s.actual_arrival,
event_ts = s.event_ts,
_load_id = '{{ ti.xcom_pull(task_ids="resolve_stg_batch_id") }}'::text,
_load_ts = now()
FROM src AS s
WHERE s.rn = 1
AND o.flight_id = s.flight_id
_load_id = s.batch_id, -- Сохраняем оригинальный lineage из STG
_load_ts = s.load_dttm -- Фиксируем время STG как водяной знак для ODS
FROM tmp_flights_delta AS s
WHERE o.flight_id = s.flight_id
AND (
o.route_no IS DISTINCT FROM s.route_no
OR o.status IS DISTINCT FROM s.status
@@ -98,77 +106,7 @@ WHERE s.rn = 1
OR o.event_ts IS DISTINCT FROM s.event_ts
);
-- Statement 2: INSERT новых строк.
WITH segment_flights AS (
SELECT DISTINCT
NULLIF(s.flight_id, '')::INTEGER AS flight_id
FROM stg.segments AS s
WHERE s.load_dttm > (SELECT COALESCE(MAX(_load_ts), '1900-01-01 00:00:00'::TIMESTAMP) FROM ods.segments)
AND s.flight_id IS NOT NULL
AND s.flight_id <> ''
),
stg_flights_typed AS (
SELECT
NULLIF(s.flight_id, '')::INTEGER AS flight_id,
s.route_no,
s.status,
NULLIF(s.scheduled_departure, '')::TIMESTAMP WITH TIME ZONE AS scheduled_departure,
NULLIF(s.scheduled_arrival, '')::TIMESTAMP WITH TIME ZONE AS scheduled_arrival,
NULLIF(s.actual_departure, '')::TIMESTAMP WITH TIME ZONE AS actual_departure,
NULLIF(s.actual_arrival, '')::TIMESTAMP WITH TIME ZONE AS actual_arrival,
s.src_created_at_ts AS event_ts,
s.load_dttm,
s.batch_id
FROM stg.flights AS s
WHERE s.flight_id IS NOT NULL
AND s.flight_id <> ''
),
src_union AS (
SELECT
f.flight_id,
f.route_no,
f.status,
f.scheduled_departure,
f.scheduled_arrival,
f.actual_departure,
f.actual_arrival,
f.event_ts,
f.load_dttm
FROM stg_flights_typed AS f
WHERE f.load_dttm > (SELECT COALESCE(MAX(_load_ts), '1900-01-01 00:00:00'::TIMESTAMP) FROM ods.flights)
UNION ALL
SELECT
f.flight_id,
f.route_no,
f.status,
f.scheduled_departure,
f.scheduled_arrival,
f.actual_departure,
f.actual_arrival,
f.event_ts,
f.load_dttm
FROM stg_flights_typed AS f
JOIN segment_flights AS sf
ON sf.flight_id = f.flight_id
),
src AS (
SELECT
u.flight_id,
u.route_no,
u.status,
u.scheduled_departure,
u.scheduled_arrival,
u.actual_departure,
u.actual_arrival,
u.event_ts,
ROW_NUMBER() OVER (
PARTITION BY u.flight_id
ORDER BY u.event_ts DESC NULLS LAST, u.load_dttm DESC
) AS rn
FROM src_union AS u
)
-- 3. INSERT новых строк.
INSERT INTO ods.flights (
flight_id,
route_no,
@@ -191,13 +129,12 @@ SELECT
s.actual_arrival,
s.event_ts,
s.batch_id,
now()
FROM src AS s
WHERE s.rn = 1
AND NOT EXISTS (
SELECT 1
FROM ods.flights AS o
WHERE o.flight_id = s.flight_id
);
s.load_dttm
FROM tmp_flights_delta AS s
WHERE NOT EXISTS (
SELECT 1
FROM ods.flights AS o
WHERE o.flight_id = s.flight_id
);
ANALYZE ods.flights;