ウィンドウフレーム

Snowflake のウィンドウ関数

Jake Roach

Field Data Engineer

ウィンドウフレーム

すべてのレコードで構成されるウィンドウの出力結果。

ウィンドウフレーム

member_idフィールドでレコードをパーティション分割して構築されたウィンドウの出力結果。

動的ウィンドウフレーム

スライディングウィンドウフレームの出力結果。

累積計算の方法

SELECT
    ...

    AVG(<1>) OVER(
        PARTITION BY ...
        ORDER BY <2>

        -- Window between the first
        -- and current row


        ROWS BETWEEN UNBOUNDED PRECEDING 
            AND CURRENT ROW

    )
...

ROWS BETWEEN を使用すると動的なウィンドウフレームを作成できます

UNBOUNDED PRECEEDING AND CURRENT ROW
先頭行から現在の行まで
「累積」計算（ローリングではない）
CURRENT ROW AND UNBOUNDED FOLLOWING

<1>: 計算対象のフィールド

<2>: 結果を順序付け、ウィンドウフレームを構築する

消費カロリーの累計

SELECT
    member_id AS m_id, 
    calories_burned AS cb,

    -- Running total!
    SUM(calories_burned) OVER(
        PARTITION BY member_id
        ORDER BY workout_date


        ROWS BETWEEN UNBOUNDED PRECEDING
            AND CURRENT ROW


    ) AS running_total

FROM fitness.workouts;


         m_id  |    cb   |  running_total
       ------- | ------- | --------------
        m_192  |   105   |      105 
        m_192  |   156   |      261 
        m_192  |    69   |      330 
        m_192  |   102   |      432  

        m_74   |   374   |      374  
        m_74   |   396   |      770  
        m_74   |   504   |     1274  

        m_233  |    51   |       51  
        m_233  |    81   |      132

CURRENT ROW AND UNBOUNDED FOLLOWING

SELECT
    member_id AS m_id, 
    calories_burned AS cb,

    SUM(calories_burned) OVER(
        PARTITION BY member_id
        ORDER BY workout_date

        -- Window between current row and last

        ROWS BETWEEN CURRENT ROW
            AND UNBOUNDED FOLLOWING


    ) AS left_to_burn

FROM fitness.workouts;


         m_id  |    cb   |  left_to_burn
       ------- | ------- | --------------
        m_192  |   105   |      432 
        m_192  |   156   |      327 
        m_192  |    69   |      171 
        m_192  |   102   |      102  

        m_74   |   374   |     1274  
        m_74   |   396   |      900 
        m_74   |   504   |      504  

        m_233  |    51   |      132  
        m_233  |    81   |       81

カロリー消費の傾向

SELECT
    member_id,
    workout_date,
    calories_burned,

    AVG(calories_burned) OVER(   -- Running average of calories burned
        PARTITION BY member_id

        -- Crate a window by workout date, from the first workout to the current workout 
        ORDER BY workout_date
        ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW

    ) AS avg_calories_burned

FROM FITNESS.workouts;

カロリー消費の傾向


            member_id  |  workout_date  |  calories_burned  |  average_calories_burned
           ----------- | -------------- | ----------------- | -------------------------
              m_192    |   2025-01-01   |        105        |          105.0
              m_192    |   2025-01-03   |        156        |          130.5
              m_192    |   2025-01-04   |         69        |          110.0
              m_192    |   2025-01-10   |        102        |          108.0

               m_74    |   2025-02-10   |        374        |          374.0
               m_74    |   2025-02-13   |        396        |          385.0
               m_74    |   2025-02-14   |        504        |          426.7

              m_233    |   2025-03-05   |         51        |           51.0
              m_233    |   2025-03-12   |         81        |           66.0

練習しましょう！

Snowflake のウィンドウ関数