How to isolate High CPU usage for Informix

Answer

• You can do onstat -u to get session ids then onstat -g ses <sessionid> to
  get threads. Finally do onstat -g ath to list threads and and look at the ones which have a status of running.
• You can see active threads with 'onstat -g act -r 2'. This will show you active
  threads every 2 seconds. If you will see same thread repeatedly, then you can
  use value of 'rstcb' column of previous output to catch session:
  
  onstat -u | grep value_of_rstcb
• Then you can get sql causing high CPU utilization with onstat -g ses session_id"
  
  You can use this sql to create a list of sessions sorted on the highest amount of cpu and including the sql the session is currently running ( note that the current sql might not be the one that used so much cpu ):
  
  SELECT s.sid, s.username, s.uid, s.pid, s.hostname, t.tid,t.name, t.statedesc, t.statedetail, q.sqs_statement, t.cpu_time
  FROM syssessions s, systcblst t, sysrstcb r, syssqlstat q
  WHERE t.tid = r.tid AND s.sid = r.sid AND s.sid = q.sqs_sessionid
  ORDER BY t.cpu_time desc;