WITH T1 AS(
    SELECT
        SESSION_ID,
        PROCESS_ID,
        RANK() OVER(
            PARTITION BY SESSION_ID
            ORDER BY EX_TIMESTAMP
        ) AS RANK
    FROM
        PROCESS_LOG
), T2 AS(
    SELECT
        SESSION_ID,
        MIN(RANK) AS LAST_SESSION
    FROM
        T1
    WHERE
        PROCESS_ID != "STEP" || RANK
    GROUP BY
        SESSION_ID
), T3 AS(
    SELECT
        PROCESS_ID,
        COUNT(PROCESS_ID)
    FROM
        T1
        LEFT OUTER JOIN T2
            ON T1.SESSION_ID = T2.SESSION_ID
    WHERE
        RANK < IFNULL(LAST_SESSION, 6)
    GROUP BY
        PROCESS_ID
)

SELECT
    *
    FROM T3