How to get LGWR lag from oracle database

Question

I have to collect the lgwr process lag overtime. This information is in the lgwr trace file, but I don't want to parse the trace files. Is there any database table or view that stores this information and I can remotely access it using DB connection. It would be great if anyone can provide me with the query.

I need to capture the following information present in lgwr .trc file. "Warning: log write elapsed time 2080ms, size 0KB". I want to capture the this time elapsed.

Answer 1

select * from DBA_HIST_SYSTEM_EVENT
where event_name ='log file parallel write'

should be close to what you want.

Answer 2

You can use the below query, this will show you the duration between every log switch. (Assuming that you have all the rights).

SELECT b.recid start_rec_id,
       to_char(b.first_time,'dd-mon-yy hh24:mi:ss') start_time, 
       a.recid end_rec_id,
       to_char(A.first_time,'dd-mon-yy hh24:mi:ss') end_time,
       round(((a.first_time-b.first_time)*25)*60,2) duration
  from v$log_history a, 
       v$log_history b
 WHERE A.recid = b.recid + 1
 AND   A.first_time BETWEEN to_date('2013-08-01:00:00:00','yyyy-mm-dd:hh24:mi:ss') AND to_date('2013-09-10:00:00:00','yyyy-mm-dd:hh24:mi:ss')
 order by a.first_time asc
/