WITH SUB1 AS(
 SELECT
  SESSION_ID,
  PROCESS_ID,
  RANK() OVER (PARTITION BY SESSION_ID ORDER BY EX_TIMESTAMP) AS RANK
 FROM
  PROCESS_LOG
 ORDER BY
  SESSION_ID ASC,
  EX_TIMESTAMP ASC
),
SUB2 AS (
 SELECT
  SESSION_ID,
  MIN(RANK) AS MIN
 FROM
  SUB1
 WHERE
  CAST(SUBSTR(SUB1.PROCESS_ID, 5, 1)AS INT) != RANK
 GROUP BY
  SESSION_ID
)

SELECT
 PROCESS_ID AS PROCESS,
 COUNT(DISTINCT CASE
            WHEN CAST(SUBSTR(SUB1.PROCESS_ID, 5, 1)AS INT) < SUB2.MIN
            OR SUB2.MIN IS NULL
             THEN SUB1.SESSION_ID
             END 
  )AS CNT
  
FROM 
 SUB1
 LEFT OUTER JOIN SUB2
  ON SUB1.SESSION_ID = SUB2.SESSION_ID
 GROUP BY 
  PROCESS_ID
 ORDER BY 
  PROCESS_ID;