SELECT X.ACCOUNT_KEY, X.INSERT_CNT, X.UPDATE_CNT,DELETE_COUNT.DELETE_CNT
FROM
(
 select insert_count.account_key from  -- I have added this line
 (
  SELECT Account_Key,COUNT(*) INSERT_CNT
    FROM HCDB_AIFA3100_HIST_V
  WHERE REC_STAT_CD = 'I'
  GROUP BY ACCOUNT_KEY,REC_STAT_CD
 ) INSERT_COUNT
 inner jOIN
 (
  SELECT Account_Key,COUNT(*) UPDATE_CNT
      FROM HCDB_AIFA3100_HIST_V
  WHERE REC_STAT_CD = 'U'
  GROUP BY ACCOUNT_KEY,REC_STAT_CD
 ) UPDATE_COUNT
 ON INSERT_COUNT.ACCOUNT_KEY = UPDATE_COUNT.ACCOUNT_KEY
) X
left outer join 
(
 SELECT Account_Key,COUNT(*) DELETE_CNT
     FROM HCDB_AIFA3100_HIST_V
 WHERE REC_STAT_CD = 'D'
 GROUP BY ACCOUNT_KEY,REC_STAT_CD
) DELETE_COUNT 
on X.ACCOUNT_KEY = DELETE_COUNT.ACCOUNT_KEY

linuxy SCOTT>!oerr ora 3706
37060, 0000, "(XSMCSESS08) %v is not a valid custom member in dimension %j."
// *Cause: No custom member or invalid custom member
// *Action: Create the custom member or use the correct custom member