refactor(dm): исправление архитектуры витрины sales_report

- Зачем:
  - исходная реализация содержала критические ошибки MPP (Load/Processing Skew) и Full Scan.
  - требуется демонстрация студентам эталонного инкрементального UPSERT.
- Что:
  - изменен ключ дистрибуции с flight_date на (departure_airport_sk, arrival_airport_sk).
  - внедрен каноничный UPSERT через TEMP TABLE (агрегация выполняется один раз).
  - добавлен инкрементальный фильтр по {{ ds }} для предотвращения Full Scan dds.fact_flight_sales.
  - проверки DQ переведены в инкрементальный режим (валидация только текущего батча).
- Проверка:
  - airflow dags test bookings_to_gp_dm 2026-02-28.

sql/dm/sales_report_load.sql

@@ -1,13 +1,66 @@
 -- Загрузка DM витрины sales_report: инкрементальный UPSERT.
 --
 -- Паттерны для студентов:
--- - GROUP BY агрегация фактов перед JOIN с измерениями
+-- - Использование TEMP TABLE: агрегация считается только ОДИН раз (канон для MPP)
+-- - Инкрементальность: мы читаем факты ТОЛЬКО за день запуска {{ ds }}, избегая Full Scan
 -- - Денормализация: города и названия тарифов тащим в витрину
 -- - UPSERT: UPDATE изменившихся + INSERT новых (нужен heap для UPDATE)
 -- - IS DISTINCT FROM для корректного сравнения NULL
 
--- Statement 1: UPDATE существующих строк.
--- Обновляем метрики и денормализованные атрибуты (на случай изменений в справочниках).
+-- Шаг 1: Считаем агрегаты для дельты (текущего батча) и кладем во временную таблицу.
+-- ON COMMIT DROP гарантирует, что таблица исчезнет после завершения транзакции (Airflow сессии).
+CREATE TEMP TABLE tmp_sales_report_delta ON COMMIT DROP AS
+SELECT
+    cal.date_actual AS flight_date,
+    dep.airport_sk AS departure_airport_sk,
+    arr.airport_sk AS arrival_airport_sk,
+    tar.tariff_sk,
+
+    -- Денормализованные атрибуты
+    dep.city AS departure_city,
+    dep.airport_bk AS departure_airport_bk,
+    arr.city AS arrival_city,
+    arr.airport_bk AS arrival_airport_bk,
+    tar.fare_conditions,
+
+    -- Атрибуты календаря
+    cal.day_of_week,
+    cal.day_name,
+    cal.is_weekend,
+
+    -- Метрики
+    COUNT(*) AS tickets_sold,
+    SUM(CASE WHEN f.is_boarded THEN 1 ELSE 0 END) AS passengers_boarded,
+    SUM(f.price) AS total_revenue,
+    AVG(f.price) AS avg_price,
+    MIN(f.price) AS min_price,
+    MAX(f.price) AS max_price,
+    -- boarding_rate: делим boarded на sold с защитой от деления на 0
+    ROUND(
+        SUM(CASE WHEN f.is_boarded THEN 1 ELSE 0 END)::NUMERIC / NULLIF(COUNT(*), 0),
+        4
+    ) AS boarding_rate
+
+FROM dds.fact_flight_sales AS f
+JOIN dds.dim_calendar AS cal
+    ON cal.calendar_sk = f.calendar_sk
+JOIN dds.dim_airports AS dep
+    ON dep.airport_sk = f.departure_airport_sk
+JOIN dds.dim_airports AS arr
+    ON arr.airport_sk = f.arrival_airport_sk
+JOIN dds.dim_tariffs AS tar
+    ON tar.tariff_sk = f.tariff_sk
+WHERE cal.date_actual = '{{ ds }}'::date  -- ИНКРЕМЕНТАЛЬНЫЙ ФИЛЬТР: читаем только нужный день!
+GROUP BY
+    cal.date_actual,
+    dep.airport_sk, dep.city, dep.airport_bk,
+    arr.airport_sk, arr.city, arr.airport_bk,
+    tar.tariff_sk, tar.fare_conditions,
+    cal.day_of_week, cal.day_name, cal.is_weekend
+DISTRIBUTED BY (departure_airport_sk, arrival_airport_sk);
+
+-- Шаг 2: UPDATE существующих строк.
+-- Обновляем метрики и денормализованные атрибуты.
 UPDATE dm.sales_report AS tgt
 SET
     departure_city     = src.departure_city,
@@ -26,55 +79,7 @@ SET
     updated_at         = now(),
     _load_id           = '{{ run_id }}',
     _load_ts           = now()
-FROM (
-    -- Агрегация фактов по зерну витрины
-    SELECT
-        cal.date_actual AS flight_date,
-        dep.airport_sk AS departure_airport_sk,
-        arr.airport_sk AS arrival_airport_sk,
-        tar.tariff_sk,
-
-        -- Денормализованные атрибуты
-        dep.city AS departure_city,
-        dep.airport_bk AS departure_airport_bk,
-        arr.city AS arrival_city,
-        arr.airport_bk AS arrival_airport_bk,
-        tar.fare_conditions,
-
-        -- Атрибуты календаря
-        cal.day_of_week,
-        cal.day_name,
-        cal.is_weekend,
-
-        -- Метрики
-        COUNT(*) AS tickets_sold,
-        SUM(CASE WHEN f.is_boarded THEN 1 ELSE 0 END) AS passengers_boarded,
-        SUM(f.price) AS total_revenue,
-        AVG(f.price) AS avg_price,
-        MIN(f.price) AS min_price,
-        MAX(f.price) AS max_price,
-        -- boarding_rate: делим boarded на sold с защитой от деления на 0
-        ROUND(
-            SUM(CASE WHEN f.is_boarded THEN 1 ELSE 0 END)::NUMERIC / NULLIF(COUNT(*), 0),
-            4
-        ) AS boarding_rate
-
-    FROM dds.fact_flight_sales AS f
-    JOIN dds.dim_calendar AS cal
-        ON cal.calendar_sk = f.calendar_sk
-    JOIN dds.dim_airports AS dep
-        ON dep.airport_sk = f.departure_airport_sk
-    JOIN dds.dim_airports AS arr
-        ON arr.airport_sk = f.arrival_airport_sk
-    JOIN dds.dim_tariffs AS tar
-        ON tar.tariff_sk = f.tariff_sk
-    GROUP BY
-        cal.date_actual,
-        dep.airport_sk, dep.city, dep.airport_bk,
-        arr.airport_sk, arr.city, arr.airport_bk,
-        tar.tariff_sk, tar.fare_conditions,
-        cal.day_of_week, cal.day_name, cal.is_weekend
-) AS src
+FROM tmp_sales_report_delta AS src
 WHERE tgt.flight_date          = src.flight_date
   AND tgt.departure_airport_sk = src.departure_airport_sk
   AND tgt.arrival_airport_sk   = src.arrival_airport_sk
@@ -89,7 +94,7 @@ WHERE tgt.flight_date          = src.flight_date
       OR tgt.arrival_city    IS DISTINCT FROM src.arrival_city
   );
 
--- Statement 2: INSERT новых строк (те, которых нет по составному ключу).
+-- Шаг 3: INSERT новых строк (те, которых нет по составному ключу).
 INSERT INTO dm.sales_report (
     flight_date,
     departure_airport_sk,
@@ -133,51 +138,7 @@ SELECT
     src.max_price,
     src.boarding_rate,
     '{{ run_id }}' AS _load_id
-FROM (
-    -- Агрегация фактов (тот же CTE, что и в UPDATE)
-    SELECT
-        cal.date_actual AS flight_date,
-        dep.airport_sk AS departure_airport_sk,
-        arr.airport_sk AS arrival_airport_sk,
-        tar.tariff_sk,
-
-        dep.city AS departure_city,
-        dep.airport_bk AS departure_airport_bk,
-        arr.city AS arrival_city,
-        arr.airport_bk AS arrival_airport_bk,
-        tar.fare_conditions,
-
-        cal.day_of_week,
-        cal.day_name,
-        cal.is_weekend,
-
-        COUNT(*) AS tickets_sold,
-        SUM(CASE WHEN f.is_boarded THEN 1 ELSE 0 END) AS passengers_boarded,
-        SUM(f.price) AS total_revenue,
-        AVG(f.price) AS avg_price,
-        MIN(f.price) AS min_price,
-        MAX(f.price) AS max_price,
-        ROUND(
-            SUM(CASE WHEN f.is_boarded THEN 1 ELSE 0 END)::NUMERIC / NULLIF(COUNT(*), 0),
-            4
-        ) AS boarding_rate
-
-    FROM dds.fact_flight_sales AS f
-    JOIN dds.dim_calendar AS cal
-        ON cal.calendar_sk = f.calendar_sk
-    JOIN dds.dim_airports AS dep
-        ON dep.airport_sk = f.departure_airport_sk
-    JOIN dds.dim_airports AS arr
-        ON arr.airport_sk = f.arrival_airport_sk
-    JOIN dds.dim_tariffs AS tar
-        ON tar.tariff_sk = f.tariff_sk
-    GROUP BY
-        cal.date_actual,
-        dep.airport_sk, dep.city, dep.airport_bk,
-        arr.airport_sk, arr.city, arr.airport_bk,
-        tar.tariff_sk, tar.fare_conditions,
-        cal.day_of_week, cal.day_name, cal.is_weekend
-) AS src
+FROM tmp_sales_report_delta AS src
 WHERE NOT EXISTS (
     SELECT 1
     FROM dm.sales_report AS tgt