WITH PROCESS1 AS (
    SELECT
        SESSION_ID,
        PROCESS_ID,
        RANK() OVER (
            PARTITION BY SESSION_ID
            ORDER BY COALESCE(EX_TIMESTAMP, '2000-01-01 00:00:00') ASC
        ) AS TIME_ID
    FROM
        PROCESS_LOG
), PROCESS2 AS (
    SELECT
        PROCESS1.*,
        RANK() OVER (
            PARTITION BY SESSION_ID
            ORDER BY PROCESS_ID ASC
        ) AS STEP_ID
    FROM
        PROCESS1
    WHERE
        PROCESS1.PROCESS_ID = 'STEP' || TIME_ID
)
SELECT
    PROCESS_ID AS PROCESS,
    COUNT(*) AS CNT
FROM
    PROCESS2
WHERE
    PROCESS2.TIME_ID = PROCESS2.STEP_ID
GROUP BY
    PROCESS2.PROCESS_ID
ORDER BY
    PROCESS2.PROCESS_ID