select
  unique INST_ID,                          -- INST_ID NUMBER
  AGENT_ID,                                -- AGENT_ID NUMBER
  MACHINE,                                 -- MACHINE VARCHAR2(64)
  PROCESS,                                 -- PROCESS VARCHAR2(9)
  PROGRAM,                                 -- PROGRAM VARCHAR2(48)
  OSUSER,                                  -- OSUSER VARCHAR2(30)
  AGT_STARTTIME,                           -- STARTTIME DATE
  AGENT_TYPE,                              -- AGENT_TYPE NUMBER
  decode(                                  -- FDS_CLASS_ID NUMBER
    AGENT_TYPE, 1, to_number(NULL), FDS_CLASS_ID),
  decode(                                  -- FDS_INST_ID NUMBER
    AGENT_TYPE, 1, to_number(NULL), FDS_INST_ID) 
from
  X$HS_SESSION